Influence of residual splenic tissue on autoantibodies in splenectomized patients.

In 42 patients splenectomized after injury of the spleen or for non-malignant diseases residual splenic tissue was detected by 99mTc scanning in 19 (Group I) and not detected in 23 (Group II). Autoantibodies detected by the indirect immunofluorescent method occurred in 16 (38%) of the splenectomized patients and in 6 (14%) of 42 age- and sex-matched controls (P less than 0.02). In patients with residual splenic tissue the incidence of autoantibodies did not differ significantly form that in the controls, whereas autoantibodies occurred significantly more often in patients without residual splenic tissue (39%) than inthe corresponding control groups (9%) (P = 0.016). Antibodies to nuclear antigens (ANA), smooth muscle (SMA), reticulin (RetA) and cytoplasm of gastric parietal cells (PA) were detected, and the antibody titres tended to be higher in the patients than in the controls. None of the patients showed any clinical signs of autoimmune disease. These findings indicate that splenectomy disturbs the regulation of autoantibody function, and it is possible that this might be caused by a reduction of the number of T suppressor cells for which the spleen is a major pool. It is suggested that residual tissue may prevent an increased occurrence of autoantibodies in splenectomized patients.