Hematology - intro

Question 1

Blood drive : name the main steps from user questionnaire to packed RBC ready to use in hospitals

Answer 1

1. donor questionnaire
2. testing of donor Hgb
3. donor self exclusion question
4. filtered as soon as returns to blood center to remove lymphocytes
5. testes for multiple infectious disease
6. Centrifuged to separate into Packed RBCs, platelets and plasma

Question 2

What contains a PRBC (packed RBC)

Answer 2

• concentrated RBCs (plasma mostly removed)
• anti-coagulant and preservative
• hematocrit higher then in vivo blood
• shelf life 42 days

Question 3

What contains fresh frozen plasma

Answer 3

• 1 unit/mL of all clotting factor including labile factor V and VII
• 400mg fibrinogen
• citrate as anticoagulant

Question 4

where do platelets come from

Answer 4

from megakaryocytes in bone marrow

Question 5

is there a nuclei in platelets?

Answer 5

no, anuclear cells

Question 6

role of platelets

Answer 6

interact with proteins from coagulation cascade and lead to blood clotting

Question 7

main function of RBC

Answer 7

carry oxygen

Question 8

characteristics of RBC

Answer 8

• biconcave disks
• bags of Hb, few organelles
• anucleate
• outnumber white cells 1000:1
• contain the plasma membrane pritein spectrin and other proteins
• major factor contributing to blood viscosity

Question 9

which form of Hb can unload oxygen to peripheral tissues

Answer 9

Oxygenated hemoglobin are in relaxed state

Question 10

What is the oxygen dissociation curve

Answer 10

• At higher partial pressures of O2 (lungs) more Hgb is oxygenated
  -At lower partial pressures of O2 (capillaries) Hgb less saturated so off loads oxyge

Question 11

What is measured in a CBC

Answer 11

• white blood cells (neutrophils/lymphocytes, monocytes, eosinophils, basophils, blasts)
• Red blood cell count/Hb/RBC indices
• Platelet count

Question 12

how to define anemia in a CBC

Answer 12

RBC number, hemoglobin or hematocrit below the normal range

Question 13

what is hemoglobin

Answer 13

oxygen carrying protein in red blood cells. Two alpha chain and two beta chains. Four heme groupes which carry O2

Question 14

Which hb chain is affected in sickle cell?

Answer 14

mutation in beta chain

Question 15

Which hb chain is affected in thalassemia?

Answer 15

defect in production of alpha or beta

Question 16

what is hematocrit

Answer 16

percentage of red blood cells in a known volume of blood

Question 17

What is a reticulocytes

Answer 17

immature RBCs which still contain robosomal RNA. These normally circulate in the peropheral blood

Question 18

What is MCV

Answer 18

Meac red blood cell volume: average size of red blood cells

Question 19

2 types of abnormal MCV

Answer 19

microcytosis or macrocytosis

Question 20

6 steps to normal herythropoiesis

Answer 20

1. pronormoblast
2. basophilic normoblast
3. poly-chromatophilic normoblast
4. ortho-chromatic normoblast
5. reticulocyte
6. red blood cells

steps 1 to 4 happen in the bone marrow and 5-6 in the blood

Question 21

which hormone controls erythropoiesis ?

Answer 21

erythropoietin a hormone produced by the renal tubule cells which sense the O2 level in the blood

Question 22

Systemic response to compensate anemia

Answer 22

1. renal tubular cells increase the production of erythropoietin
2. the bone marrow should increase RBC production
3. The number of reticulocytes in the blood should increase

Question 23

2 only options to explain anemia (general)

Answer 23

-upset in the balance of RBC production
- RBC destruction or loss

Question 24

6 specific causes of anemia

Answer 24

1. deficiency of building block for RBCs
2. Congenital abnormality of the content of RBC
3. Abnormality in the production site of RBC
4. loss of RBC (bleesing)
5. Decreased lifespan of red blood cells in the circulation (hemolysis)
6. chronic illness: suppressed erythropoiesis

