Hereditary abnormality of platelet aggregation attributable to nucleotide storage pool deficiency

An abnormality of platelet aggregation has been detected in six family members with mild bleeding tendencies. In citrated platelet-rich plasma, primary aggregation induced by ADP or epinephrine and agglutination in response to ristocetin were present but second wave aggregation and aggregation in response to collagen suspension were absent or greatly reduced. Sodium arachidonate-induced aggregation was normal although aggregation in response to prostaglandin G2 was reduced and depended entirely on the presence of plasma or ADP. Further tests indicated that the platelets produced prostaglandins but did not release ATP in response to thrombin or sodium arachidonate. Platelets from the patients were found to contain reduced amounts of ADP and 5- hydroxytryptamine and to be unable to retain radioactivity during prolonged incubation at 37 degree C with radiolabeled 5- hydroxytryptamine. Although electron microscopy revealed an absence of very dense bodies, the platelets appeared otherwise normal. The findings are discussed in relation to previous studies of nucleotide storage pool deficiency and the light they shed on platelet physiology in general.