Therapeutics & Investigations 2 (Part 1)

Question 1

What is (nutritional) anaemia

Answer 1

• Condition when # of RBCs + therefore their o2 carrying capacity is insufficient to meet bodily needs
• Fall in Hb concentration, seen with not enough RBCs

Question 2

What is haemoglobin

Answer 2

• Iron containing o2 transport, metalloprotein that is within RBCs

Question 3

what happens when there is a fall in Hb

Answer 3

• Reduction in Hb causes anaemia, a reduction in o2 carrying capacity
• Changes how it gives oxygen to the different tissues
• In the LAB measure = always done by haemoglobin concentration

Question 4

components of blood?

Answer 4

• Made of RBC, WBCs, platelets

- Bone marrow is in the long bones of an adult/ pelvic bones, femur and sternum etc

Question 5

what is anaemia?

Answer 5

• Condition where # RBCs and their o2 carrying capacity, is insufficient to meet body physiologic needs.
• Anaemia is decrease in # RBCs / less than normal quantity of Hb in the blood

Question 6

how would you clinically diagnose anaemia?

Answer 6

• Measured in g/L (or decilitre)
• Less than 6 months = high Hb, and then become a lower level for the first 6 months until about 5 year as you are growing and have more needs
• Then goes higher in childhood
• By adolescence = at normal range for an adult
• Females = always losing blood
• Normal range drops even further for pregnant ladies because there is a rise in ones physiological volume
• Lower Hb = more severe anaemia

Question 7

what are the 4 needs of RBC maturation?

Answer 7

1. Vitamin B12 and folic acid 2. DNA synthesis 3. Iron synthesis 4. Hb synthesis (iron needed for Hb synthesis)

Question 8

Describe normal erythropoesis

Answer 8

• Maturation of RBCs has 4 needs: 1. Vitamin B12 and folic acid 2. DNA synthesis 3. Iron synthesis 4. Hb synthesis (iron needed for Hb synthesis)
• Vitamins, cytokines (erythropoeitin)
• Healthy environment for bone marrow (functional bone marrow )
• Erythropoiesis = production of red blood cells

Question 9

what are the mechanisms of action for anaemia

finding out why the persons iron is low

Answer 9

1 - Failure of production of RBCs
• = Hypoproliferation, Reticulocytopenic (early RBCs which can be measured)
2 - Ineffective erythropoiesis
• All of the right bits = enough iron, b12 etc but the bone marrow cannot do the right things with it
3 - Decreased survival :
• Blood loss, haemolysis (RBC destruction), reticulocytosis
• Either not producing it or losing / destroying it too much

Question 10

describe - Failure of production of RBCs as a mechanism of action of anaemia

Answer 10

• = Hypoproliferation, Reticulocytopenic (early RBCs which can be measured)

Question 11

describe - Ineffective erythropoiesis as a mechanism of action of anaemia

Answer 11

• All of the right bits = enough iron, b12 etc but the bone marrow cannot do the right things with it

Question 12

describe - Decreased survival : as a mechanism of action of anaemia

Answer 12

• Blood loss, haemolysis (RBC destruction), reticulocytosis

* Either not producing it or losing / destroying it too much

Question 13

Anaemia = one of causes if low Hb levels
after getting full blood count, also get a marker of what size the RBC are
WHAT DO MICROCYTIC CELLS LOOK LIKE?

Answer 13

• Iron deficiency, heme deficiency
• Thalassamia - globin deficiency
• Anaemia of chronic disease

Question 14

Anaemia = one of causes if low Hb levels
after getting full blood count, also get a marker of what size the RBC are
WHAT DO NORMOCYTIC CELLS LOOK LIKE?

Answer 14

• Anaemia chronic disease
• Aplastic anaemia
• Chronic renal failure
• Bone marrow infiltration
• Sickle cell disease

Question 15

Anaemia = one of causes if low Hb levels
after getting full blood count, also get a marker of what size the RBC are
WHAT DO MACROCYTIC CELLS LOOK LIKE?

Answer 15

• B12 deficiency, folate deficiency
• Myelodysplasia
• Alcohol induced
• Drug induced
• Liver disease
• Myxoedema

Question 16

what are nutritional anaemias

Answer 16

• Lack of essential ingredients that the body gets from food sources
• Iron, vitamin B12, folate deficiency
• Patient with reduced concentration of Hb because they have not been able to get building blocks from their food

Question 17

what are the characteristics of iron

Answer 17

• Essential for oxygen transport, most abundant trace in the body. Daily need for iron for erythropoesis varies, depending on gender + physiological needs (e.g. pregnancy or normal )
• Needs differ at various stages of development.
  • Meat, seafood (gives you haem which is more easy to absorb - good value for iron content),
  • Vegetables like spinach (non haem, so more is needed), wheat products, fruits and eggs etc have high iron levels.
• No natural way for the body to excrete iron = unless you are bleeding or using the muscles - need slightly varied levels of iron
• Milk based diet = do not absorb iron levels as much. In growing years / pregnancy = should keep up with daily losses.

Question 18

What do fe3+ ions bind to when they circulate

Answer 18

• Bind to plasma transferrin

- Accumulate in the cells in form of ferritin.

Question 19

describe iron metabolism and the states that it exists in

Answer 19

• There is more than 1 stable form of iron
  Exists in 2 states
  
  1. FERRIC state = 3+
  2. FERROUS state = 2+
• Humans contain 4-5g iron, and most of the iron in the body is there as circulating Hb, at about 2.5g
• Nearly all of the remainder is as storage proteins - ferritin, which is a storage protein, and haemosiderin. These are found in the liver cells, spleen and bone marrow.
• Iron gets absorbed from the duodenum via the enterocytes into plasma, binds to transferrin

Question 20

What are the iron containing proteins? - haem

Answer 20

• Has porphyrin complex
• Ferrous Fe2+
• Exists in Hb, Myoglobin, catalases, peroxisases

Question 21

What are the iron containing proteins? - non haem

Answer 21

• Iron transport proteins like lactoferrin and lactoferrin
• Iron storage proteins
• Ferritin = short term
• Haemosiderin = long term

Question 22

describe Iron absorption

Answer 22

• This is regulated by GI mucosal cells mechanism: maximal absorption in the duodenum and the proximal jejunum
• The amount that is absorbed is the type that is ingested - heme, ferrous (red meat, used to contain Hb) > than non heme, ferric forms which is bound to other substances
• Heme iron makes up 10-20% of dietary iron
• Other foods, GI acidity, state of iron storage levels and bone marrow activity - these are all factors that affect absorption.
• Taking vitamin C helps with absorption - things like milk and dairy/tea can stop absorption,

Question 23

describe Iron transport and storage

Answer 23

• From the duodenum into the mucosal cells, and then combine with Apoferritin –> ferritin. Or cross to the plasma where they bind to transferrin, so can enter cells via transferrin receptor (e.g. erythroid precursors).

Question 24

what are the characteristics of Hepcidin - nearly 13 years old: iron regulatory mechanism process

Answer 24

• Body also has this system of regulating how much we need
• Iron regulatory hormone hepcidin and its receptor and iron channel ferroportin, control dietary absorption, storage, iron tissue distribution
• Hepcidin goes up when we have got enough iron. Hepcidin = abundance

Question 25

What controls dietary absorption of iron?

Answer 25

- Hepcidin = iron regulatory hormone, and its receptor - Ferroportin = iron channel - There is transferrin receptor on the early RBCs - Transferrin is trying to get as much iron as possible into the red blood cells

Question 26

What does hepcidin cause?

Answer 26

- It causes ferroportin internalisation, and degradation (the iron channel). This will therefore decrease iron transfer into the blood plasma from the duodenum, from macrophages involved in recycling senescent erythrocytes + from iron storing hepatocytes. - Hepcidin = feedback that is regulated by iron concentrations in the plasma and the liver, and by erythropoietic demand for iron.

Question 27

describe the gastrointestinal transport mechanisms (11 main steps)

Answer 27

1. Dietary iron is either derived from haemoglobin/myoglobin (haem iron) or is bound to other substances (nonhaem iron). Haem iron makes up to 10-20% of the dietary iron and is found in animal foods that originally contained hemoglobin, such as red meats, fish, and poultry. It is well absorbed. 2. Haem is digested enzymatically free of globin and enters the cell as an intact metalloporphyrin, presumably by a vesicular mechanism. 3. It is degraded within the enterocyte by heme oxygenase with release of inorganic iron that traverses the basolateral cell membrane in competition with nonhaem iron to bind transferrin in the plasma. 4. Non-haem iron makes up 80-90% of the iron in food. It is less well absorbed. This is the form of iron added to iron-enriched and iron-fortified foods. 5. Both calcium and tannins (found in tea and coffee) reduce nonhaem iron absorption. 6. Most dietary inorganic iron is ferric iron. 7. Ferric iron can enter the enterocyte via the integrin-mobilferrin pathway (IMP) 8. Some ferric iron is reduced in the intestinal lumen by membrane reductase duodenal cytochrome B (DTC1). 9. Ferrous iron is transported across the plasma membrane by the divalent metal transporter DMT-1. 10. Within cells, iron is stored as ferritin (to protect the cell from oxidative damage) or exported across the basolateral surface by the iron transporter ferroportin. Exported iron is converted to ferric iron by the membrane oxidase hephaestin and bound to transferrin for distribution to tissues. 11. The enterocyte is informed of body requirements for iron by transporting iron from plasma into the cell using a holotransferrin receptor.

Question 28

describe the interactions of hepcidin

Answer 28

- Hepcidin interaction with ferroportin controls the main iron flows into plasma. - Iron flows and reservoirs are depicted in blue - Iron in hemoglobin in red, and hepcidin and its effect in orange. - RBC indicates red blood cell; and Fpn, ferroportin.

Question 29

Iron deficiency - describe reasons

Answer 29

- Can be because not enough is in, or losing too much - Not enough in: poor diet, malabsorption (eatinng what should be enough but body is not absorbing it properly), increased physiological needs - Losing too much: blood loss, menstruation, GI tract loss, paraistes

Question 30

describe the Lab investigations for ion deficiency

Answer 30

- 1st = FBC (checks for red blood cells) - Hb, MCV, MCH, reticulocytes + blood film - Iron studies : ferritin, transferring saturation, TIBC - Other studies = BMAT and iron stains - Always include a blood film when asked which measurements that you should do Take out some of the bone marrow from the back, look at the early red blood cells and stain with iron

Question 31

describe the Iron studies laboratory tests - the blood tests that you can do. (BLOOD TEST: FERRITIN)

Answer 31

- Primary storage protein, and providing reserve, water soluble Reliable for iron deficiency = if this is low then you know that you do not have enough stored iron

Question 32

describe the Iron studies laboratory tests - the blood tests that you can do. Urine test : Haemosiderin

Answer 32

- Water insoluble, Fe - protein complex

Question 33

describe the Iron studies laboratory tests - the blood tests that you can do. Blood test : Transferrin saturation

Answer 33

- Made by liver inversely proportional to Fe stores. This is vital for Fe transport. - Uptake of Fe from protein, needs transferring to be attached to the cell via the transferrin receptor. - Looking at the ratio of serum iron and total iron binding capacity, revealing the percentage of transferring binding sites that have been occupied by iron - Can test for saturation "seeing how many full seats on a bus there is " - if you are iron deficient then this will be lower

Question 34

describe the Iron studies laboratory tests - the blood tests that you can do. Blood test: Iron binding capacity

Answer 34

- Irons capacity to bind with transferring. | - Maximum amount of iron that it can carry - which indirectly reflects transferrin levels

Question 35

describe the Iron studies laboratory tests - the blood tests that you can do. Blood test: Transferrin saturations

Answer 35

- How much transferrin is available to be able to bind iron - how much of the serum iron is actually bound - E.g. value of 10% means, that 10% iron binding sites of transferrin is getting occupied by iron at that point.

