CLINICAL AND IMMUNOLOGICAL EFFECTS OF T-ACTIVIN THERAPY IN EARLY-STAGE MELANOMA PATIENTS

We investigated the clinical and immunological effects of T-activin th erapy in early stage melanoma patients. Several immune parameters (the number of T cells - E-RFC and CD3+, their subsets - CD4+ and CD8+, th e number of CD38+ and CD16+ cells, and mitogen-induced lymphoprolifera tive response - LPR) were analyzed in relation to the clinical course of the disease in patients treated by T-activin in addition to the sur gery (n = 8), and in control patients treated by the surgery alone (n = 9). Immunological tests were performed before therapy and one month after the last (6th) cycle of T-activin, i.e. six months after surgery in controls. The patients were followed-up from February 1991 to Augu st 1995. Clinical evaluation showed that disease-free interval for obs erved period was similar in both groups of patients (17.5 and 13 month s), while the survival time was longer in T-activin-treated patients t han in controls (40 vs. 24 months), although this difference was not s ignificant. The phenotyping analysis of peripheral blood lymphocytes s howed no changes of the pretreatment values of total T cells and their subpopulations regardless the clinical course of the disease in both groups of patients. The number of NK cells (CD16+) was significantly i ncreased after T-activin therapy, but this increase was not associated with clinical benefit, since it was seen in patients with the progres sion of the disease. In control patients, the initial number of CD16cells did not change significantly, irrespective of the clinical cours e. The lymphoproliferative response increased significantly in 4 out o f 5 T-activin-treated patients with the progression of the disease, wh ile a slight increase of this lymphocyte function was seen in 3 diseas e-free patients. In patients treated by surgery alone, especially thos e with disease progression, the LPR was significantly decreased six mo nths after tumor excision. These findings, although obtained in small number of patients, suggest an immunomodulatory action of T-activin th erapy in early stage melanoma patients, which did not correlate with t he clinical course of the disease. On the other hand, an almost double d survival time in T-activin-treated patients in comparison to the con trols, may indicate a possible effect of T-activin therapy on some oth er immune functions not evaluated in this study. Further investigation s in a larger number of patients is needed for assessment of the true effectiveness of such therapy.