Autoantibody against platelet glycoprotein IIb/IIIa in a patient with non-Hodgkin's lymphoma.

An autoantibody to platelet glycoprotein (GP) II b/III a was produced in a 38 year-old woman who had a previous history of the malignant lymphoma of the stomach. The aggregations of the patient's platelets showed losses of the primary waves in response to ADP and epinephrine and marked hypoaggregation in response to collagen, while agglutination by ristocetin was normal. Crossed immuno-electrophoresis (CIE) of her platelets solubilized by 1% Triton X-100 revealed an abnormal biphasic precipitate line of GP II b/III a complex. Nine months later, she developed severe thrombocytopenia along with a relapse of the lymphoma in the cervical lymph nodes. The patient's IgG, which was collected during her thrombocytopenic period and purified, inhibited ADP-, epinephrine- and collagen-induced aggregations of normal platelets. In CIE, the 125I-labelled IgG of the patient, inserted into the intermediate gel, was incorporated into the precipitation line of the GP II b/III a complex of normal platelets. Radiation treatment to the cervical lymph nodes dramatically normalized both the function and the count of the patient's platelets. From these findings, it is suggested that an autoantibody to the GP II b and/or III a was produced by the lymphoma cells.