Haematology

Question 1

What are the subtypes of Hodgkin’s lymphoma?

Answer 1

Nodular sclerosing (70% - good prognosis and more common in women).

Mixed cellularity (20% - good prognosis)

Lymphocyte predominant (5% - best prognosis)

Lymphocyte depleted (rare - worst prognosis)

Question 2

Summarise the pathophysiology of Factor V Leiden.

Answer 2

There is a mutation of Factor V that makes it resistant to the action of activated Protein C.

It is the most common inherited thrombophilia.

Question 3

What are band cells?

Answer 3

Band cells are an immature form of neutrophils.

Question 4

What are the crises seen in Sickle-Cell disease?

Answer 4

• Thrombotic, “painful” crises (vaso-occlusice crises - precipitated by infeciton, dehydration, low O2))
• Sequestration crisis
• Aplastic crisis (Parvo B19)
• Haemolytic crisis (increase rate of haemolysis)
• Acute chest syndrome (dypnoea, chest pain, pulmonary infiltrates)

Question 5

What do a raised ESR together with osteoporosis signify?

Answer 5

A raised ESR and osteoporosis represents multiple myeloma unless proven otherwise.

Question 6

How often should patients with splenic dysfunction get the pneumococcal vaccine?

Answer 6

Every 5 years

Question 7

Below what leve is a platelet transfusion indicated?

Answer 7

Platelet transfusion is appropriate for patients with a platelet count < 30 x 10⁹ and clinically significant bleeding.

Platelet thresholds for transfusion are higher (maximum < 100 x 10⁹) for patients with severe bleeding, or bleeding at critical sites, such as the CNS.

Question 8

What are the transfusion thresholds for RBCs?

Answer 8

Question 9

Under normal circumstances, at what speed are RBCs transfused?

Answer 9

1 unit over 90-120 minutes is the norm.

In emergency situations, the RBCs may be transfused STAT.

Question 10

What are recognised complications of blood transfusions?

Answer 10

• Immunological:
  
  • Acute haemolytic
  • Non-haemolytic febrile
  • Allergic/analphylactic
• Infective
• TRALI -> ARDS
• TACO
• Hyperkalaemia, iron overload, clotting disorders (due to citrate addition)

Question 11

What is the main component of cryoprecipitate?

Answer 11

Factor VIII (8). It is mainly indicated in massive haemorrhage and uncontrolled bleeding due to haemophilia A.

It is made form plasma; other components are fibrinogen (Factor I), vWF and factor XIII (13).

Question 12

What is the MoA of dabigatran?

And Rivaroxiban?

ANd heparin and fondaparinux?

Answer 12

Dabigatran: direct thrombin inhibitor.

Rivaroxiban: Direct factor Xa inhibitor

Heparin: potentiates the action of antithrombin III, which breaks down thrombin, Xa.

Fondaparinux: increases antithrombin action to inactivate Xa

Question 13

Summarize the referral pathway for young people with suspected malignancy?

Answer 13

A 48 hour blood test is recommended for young people with general symptoms or signs of leukaemia.

However, if either hepatosplenomegaly or unexplained petichiae are present the patient should be referrred for immediate assessment.

Question 14

Why is aPTT prolonged in von Willebrandt disease?

Answer 14

This is because F VIII is protected by vWF - so with a deficiency, there is less FVIII and hence a prolonged aPTT.

Bleeding is prolonged as vWF is requried for primary plaque formation, which is thus disturbed in its absence.