Prothymosin α Restores the Depressed Autologous and Allogeneic Mixed Lymphocyte Responses in Patients with Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is characterized by a variety of profound T-cell abnormalities among which are decreased autologous and allogeneic mixed lymphocyte reactions (auto-MLR and allo-MLR, respectively). In a group of 10 patients with SLE, the mean auto-MLR and allo-MLR responses, tested by tritiated thymidine incorporation, were significantly decreased. If optimal doses of highly purified prothymosin alpha (ProT alpha) were present during the auto- of allo-MLR, the T-cell proliferative responses of SLE patients were increased to normal levels. ProT alpha had more pronounced enhancing effect in patients than in normal individuals. Among patients, ProT alpha was more effective in those who had active disease and low proliferative responses. These results demonstrate that ProT alpha can fully restore the deficient T-cell proliferative responses in auto- and allo-MLR in patients with SLE. ProT alpha, or a certain peptidic fragment of it, could prove potentially useful in the treatment of SLE.