Condition- Polycythaemia

Question 1

State a primary cause of polycythaemia

Answer 1

Polycythaemia Rubra Vera

Question 2

A mutation in which gene leads to polycythaemia vera?

Answer 2

JAK2

JAK2 is a gene found in haematopoietic stem cells. It is usually activated in response to EPO and it results in the proliferation and differentiation of haematopoietic stem cells. When this gene becomes mutated => uncontrolled autonomous haematopoiesis.

Question 3

List some ‘relative’ causes of polycythaemia

Answer 3

Dehrydration, stress

Decrease in volume => relative increase in Hb conc

Question 4

Polycythaemia can develop secondary to an increase in EPO. When might there be an appropriate release in EPO => Secondary Polycthaemia?

Answer 4

Secondary to hypoxia:

• COPD
• Altitude
• Sleep apnoea

Question 5

Polycythaemia can develop secondary to an increase in EPO. When might there be an inappropriate release in EPO => Secondary Polycthaemia?

Answer 5

• Usually tumours secrete EPO
  
  • Renal Cell carcinoma
  • HCC
  • Cerebellar haemangioblastoma
  • Fibroids

Question 6

List some of the presenting symtpoms of Polycythaemia

Answer 6

• Symptoms of Hyprviscosity:
  
  • Fatigue
  • dizziness
  • Increased sweating
  • Redness in face
  • Blurred vision
• Symptoms of thrombosis:
  
  • Stroke
  • Heart Attack
  • DVT
  • Budd-chiari syndrome => PHT
• Pruritus (esp after a hot shower) due to increase in basophils and eosinophils
• Gout- due to increase in cell turnover => increased uric acid production

Question 7

What would you see in the bloods of someone with Polycythaemia vera?

• Blood cells
• EPO

Answer 7

• High RBC, High Hb, High Hct, Low MCV (due to IDA)
• High WCC, High platelets
• Low EPO

Question 8

What would you see in the bone marrow biopsy of someone with polycythaemia vera?

Answer 8

• Erythroid hyperplasia
• Increase in megakaryocytes

Question 9

What happens to the EPO in patients with secondary polycythaemia?

Answer 9

Increase in EPO