Objectives. To investigate the impact of polychemotherapy on cellular immunity in patients with testicular cancer.

Methods. Lymphocyte subpopulations, lymphoproliferative responses to mitogenic stimulation, and mitogen-induced release of soluble interleukin-2 receptor from peripheral blood mononuclear cells were investigated in 15 patients with testicular germ cell tumors a median of 61 months (range 7 to 73) after polychemotherapy with bleomycin, etoposide, and cisplatin (BEP).

Results. The numbers of peripheral blood T cells (CD3+), CD4+ and CD8+ subsets, and lymphoproliferative responses to pokeweed mitogen, phytohemagglutinin, and concanavalin A in patients were comparable to those of healthy control subjects. When two groups of patients were formed according to elapsed time from BEP polychemotherapy and study onset (group A, 12 months and group B, 69 months after termination of BEP), a significant increase in lymphoproliferative response to concanavalin A (P <0.05) was found in group A 1 year after chemotherapy.

Conclusions. BEP chemotherapy administered to patients with testicular cancer does not result in impairment of cellular immunity but rather leads to a significant increase in the capacity of patients’ lymphocytes to respond to mitogenic stimulation up to 1 year after polychemotherapy. Moreover, the increased T-cell activity found after BEP therapy may contribute to the high rate of long-term complete remission.