Question 36

describe the Iron studies laboratory tests - the blood tests that you can do. (Serum Fe)

Answer 36

- Massively variable throughout the day - increases if you have just had a meal - Not that useful , but can put into context with the others

Question 37

what are the characteristics of Transferrin / Transferrin receptors

Answer 37

- Made by the liver, production inversely proportional to Fe stores. - Vital for Fe transport, uptake of Fe from the protein needs transferrin to be attached to the cell via the transferrin receptor

Question 38

What is the total iron binding capacity?

Answer 38

- Measurement of the capacity of transferrin, to bind iron - Amount of space that is still left for iron binding - Indirect measurement of transferrin - a transport protein that carries iron. - TIBC is technically easier to measure in the lab than transferrin levels directly, - In IDA, TIBC will be high • This is because there is more transferring produced, aiming to transport more iron to tissues that are in need.

Question 39

what results would you get in iron deficiency anaemia?

Answer 39

reduced: - Hb, MCV, MCH, serum iron, serum ferritin, TIBC (reflects transferrin), Transferrin saturation. Bone marrow iron studies

Question 40

what are the stages of development of iron deficiency anaemia?

Answer 40

- Before anaemia develops, iron deficiency occurs in several stages. - Serum ferritin is the most sensitive laboratory indicators of mild iron deficiency. - Stainable iron in tissue stores is equally sensitive, but is not performed in clinical practice. - % saturation of transferrin with iron and free erythrocyte protoporphyrin values do not become abnormal until tissue stores are depleted of iron. - Decrease in the [Hb] = when no iron available for haem synthesis. - MCV and MCH do not become abnormal for several months after tissue stores are depleted of iron. - Go from being normal, to full blown iron deficiency anaemia - serum ferritin starts to fall as you go towards the right - If you have no iron stores = deficient but not anaemic yet - Ferritin = answers easily if someone is iron deficient Low : iron, transferrin saturation High : TIBC Serum iron : low and normal Hepcidin = fat controller

Question 41

23 year old female that is tired and lacks concentration Full blood count measurement. - Reviewing the blood count of our patient, we can notice that she has a moderate anaemia, since her [Hb] is 9.7 g/dl.

Answer 41

- Reviewing the blood count of our patient, we can notice that she has a moderate anaemia, since her [Hb] is 9.7 g/dl. - The anaemia is: • Microcytic (MCV 69.7 fl) and • Slightly hypochromic (MCHC 32.4 g/dl). - small red blood cells and a low Hb - The mean cell Hb is also low (22.6 pg). - The reticulocyte count is inappropriately normal, since we would expect the bone marrow to compensate the anaemia by producing more new red cells - not making new RBCs

Question 42

Iron deficiency anaemia symptoms and signs

Answer 42

Symptoms - Fatigue, Lethargy, Dizziness Signs - Pallor of mucous membranes - Bounding pulse - Systolic flow murmurs - Smooth tongue, koilonychias

Question 43

characteristics of B12 and folate deficiency

Answer 43

- Both have similar lab findings + clinical symptoms. Can be found together, or separately. - Macrocytic anaemia - low Hb, and high MCV, with normal MCHC.

Question 44

describe megaloblastic macrocytic anaemia?

Answer 44

- Vitamin b12 folic acid deficiency - Drug realted - Interference with B13/FA metabolism - Seen in B12 and FA deficiency = peripheral smear by the macroovalocytes *megaloblastic vs non megaloblastic slide* - There are 7 lobes on this one when there should usually be 4. - Hypersegmented neutrophil

Question 45

describe non megaloblastic macrocytic anaemia?

Answer 45

- Alcoholism - impairs folate metabolism (direct toxicity with increased exposure of alcohol on the bone marrow) - Hypothyroidism - Liver disease - Myelodysplastic syndrome: pre cancerous cells, natur - Reticulocytosis

Question 46

What are some causes of b12 deficiency - IMPAIRED ABSORPTION

Answer 46

- pernicious anaemia, gastrectomy or ileal resection, zollinger ellison syndrome, parasites

Question 47

What are some causes of b12 deficiency - DECREASED INTAKE

Answer 47

- malnutrition, veganism

Question 48

What are some causes of b12 deficiency - CONGENTIAL CAUSES

Answer 48

- intrinsic factor receptor deficiency. | - cobalamin mutation (CG1 gene )

Question 49

What are some causes of b12 deficiency - INCREASED REQUIREMENTS

Answer 49

- haemolysis, HIV, pregnancy, growth spurts

Question 50

What are some causes of b12 deficiency - MEDICATION

Answer 50

- alcohol, NO, PPI (H2 antagonists), Metformin

Question 51

What are the haematological consequences of vitamin B12 deficiency?

Answer 51

MCV = normal / raised Hb = normal or low Retic. count = low LDH = raised Blood film = Macrocytes, ovalocytes, hypersegmented neuts BMAT = hypercellular, megaloblastic, giant metamyelocytes MMA = increased

Question 52

Clinical consequences of Iron deficiency - BRAIN

Answer 52

- Cognition - Depression - Psychosis

Question 53

Clinical consequences of Iron deficiency - Neurology

Answer 53

- Myleopathy - Sensory changes - Ataxia Spasticity (SACDC)

Question 54

Clinical consequences of Iron deficiency - Tongue

Answer 54

- Glossitis | - Taste impairment

Question 55

Clinical consequences of Iron deficiency - Blood

Answer 55

- Pancytopenia

Question 56

what is pernicious anaemia?

Answer 56

- Autoimmune disorder, that is a lack of IF, lack of B12 absorption, gastric parietal cell antibodies, IF antibodies. - Either making antibodies against the gastric parietal cells or against the intrinsic facto themselves - Treatment = vitamin B12 injections every 3 months = hyper segmented - Issues with the nervous system and the brain, cardiac disease, infertility. - Can affect WBC and platelet count as well

Question 57

describe folate deficiency + characteristics of folate.

Answer 57

- Present in most foods, similar presentations to B12 deficiency but no neurological consequences. - Necessary for DNA synthesis - adenosine, guanine, and thymidine synthesis. - because of increased demand, decreased intake/absorption

Question 58

Iron deficiency treatments?

Answer 58

- Diet, oral, parenteral iron supplementation | - Stopping the bleeding

Question 59

Folic acid deficiency treatments?

Answer 59

- Oral supplements

Question 60

Vitamin B12 deficiency treatments

Answer 60

- Oral vs intramuscular treatment

Question 61

What are the causes of macrocytic anaemia? [MEGALOBLASTIC]

Answer 61

* This is a low reticulocyte count | * Vitamin B12/ folic acid deficiency, drug related, interference with B12/FA metabolism

Question 62

What are the causes of macrocytic anaemia? [NON - MEGALOBLASTIC]

Answer 62

- Alcoholism, hypothyroidism, liver disease, myelodysplastic syndromes, reticulocytosis (haemolysis) - This gives you the fact that someone is anaemic and then size of their RBCs - LOW B12 and low folate = malabsorption - Folic acid is what you are given but folate is naturally in the body - can do a serum folate levels

Question 63

What is normal haematopoiesis?

Answer 63

- Blood cell production - Bone marrow, long bones - Maturation occurs in bone marrow. There are mature cells within peripheral blood - Progenitor cells mature and develop and once they get to a completed stage get kicked out into the circulating blood : testing what is circulating in the blood

Question 64

what is the definition of the FBC (full blood count), what does it look for?

Answer 64

- Each set of blood tests that are requested go to different tubes = purple tops contain EDTA to stop the blood clotting - if you let it stand for long enough then it will start to sediment out Red blood cell results: - Hb = [haemoglobin] in our blood = not commenting on the number of red blood cells; but g/L - Hct = % of blood volume of RBC (percentage of the cell volume that are red blood cells = usually 50ish%.) - MCV = average size of RBC • Could have severe iron and b12 deeficiency anaemia and then have normal MCV as that is the norm - MCH = average Hb content in each RBC (MCHC mean cell HB concentration) - RDW = range of deviation around the RBC size • Variation in sizes of the red blood cells • Small RDW if they are really monomorphic and all similar sizes = someone with b12 and iron deficiency, even though you have a normal mean cell volume you will have a really high RDW. - Reticulocyte count - Blood film - useful to look at these for particular issues when numbers do not make sense

Question 65

what, apart from the FBC could you look at?

Answer 65

White blood cells results - Total WBC and differential - Neutrophils, lymphocytes, monocytes, basophils, eosinophils Platelet results - Platelet count, and size of platelet - Platelet count is low = look at blood fim, to see if the cells that we have look normal Others = warning flags. - Picks up abnormal cells that are not any of the ones that we know of - LUCs (large, unidentified cells)

Question 66

what are some things that blood films show? [general]

Answer 66

- Confirming numbers - Morphology = if the cells are normal - If there are cells present that there shouldn’t be

Question 67

what are some things that blood films show? [red cells only]

Answer 67

- Size: big or small, anisocytosis - Colour : Hb content - Shape: round, TDP, irregular, ellipocytes, poikylocytosis - variation in the shape, looks chaotic - Polychromasia • Early red cells coming though, looks a bit more purple - Inclusions: if there are other things sitting there that there shouldn’t be

Question 68

what are some things that blood films show? [white cells only]

Answer 68

- Numbers: too many or too few - Normal morphology - dysplastic features - Immature cells : myelocytes and precursors - Abnormal cells: blasts, atyprical lymphoid cells - Inclusions

Question 69

Different blood tests use different tubes - describe what they are?

