Platelet defect of infectious mononucleosis.

Platelet function has been studied in 16 patients with uncomplicated infectious mononucleosis. Some abnormality of platelet aggregation and/or release of platelet factor III or platelet factor IV was found in all patients. Six patients with platelet defects were retested after three to four months and were found to have normal platelet function and appreciably higher platelet counts. Abnormal platelet function may reflect a platelet defect which predisposes to premature platelet destruction. Recent viral illness should be excluded before attributing abnormal platelet function to other factors or to a congenital disorder.