Controlled trial of a thymic hormone extract (Thymostimulin) in 'autoimmune' chronic active hepatitis.

A randomised controlled trial of thymic hormone extracts (Thymostimulin) (1 mg/kg/day for seven days; 1 mg/kg/weekly thereafter) was undertaken in 30 patients (21 women, nine men) with treated, apparently inactive 'autoimmune' chronic active hepatitis during withdrawal of maintenance corticosteroid and azathioprine therapy. Reactivation of disease occurred in 26 patients (86%) during or after treatment withdrawal and was as frequent in the Thymostimulin treated (11 of 13; 84%) and untreated (15 of 17; 88%; p greater than 0.05) groups. Reactivation of disease was accompanied by a severe defect in concanavalin A induced suppressor cell activity, the magnitude of which was similar in the Thymostimulin treated and untreated groups (mean % suppression = 16.4 and 3.2 respectively; p greater than 0.05 vs 84.4 in control subjects). Further studies assessing the optimal dose, duration of treatment, and mode of administration are required to establish a therapeutic role for thymic hormone extracts in 'autoimmune' chronic active hepatitis.