Answer 69

``` Pink = EDTA, blood transfusion Black = ESR, erythrocyte sedimentation rate Rust = biochem. Clots, can use the plasma Green = lithium ```

Question 70

describe the iron deficiency anaemia

Answer 70

- Small rims of Hb around the edge, platelets - Small RBCS and target cells have "bullseye" in the middle - Key = small and hypochromic

Question 71

Describe macrocytic megaloblastic anaemia | Presence of big cells

Answer 71

- this is when presence of big cells - really large - ovalocytes are present - Try to then find out if this was caused by folate or vitamin B12 Could be deficient of both if you do not have stomach = no gastric parietal cells = less IF

Question 72

describe acquired haemolytic anaemia - there is polychromasia and spherocytes

Answer 72

- High reticulocyte count and his bone marrow is trying to keep up - Polychromasia = these large purpley cells, pick up stain in a different way - Lots of them are missing their area of central pallor - Could have devloped an antibody that recognises his own red blood cells as foreign = spleen picks them all up - Haemolysing (destroying) his own red blood cells - Spleen is working hard and taking in all of the abnormal blood cells which is why it is larger

Question 73

describe Sickle cell anaemia

Answer 73

- Have boat shaped cells Should be able to diagnose because you can easily see these shapes

Question 74

Tear drop Poikilocytosis - myelofibrosis or bone marrow infiltration with malignant disease

Answer 74

- Pointy head - Suggests that there is something else like leukameia and fibrosis sitting inside the bone marrow - Would not be able to pick this up from the number - Slightly anaemic but might not have triggered the warning signs

Question 75

Examples of full blood count results and their blood films : white blood cell abnormalities

Answer 75

- Neutrophil leucocytosis - Nearly all of these will be neutrophils = someone who is unwell with something like sepsin so neutrophils have gone up and red cells are not working as well

Question 76

Acute myeloblastic leukaemia - blast cells are present

Answer 76

- Literally one platelet | - All of the cells are myeloblasts = leukamia cells. Only one neutrophil which is circled.

Question 77

Chronic granulocytic leukaemia - all stages of cell maturation are represented

Answer 77

- Left sided abdominal pain - Chronic leukaemia, there are some mature cells = chronic is at a later stage. Still needs treaetment - blasts, microcytes and monocytes.

Question 78

Malarial parasitization of the red cells - rare : describe the characteristics

Answer 78

- Can do a malarial antigen test - Febrile, confused, recently in Kenya - FALCIFERUM malaria = characteristic marks in each

Question 79

Describe the haemostatic response to injury

Answer 79

- Involves the vessel wall, platelets, coagulation, fibrinolysis - There are coagulation tests and they need interpretation

Question 80

What is haemostasis

Answer 80

- This is a protective process that we have evolved in order to maintain a stable physiology - explosive reaction that is designed to curtail blood loss, restore vascular integrity, and preserve life.

Question 81

describe infections that can occur - Horseshoe crab, which lives in sandy banks

Answer 81

- Limulus polyphemus, a primitive coagulation pathway that can be initiated by endotoxin - Has funny blood supply - no Hb, amebocyte is the main blood cell which has all of the coagulation proteins within it. Releases immune cells that release coagulation factors

Question 82

Haemolymphs contain amebocytes - what are amebocytes

Answer 82

- These are proteins of the coagulation system, and proteins and peptides of the immune system

Question 83

what is Disseminated intravascular coagulation (DIC)

Answer 83

Coagulation is activated by infection, and wards off bacteria from getting to more vital places in the body. Trying to ward off the bacteria from getting to more important parts of the body

Question 84

Haemostasis continued (4 key components + definition)

Answer 84

- Life preserving processes that are designed to maintain blood flow, respond to tissue injury, curtail blood loss, restore vascular integrity and promote healing and limit infection - There are 4 key components of haemostasis, Endothelium (blood vessel wall), Platelets, Coagulation, Fibrinolysis Respond to tissue injury, stop blood loss, limit infection.

Question 85

what are the factors that make up the blood clot?

Answer 85

- Life preserving processes that are designed to maintain blood flow, respond to tissue injury, curtail blood loss, restore vascular integrity and promote healing and limit infection - There are 4 key components of haemostasis, Endothelium (blood vessel wall), Platelets, Coagulation, Fibrinolysis Respond to tissue injury, stop blood loss, limit infection.

Question 86

broad overview of the haemoastasis process?

Answer 86

1. Vessel damage and blood loss 2. Vascular spasm/vasoconstriction 3. Platelet plug formation 4. Coagulation

Question 87

describe the 2nd step of haemostasis, vascular spasm / vasoconstriction?

Answer 87

- With activation of the endothelial cells - Diameter of the blood vessel becomes smaller - Lots of smooth muscle around the blood vessel which undergoes vasoconstriction

Question 88

describe the 3rd step of haemostasis, Platelet plug formation?

Answer 88

- Act like putty, recognise the place that is damaged and stick to this area, but this is not very strong

Question 89

describe the 4th step of haemostasis, coagulation?

Answer 89

- Stronger. The fibrin comes and forms this mesh.

Question 90

there are 3 phases to the haemostatic system - what are they?

Answer 90

1. Primary haemostasis 2. Secondary haemostasis, 3. Fibrinolysis

Question 91

what happens during Primary haemostasis

Answer 91

- Vasoconstriction, immediate - Platelet adhesion within seconds, platelets changing shape and releasing lots of things to form this putty, which sticks on a short term basis. - Platelet aggregation and contraction, within minutes

Question 92

what happens during secondary haemostasis

Answer 92

- Activation of coagulation factors, within seconds - Formation of fibrin, within minutes • ( Phase 1 and 2 happen at the same time )

Question 93

what happens during fibrinolysis

Answer 93

- Activation of fibrinolysis, within minutes - Lysis of the plug, within hours - *hoovering mechanism* - this also happens almost straight away

Question 94

Haemostasis at rest: triggers and cofactors separated

Answer 94

- This is the lumen of the blood vessel, and has lots of components for haemostasis. Platelets, and von willebrand factor which is really important. People who do not have it, have von willebrands disease and will bleed excessively. This is the factor for platelets to adhere to the site of injury - Most of them circulate in a non activated form. One circulates in small amounts, which is factor 7a which is like the initiator of coagulation. - Endothelium is the barrier between all of these haemostatic components. Things in the sub endothelium are t he initiatiors when you injure yourself - Collagen = sticky protein - Tissue factor = vital for the development of clotting

Question 95

describe Phase 1 of haemostatic system: Primary Haemostasis

Answer 95

- Involves collagen. Will interact with VWF in blood which makes it unravel and act as the anchor for platelets to stick to this damaged area - When platelets do this they change shape themselves and produce suloperdia and increase their surface area and release components which make even more platelets and VWF to join on - This creates a phospholipid surface for the development of fibrin

Question 96

Activity of v WF activity under shear stress

Answer 96

- VWF is released from the endothelium when something is damaged Gets unravelled, and platelets come and stick to it.

Question 97

what is the benefit of platelet aggregation?

Answer 97

- This prevents the excessive blood loss at the site of injury VWF= ligand / anchor to stick platelets to the damaged area fast.

Question 98

in platelet activation, what changes do the platelets go through?

Answer 98

1. resting platelet 2. activation 3. adhesion + spreading

Question 99

What is the role of platelets in haemostasis

Answer 99

- The plug of activated platelets is localised to the injury site. Provides phospholipid surface upon which secondary haemostasis occurs. - Tissue factor leads to thrombin and fibrin formation - Collagen causes platelets to adherer to them through VWF - More and more migration of platelet into the area that the platelet plug forms.

Question 100

haemostatic plug formation overview?

Answer 100

vessel constriction --> formation of unstable platelet plug (+platelet adhesion and aggregation) --> stabilisation of the plug with fibrin blood coagulation --> dissolution of the clot + vessel repair fibrinolysis

Question 101

what is dissolution

Answer 101

remodelling of the clot

Question 102

Role of the fibrin mesh

Answer 102

- It binds, and stabilises the platelet plug and other cells - Can see the red cells, platelets and fibrin mesh. - There are clotting factors that circulate in the plasma, most are made in the liver and most are q complex.

Question 103

describe the Revised waterfall hypothesis

Answer 103

- Coagulation is not what happens in the body = helps interpretation of clotting tests - Each reaction needs Ca2+, phospholipid, specific co factors - 7a binds a complex with tissue factor. Tissue factor is hidden in the sub endothelium. Can make a complex between the 2 and can drive forward coagulation. - Can activate factor 10 in the presence of factor 5 can turn pro thrombin into thrombin - Thrombin can convert fibrinogen into fibrin - X = extrinsic pathway, because tissue factor is extrinsic to blood - I = intrinsic pathway - clots because of foreign surface. Due to changes in ionic charge - Blood in a tube = if there is nothing there to stop it clotting then it will still clot when it comes into contact with a non physiological changes - 10 can cause thrombin to form and then eventually fibrin. Do not have clotting factors = bleeding. Some factors cause more bleeding that others when deficient - E.g. no factor 7 = 7 bleeding disorder because you do not have tissue factor 7 complex to drive forward coagulation - But losing factor 12 = no bleeding disorder

Question 104

Revised cascade: initiation process

Answer 104

- TF is outside the lumen, and there is formation of TF-FVIIa complex - Recruitment of FX, and formation of thrombin - Damage will lead to 7a coming into contact with the tissue factor and the complex is the initiator - Prothrombin becomes thrombin and this will then lead to fibrin

Question 105

What is the cell based model of coagulation | SECONDARY HAEMOSTASIS

Answer 105

- Forms a complex with factor 7, v important regulator. 7a cannot do this alone = have to activate lots of other factors, all on the surface or a platelet to allow this to happen. This will lead to the production of fibrin and fibrin mesh. - Process of forming a small amount of thrombin and then having to make more - development of more and more activated surfaces to make a huge amount of thrombin

Question 106

What is fibrinolysis definition, + its main functions.

Answer 106

- The process of clot dissolution. Limits where the clot forms = otherwise it could keep extending. - The main function is as a clot limiting mechanism and repair and healing mechanism. - Works via a series of tightly regulated enzymatic steps, feedback potentiation and inhibition. - The main key players are plasminogen, tissue plasminogen activation (t-PA) + urokinase (u-PA), plasminogen activator inhibitor -1 and -2, and alpha2 plasmin inhibitor (which are both negative regulators )

Question 107

What are the main key players of fibrinolysis?

Answer 107

- The main key players are plasminogen, tissue plasminogen activation (t-PA) + urokinase (u-PA), plasminogen activator inhibitor -1 and -2, and alpha2 plasmin inhibitor

Question 108

what are the steps of fibrinolysis

Answer 108

- plasminogen --> plasmin which is done by TPA (tissue plasminogen activator) - Plasmin is the active enzyme that will remove the clot, in doing so get some end products developed

Question 109

When are fibrin degeneration products (FDP) made

Answer 109

- When non cross linked fibrin, or fibrinogen gets broken down.

Question 110

Haemostasis and thrombosis - is a balance: describe this!

Answer 110

- Blood needs to be in a state of Eqm and not just clot all the time. - 4 factors = coag factors, platelets, fibrinolytic factors, anticoagulant proteins

Question 111

what happens during thrombosis?

Answer 111

- there is leaning towards coagulation factors, platelets and less towards fibrinolytic factors + anticoagulant proteins when there is too many platelets, there is too much clotting

Question 112

Bleeding - what happens

Answer 112

- There is a rise in fibrolytic factors (no clotting factors and not enough platelets ) and anticoagulant proteins - And a decrease in coagulation factors and platelets

Question 113

Easy bruising - echymosis

Answer 113

- Basically all bleeding disorders and often in mild situations, or heavy periods.

Question 114

Objectives 2 - coagulation tests and their interpretation

Answer 114

- Platelets are really small even on high power so you cannot tell what problem is - Patients platelets not working = specialised tests - VWF = not measured in most coagulation tests

Question 115

What are the principles of clotting tests

Answer 115

- Incubate plasma with reagents that are needed for coagulation - phospholipid, co factor. Trigger or activator. Calcium. - Then measure the time that is taken to form the fibrin clot. - Want to isolate the coagulation factors from the blood sample and administer triggering pathways, something like tissue factor

Question 116

what is PT Prothrombin Time

Answer 116

- This is sensitive to the extrinsic pathway, and to a lesser extent, the common pathway - It is TF driven. - PT time = one of the coagulation screening tests, tries to look at X path to see how long these reactions will take to occur, takes anything from 9-13 seconds, quite fast

Question 117

What is APTT - activated partial thromboplastin time

Answer 117

- Sensitive to intrinsic pathway, and to a lesser extent common pathway. Contact activated - Measures the intrinsic path and ability for blood to clot. Have to add something to activate 12, want to add a foreign substance (something like sand) which will rapidly cause the blood to clot. APTT is the slower way to make a clot = if it becomes a minute or longer = investigate what is missing in pathways.

Question 118

What is TT - Thrombin time

Answer 118

- Sensitive to defects in the conversion of fibrinogen to fibrin - Addition of thrombin = it will clot. Good to make sure that the end point is right

Question 119

Overview of coagulation pathways

Answer 119

- Ex = tissue factor added and making a clot | - Intrinsic = addition of clotting factors to make a clot

Question 120

Give an overview of the total testing process

Answer 120

1. Patient preparation and identification 2. Specimen Collection 3. Transportation and analysis 4. Report 5. Interpretation, clinical use of test result 6. Proper order and test collection

Question 121

Describe the process of blood sample collection for haemostasis testing

Answer 121

- Accuracy of haemostasis lab tests depend on the quality of the specimen submitted, blood is anticoagulated with 3.2% (0.1009 M) sodium citrate - Most of the tubes contain 0.3mL anticoagulant, and need 2.7mLs of blood - Under filling the tube yields grossly inaccurate results :( - People are often difficult to bleed which is the issue.

Question 122

Give examples of the pre analytical errors that can occur with haemostasis testing - Problems with blue top tube

Answer 122

Partial fill tubes, vaccuum leak and citrate evaporation

Question 123

Give examples of the pre analytical errors that can occur with haemostasis testing - Problems with phlebotomy

Answer 123

- Heparin contamination - Wrong labelling, slow fill, under fill, vigorous shaking - Different venepuncture

Question 124

Give examples of the pre analytical errors that can occur with haemostasis testing - Biological effects

Answer 124

- Hct > 55 or > 15 (too many RBC or cholesterol) | - Lipaemia, hyperbilirubinaemia, haemolysis

Question 125

Give examples of the pre analytical errors that can occur with haemostasis testing - Laboratory errors

Answer 125

- Delay in testing, prolonged incubation at 37 degrees celscius - Freeze/thaw deterioration

Question 126

The components of the tube

Answer 126

- Made up of 55% plasma, and 45% formed elements (cells) | - Plasma is made up of water, salt, plasma proteins, substances that are transported by the blood

Question 127

What is the process of manual coagulation

Answer 127

- Would tilt 3 times every 5 seconds + Once you have got the plasma then you can do manual APTT

Question 128

Can also so automated coagulation

Answer 128

Uses computer systems, where the end point is much more easily measured

Question 129

Can do mixing studies = factor deficiency

Answer 129

- Clotting factor tests are abnormal and prolonged. Usually because there is a factor deficiency - Clotting factor NR 50-150 IU/dL - APTT normal (24-34s) if factor level within range - 50:50 mix 32s/28s - APTT of 95 - should be 30-40 seconds so this is taking too long. Can mix with control pattern. Lots of plasma in the lab which should give normal time - the normal time that we expect is APTT of 28 - If normal, we can assume that clotting factors are also normal. - Mix test + control together, in theory you would be replacing all of the clotting factors = if all deficient in something and mix with normal then this should replace the deficiency - Might get 50% of all clotting factors = enough to make up the time and brings it back down to normal If it DOES correct then this means that the test patient is deficient in something

Question 130

Mixing studies: Inhibitors

Answer 130

- The antibody is in excess, and inhibits added factor. - 50:50 mix, 75 seconds/30seconds - Situation where this will not correct = still too high. Starts off 2x normal volume, when mixed doesn’t come down because the patient has antibodies. - Still ab in the patient plasma, which interacts with the additional normal plasma that has been added, still get a normal APTT. Mixing studies do not work always.

Question 131

describe Mixing studies?

Answer 131

- The antibody is in excess, and inhibits added factor. - 50:50 mix, 75 secs/30secs - Situation where this will not correct = still too high. Starts off 2x normal volume, when mixed doesn’t come down because the patient has antibodies. - Still ab in the patient plasma, which interacts with the additional normal plasma that has been added, still get a normal APTT. Mixing studies do not work always.

Question 132

describe what you would do during mixing studies?

Answer 132

- Can mix patient plasma and normal plasma, in equal volumes (50:50 mix) - Repeat abnormal coagulation test - Test normalises, factor deficiencies - Test stays abnormal - inhibitor (usually antibody) - Does not correct back to normal = antibody usually responsible

Question 133

Situation of Normal PT, abnormal APTT Tests to see which of the factors is abnormal. [the test for inhibitor activity]

Answer 133

- Specific inhibitors, 8,9,11 | - Non specific (anti phospholipid Ab)

Question 134

Situation of Normal PT, abnormal APTT Tests to see which of the factors are abnormal + [the test for ifactor deficiency]

Answer 134

- Isolated deficiency in instrinsic pathway - factors 8, 9, 11 - Multiple factor deficiencies (rare)

Question 135

Situation of Abnormal PT, Normal APTT : [Test for inhibitor activity]

Answer 135

- Specific inhibitors, 7 | - Non-specific (anti phospholipid)

Question 136

Situation of Abnormal PT, Normal APTT : [Test for factor deficency]

Answer 136

- Isolated deficiency of factor 7 (rare) - Multiple factor deficiencies (common) • Liver disease, vitamin K deficiency, warfarin, DIC

Question 137

Situation of abnormal PT, abnormal APTT [Test for inhibitor activity]

Answer 137

- Specific inhibitors, 5, 10, 2, 1 (rare) | - Non specific: anti phospholipid (common)

Question 138

Situation of Abnormal PT, Normal APTT : [Test for factor deficency]

Answer 138

- Isolated deficiency of factor 5, 10 - prothrombin, fibrinogen - Multiple factor deficiencies (common) • Liver disease, vitamin K deficiency, warfarin, DIC

Question 139

Situation of normal PT and abnormal APTT - normal

Answer 139

- Dysfibrinogenaemia - Abnormal fibrinolysis • e.g. anti plasmin deficiency - Elevated FDPs

Question 140

Situation of normal PT and abnormal APTT - abnormal

Answer 140

- Von willebrands disease - Platelet disorder - FX111 deficiency Non coagulation defect (e.g. vascular disorder)

Question 141

Laboratory evaluation - describe D Dimer testing

Answer 141

- This is a measure of the D dimer. D dimer is a fibrin degradation product. - This is elevated in the situation of enhanced fibrinolysis, thrombosis, DIC - Not specific for thrombosis, also elevated as an acute phase reactant - A negative result is useful if clinical suspicion of VTE is low D dimer = the breakdown products of fibrinolysis Someone who clots a lot will have a lot of D dimer D dimer test can be used as a negative diagnostic test for DVT

Question 142

Laboratory investigation of haemostasis test - FBC + smear

Answer 142

Platelet count RBC and platelet morphology Thrombocytopenia TTP, DIC etc

Question 143

Laboratory investigation of haemostasis test - Coagulation

Answer 143

