Some characteristics of spontaneous platelet aggregation in young insulin-dependent diabetic subjects

Spontaneous platelet aggregation (SPA), a phenomenon observed in vitro, was noted in 29 of 74 (39%) children and adolescents with insulin-dependent diabetes. Its occurrence was independent of age of onset, duration of diabetes, HbAI levels or presence of background retinopathy but varied between normal and abnormal in given individuals tested repeatedly over some time. Plasma beta-thromboglobulin, the platelet protein specific for Phase II of the release reaction, was elevated in the diabetic subjects but was independent of the occurrence of SPA. SPA in the diabetic children and adolescents, in contrast to SPA in other conditions, was not suppressed by either acute or chronic administration of aspirin adequate to suppress ADP induced second wave aggregation. SPA was uniformly suppressed by addition to the in vitro system of EDTA, adenosine, antisera to human fibrinogen or vitamin E. The data suggest that SPA is ADP induced and reflects either abnormal platelet membrane permeability to the nucleotide or its abnormal release, or abnormal platelet sensitivity to normal plasma levels of ADP.