Platelet production and platelet survival in polycythaemia vera with special reference to the spleen size.

Abstract

Studies of platelet survival and of platelet production rate were performed in 20 patients with active polycythaemia vera (PV). 8 of them were classified as non‐splenomegalic and 12 had splenomegaly. The results were compared with a control material consisting of 16 haematologically normal subjects of similar age. Platelet recovery was significantly lower in splenomegalic as compared with non‐splenomegalic PV patients. Platelet recovery in the latter group was, however, also significantly lower than in control subjects.Platelet mean life span and platelet half‐life time were obtained by fitting the experimental data to an arbitrary mathematical function by using a digital computer. The results indicate that platelet survival is shorter in PV patients with splenomegaly as compared with PV patients wihout splenomegaly.Irrespective of the peripheral platelet count the platelet production rate in all PV patients exceeded the upper range for the control subjects. The mean platelet production rate was approximately 9 times normal in the splenomegalic group, and 5 times normal in the group without splenomegaly. There was a large individual variation for the platelet production rate, and the dispersion of values was more pronounced in the splenomegalic group.