Familial abnormalities of lymphocyte function in a large Sjögren's syndrome kindred.

A large kindred (32 members), whose proband had primary Sjögren's syndrome, was investigated to ascertain whether abnormalities of lymphocyte function were present in family members of patients with Sjögren's syndrome. Ten members of the kindred with autoimmune diseases, 17 blood relatives, 5 spouses, and 32 matched controls were studied. Concanavalin A induced suppression of pokeweed mitogen stimulated immunoglobulin synthesis was decreased in patients and blood relatives both with and without autoimmune diseases. Elevations of the mean T4/T8 ratio, due to decreased numbers of suppressor/cytotoxic lymphocytes, were present in both the disease group and the blood relatives. These abnormalities occurred independently of HLA and were not necessarily associated with autoantibodies.