Question 25

function of iron and where it is stored

Answer 25

part of the heme group, shich carries oxygen. stored in the form of ferritin

Question 26

Role of B12 and Folate

Answer 26

B12 : vitamin essential for DNA synthesis Folate: vitamin essential for DNA synthesis

Question 27

what could explain abnormality in the production site of RBC

Answer 27

empty bone marrow (aplastic anemia), leukemia, pymphoma, cancer

Question 28

kind of renal disease that could cause anemia

Answer 28

renal disease (cant secrete erythropoietin) or other diseases lead to cytokine and bone marrow suppression

Question 29

where is thalassemia more common

Answer 29

Mediterranean and equatorial regions of Asia and Africa.

Question 30

where is sickle cell anemia most common

Answer 30

african descent

Question 31

G6Pd deficiency

Answer 31

african, mediterranean, asian descent

Question 32

what can lead to b12 dificiency

Answer 32

vegetarian diet. and poor diet may lead to folate deficiency

Question 33

signs of anemia

Answer 33

pallor, nails changes, tachycardia

Question 34

one sign of rapid hemolysis

Answer 34

jaundice

Question 35

What information does the reticulocytes count give?

Answer 35

The retic count give indirect information on the bone marrow's ability to respond to anemia if anemia and increased retic : bone marrow is functioning normally suggesting bleeding or hemolysis if anemia and normal or decreased retic: abnormal erythropoiesis or bone marrow dysfunction

Question 36

What can lead to megaloblastic anemia (macrocytosis, MCV > 95)

Answer 36

abnormality in DNA synthesis, vitamin b12 deficiency, folate deficiency, drugs (chemotherapy drugs)

Question 37

what type of anemia presents with: low MCV, normal MCV, high MCV

Answer 37

Question 38

other lab test that can be ordered to investigate anemia (other than CBC)

Answer 38

- Iron studies: ferritin, serum iron, %sat, liver function test, renal function test, thyroid function - B12/folate levels - hb electrophoresis - bone marrow aspirate and biopsy

Question 39

what means hemolysis

Answer 39

increased breakdown of red blood cells. An elevated reticulocyte count is often the first clue

Question 40

Hemolysis refers to the breakdown of red blood cells (RBCs), and it can be classified based on the underlying cause of the RBC destruction. name 4

Answer 40

1. extra-corpuscular 2. red blood cell membrane 3. hemoglobin 4. enzyme defects

Question 41

explain what extra-corpuscular hemolysis is

Answer 41

This term refers to causes of hemolysis that are related to external factors outside the RBC itself. Examples include mechanical destruction from artificial heart valves or shear stress in the bloodstream.

Question 42

examples of red cell membrane defect that cause hemolysis

Answer 42

hereditarry elliptocytosis hereditary spherocytosis

Question 43

examples of hemoglobin defect that cause hemolysis

Answer 43

sickle cell, thalassemia

Question 44

examples of enzyme defect defect that cause hemolysis

Answer 44

G6PD deficiency, pyruvate kinase deficiency

Question 45

A 23 year old female presents to your office because of fatigue and palpitations. You note pallor and koilonychia on physical exam: Laboratory: WBC 6.5 x 109/L Hgb 107 g/L (120-160 g/L) MCV 78 fl (80-95 fl) Plt 450 x 109/L

Answer 45

Microcytic anemia

Question 46

differential for microcytic anemia

Answer 46

iron deficiency, thalassemia, chronic disease

Question 47

An 81 year old gentleman is referred for investigation of anemia prior to heart surgery: you note mild jaundice and a palpable spleen on examination Laboratory: WBC 6.5 x 109/L Hgb 85 g/L (120-160 g/L) MCV 102 fl (80-95 fl) Plt 350 x 109/L

Answer 47

Macrocytic anemia

Question 48

diffential for macrocytic anemia

Answer 48

Megalloblastic Vit B12 def Folate def Drugs Myelodysplastic Non-megalloblastic: Reticulocytosis Liver disease Thyroid disease