Qualitative Platelet Defects with Reduced Life-Span in Acute Leukaemia*

Summary: Qualitative platelet abnormalities, as well as thrombocytopenia, may contribute to the haemorrhagic diathesis in acute leukaemia. The prevalence of impaired platelet function, as reflected by aggregation response to ADP, adrenaline and Ristocetin, and platelet factor III activity, was assessed in 21 patients with acute leukaemia. During the phases of active disease or partial remission, impaired aggregation and/or defective platelet factor lll release occurred in eleven of fifteen patients with active disease and in three of five patients in partial remission. In complete remission, platelet function was normal. In patients with active disease or in partial remission, defective platelet function was associated with reduced autologous platelet life-spans, whilst normal platelet function was coupled with normal platelet survival. Although the mechanisms for the production of thrombocytopenia in acute leukaemia are multifactorial, it is suggested that the acquisition of defective platelets with associated reduced survival may play a contributory role.