The present state of pathophysiology and therapeutic trials in polycythemia vera

Polycythemia vera shares basic features of pathogenesis with other subtypes of the group of chronic myeloproliferative disorders. All myelopoietic cells are derived from one transformed hemopoietic stem cell. Genetic instability of mitotic clonal cells explains the risk of leukemic transformation, which may be enhanced by cytoreductive treatment. Recent data show that erythroid hyperplasia is not due to erythropoietin hypersensitivity, but rather to abnormal stimulation by other cytokine growth factors. Treatment as established by clinical trials has almost normalized life expectancy in older patients, but the optimal strategy for subgroups of patients is still unknown. For younger patients, new and potentially curative approaches should be investigated.