Polycythaemia

Question 1

What is Polycythaemia?

Answer 1

• Polycythaemia is the elevation of Red Blood Cells
• This is seen on blood results as a raised haemoglobin in the FBC

Question 2

What blood test would you order?

Answer 2

• FBC

Question 3

What are the Primary Causes of Polycythaemia?

Answer 3

• Polycythaemia Vera - myeloproliferative disorder caused by proliferation of haematogenic progenitor cells

Question 4

What are some of the secondary causes of Polycythaemia?

Answer 4

• 1. Hypoxia induced EPO rise: smoking, obesity, chronic lung disease and obstructive sleep apnoea
• 2. Inappropriate EPO rise: Tumours (Renal Cell Cancer, Adrenal Tumours and Wilm’s Tumour), Illicit EPO use and Androgen use

Question 5

What is the Pathophysiology of Polycythaemia Vera?

Answer 5

• A mutation in the JAK2 gene
• leading to proliferation of the haematogenic progenitors

Question 6

What are the clinical features of a high Hb?

Answer 6

• Headache and Fatigue
• Visual Disturbance (blurring/ transient blindness)
  -Pruritus (itching)
• Thrombotic and bleeding events (Budd Chiari Syndrome)
• Secondary Erythromelagia (pain and redness of hand and feet)

Question 7

What are the investigations for Polycythaemia?

Answer 7

• Genetic testing for Jak2 mutations
  -Bloods: FBC (male >185, female >165)
  Renal Function, LFT, Serum EPO, Serum Ferritin and Serum Uric Acid

Question 8

What blood results is classically seen in Polycythaemia Vera?

Answer 8

• Polycythaemia, raised WCC and raised platelet count

Question 9

What is the single best investigation to determine the cause of the Polycythaemia?

Answer 9

• Bone marrow biopsy

Question 10

How do you diagnose Polycythaemia Vera?

Answer 10

• 1. High Haematocrit (>0.52 in men and >0.48 in women) or a raised red cells mass
• 2. Mutation in JAK2

Question 11

What is the value of the ferritin level in polycythaemia vera?

Answer 11

• Typically low
• However do not replace as there is a risk of hyperviscosity and vascular events
• “iron deficiency is protecting”

Question 12

What is the management of Polycythaemia?

Answer 12

• Venesection at 200ml- 500ml at a time
• Low dose aspirin therapy 75mg once daily
• Cytoreductive therapy - age >65 and prior pv-associated venous thrombosis