``` Prothrombin time Partial thromboplastin time Coagulation factor assays 50:50 mix Fibrinogen assay Thrombin time FDPs or D dimer ``` ``` Ex and intrinsic common pathways Specific factor deficiencies Inhibitors, like antibodies Decreased fibrinogen Qualitative and quantitative fibrinogen defects fibrinolysis ```

Question 144

Laboratory investigation of haemostasis test - Platelet function

Answer 144

Von willebrand factor Bleeding time Platelet function analyser (PFA) Vwd platelet disorders, in vivo test (non specific), qualitative platelet disorders

Question 145

describe the haemocytometer Neubauer Chamber

Answer 145

- Old method of counting cells = put blood into this rectangle - Each of the squares contain 0.1ml of blood - This is an approximation and is older fashioned method. - Takes 5 minutes + to do single blood counts

Question 146

What would advia results look like

Answer 146

- blood goes in, results come out - Drawing blood through fine capillary tube, applies electrical field across capillary and change electrical field which causes a characteristic change in current - MEASURING CHANGES IN CURRENT - Larger cells with more internal complexity will be on the sides - by applying certain standard settings the machines can separate the cells into different populations - If population of cells if abnormal then will flag this and look abnormal - Cells that do not fit criteria = machines will not get it right - Gives you directly measured parameters - reveals how much Hb is within them and dividing amount of Hb that are from each of the cells - Able to differentiate directly measured and derived variables - Directly measured - Derived variables = calculated from the directly observed numbers - Differential white cell count - Machine separates characteristics and determines whether they are normal or not. - The most common white blood cell is a neutrophil.

Question 147

What is the full haemoglobin blood count (FBC)

Answer 147

Normal male - 130 - 180g /L | Normal female - 120 - 160g /L

Question 148

White cell blood count - what is the FBC

Answer 148

Normal adult - 4.0 - 11.0 x 109 / L | - Slight variations in different labs (million per microlitre)

Question 149

what is the full platelet count?

Answer 149

Normal adult - 150 - 400 x 109 / L | Way more platelets in the blood, than white cells. Expect to see a lot more platelets

Question 150

Normal WBC differential?

Answer 150

- The most common type are neutrophils, then lymphocytes, monocytes, eosinophils, and basophils respectively These differences could be due to ethnic variations africans = fewer neutrophils

Question 151

Peripheral blood film

Answer 151

- Take a drop of blood that is put at the head and take a slide and put in 30-40 degree angle so that the blood will spread along the edge of the slider, slide forward and spread the blood thin enough to look at individual cells

Question 152

What are the components of a Romanowsky stain

Answer 152

- 2 stains are needed to separate the white cells well, staining with 2 different stains then you are staining different structures and blood cells. 1. Azure B or methylene blue stain, basic dyes. 2. Eosin Y, acidic dye - Buffer pH 6.8 - Both are combined in the Romanowsky stain

Question 153

Morphology of normal neutrophils

Answer 153

- Neutrophils recognised because they are segmented. Chain with rings around them, up to 5 is normal, and can easily recognise because they have segmented nucleus

Question 154

Lymphocytes characteristics + what are the 3 types? + what is their major role.

Answer 154

- Major role of lymphocytes is in the adaptive Immune Response - Differentiation between self and non self - Viral attack - lymphocytes, produce antibodies to destroy that virus. Memory cells - 3 major types of lymphocytes are T cells, B cells, Natural killer NK cells

Question 155

characteristics of T cells

Answer 155

- Cell mediated immunity - CD4+ T helper cells - CD8+ Cytotoxic T cells - Directly attack the infected cells and kill it

Question 156

characteristics of B cells

Answer 156

- In humoral immunity, like antibody production - Make antibodies that bind to organisms and coat cells that are affected - When cell gets infected by the virus parts of the virus get expressed on the surface

Question 157

characteristics of NK cells

Answer 157

- Innate immune system, attacks virally infected cells + tumour cells

Question 158

What is other name for NK cell

Answer 158

Large granular lymphocyte cell

Question 159

Characteristics of NK cells (large granular lymphocyte cells)

Answer 159

- Blueness of cytoplasm comes from the antibodies, antibodies stay blue because they basophilic - Large granular lymphocytes, leukaemia = clonal expansion of these

Question 160

Characteristics of monocytes Next most likely to see in the blood

Answer 160

- Part of the innate immune system. Also phagosytosing cells, similar to neutrophils that are trying to engulf organisms - Monocytes try and do this too, do not have lots of visible granules - Usually only have 1 lobe, nucleus can look funny shaped. Recognise partly by shape and colour of nucleus and usually does not have any visible granules in sight, vacuoles present Pale grey/blue granules - easily recognised

Question 161

What is seen in things like hives and allergic reactions like eczema and asthma

Answer 161

Degranulation of eosinophils

Question 162

what are the characteristics Basophils

Answer 162

- Seeing too many means that you are worried person has a myeloproliferative disorder - Basophils are in the blood = eosinophils, have the power to go in and out of the blood stream - Blood is arguably the least important place for them to be - they go into the tissue and do their jobs, and then they die - Typical life span is 14 days of basophils - Red cells last for 120 days - Once made from the bone marrow = goes to the blood, then to the cell and then die. Same for the lymphocytes where you have a bank of memory cells - stay back as neurological memory and start multiplying again = do not get mumps /measles twice

Question 163

Describe the development of cells in the bone marrow

Answer 163

- Pluripotent haemopoietic stem cells - THIS ALL HAPPENS IN THE BONE MARROW - need millions to keep up with the demand. Neutrophils only last for a few hours - Stem cells can be anything = they are asymmetrical - Production line that works via supply and demand, tightly regulated system - body signals the bone of what needs producing and will make it in response - Big demand for white cells = stem cells will go through a number of precursor stages through the bone marrow before getting to the finished article - Have 2 lines that are separating = lymphoids go on to produce the B lymphocyte, T lymphocyte and the rest of the cells

Question 164

Normal adult WBC count?

Answer 164

4.0- 11.0 x 109 / L

Question 165

What is leucocytosis

Answer 165

increase in white cells

Question 166

What is leucopenia

Answer 166

decrease in white cells

Question 167

Normal adult neutrophils count

Answer 167

Normal adult neutrophils

Question 168

What is neutropenia?

Answer 168

Decrease in neutrophils | Certain drugs, like ones that cause bone marrow failure can cause this.

