All of the following are seen in polycythemia rubra vera except :

Answer is B (Decreased LAP Score): Leucocyte alkaline phosphatase is increased in polycythemia vera Characteristic features associated of polycythemia vera Elevated Red Cell Mass/ haematocrit (polycythemia)Q Normal aerial oxygen saturation (a low oxygen saturation would be a physiological stimulus) Plasma erythropoetin levels < 4 mu/ml (normal range : 4-26 mu/ml) (not increased) Q Increased Leucocyte alkaline phosphatase Increased uric acid Q? Increased serum vitamin B12 or vitamin B12 binding capacityQ Massive splenomegaly or in the absence of splenomegaly leucocytosis & thrombocytosisQ No increase in ESRQ Memo : LAP score is decreased in CML PNH