Changes in T and B lymphocyte subpopulations before, during and after chemotherapy for malignant melanoma.

The behaviour of T and B lymphocyte subpopulations before, during and after chemotherapy with DTIC or CCNU was studied in 87 melanoma patients. The effect on immune status of DTIC administered as adjuvant therapy was also reported. The immunosuppressive effect was found to be higher in patients with normal pretreatment T-cell values than in patients with low pretreatment values, and it was higher in metastatic than in nonmetastatic patients. Where T and B lymphocyte subpopulations were assessed in 10 metastatic patients after each course of chemotherapy, a progressive reduction of T-lymphocytes was observed, indicating a cumulative effect of the drugs with advancing course. The reduction of T lymphocytes was mainly due to the decrease of OKT4+ cells. A normalization of T lymphocyte subpopulations was observed after the suspension of therapy. No significant decrease in the number of B cells was observed in the DTIC treated metastatic patients, whereas a significative reduction in the absolute number was found in those treated with CCNU.