Question 169

Terminology related to neutrophilias: Toxic granulation

Answer 169

- Toxic granulation | - Granules increasing the toxic granules within them

Question 170

Terminology related to neutrophilias: | Shift to the LEFT

Answer 170

Myeloid maturation In the development of the white cells within the bone marrow, to arrive at the mature segmented neutrophil In the bone marrow drill out and see all of these stages in the bone marrow the blasts are the most immature parts and they gradually get more granules. Segmentation eventually = then neutrophil is typically released This is called Left shift, in acute severe infection you might see some precursors Left shift =usually points towards infection

Question 171

Terminology related to neutrophilias: Shift to the RIGHT

Answer 171

- Hypersegmented neutrophil | - Right shift = look at vitamin B12 + folic acid levels

Question 172

Terminology related to neutrophilias: Dohle bodies

Answer 172

- Innate issues and errors of neutrophil function - Dohle bodies = large bluish forms of granules - Large bluish longitudinal shapes, infections and inflammations. 3 things = the dohle body, toxic granulation and thirdly non fully segmented neutrophil

Question 173

Neutrophilia

Answer 173

- Neutrophils become much more numerous - Maybe a neutrophil count of 20-30 - Increased number of neurophils, they are left shifted and there is toxic granulation. Other causes of neutrophilia : - Bacterial infection, inflammation, vasculitis, myocardial infarction, carcinoma, steroid treatment, myeloproliferative disorders, treatment with myeloid growth factors - Neutrophils try to go to the site of the blood vessels - go to the side of the blood flow so that they can leave Bone marrow

Question 174

How would you do an investigation of neutrophilia

Answer 174

1. FBC, and differential white cell count. 2. Blood film examination. 3. Bacterial culture screen for infection 4. Bone marrow examination and chromosome analysis for chronic myeloid leukaemia 5. Philedelphia chromosome: translocation between chromosomes 9 + 22 6. Molecular analysis for BCR - ABL oncogene - Fusion gene product is what drives hematopoiesis - Clone that comes from this abnormality starts drawing out - Chromosomal abnormalities w microscope but can also look for product of this fusion gene

Question 175

what is Neutropenia

Answer 175

- Viral infection, drug induced like sulphonamindes - Radiotherapy and chemotherapy, part of pancytopenia in bone marrow failure (aplastic anaemia) or infiltration e.g. leukaemia - reduces the progenitors in the marrow, altogether - Racial = benign ethnic neutropenia Marrow infiltrated with what should not be there interferes with the production of RBCs

Question 176

how would you do Investigation of eosinophilia

Answer 176

- FBC + differential white cell count - Blood film examination - Stool examination for the ova and parasites

Question 177

Investigation of monocytosis

Answer 177

- FBC and differential white cell count - Blood film examination - for abnormal white blood cells, for malarial parasites - Bone marrow examination - leukaemia TB cultures

Question 178

Lymphocytosis - cells that are clear cut - Normal physiological status

Answer 178

- Lymphocytosis of childhood (1-6 years) | - Normal = 5.5 -8.5 x 109 / L

Question 179

Infectious mononucleosis (glandular fever)

Answer 179

- Hererophile antibodies - Abs that react against antigen which is totally unrelated to the antigen which originally stimulated it. - Like human antibodies reacting against sheep/horse/bovine cells

Question 180

describe Clearview infectious mononucleosis

Answer 180

- Take serum from a patient that you think has the infection, run on little bit of acetate cgel and then there are antibodies against antibodies whne you detect this - Form a line a precipitate Test is fast = wide looking cells in the blood have mono nucleosis, in the 1st few days of the disease this might not show up.

Question 181

how would you investigate lymphocytosis + what do findings suggest

Answer 181

- Mature lymphocytes, could mean chronic lymphocytic leukaemia or lymphoma - Immunophenotying to determine if the lymphocytes are B cells or T cells • B cells = demonstrate clonality by light chain restriction • T cells = demonstrate clonality by T cell receptor gene rearrangement studies

Question 182

What would you look for in investigation of white cell disorders

Answer 182

- FBC and differential white cell count, blood film examination - These are the 2 factors that you must look at when you are investigating a white cell disorder

Question 183

What is anaemia?

Answer 183

- Reduced Hb level, for the age + gender of the person

Question 184

What is haemolytic anaemia?

Answer 184

Anaemia. Due to shortened RBC survival

Question 185

Describe the normal RBC cycle?

Answer 185

RBCs= made in the bone marrow. BM needs: Ø Iron to make Hb Ø B12 and folate for the DNA synthesis Ø Make portophyrins that make haem Ø Need erythropoietin, drives haemotopoieses (which is driven by the kidneys) Ø Make globin chains - RBCs leave bone marrow. Leave nucleus behind and get matured anucleated cells circulating - Survive 120 days and get old and senescent and then removed by the liver

Question 186

Mature RBC metabolic pathways

Answer 186

- Glycolytic pathway - Hexose - monophosphate shunt • These are important for the survival of the red cells • Generates glucose metabolism

Question 187

Mature RBC membrane characteristics

Answer 187

- Membrane =biconcave disk, • High surface area so able to deform and pass through small surfaces and can also pass through the spleen - Haemoglobin is contained inside.

Question 188

what occurs in Haemolysis (general)

Answer 188

- There is shortened red cell survival (30-80days). - If you have all of the correct building blocks: this makes the bone marrow compensate with increased RBC production. There are therefore more young cells in the circulation - reticulocytosis +/- nucleated RBC. - If you have brisk compensation you will get nucleated RBCs because of the bone marrow compensation

Question 189

What happens in compensated haemolysis (+ what happens to Hb)

Answer 189

- RBC production is able to compensate for the decreased RBC life span - = normal Hb. - Able to produce enough RBCs to maintain Hb. - If you can't compensate = end up with anaemia.

Question 190

What is incompletely compensated haemolysis (+ what happens to Hb)

Answer 190

- RBC production is not able to keep up with decreased RBC life span So there is decreased Hb

Question 191

What are the Clinical findings in haemolytic anaemia

Answer 191

- Jaundice, Pallor and fatigue, splenomegaly, dark urine - Unconj. Bilirubin making breakdown product - More conjugated = more bilirubin Red cell removal usually happens at spleen = if the spleen is enlarged this could be an issue.

Question 192

What happens in a haemolytic crises

Answer 192

- Haemolytic crises = increased anaemia and jaundice with infections and preciptants. This is a complication. Start to haemolyse more due to infections or drugs.

Question 193

What happens in aplastic crises | • Long term haemolytic anaemias

Answer 193

- Anaemia, reticulocytopenia, with parovirus infection (common in children) If bone marrow is already going on overdrive and you are dependent on it to maintain you Hb then this could easily slightly fall.

Question 194

what are the clinical findings of haemolytic anaemia

Answer 194

- Gallstones with pigment, leg ulcers, folate deficiency (increased use.) from the breakdown of RBCs. - Severe haemolysis = folate deficient because our body easily depletes our folate stores if we have rapid erythropoesis - Free Hb acts as NO scavenger. - Can get leg ulcers. This can also occur with other haemolytic anaemias

Question 195

The lab findings of haemolytic anaemia: total

Answer 195

``` INCREASE IN: - Reticulocyte count • Making more red cells to compensated - Unconjugated bilirubin - LDH (lactate dehydrogenase) • Released from the red cells - Urobilinogen • If there is intravascular haemolysis. Reabsorption in the tubules and then you will later see haemosiderin in the urin after about a week - Urinary haemosiderin - Blood film is abnormal. - Low serum haptoglobin, which is the protein that binds free haemoglobin. ```

Question 196

CLINICAL features of haemolytic anaemia

Answer 196

Jaundice Pallor Sphenomegaly Pigment gallstones (chronic) Inherited anaemia = gallstones by teenage yrs. Risk of aplastic crisis from parvovirus B19

Question 197

LAB features of haemolytic anaemia

Answer 197

- Normal / low Hb, reticulocytosis (+/- NRBC), raised LDH, raised unconjugated bilirubin, - decreased haptoglobin, - decreased haptoglobin, - increased urobilinogen (+/- haemoglobinuria). - urine dip stick • Normal does not rule out anything - Abnormal blood film

Question 198

Classifying haemolytic anaemias

Answer 198

- Can look at the site of the red cell destruction. Some happening inside the vessels - TTP = intravascular - Extravascular = red cell removal outside the vessels - Looking at where the origin of the red cell damage is

Question 199

describe Acquired haemolytic anaemias

Answer 199

Immune, drugs, mechanical, microangiopathic, infections, burns, paroxysmal nocturnal haemoglobinuria.

Question 200

describe RBC Membrane disorders

Answer 200

- Normal red cell membrane structure • Lipid bilayer, integral proteins, membrane skeleton + various proteins within it that hold it all together • Important for allowing the red cell to deform and then regain its normal shape • Can get defects in the sets of protein • Vertical issues = spherocytic changes. SPECTRIN ○ Hereditary sperocytosis • Horizontal issues = hereditary ellipocytosis. Blood films that look like ellipocytes - Defects in vertical interaction - (hereditary spherocytosis) - Spectrin, Band 3, Protein 4.2, Ankyrin - Defects in horizontal interaction (hereditary elliptocytosis) Protein 4.1, Glycophorin C, (spectrin - HPP)

Question 201

Describe Hereditary spherocytosis

Answer 201

- Usually known that one parent has it because it is autosomal dominant. Spleen loses membrane as the red cell goes through = end up with a spherical cell rather than biconccave disk - Common hereditaray haemolytic anaemia, inherited in autosomal dominant fashion (75%), defects in proteins are involved in vertical interactiosn between the membrane skeleton + the lipid bilayer. - Decreased membrane deformability. Bone marrow makes biconcave RBC. But as the membrane is lost, the RBC becomes spherical.

Question 202

describe the appearance of Spherocytes

Answer 202

- Lost central pallor and there are rounder - This is what you would get as you lose the membrane - Go from being a biconcave disk to a sphere - Normal Hb = abnormal blood film and increased reticulocyte count --> severe haemolysis that makes you transfusion dependent Clinically can look like the following below: like the other haemolytic anaemias

Question 203

Clinical features Hereditary spherocytosis?

Answer 203

- Asymptomatic to severe haemolysis, neonatal jaundice - Jaundice, splenomegaly, pigment gallstones - Reduction in eosin-5-maleimid (EMA) binding - binds to band 3 in the membrane. This is reduced in most people with spherocytosis - Positive family history - one may already have spherocytosis - Negative direct antibody test • Do not have antibodies binding to the red cell membrane, not an immune mediated process.

Question 204

Management of Hereditary spherocytosis?

Answer 204

- Monitoring • Warn of risk of aplastic crises and gallstones - Folic acid (supplementary) - Transfusion, splenectomy - Spleen = main site of removal. Tranfusion dependent = look at taking the spleen out. Enough to make them not transfusion dependent - There are some spherocytic cells where haemolysis is much less

Question 205

describe Hereditary ellitocytosis

Answer 205

- Slightly less common - Elliptoid cells - Mild haemolysis = not even anaemic often and its an incidental pick up from a blood film - If they have 2 mutations Slightly more severe haemolysis

Question 206

ENZYMOPATHIES: RBC metabolic pathways

Answer 206

- Glycolysis - energy - ATP. - Na/K pump, with 3Na+ OUT and 2K+ IN - ATP becomes ADP + Pi. - HMS = reducing power, NADPH /GSH - There are lots of metabolic pathways in the RBCs that do functions for red cell survival. - There are pathways that generate ATP and glutathione - The 2 most common mutations = ○ G6PD mutation § Hexose monophosphate shunt abnormality. § Hb is susceptible to oxidation by free radicals § Clumps together and aggregates and forms a heinz body § These both reduce red cell deformability. § X linked = common when seen with malaria. More severe in medeterranian § Lyeinasation = females can also be affected as well as males § Can be asymptomatic as well as having acute haemolytic crises. § Anaemia = usually driven by oxidative stress which can be caused by any bacterial or infections.

Question 207

What is the Rapoport Luebering shunt

Answer 207

When there is 2,3 Bi Phosphoglycerate (2,3 BPG) = that modulates the o2 binding to haemoglobin.

Question 208

Describe Glucose 6 phosphate deficiency - What is the role of the HMP shunt

Answer 208

- Makes reduced glutathione, and protects the cell from oxidative stress

Question 209

Describe Glucose 6 phosphate deficiency - What are the effects of oxidative stress

Answer 209

- Hb oxidation by oxidant radicals This leads to denatured Hb aggregates + forms Heinz bodies which clump to the sides

Question 210

How are heinz bodies formed

Answer 210

- When there is oxidation of Hb, by oxidant radicals Which leads to denatured Hb aggregates. This will form Heinz bodies , which bind to the membrane. Oxidised membrane proteins = reduced RBC deformability

Question 211

What happens when there is G6PD deficiency

Answer 211

- This is a hereditary, X linked disorder which is common in African, Asian, Mediterranean & Middle Eastern Populations - Mild in African (type A) and more severe in Mediterraneans (Type B) - Clinical features range from asymptomatic to acute episodes, to chronic haemolysis. - Get blister cells where the Hb is blistered away from the Hb - Reduced G6PD on enzyme assay - have more of all of the enzyme. High reticulocyte count = means that you can get false normal enzyme activity because there are more younger cells.

Question 212

Morphology of oxidative haemolysis

Answer 212

- Bite cells = where macrophages have taken "bites" out of the red cells. They are also called helmet cells. - Pyruvate kinase = generates ATP which is essential for powering membrane cation pumps which is important for membrane deformability - Depending of the degree of deficiency, can be transfusion dependent anaemia or other type. - See compacted cells with spikes around them which are called Sputnick cells.

Question 213

What happens in a pyruvate kinase deficiency

Answer 213

- Needed to make ATP. Essential for membrane cation pumps (deformability). Autosomal recessive. Chronic anaemia. ○ Mild to transfusion dependent Improves with splenectomy

Question 214

describe Haemoglobinopathies

Answer 214

- Hb made from haem and globin chains - This is issue with the GLOBIN CHAINS - Normal Hb

Question 215

descrobe Normal haemoglobin

Answer 215

- Adult - HbA which is 2x alpha chains from chromosome 16 and 2x beta from chromosome 11 - Uterine life = make early Hb called portland and gower. Alpha chains are needed from early on in fetal life. Main fetal Hb = 2 alpha and 2 gamma chains - From the 3rd trimester they go quickly HbA = percentage goes up from first year of life until there is adult Hb.

Question 216

What can go wrong: Quantitative - thalassaemias

Answer 216

• Production of increased / decreased amount of a globin chain - structurally normal • Do not make enough alpha chains or beta chains • What you produce is normal but there is just not enough If there is XS they all bind together - but they will damage the cells

Question 217

What can go wrong: Qualitative - variant haemoglobins

Answer 217

• Production of a structurally abnormal globin chain

Question 218

descrobe Thalassaemias

Answer 218

- Imbalanced alpha and beta chain production, alpha and beta chain production - There are excess unpaired globin chains, which are unstable • Precipitate and damaged RBC + their precursors • Ineffective erythropoiesis in bone marrow Haemolytic anaemia

Question 219

How would you diagnose for the thalassaemia trait

Answer 219

- Asymptomatic. Microcytic hypochromic anaemia. Low Hb, MCV, MCH - Increased RBC. Often confused with a FE deficiency. HbA2 increased in Beta thalassaemias trait (daignostic) - A - thal trait is often by exclusion - Globin chain synthesis, rarely done now DNA studies

Question 220

Beta thalassaemia major - characteristics

Answer 220

- The transfusion is dependent in the 1st year of life - if there is NOT a transfusion then the following will happen: Failure to thrive, progressive hepatosplenomegaly, bone marrow expansion + skeletal abnormalities, death in 1st 5 years of life from anaemia

Question 221

What are the side effects of transfusion to overcome beta thalassaemia's major

Answer 221

- Iron overload. • Endocrinopathies • Heart failure • Liver cirrhosis

Question 222

What are the clinically significant sickling syndromes:

Answer 222

• HbSS, HbSC, • HbS- D punjab • HbS- O Arab • HbS- B thalassaemia Common inherited disorder. Shape of cells = sickle shaped. Presence of at least HbS mutation, which is a point mutation. In combination with another S mutation or another mutation Commonest = SS and SC. All result in sickle cell disease Polymerisation = gives them long sickled shape. Can get leucocytosis Patients with sickle = higher white cell counts and get more problems. Haemolysis which acts as a NO scavenger that can lead to things like stroke, pulmonary occlusion Vascular occlusion = leads to pain and is when the RBCs get stuck in the vessels.

Question 223

Pathophysiology of SCD

Answer 223

Abnormal vessel formation, progressive visual loss, pulmonary hypertension

Question 224

what are the Acute complications of SCD

Answer 224

