Polycythaemia vera - Diagnosis and therapy

Polycythaemia vera is a clonal myeloproliferative disorder mainly involving proliferation of the erythropoiesis. The symptoms are varied and usually u nspecific. The most serious complications of the disease are a thrombotic t endency and myeloid metaplasia. Thromboses mainly (2/3) occur in the arteri al and less often (1/3) in the venous system and are the most common cause of death. Criteria have been established for the diagnosis of polycythaemia vera which should be strictly observed in order to distinguish between thi s disease, spurious polycythaemia, essential thrombocythaemia and secondary erythrocytosis. The goal of treatment is the prevention of thromboembolic complications and of myeloid metaplasia. The initial treatment always consi sts of phlebotomies until a hematocrit < 45% is achieved. The decision rega rding maintenance therapy is difficult. While hydroxyurea or radiophosphoru s is the treatment of choice in older patients (> 70 years of age), it is m ore difficult to select the appropriate therapy for younger patients (< 60 years), since recent studies have indicated that hydroxyurea treatment migh t increase the risk of leukemia. Interferon is effective but its role in th e treatment of polycythaemia vera has not been established.