Severe platelet dysfunction in a man with a normal bleeding time.

Abstract

A man who bruised easily and had had recurrent epistaxis since childhood leading to splenectomy was found to have failure of platelet aggregation in platelet-rich plasma in response to adenosine diphosphate, collagen, and norepinephrine. He also had decreased retention of platelets in glass bead filters and poor clot retraction, as did his mother. In spite of these abnormalities of platelet function in vitro, his bleeding times were consistently normal. These unusual observations suggest that a normal bleeding time does not exclude platelet dysfunction as the cause of a bleeding tendency.