Immunorestorative properties of thymostimulin (TS) in patients with Hodgkin's disease in clinical remission.

Fifteen Hodgkin's disease patients (8 male, 7 female) aged 19-72 years, who had been in complete unmaintained remission for 1 year or more when the study was initiated, were given 50 mg thymostimulin (TS) IM daily for 60 consecutive days. When compared with 26-30 age- and sex-matched controls, as a group the patients' circulating ENR+, OKT+3, and OKT+4 cells were depressed (0.001 less than or equal to P less than or equal to 0.06), whereas their OKT+8 cell population was not. Low (greater than 1 SD or greater than 2 SD below mean in controls) or borderline (mean value of two subsequent tests greater than 1 SD below mean in controls) values of ENR+, OKT+3, and OKT+4 cells were seen in nine (group I) of the 15 patients tested, while the remaining six patients (group II) had normal T-cell proportions. Following TS treatment, the proportions of ENR+, OKT+3, and OKT+4 cells increased to normal in all group I patients. The T-cell levels, however, decreased to pretreatment values 60-70 days after completion of TS therapy. TS had no effect on the group II patients whose T-cell percentages had initially been normal. Spontaneous cell-mediated cytotoxicity (SCMC) was assessed in 11 patients, and irrespective of the baseline values, there was a significant enhancement (P less than 0.005) by day 15 of TS administration, which was maintained during treatment. SCMC, however, returned to pretreatment levels 60-70 days after TS was discontinued. The delayed skin test reactivity to DNCB was significantly depressed in all cases. Although TS restored the T-cell proportions, it failed to reverse DNCB reactivity from negative to positive in any of the patients tested. TS can thus restore defective T-cell frequencies and can enhance cytolytic functions that are potentially important in host immunosurveillance, but it apparently failed to improve the skin reactivity to neoantigen.