Anaemia 2

Question 1

What are the causes of macrocytic anaemia? (6)

Answer 1

B12 or folate deficiency, liver disease, alcoholism, myelodyspasia, some haemolytic anaemias, bone marrow failure, anticonvulsants, chemotherapy

Question 2

What is B12, where is it found, how is it absorbed?

Answer 2

Water soluble vitamin. Found in meat, eggs, etc. Not destroyed by cooking. 3 years worth can be stored. Bound to IF in stomach and absorbed in ileum.

Question 3

What is B9, where is it found, how is it absorbed?

Answer 3

Water soluble. Liver, veg, yeast. Destroyed by cooking. 4 months stored. Absorbed in duodenum/ jejunum.

Question 4

B12/ folate deficiency test results?

Answer 4

Low Hb, MCV >120, decreased platelets and WBC.
Oval macrocytes and hypersegmented neutrophils
Increased LDH and bilirubin

Question 5

What are the causes of B12 deficiency?

Answer 5

Diet. Gastric malabsorption- pernicious anaemia. Intestinal malabsorption- Crohn’s, ileal disease, hookworm.

Question 6

What is pernicious anaemia?

Answer 6

Autoimmune. Autoantibodies produced against IF and gastric mucosa. Leads to gastric atrophy, decreased acid and IF. Associated w fair hair, blue eyes, blood group A.

Question 7

What are the symptoms of pernicious anaemia?

Answer 7

Anaemia, glossitis, mild jaundice, neurological symptoms: peripheral neuropathy, spinal column damage, dementia, optic atrophy

Question 8

How is pernicious anaemia treated?

Answer 8

IM B12 every 3 months

Question 9

What are the causes of folic acid deficiency? (4)

Answer 9

Poor diet, alcoholism, malabsorption from coeliac or Crohn’s, excess utilisation because of pregnancy, lactation, psoriasis, haemolytic anaemia. Anticonvulsants

Question 10

What are the three main categories of erythrocyte abnormalities?

Answer 10

Membrane, haemoglobin, enzymes

Question 11

Biochemistry of extravascular haemolysis?

Answer 11

Increased serum unconjugated bilirubin, LDH, urinary urobilinogen

Question 12

What are the causes of extravascular haemolysis? (5)

Answer 12

Sickle cell, thalassaemia, antibody induced haemolytic anaemia, Rhesus mismatched transfusion, hereditary spherocytosis

Question 13

Where does extravascular haemolysis occur? (3)

Answer 13

Spleen, liver, bone marrow

Question 14

What are the causes of intravascular haemolysis? (3)

Answer 14

ABO mismatched transfusion, snake bites, some infections

Question 15

What are the signs of haemolytic anaemia? (4)

Answer 15

Pallor, jaundice, gallstones, splenomagaly

Question 16

What is hereditary spherocytosis?

Answer 16

Autosomal dominant. Defect in cytoskeleton. Chronic splenic haemolytic anaemia. Spherocytes in peripheral blood.

Question 17

What is G6PD deficiency?

Answer 17

G6P dehydrogenase reverses oxidation. Result of 400 different X linked mutations.

Question 18

What are the signs of G6PD deficiency? (3)

Answer 18

Neonatal jaundice, acute haemolysis with oxidant drugs, triggered by some foods eg favs beans

Question 19

What is sickle cell anaemia?

Answer 19

Point mutation; glutamine to valine. Autosomal recessive. Hb forms rods when O2 declines. Blocks microcirculation-> ischaemia, pain

Question 20

What is AIHA?

Answer 20

Autoimmune haemolytic anaemia- self reacting IgG triggers removal by spleen.

Question 21

How is AIHA tested for?

Answer 21

Direct Coombs test. Sample incubated with Coombs reagent- antihuman antibodies. Erythrocytes agglutinate.

Question 22

What are the causes of AIHA? (4)

Answer 22

50% idiopathic. Drugs- penicillin, methyldopa. Connective tissue disease- SLE, RA. Blood transfusion.