haematology formative learning points

Question 1

pathophysiology of sickle cell disease?

Answer 1

point mutation in the beta chain and this predisposes the haemoglobin to polymerise resulting in sickled cell

Question 2

what forms HbS and what disease does it cause

Answer 2

glutamic acid to valine substitution in the beta chain of haemoglobin

2x HbS causes sickle cell disease, 1 causes sickle cell trait which will only cause effect in times of stress

Question 3

what forms HbA2

Answer 3

2 alpha chains and 2 gamma chains

Question 4

how does clopedigrel work?

Answer 4

Clopidogrel selectively inhibits the binding of adenosine diphosphate (ADP) to its platelet receptor, stops activation of glycoprotein GPIIb/IIIa complex thereby irreversibly inhibiting platelet clumping

Question 5

how does aspirin work

Answer 5

inhibit the activity of the enzyme now called cyclooxygenase (COX) which irreversibly stops production of thromboxane (and stops prostaglandin production)

Question 6

describe a eosinophil

Answer 6

pink with granules and bilobed (basophil is purple)

Question 7

describe a monocyte

Answer 7

purple with kidney bean shaped nucleus

Question 8

The blood film shows macroovalocytes and hypersegmented neutrophils… what is diagnosis?

Answer 8

b12/ folate deficiency

Question 9

what are auders rods and what are they found in?

Answer 9

distinct needle like crystals that contain peroxidase found in RBC
acute myeloid leukemia

Question 10

how does rituximab work?

Answer 10

monoclonal antibody directed against CD20, expressed on B cells and B cell lymphomas

Question 11

how does imatinib work?

Answer 11

tyrosine kinase inhibitor that is inhibits BCR-ABL-1 protein unique to chronic myeloid leukaemia

Question 12

how does factor V leiden cause thrombophilia?

Answer 12

factor V (which normally helps clotting) is normally turned off by activated protien c and slows down clotting, when mutation in F5 gene APC no longer works on factor 5

Question 13

where does factor VIII work?

Answer 13

intrinsic pathway

Question 14

vit k is?

Answer 14

Vitamin K is absorbed in the upper intestine, responsible for bile salt absorption, carboxylates specific preformed clotting factors, is antagonised by warfarin, fat soluble

Question 15

what causes a Febrile non-haemolytic transfusion reaction

Answer 15

antibodies directed against donor leukocytes and HLA antigens present of cytokines

Question 16

what type of patients does a transfusion associated circulatory overload (TACO) occur?

Answer 16

chronic anaemia and a compensatory high cardiac output and causes a pulmonary oedema

Question 17

transfusion related acute lung injury

Answer 17

happens when donor anti leucocyte antibodies bind to the patients white cells and cause degranulation. pulmonary infiltrate can be seen on CXR

Question 18

what would you see in autoimmune haemolytic anaemia?

Answer 18

Direct antiglobulin test (Coombs’ test) strongly positive, reticulocytosis and serum lactate dehyrogenase

Question 19

when would you see bence jones protiens?

Answer 19

multiple myeloma due to the excretion of ig light chains

Question 20

when are smudge cells seen?

Answer 20

CLL

Question 21

what clotting results would you get in a patient with vWB disease?

Answer 21

decreased factor VIII activity, normal PT time, and prolonged APTT, and prolonged bleeding time

Question 22

Howell–Jolly bodies

Answer 22

single peripheral bodies within red cells representing DNA material seen in splenectomy/ functional hyposplenism

Question 23

haemophillia a=… b =…

Answer 23

a= deficiency in factor VIII
b= deficiency in factor IX

Question 24

how does warfarin work?

Answer 24

inhibits II, IX, X, VII and prothrombin (aswell as protein c and s)

Question 25

multiple myeloma being about b cells vs lymphoma

Answer 25

ask katie

Question 26

what does heparin inhibit

Answer 26

Xa and thrombin