``` LIST Ø ischaemic stroke & haemorrhagic Ø Cholecystisis Ø Hepatic sequestration Ø Dactylitis Ø Bone pain + infarcts Ø Osteomyelitis Ø Retinal detachment Ø Vitreous haemorrhage Ø Chest syndrome Ø Splenic seqeuestration Ø Haematuria: papillary necrosis Ø Priapism Ø Aplastic crises Ø Leg ulcers ```

Question 225

what are the chronic complications of SCD

Answer 225

``` LIST Ø Silent infarcts Ø Pulmonary hypertension Ø Chronic lung disease, bronchiestasis Ø Erectile dysfuntion Ø Azoospermia Ø Chronic pain syndromes Ø Delayed puberty Ø Moya moya ``` Retinopathy, visual loss

Question 226

Clinical features of SCD?

Answer 226

- Painful crises, aplastic crises - If child is born in UK diagnosis is made at birth to make sure they are started on penicillin by 3 months of age to reduce infant morality - People present with acute pain - Infections - Acute sickling • Chest syndrome • Splenic sequestration • Stroke - Chronic sickling effects (chronic organ damage) • Renal failure • Avascular necrosis bone

Question 227

Laboratory features of SCD?

Answer 227

``` - Anaemia • Hb often 65-85 - Reticulocytosis - Increased NRBC - Raised bilirubin ``` Low creatinine

Question 228

How would you confirm the diagnosis of sickle cell anaemia: solubility

Answer 228

- Confirm that there is Sickle Hb - Which will precipitate out and cause a cloudy solution. - Solubility test, expose the blood to reducing agent, HbS precipitated - Positive in trait + disease

Question 229

How would you confirm the diagnosis of sickle cell anaemia - electrophoresis

Answer 229

- Electrophoresis To differentiate between SCD and sickle trait

Question 230

HPLC drawbacks?

Answer 230

- Not definitive. Need sickle solubility test. | - Can get other Hb variants that would elute out at the same time as sickle Hb.

Question 231

Acquired haemolytic anaemias: Immune haemolysis [autoimmune]

