haematology formative

Question 1

what is the direct coomb’s test

Answer 1

used to detect antibodies attached to the surface of RBC

Question 2

when would you use the direct coombs test

Answer 2

autoimmune haemolytic anaemia
rhesus compatability
acute haemolytic reaction
sickle cell

Question 3

what is haemoglobin analysis by high performance liquid chromatography (HPLC) used for

Answer 3

used to identify the different types of haemoglobin present in the blood
- thalassaemias

Question 4

microcytic anaemia found at antenatal clinic- investigation?

Answer 4

HPLC of hb to look for thalassaemia

Question 5

normal or low hb, raised WCC, normal or low platelet count

Answer 5

chronic lymphocytic leukaemia

Question 6

key investigation for chronic lymphocytic leukaemia

Answer 6

Immunophenotyping by flow-cytometry
- looks for antigens on the WBC

Question 7

what is osmotic fragility test used for

Answer 7

hereditary spherocytosis and thalassaemia

Question 8

causes of hereditary thrombophilias

Answer 8

factor V leiden- most common
prothrombin 202010 mutation
antithrombin deficiency
protein C deficiency
protein S deficiency

Question 9

aetiology of sickle cell anaemia

Answer 9

point mutation in codon 6 of the beta globin gene that substitutes glutamine to valine

Question 10

defintion of sickle syndromes

Answer 10

group of genetic disorders that affect the structure of haemoglobin
resulting in the production of HbS

Question 11

what is myelodysplasia

Answer 11

acquired DNA mutations in haematopoietic stem cells
immature blood cells in the bone marrow do not mature to become healthy blood cells

Question 12

definition of thalassaemia

Answer 12

autosomal recessive inherited disorders of haemoglobin causing reduced globin chain synthesis, resulting in impaired haemoglobin production

Question 13

definition of hereditary spherocytosis

Answer 13

mutation in one of the structural red cell membrane proteins resulting in reduced red cell deformability and so membrane is removed in spleen and reduced red cell survival

Question 14

where is vitamin K absorbed

Answer 14

upper intestine
- require bile salts for absorption

Question 15

what factors are carboxylated by vit K

Answer 15

factors II, VII, IX, and X

Question 16

causes of vit K deficiency

Answer 16

poor dietary intake
malabsorption
obstructive jaundice
vit k antagonists (warfarin)
haemorrhagic disease of the newborn

Question 17

mechanism of action of clopidogrel

Answer 17

selectively inhibits the binding of adenosine diphosphate (ADP) to its platelet receptor and the subsequent ADP-mediated activation of the glycoprotein IIb/IIIa complex
= inhibiting platelet aggregation
basically is a ADP antagonist

Question 18

aspirin mechanism of action

Answer 18

Inhibits cyclo-oxygenase which is necessary to produce thromboxane A2 (a platelet agonist released from granules on activation)

Question 19

mechanism of action of dipyridamole

Answer 19

Phosphodiesterase inhibitor - increases production of cAMP which inhibits platelet aggregation

Question 20

mechanism of action of heparin

Answer 20

potentiates antithrombin

Question 21

mechanism of action of warfarin

Answer 21

inhibition of vit K
factors II (prothrombin), VII, IX and X (+protein C and S) require vit k for final carboxylation step essential for function

Question 22

mechanism of action of riveroxiban

Answer 22

competitively inhibits factor Xa
factor Xa along with factor Va for the prothrombinase complex which converts prothrombin to thrombin

Question 23

low Hb, platelets, neutrophils but high WCC and auer rods

Answer 23

acute myeloid leukaemia

Question 24

mechanism of action of rituximab

Answer 24

complement-mediated cytotoxicity and antibody-dependent cell mediated cytotoxicity
targets CD20

Question 25

mechanism of action of Imatinib

Answer 25

inhibits the enzyme activity of bcr-abl (?)

Question 26

what does an isolated prolonged partial thromboplsatin time mean

Answer 26

deficiency of factors involved in the intrinsic pathway of coagulation or presence of anti-phospholipid antibody - VIII/IXa

Question 27

what does an isolated prolonged prothrombin time reflect

Answer 27

deficiency of factors involved in the extrinsic pathway but not common = factor VII

Question 28

uncontrolled production of essentially normally functioning blood cells

Answer 28

polycythaemia vera

Question 29

uncontrolled production of immature blood cells in the bone marrow

Answer 29

acute myeloid leukaemia

Question 30

clonal B cell disorder usually resulting in a large number of circulating malignant cells

Answer 30

chronic lymphocytic leukaemia

Question 31

fever but no haemolysis post transfusion

Answer 31

febrile non-haemolytic transfusion reaction

Question 32

first line treatment of autoimmune haemolytic anaemia

Answer 32

steroids- prednisolone folic acid

Question 33

features of autoimmune haemolytic anaemia

Answer 33

anaemia reticulocytosis low haptoglobin raised LDH spherocytes and reticulocytes

Question 34

management of chemo inducing pancytopenia

Answer 34

red cell transfusion

Question 35

red cells that have lost central pallor

Answer 35

spherocytes