Aneamia

Question 1

what is the normal range for bilirubin?

Answer 1

below 17 umol/L

Question 2

what does high unconjugated bilirubin suggest?

Answer 2

prehepatic jaundice e.g. haemolysis

Question 3

cause of spherocytes?

Answer 3

hereditary spherocytosis
Disruption of vertical linkages in membrane of erythrocyte usually ankyrin and spectrin

Question 4

What is reticulocytisis a sign of

Answer 4

haemolysis → underdeveloped cells in circulation means RBC turnover is happening too quickly

Question 5

what is the difference between haemolysis and haemolytic anaemia?

Answer 5

haemolysis is RBC breakdown, haemolytic anaemia = lifespan reduced to the extent that Hb is low

Question 6

treatment options for haemolytic anaemia?

Answer 6

folic acid → supports increased requirement for erythropoiesis

splenectomy if severe → increase RBC life span

Question 7

one consequence of haemolysis?

Answer 7

Gallstone formation due to increased breakdown of haemoglobin to bilirubin causing obstructive jaundice
Liver can still conjugate bilirubin but it’s not passing from the bile ducts and gallbladder into the duodenum

Question 8

what does it mean for bilirubin to be conjugated vs unconjugated

Answer 8

water soluble, not as attached to albumin

Unconjugated is insoluble in blood and attached to albumin

Question 9

How does conjugated vs unconjugated bilirubin affect the body and how are they excreted

Answer 9

unconjugated toxic to tissues and organs, can’t be excreted in urine,accumulates in prehepatic jaundice

conjugated pretty non-toxic, excreted in urine (dark),accumulates in post hepatic jaundice

Question 10

what is autoimmune haemolytic anaemia?

Answer 10

haemolysis mediated by autoantibodies against own RBCs

Question 11

How is autoimmune haemolytic anaemia diagnosed

Answer 11

DAT (direct antiglobulin test) checking for autoantibodies

Question 12

AIHA aetiology

Answer 12

idiopathic, related to other immune disorders e.g. SLE, underlying lymphoid cancers

Question 13

Signs of Haemolysis

Answer 13

raised LDH, unconjugated hyperbilirubinaemia, low haptoglobins

Bone marrow responds via reticulocytosis

Defect in rbc means inherited and defect in rbc environment means acquired

Question 14

• what are irregularly contracted cells and Heinz bodies a sign of?

Answer 14

Oxidant damage to rbc which indicates G6PD deficiency

Question 15

What does G6PD do

Answer 15

important in HMP shunt → coupled to glutathione metabolism → protects from oxidant damage

Question 16

sources of oxidants?

Answer 16

generated in the blood stream e.g. during infection

exogenous e.g. fava beans, drugs like naphthalene

Question 17

what is intravascular vs extravascular haemolysis?

Answer 17

intravascular = acute damage

extravascular = removal by spleen

Question 18

what does ferritin do?

Answer 18

Iron stores in liver

Question 19

Transferrin

Answer 19

Allows iron to be transported in blood

Question 20

what does low transferrin indicate?

Answer 20

Iron overload (as becomes saturated with iron)

Question 21

signs of iron deficiency anaemia?

Answer 21

fatigue, koilonychia, angular stomatitis, glossitis, microcytic anaemia

Question 22

Causes of iron deficiency anaemia

Answer 22

bleeding e.g. GI (would see dysphagia, dyspepsia,abd pain)or menstrual, diet, hookworm, malabsorption e.g. coeliac disease or h. pylori gastritis,change in bowel habit (haematemesis,rectal bleeding,melaena),NSAIDS

Question 23

when might increased iron be required?

Answer 23

Pregnancy
Infancy

Question 24

what measurement abnormality does RBC hypochromia indicate?

Answer 24

Low MCHC

Question 25

treatment of iron deficiency?

Answer 25

iron replacement e.g. ferrous sulphate tablets

Question 26

what causes increased iron absorption from the gut and increased release from storage?

Answer 26

low hepcidin

Question 27

Normal Hb range

Answer 27

133-167

Question 28

does a normal ferritin always exclude iron deficiency?

Answer 28

no → can be normal if both iron deficiency and anaemia of chronic disease

Question 29

what is the difference between macrocytic and megaloblastic anaemia?

Answer 29

megaloblastic is a type of macrocytic anaemia Megaloblasts are large with nucleocytoplasmic dissociation

Question 30

what is megaloblastic anaemia commonly caused by?

Answer 30

Folate or B12 deficiency Can occur secondary to agents or mutations that impair dna synthesis eg Drugs azathioprine cytotoxic chemo Folate antagonist eg methotrexate BM cancers eg myelodysplatic syndrome

Question 31

What does b12 and folate do

Answer 31

B12: DNA synth, integrity of nervous system folate: DNA synth, homocysteine metabolism

Question 32

colour status of normocytic, macrocytic and microcytic anaemia RBCs?

Answer 32

normocytic and macrocytic = normochromic microcytic = hypochromic

Question 33

what does microcytosis result from?

Answer 33

Reduced synthesis of HB

Question 34

haem and globin issue examples respectively?

Answer 34

haem: iron deficiency, anaemia of chronic disease globin: thalassaemia

Question 35

causes of normocytic anaemia?

Answer 35

recent blood loss bone marrow failure e.g. chemo, leukaemia → RBC production failure pooling of RBCs in spleen

Question 36

Environmental factors which can damage rbc

Answer 36

Environmental factors affected rbc Non immune-microangiopathic,haemolytic uraemic syndrome,malaria,snake venom,drugs Immune mediated-autoimmune,allo immune (post blood transfusion)

Question 37

Ghost cells

Answer 37

Are cells that are pale due to loss of haemoglobin content Can be due to Intravascular haemolysis which include conditions such as G6PD deficiency,autoimmune haemolytic anaemia and toxins such as snake venom

Question 38

Haemolytic anaemia inherited vs acquired causes

Answer 38

Inherited Abrnkmak rbc membrane eg Heridetary spherociytosis Abnormal Hb eg sickle cell anaemia Defect in glycolytic pathways eg Pyruvate kinase deficiency Deficiency in G6PD Acquired Damage to rbc membrane via AIHA or snake bite Damage to whole rbc eg MAHA (microangiopathic haemolytic anaemia) Oxidant exposure damage to rbc and Hb eg dapsone or primaquine

Question 39

Anaemia of chronic disease

Answer 39

Hb low,MCV low or normal,ferritin **high**,,serum iron low,transferrin **normal/low** Hepcidin made by liver when iron stores high and also made when inflammation has occurred eg in infection such as TB/HIV,rheumatoid arthritis,malignancy,autoimmune disease Treatment needs to target underlying cause

Question 40

Why does b12/folate deficiency occur

Answer 40

B12:due to diet eg veganism,gastric eg gastrectomy or autoimmune (pernicious anaemia -anti gastric parietal cell and intrinsic factor antibodies),terminal ileum eg chrons disease or ileal resection. Can treat via supplements for diet but other two require hydroxocobalamin injections Folic acid-diet (poverty/alcholism),malabsorption due to coeliac disease or jejunal resection,increased demand due to pregnancy,lactation or increased cell turnover (Haemolysis). For all give supplements

Question 41

Spheroctyes are present jn acquired haemolytic anaemia and hereditary spherocytosis how can you differentiate between the two

Answer 41

Direct anti globulin test