incidences of polycythaemia vera, essential thrombocytosis, and myelofibrosis were 10x higher among Ashkenazi Jews in northern Israel than in persons of Arabic descent in the region.
most cases occur in those 40-60 yrs old and are due to acquired (not inherited) mutations in genes such as JAK2, TET2
rarely, risk of PRV may be inherited in an autosomal dominant manner
clinical features
usually discovered on routine blood testing
may cause:
non-specific symptoms including headaches
40% develop pruritis after showers/baths
high RBC may cause a ruddy complexion
hypertension due to increased blood volume which may get to twice normal
those who are JAK2 negative may need bone marrow biopsy
treatment
there is no current curative Rx, but most patients have an almost normal life span with life-long treatment
low dose aspirin seems to halve the risk of thrombotic complications in those with no PH thrombotic events 1)
asymptomatic patients aged < 40 years can be considered for therapeutic phlebotomies alone to maintain a hematocrit level of less than 45% although this Rx is being re-evaluated
other patients can undergo myelosuppressive therapy with hydroxyurea 500 mg PO twice per day (titrated to effect)
Ruxolitinib (Jakafi) 10 mg PO twice per day appears to be superior to hydroxyurea for disease control HOWEVER:
serious withdrawal symptoms make gradual dose reduction important
82% developed anaemia, 67% thrombocytopenia and 15% neutropenia hence need to monitor FBE
radioactive phosphorous can be used as an alternative therapy in older patients
a 2025 retrospective study of over 84,000 patients with PRV suggested those on glucagon-like peptide-1 (GLP-1) peptide analogs (eg. Ozempic) had much lower rates of myelofibrosis progression, VTE, acute kidney injury and mortality during the study period 2)