Polycythaemia rubra vera (PRV,PV)
Last updated: Friday, 28, January, 2011
A haemopoietic stem cell proliferative disorder with polycythaemia and variable associated neutrophilia and thrombocytosis. It is one of the myeloproliferative disorders.
In ~5% of cases a transformation to acute leukaemia may occur. Bleeding and thrombosis commonly occur in this disorder. The primary management of PV is venesection, commonly to a haematocrit of <45%. Many patients eventually develop myelofibrosis.
The most common secondary causes of polycythaemia are chronic lung disease and smoking (see Polycythaemia).
Erythropoietin may assist to distinguish polycythaemia vera from secondary erythrocytosis (low in PV and normal-elevated in secondary polycythaemia)
Presence "invitro" of formation of spontaneous erythroid colonies (SEC's) in the absence of EPO is sensitive but not specific finding in PRV. Low EPO is of high diagnositc specificity for PRV.
The presence of the JAK-2 mutation confirms a myeloproliferative disorder.
Bone marrow aspiration and trephine biopsy with cytogenetics is sometimes useful.
Thrombosis (arterial or venous)
Often from local lesion (eg, peptic ulcer, epistaxis) but may be associated with platelet dysfunction.See Bleeding disorders
|See Myelodysplastic syndrome|