THE DIAGNOSTIC-CRITERIA OF POLYCYTHEMIA RUBRA VERA

There is no single diagnostic marker for polycythaemia vera (PV). The Polycythemia Vera Study Group established diagnostic criteria more tha n twenty years ago. Since some new laboratory and clinical investigati ons have developed, these criteria can now be updated. It is proposed that the overall pattern of major and minor criteria should remain. A raised red cell mass (greater than 25% above the patient's mean normal predicted value based on surface area) and absence of a cause of seco ndary polycythaemia are essential criteria. Then either palpable splen omegaly or the presence of a marker of clonal haemopoiesis would suppo rt the diagnosis of PV. In the absence of both of these latter major c riteria, at least two minor criteria must be present to secure the dia gnosis. These are: platelet count >400 x 10(9)/l; neutrophil count >10 x 10(9)/l; splenomegaly demonstrated by a scanning technique; charact eristic BFU-E growth or reduced serum erythropoietin value.