Answer 231

``` - Idiopathic - for no good reason • Usually warm, IgG, IgM - Drug meditated - Cancer associated • LPDs (proliferative disoder) + autoimmune syndromes like lupus - See in diff circumstances ``` Make antibodies against self

Question 232

Acquired haemolytic anaemias: Immune haemolysis - Alloimmune - Either in the neonatal period or in the transfusion reagent

Answer 232

- Transplacental transfer • Haemolytic disease of the newborn: D, c, L • ABO incompatability - Transfusion related • Acute haemolytic transfusion reaction, ABO - Delayed haemolytic transfusion reaction • Rh groups, duffy

Question 233

describe Non immune acquired haemolysis

Answer 233

- Paroxysmal noctural haemoglobin - Fragmentation haemolysis • Mechanical, microangiopathic haemolysis ○ Platelet consumption + red cell consumption • Disseminated intravascular coagulation • Thrombotic thrombocytopenic purpura - Other: severe burns, some infections like malaria.

Question 234

features of haemolysis?

Answer 234

- Reticulocytosis, unconjugated hyperbilirubinaemia - Raised LDH - If you have not already got antibodies then they will give you anti D during pregnancy to bind with any D positive cells that will come through from the baby - Most of ABO = IgM but you have some IgG and ABO.

Question 235

How can someone get haemolytic anaemia

Answer 235

- Can be inherited or acquired. - Membrane /enzyme/haemoglobin - Extrinsic: immune vs non immune - Clinical features with morphology + specialised tests can help to determine cause.

Question 236

Blood group antigens + blood group antibodies: what are antigens

Answer 236

- Antigens are part of the surface of cells. | - All blood cells have antigens. [+ therefore specific surfaces]

Question 237

What are antibodies?

Answer 237

- Found on the surface of cells. They are protein molecules (immunoglobulins, Ig), which are usually of the Ig classes IgG and IgM. Found in the plasma, and produced by the immune system when there is foreign antigen.

Question 238

When do reactions to blood usually occur?

Answer 238

- When the antibody that is in the plasma, reacts with an antigen that is on the cells.

Question 239

Blood group antigens

Answer 239

- There are 26 blood groups that we know of. ABO + Rh are the clinically most important. - Antigens that are in transfused blood can make patient produce an antibody, only if the patient themselves do not have this antigen. - Freq. of antibody production is low - but increases, the more transfusions that are given.

Question 240

How many blood groups exist? + which are the most important.

Answer 240

26. ABO + Rh are the most important groups.

Question 241

Stimulation of antibody production: methods

Answer 241

Blood transfusion • Blood carrying antigens foreign to the patient Pregnancy • Fetal antigen that enters the maternal circulation during pregnancy / at birth Environmental Factors • Naturally acquired. e.g. Anti A and Anti - B

Question 242

Examples of antibody - antigen reactions In vivo antibody - antigen reactions examples

Answer 242

- Leads to the direct destruction of the cell. • Directly: when the cell breaks up in the blood stream (intravascular) • Indirectly: when liver + spleen remove cells that are coated in antibodies (extravascular)

Question 243

Examples of antibody - antigen reactions In vitro antibody - antigen reactions

Answer 243

Reactions are normally seen as agglutination tests

Question 244

What is agglutination

Answer 244

- Clumping together. Of red cells into visible agglutinates by antigen - antibody reactions. Results from antibody cross linking with the antigens.

Question 245

What can agglutination identify

Answer 245

1. Presence of a red cells antigen (blood grouping) | 2. Presence of an antibody in the plasma (antibody screening + identification.)

Question 246

What is the clinical significance of the ABO grouping system?

Answer 246

- A + B antigens are really common. (55% in the UK). Anti-A, Anti-B, or Anti-A,B antibodies are really common, in 97% in UK. - There is a high risk of A/B cells being transfused into someone with the antibody in a random situation. ABO antibodies can activate complement, which causes intravascular haemolysis. - Almost all serious/fatal transfusion reactions b/c of technical/clerical error are due to ABO incompatibility ABO = Blood cells either have a antigen, or b antigen, or either. A antigen on their cell surface, or B antigen on their cell surface. If they have neither then they are group O. They happen converesely. Someone who is A will have naturally occurring anti B antibodies Someone who is group O will have anti a and anti b antibodies. - If you selected a unit randomly in the blood bank there is therefore a high chance that something will go wrong.

Question 247

What does activation of complement cause?

Answer 247

Intravascular haemolysis.

Question 248

What are the genetics of ABO? | *last year there was a question about this.*

Answer 248

- A + B phenotype is inherited codominantly.

Question 249

What are the ABO groups

Answer 249

Different blood groups Ø Antigens poke out of RBC surface. Ø Antibodies = made via B cells, T cells help + plasma cells. Before this can happen, antigens are made via the immune system. Ø The immune system recognises something as non self. Ø When there is exposure to a non self antigen (e.g. cold virus) = body makes Abs, to neutralise the virus. Ø Abs made when there is recognition of non self things, and can be passed through the placenta. Ø There are "A" & "B" like antigens on the gut Ø See B antigens as non self = Abs against it are produced. Ø B antigen is on the surface of group B.

Question 250

Blood groupings: HOW YOU WOULD TEST: Test red cells with: | • Anti A , B, D

Answer 250

- Agglutination? show that a certain antigen is on the red cells. - No agglutination? will show the antigen is absent

Question 251

Blood groupings: HOW YOU WOULD TEST: Test patient plasma w/ A cells , B cells

Answer 251

- Agglutination? Shows that a particular antibody is in the plasma / serum - No agglutination? Shows that the antibody is absent

Question 252

agglutination reactions

Answer 252

- There are cards with wells. Ø Gel = impregnated with anti A and anti B. Ø Put patients RBCs on top, and then spin. Ø If there is an antibody-antigen reaction there is agglutination. - When there is agglutination in gel cards = it will be thicker and therefore can't pass through the cards.

Question 253

FORWARD GROUP | agglutination reactions

Answer 253

• Looking at the antigens on the patients red cells - Put the red cells in, there is ANTI X antibody. - This interaction = agglutination. - Agglutinate cannot pass through during centrifugation - Therefore if there is agglutination, does not move downwards. It will sit on the top.

Question 254

REVERSEGROUP | agglutination reactions

Answer 254

• Looking at the antibodies in the patients plasma - B Cells agglutination. Therefore there must be anti B present in the B cells. - If someone is blood group A B = have A antigens and B antigens so do not expect them to have any antibodies.

Question 255

ABO compatibility

Answer 255

O = used to be known as the universal donor because they do not have A antigens or B antigens so there will not be agglutination when there is antibody-antigen reactions --> agglutination --> haemolysis.

Question 256

Rh grouping system - describe

Answer 256

There are 50+ antigens - The most important antigen is called D. People with D antigen are RhD positive. (85% of UK). People who do not make D antigen, are RhD negative (15%)

Question 257

What are the other main 4 Rh antigens that are known?

Answer 257

What are the other main 4 Rh antigens that are known? - C, c, E, e

Question 258

Rh (D) typing

Answer 258

- Most important after ABO. Has to be tested in duplicate (or tested each time + compared to a historical result). Patient / donor classified as RhD positive, or RhD negative.

Question 259

What is the clinical significant of Rh

Answer 259

Transfusion - D antigen = very immunogenic and Anti D is easily stimulated. Prevention! - All Rh antibodies are capable of causing severe transfusion reaction - antibody detection Pregnancy - Rh antibodies are usually IgG. Can cause haemolytic disease of the newborn. - Anti-D is still most common cause of severe HDN.

Question 260

Describe the characteristics of Haemolytic Disease of the Newborn. (HDN) (What actually happens)

Answer 260

1. Rh+ father. 2. Rh- mum, carrying her 1st Rh+ fetus, there are Rh antigens from the developing fetus that can enter the mothers blood during delivery. 3. In response to the fetuses Rh antigens, the mother makes anti RH antibodies. 4. If woman gets pregnant with another Rh+ fetus, her anti-Rh antibodies will cross over the placenta + damage the fetal red blood cells. - At delivery some of the fetal cells will escape into the mothers circulation

Question 261

HDN - laboratory testing

Answer 261

- Blood group + antibody screen @ antenatal booking. Identify pregnancies @ risk of HDN. - There could be RhD negative women, who may need anti D prophylaxis. Blood group + antibody screen @ 28 weeks.

Question 262

What is RAADP

Answer 262

- Injection. Of Anti D Ø Binds to + removes any fetal RhD positive RBCs in circulation. - 1500iu of anti D is given @ 28 weeks + a smaller dose - Usually 500 iu after delivery if baby RhD+ - Can also give 2X smaller (500 iu) doses @ 28 + 34 weeks rather than 1 larger dose. - Anti D is also given, after anything that could cause a feto-maternal haemorrhage (bleed between the mum and the fetus) - like abdo trauma, intrauterine death, spontaneous or therapeutic abortion.

Question 263

Antibody screening - why?

Answer 263

- Screen for clinically significant antibodies, that can cause haemolytic transfusion reaction. - if detected, antigen negative blood can be given = avoids immune reaction.

Question 264

Antibody screen: what happens if we detect an antibody

Answer 264

- If an antibody is detected then we have to 1. Identify the antibody 2. 2. Assess its clinical significance. 3. For transfusion + in pregnancy. There is an antibody in the patient plasma therefore there is agglutination

Question 265

How to identify an antibody

Answer 265

You would compare pattern of reactions with each reagent cell of ID panel - with the pattern of antigens on the reagent cells. Matching pattern will identify the antibody.

Question 266

Describe the ID panel profile

Answer 266

- 10 cells, indirect antiglobulin test (IAT), anti D, panels get automated and then BMS will interpret.

Question 267

describe Zeta potential?

Answer 267

Ø IgM antibodies can span the gap that is between 2x red blood cells. Ø IgG antibodies cannot span this cap, because they are too small to be able to overcome the ZETA potential (positive charge) ○ LISS = Low Ionic Strength Saline = negatively charged. Will neutralise + charge - = IgG can now span the gap. - Agglutination detected if Ab can connect RBCs. - Have to get rid of the + charge ionic cloud = using LISS to neutralise ionic cloud.

Question 268

Why does LISS allow IgG to span the gap between 2 RBCs

Answer 268

- Usually IgG antibodies are too small to span the gap, as they cannot overcome ZETA (positive) potential charge. LISS, which is low ionic strength saline is negatively charged & neutralises this positive ZETA potential.

Question 269

What is the indirect anti globulin test (IAT) used for

Answer 269

- Used to detect IgG antibodies. LISS counteracts ZETA potential. Results in agglutination = they are able to stick together. - Used for: 1. Screening for antibodies, 2. Identifying antibodies 3. Cross matching donor blood with recipient plasma, where there are known Abs/ previous antibody history.

Question 270

What are the 3 uses of the indirect anti globulin test (IAT)

Answer 270

1. Screening for antibodies, 2. Identifying antibodies 3. Cross matching donor blood with recipient plasma, where there are known antibodies or a previous history of antibodies.

Question 271

Describe the process of cross matching. - immediate spin cross match

Answer 271

- Antibody screen, is negative - Checking donor red cells against patient plasma • ABO check, incubate for 2 to 5 minutes, room temp, spin + read# - ISX is basically checking the ABO group - therefore IgM antibodies, therefore no problem with ZETA potential - therefore there is no need to IAT.

Question 272

Describe the process of cross matching. Full indirect Antiglobulin Test (IAT) cross match

Answer 272

- Antibody screen, positive or patient has known antibody history - Select antigen negative donor red cells, and incubate with patient serum for 15 minutes @ 37 degrees celsius.

Question 273

Describe the process of donor blood testing

Answer 273

- Blood establishment - MHRA manufacturer of blood and products - Collection procedure arm cleansing / diversion pouch - Comprehensive testing of all products: viral • HIV 1 + 2, Hep B, Hep C, Syphilis, HTLV - Platelets, bacteria. We do not test variant CDG = economic argument.

Question 274

Red cells characteristics

Answer 274

- []RBCs. Packed cells in suspension of SAGM. These RBCs have o2 carrying capacity - Symptomatic anaemia. - If there is significant bleeding anticipated, can activate the major haemorrhage protocol.

Question 275

describe Fresh frozen plasma

Answer 275

- FFP contains all clotting factors - given for coagulopathy with associated bleeding. Needs clotting screens to monitor. Only has 24hr life after thawing.

Question 276

Platelet characteristics

Answer 276

- []RBCs. Packed cells in suspension of SAGM. These RBCs have o2 carrying capacity - Symptomatic anaemia. If there is significant bleeding anticipated, can activate the major haemorrhage protocol.

Question 277

Cryoprecipitate components

Answer 277

- Contains factor 8, VWF and fibrinogen | - 2 units are usually given @ one time, monitor fibrinogen levels by clotting screens

Question 278

How are blood glucose levels maintained from several sources? (where we get glucose from)

Answer 278

- Dietary carbohydrates - Glycogenolysis - breakdown of glycogen to glucose Gluconeogenesis -making of glucose from not glucose sources

Question 279

What is the livers role in glucose metabolism

Answer 279

- After meals = store glucose as glycogen Ø If there is XS glucose in the plasma, is stored as glycogen in the liver Ø When fasting the liver breaks glycogen down --> glucose available for the body Ø (Can also use amino acids, glycerol etc. maintains certain level of glucose in the plasma) - During fasting - this will make glucose available through glycogenolysis + gluconeogenesis

Question 280

Why should glucose levels be regulated

Answer 280

- Brain + erythrocytes need a continuous supply and avoid deficiency - cannot make glucose on their own. - High glucose + metabolites cause pathological tissues : • micro/macro vascular diseases, including (diabetic) neuropathy - avoid excess + retinopathy

Question 281

What are the characteristics of insulin + where is it synthesised

Answer 281

- There is a C chain in between which is removed and then a disulfide bond is formed. This produces insulin as well as the C peptide in circulation. - Insulin is the main regulator of glucose - Peptide hormone, 51 amino acids - Made in the B cells of the pancreas, as pro-insulin, which have amino terminal B chain and carboxyl terminal A chain. - In the endoplasmic reticulum there are peptidases - cleave to form C peptide on its own + insulin • Cleaved, to insulin and C peptide - Secretion is stimulated by a rise in blood glucose levels

Question 282

Describe the metabolic effects of insulin? in Increased: amino acid uptake, glycogen synthesis, fatty acid synthesis

Answer 282

- Fall in ketogenesis - Gluconeogenesis - Glycogenolysis

Question 283

