Haematology

Question 1

What are causes of splenomegaly?

Answer 1

Increased splenic activity:

• Haemolytic anaemia: spherocytosis, thalassaemia, Sickle cell
• Infection response:
  
  • Viral (CMV, EBV)
  • Bacterial (TB, brucella)
  • Parasitic (Malarial)
• Immune:
  
  • Rheumatoid
  • SLE or other CTDs
• Extramedullary haematopoiesis:
  
  • Myelofibrosis (massive splenomegaly)
  • Leukaemias + lymphomas

Decreased venous drainage:

• Portal hypertension due to liver cirrhosis or vein obstruction

Splenic infiltration leading to suppression of splenic tissue:

• Lymphomas
• Leukaemias
• Metastatic tumours (e.g. melanoma)
• Metabolic disease: Gaucher, Amyloidosis

Question 2

What are causes of hyposplenism?

Answer 2

Hyposlenism is almost always acquired:

• Following splenectomy or rupture due to trauma
• Autosplenectomy e.g. sickle cell disease
• Functional hyposplenism:
  
  • Coeliac disease
  • Ulcerative colitis

Question 3

What do coagulaion studies look like in DIC?

Answer 3

• Low platelets
• Prolonged APTT
• Prolonged PT
• Pronlonged bleeding time

Question 4

What is in cryoprecipitate?

Answer 4

• Factor 8
• Fibrinogen
• vWF
• Fibrin (Factor 13)

Question 5

How do you treat an iron deficiency anaemia in a person that is due to undergo surgery?

Answer 5

Oral iron takes a minimum of around 2-4 weeks before it works (2-3 months for decent response).

As such, if a quicker response is required, IV iron repeated 1 week later is the treatment of choice.

Question 6

what is the most common inherited bleeding disorder?

Answer 6

von Willebrandt’s disease: deficiency in functioning vWF. vWF is required for platelet adhesion to damaged entothelium.

Question 7

Which test can be used to confirm immune mediated haemolysis due to incompatability after blood transufsion?

Answer 7

Direct Coomb’s test.

Question 8

What is the managment of von Willebrandt’s disease?

Answer 8

• Tranexamic acid for mild bleeding
• Desmopressin (DDAVP) - raises the levels of vWF
• Factor VIII concetrate

Question 9

What do coagulation studies show in a patient with vWF?

Answer 9

• Prolonged bleeding time
• APTT may be prolonged
• Factor VIII levels may be moderatly reduced
• (Defective platelet aggregation with ristocetin)

Question 10

What is the reversal agent for dabigatran?

Answer 10

Idarucizumab

Question 11

How do the 3 DOACs, dabigatran, rivaroxiban, apixiban, work?

Answer 11

• Dabigatran: Direct thrombin inhibitor
• Rivaroxiban and apixiban: direct factor 10a inhibitor.

Question 12

What is present in prothrombinase complex?

Answer 12

contains concentrated Factor VIII:C, von Willebrand factor, fibrinogen, Factor XIII and fibronectin, produced by further processing of Fresh Frozen Plasma (FFP).

Clinically it is most commonly used to replace fibrinogen. E.g. in DIC.

Question 13

What is the mode of inheritance of G6PD?

What commonly triggers G6PD?

Answer 13

X-linked recessive. It can therfore only affect males.

Triggers include:

• Anti-malarials (primaquine)
• Ciprofloxacin
• Sulpha durgs (sulphonamides, sulfonylurea, sulphasalzine)

Question 14

What is the purpose of irradiating RBCs?

Answer 14

Irradiated RBCs are frequently given to BMT patients, as this blood doesn’t contain lymphocytes, which could lead to GVHD in BMT patients.

Question 15

What is the Philadelphia Chromosome?

Answer 15

This is the translocation t(9;22) - it is seen in ~95% of CML patients. (around 25% of adult ALL cases also have this.)

Question 16

What are the side effects of EPO?

Answer 16

• Hypertension (can lead to encepalopathy and seizures)
• Bone aches
• Flu-like symptoms
• Skin rashes + urticaria
• Pure red cell aplasia (as Abs form against EPO)
• Increased risk of thrombosis
• IDA