The relation of platelet kinetics to bone marrow megakaryocytes in chronic granulocytic leukaemia.

The relation of thrombokinetics to quantitative determinations of megakaryocytes (mgkc) in bone marrow sections was studied in 11 consecutive cases of untreated Ph1-positive chronic granulocytic leukaemia (CGL). The results were compared with controls and with previously obtained data in polycythaemia vera (PV), primary thrombocythaemia (PT) and in idiopathic thrombocytopenic purpura (ITP). Platelet survival was significantly reduced in CGL. Platelet production was 5.8 x normal and the mgkc number and volume/microliter bone marrow were significantly increased as compared to controls. The increase in mgkc volume was not in proportion to that of number due to a significant decrease of mgkc size. Platelet production was strongly related to mgkc number/mm2 and to the mgkc volume/microliter bone marrow. The platelet production rate in relation to a unit of mgkc volume/microliter bone marrow was, however, greater in CGL than in controls, PV, PT and ITP. The chief reason for this is most probably the greater expansion of the total bone marrow mass in CGL.