Describe the metabolic effects of insulin? in Increased: glucose uptake

Answer 283

- In general tissues

Question 284

Describe the metabolic effects of insulin? in Increased: lipogenesis

Answer 284

- Fall in lipolysis

Question 285

Describe the metabolic effects of insulin? In ncreased: amino acid uptake, glycogen synthesis

Answer 285

Fall in protein breakdown - reduce the uptake of proteases in muscle tissues therefore reduces the breakdown of proteins

Question 286

What are the 4 glucose counter regulatory hormones? + their actions

Answer 286

- Glucagon, adrenaline, growth hormone, cortisol Counteract the actions of insulin - storage of glucose in the form of glycogen. In fasting state, then the glycogen is broken down by glucagon

Question 287

Characteristics of GLUCAGON - (gcrh)

Answer 287

- Secreted by the a cells of the pancreas. In response to hypoglycaemia. - Stimulates glycogenolysis + gluconeogenesis

Question 288

Characteristics of ADRENALINE - (gcrh)

Answer 288

- Increased glycogenolysis + lipolysis

Question 289

Characteristics of GROWTH HORMONE - (gcrh)

Answer 289

- Increased glycogenolysis + lipolysis

Question 290

Describe diabetes mellitus

Answer 290

- Metabolic disorder • Chronic hyperglycaemia • Glycosuria • Associated abnormalities of lipid + protein metabolism. Should also include polydipsia (more glucose in circulation and peeing and drinking a lot) - abnormalities in metabolism of lipids and proteins - There is hyperglycaemia because of increased hepatic glucose production + fall in cellular glucose uptake - Blood glucose = BEYOND > 10mmol/L = exceeds renal threshold (There is excess in the kidney and it can only take a certain amount)- glycosuria - If there is lots of glucose in renal tubules, will produce osmotic effect - taking water from body = thirst + will make you drink more. - Long term complication = micro/macrovascular diseases.

Question 291

How would you diagnose Diabetes Mellitus: IN presence of symptoms like polyuria, polydipsia, weight loss - Random plasma glucose

Answer 291

>11.1 mmol/L (200mg/dl) - Check blood for presence of glucose at any given time - If you have symptoms and you are above the above levels then you have DM

Question 292

How would you diagnose Diabetes Mellitus: IN presence of symptoms like polyuria, polydipsia, weight loss - Fasting plasma glucose

Answer 292

>7.0 mmol/L (120 mg/dl) Fasting = defined as no caloric intake for at least 8hrs - Equal or more than 7millimol = have DM. Or 2h plasma glucose > 11.1mmol/L (200mg/dl); 2hrs after 75g oral glucose tolerance test (OGTT)

Question 293

How would you diagnose Diabetes Mellitus: IN presence of symptoms like polyuria, polydipsia, weight loss - Oral Glucose Tolerance Test

Answer 293

>11.1mmol/l

Question 294

How would you diagnose Diabetes Mellitus: WITHOUT presence of symptoms

Answer 294

- w/o Weight loss, polyuria, polydipsia | Test the blood samples, on 2 separate days

Question 295

describe Impaired Glucose Tolerance (IGT) Pre diabetic state

Answer 295

- Fasting plasma glucose (6.1-6.9 mmol/L) | - OTTG value of

Question 296

Impaired Fasting Glycaemia (IFG)

Answer 296

- Fasting plasma glucose

Question 297

The Oral Glucose Tolerance Test: who should OGTT be carried out on

Answer 297

- In patients with Impaired Fasting Glycaemia - Unexplained glycosuria - In clinical features of diabetes with normal plasma glucose values - For the diagnosis of acromegaly, which is increased GH • When you give them 5-7g glucose in normal person, GH falls. • Will stay high in those who have acromegaly.

Question 298

How would you to the OGTT (Oral Glucose Tolerance Test

Answer 298

- 75g glucose, Test after 2 hours. Blood samples collected at 0 and 120 minutes after glucose. - Subjects tested fasting, after 3 days of normal diet that contains at least 250g carbohydrate

Question 299

What are the characteristics of the classifications of diabetes

Answer 299

Type 1, Type 2, Gestational, Secondary

Question 300

What are the characteristics of Type 1 DM

Answer 300

- Insulin secretion deficiency. Because of autoimmune destruction of the B cells in the pancreas, by T cells - Autoimmune destruction of B cells. Environment + genetic factors interact - There is a strong link with the HLA genes within the MHC region on chromosome 6 - Predominantly in children + young adults [NICK JONAS] & Sudden onset = days/weeks - Appearance of symptoms might come after pre-diabetic period of several months

Question 301

What happens in Type 1 DM

Answer 301

Autoimmune B cell destruction. HLA genes in the MHC region on chromosome 6 involved. + (environment & genetic involvement)

Question 302

Describe, in detail the pathogenesis of Type 1 DM

Answer 302

- HLA class 2 cell surface. Normal will present as FOREIGN + SELF ANTIGENS to the T lymphocytes - This will initiate an autoimmune response - Circulating autoantibodies to various cell antigens, for instance: • Glutamic acid decarboxylase • Islet auto-antigen • Tyrosine-phosphatase-like molecule

Question 303

action of Glutamic acid decarboxylase in pathogenesis of Type 1 DM

Answer 303

○ Found in the pancreas - if there are auto antibodies to this there is desctruction to the beta cells / pancreas

Question 304

action of islet auto antigen in pathogenesis of Type 1 DM

Answer 304

○ Auto immunity = can be T cell mediated, or antibody mediated. is the most commonly detect antibody associated with Type 1 DM

Question 305

What are the circulating autoantibodies that are involved in the pathogenesis of Type 1 DM

Answer 305

* Glutamic acid decarboxylase * Islet auto-antigen * Tyrosine-phosphatase-like molecule * (most commonly detected antibody associated with T1 DM = islet cell antibody) * More than 90% of newly diagnosed people with T1 DM have 1+ of these antibodies. (Glutamic acid autoantibody, islet autoantibody) Destruction of the B cells will therefore cause hyperglycaemia - as they cannot make insulin

Question 306

What happens when there is destruction of the pancreatic B cells (Type 1 DM)

Answer 306

- Hyperglycaemia. Because of absolute deficiency of both: INSULIN + AMYLIN - Amylin = glucose regulatory peptide hormone

Question 307

What is Amylin + how does it lower blood glucose?

Answer 307

- Glucoregulatory peptide hormone. That is co secreted with insulin - Lowers blood glucose, by: 1. Slowing gastric emptying Ø Do not feel hungry that much, do not eat a lot, so glucose level does not get too high 2. Suppressing glucagon output from the pancreatic cells

Question 308

What are the metabolic complications of Type 1 DM

Answer 308

Ø Become volume depleted - taking water from the body due to osmotic effect in the kidneys = makes you dehydrated Ketoacidosis = More ketone bodies are produced = diabetic coma Ø Hyperglycaemia = if too much glucose goes through the kidney and it gets overwhelmed = cannot reabsorb all of the glucose from the renal tubule Ø High level of glucose in the kidney = osmotic effect and dras water in the tubule, which increases amount of urine that you pass

Question 309

What are the characteristics of Type 2 DM

Answer 309

- HyperOsmolar, Non Ketotic state (HONK) - Ketone bodies are NOT produced. They are only produced because you do not have insulin - Absence of insulin there is increased lipid breakdown - Development of severe hyperglycaemia - extreme dehydration and the pathophysiology is the same as T1 DM. There are no ketone bodies.

Question 310

What are the metabolic complications of Type 2 DM

Answer 310

- HyperOsmolar, Non Ketotic state (HONK) • Development of severe hyperglycaemia, extreme dehydration, increased plasma osmolality • No ketosis, minimal acidosis • Impaired consciousness: death if untreated.

Question 311

What are the aims of monitoring Type 2 DM

Answer 311

- Avoid hypoglycaemia. Glycated Hb (HbA1c) - aim at

Question 312

How can you self-monitor Type 2 DM

Answer 312

1. Capillary blood measurement 2. Urine analysis: glucose in the urine, gives indications of blood glucose 3. Concentration above renal threshold

Question 313

describe Stepwise treatment of Type 2 diabetes

Answer 313

1. Diet + exercise 2. Oral monotherapy (metformin) 3. Oral combination (sulphonylureas, Gliptins, GLP 1 analouges) Ø If all of these drugs do not work then you would give insulin injections Insulin + oral agents

Question 314

What are the long term complications of Type 1 and 2 diabetes

Answer 314

- Microvascular diseases • Retinopathy, nephropathy, neuropathy • Increased levels of insulin can lead to glycation of the proteins = damage to the small blood vessels cause damage to the kidneys - Macrovascular disease • Related to atherosclerosis heart attack + stroke • Changes in compliance which can lead to these long term complications

Question 315

How do you reduce the cardiovascular risk in DM

Answer 315

- Get normal weight + waist circumference, eat low fat and salt, exercise, stop smoking - Maintain HbA1c

Question 316

What is hypoglycaemia + what does it result in

Answer 316

- Plasma glucose than is less than (

Question 317

What are the causes of hypoglycaemia - insulinoma

Answer 317

- When the body / pancreas makes XS insulin, lowers the blood glucose levels

Question 318

What are the causes of hypoglycaemia - drugs

Answer 318

- Sulphonylureas, insulin, alcohol abuse - Can all also cause hypoglycaemia - alcohol can affect liver, which is important in gluconeogeneis - Liver is not able to make the glucose from non-glucose substances (like lactate & amino acids)

Question 319

What are the causes of hypoglycaemia - Inherited metabolic disorders

Answer 319

- Glycogen storage diseases - Galactosaemia - Hereditary fructose intolerance

Question 320

What are the causes of hypoglycaemia - Endocrine diseases

Answer 320

- Like cortisol disorder | + severe liver disease, non-pancreatic tumours, post gastrectomy

Question 321

What are the adaptations to falling glucose levels in fasting

Answer 321

- Insulin levels fall. This limits glucose entry into non cerebral tissues Ø Hepatic gluconeogenesis will be stimulated Ø Glycogen breakdown will be activated Ø Fatty acid oxidation will be activated Ø There will be released of counter regulatory hormone, raising glucose Glucagon

Question 322

What are the symptoms of hypoglycaemia (list the 2)

Answer 322

Neurogenic [autonomic] 2. Neuroglycopaenia

Question 323

What are the NEUROGENIC (autonomic) symptoms of hypoglycaemia and what is it triggered by?

Answer 323

- Triggered by falling glucose levels. Activated by ANS + mediated by: • Sympathoadrenal release, of catecholamines + Ach - Shakiness, anxiety, nervousness, palpitations, sweating, dry mouth, pallor + pupil dilation

Question 324

What is insulinoma + what are the symptoms of it?

Answer 324

- Tumour, in the insulin secreting B cells of the pancreas. Keep secreting insulin and insulin conc will go up to that low level of glucose. - Insulin is usually made as proinsulin, more proinsulin = more c peptide available in the blood as well as more insulin. - Symptoms = fasting hypoglycaemia, patients might present with behavioural changes, inappropriate high insulin concentration at a time when plasma glucose is low, and LESS Than 2.5 mmol/L - C peptide should be measured

Question 325

What are the NEUROGLYCOPAENIA symptoms of hypoglycaemia and what is it triggered by?

Answer 325

- Because of neuronal glucose deprivation Sign + symptoms include confusion, difficulty speaking, ataxia, paresthesisa, seizures, coma + death

Question 326

Inherited metabolic diseases : list

Answer 326

1. Glycogen storage disease type 1 (Von Gierkes dieease) 2. Galactosaemia 3. Hereditary fructose intolerance

Question 327

Describe the inherited metabolic disease, GLYCOGEN STORAGE DISEASE TYPE 1 (Von Gierkes)

Answer 327

- Deficiency of G6Phosphatase - There is impaired glucose release from glycogen - Glucose synthesis is blocked in this disease = blockage of the synthesis of glyocgen and also gluconeogenesis by the liver - Made in early infancy - Buildup of lactate which can also lead to acidosis. • Uncooked cornstarch, or slow releasing glycogen solution.

Question 328

Describe the inherited metabolic disease, GALACTOSAEMIA

Answer 328

- There is a deficiency of Galactose 1 Phosphate, Uridyl Transferase: - Which means that there is liver damage

Question 329

Describe the inherited metabolic disease, HEREDITARY FRUCTOSE INTOLERANCE

Answer 329

- Deficiency of fructose 1 phosphatase adolase B Accumulation of fructose 1 phosphate in the liver

Question 330

Glycogen storage disease Type 1a

Answer 330

- Autosomal rec. disorder. - Glucose synthesis from glycogen, or gluconeogenesis is blocked - Presents in: • Early infancy • Severe fasting hypoglycaemia • As the only source of glucose is dietary carbohydrate

Question 331

What does accumulation of glycogen cause

Answer 331

- Hepatomegaly - Inability to produce glucose from lactate, causes acidosis - TX = uncooked cornstarch: which is a slow releasing glucose prep.

Question 332

Describe hepatic glycogen metabolism

Answer 332

- If G6P is deficent then there is a limit to how much glucose that you can make Build up of glycogen = hepato megaly

Question 333

What is galactosaemia? - another metabolic disorder

Answer 333

- Defects in 3 enzymes can cause galacatosaemia. - Most common defect = galactose 1 phosphate uridyl transferase deficiency - Autosomal recessive disorder. Deficiency of Galactose 1 Phosphate Uridyl Transferase (G-1-PUT) impairs the conversion of : • Galactose 1 phosphate, to G1P - GaI1 phosphate accumulates in the liver = toxicity to the liver - Hypoglycaemia + vomiting / diarrhoea after starting milk feeds when these infant are fed / have diarrhoea. - Galactose excreted in the urine - Tx = exclude galactose from the diet

Question 334

What is the most common enzyme defect involved in galactosaemia?

Answer 334

- Galactose 1 phosphate uridyl transferase deficiency | • Impairs the conversion of Galactose 1 phosphate to G1P.

Question 335

What is hereditary fructose intolerance

Answer 335

any deficiency of F1P will - Autosomal reccessive disorder that affects children - Deficiency of fructose 1 phosphate aldolase B when ingested fructose accumulates. Ø This inhibits glycogenolysis @ phosphorylase step - Severe hypoglycaemia + vomiting after eating fruit and sweetened food - Fructose is detected in urine, where it is detected. - So avoid ingestion of fructose and sucrose - Benign fructose intolerance - because of absence of fructokinase

Question 336

Describe the metabolism of fructose

Answer 336

any deficiency of F1P will inhibit this whole pathway = kidney cannot reabsorb and fructose will be found in the urine

Question 337

Adaptations to falling glucose levels in fasting

Answer 337

- Fall in insulin levels = limits glucosek entry into non cerebral tissues - Hepatic gluconeogenesis is stimulated - Glycogen breakdown is activated - Fatty acid oxidation is activated - There is release of counter regulatory hormone raising glucose • Glucagon (

Question 338

neurogenic symptoms of hypoglycaemia

Answer 338

- Triggered by falling glucose levels - Activated by ANS Ø Mediated by sympathoadrenal release of catecholamines and Ach Shakes, anxiety, nervousness, palpitations, sweating, dry mouth, pallor, pupil dilation

Question 339

NEUROGLYCOPAENIA symptoms of hypoglycaemia

Answer 339

- Because of neuronal glucose deprivation Confusion, hard to speak, ataxia, paresethesia, seizures, coma, death

Question 340

What are the characteristics of Gestational Diabetes

Answer 340

- Occurs for the 1st time in pregnancy | - Glucose levels get higher during pregnancy but then falls again once the mother has given birth.

Question 341

What are the characteristics of Secondary Diabetes

Answer 341

- Chronic pancreatitis - Pancreatic surgery Secretion of antagonists