Myeloproliferative Disorder: Polycythemia Rubra Vera Flashcards
What is it?
Uncontrolled production of red cells in bone marrow despite erythropoietin production being switched off
The increase in red cell volume is often accompanied by overproduction of what?
Neutrophils and platelets
What mutation is present in approximately 95% of those with polycythemia Vera?
Mutation in JAK2
What age group is it most common in?
Peak in sixth decade
The excess RBCs, platelets and WBCs leads to…
Hyperviscosity and thrombosis
How does it present?
May be asymptomatic and detected on FBC Symptoms due to hyperviscosity- headaches, dizziness, tinnitus, visual disturbance, reduced cognition Pruritis - typically after hot bath Burning sensation in fingers and toes Lethargy
What signs are associated?
Splenomegaly
Plethoric complexion
Why may gout occur?
Increased urate from increased RBC turnover
What features of thrombosis may occur?
Arterial: cardiac, cerebral, peripheral
Venous: DVT, cerebral, hepatic
What does FBC show?
Raised RBC count
Raised haemoglobin
Raised haematocrit (HCT) / packed cell volume (PCV)
Often also raised WBCs and platelets
What other blood tests should be done?
LFTs (ALP raised)
U&Es
ESR (reduced)
What does bone marrow show?
Hypercellularity with erythroid hyperplasia
How will serum EPO be effected?
Reduced
JAK2 positive diagnosis requires…
1) Mutation in JAK2
2) High haematocrit (>0.52 in men and >0.48 in women)
OR raised red cell mass > 25% above predicted
How is it managed?
Aim to keep HCT less than 0.45 to reduce thrombosis risk
In younger patients at low risk - venesection
If high risk (older than 60 and previous thrombosis) hydroxycarbamide used and aspirin 75mg daily
