OBJECTIVE: To investigate the effect of active immunotherapy with anti-idiotypic vaccine in patients with nasopharyngeal carcinoma (NPC). METHODS: Anti-idiotypic antibodies (2H4/5D3) bearing the internal image of the NPC antigen were used in active immunotherapy in NPC patients receiving radiotherapy. Antibodies and cytokine levels in patient sera were determined using ELISA before and after active immunotherapy. IL-2 mRNA expression in the peripheral blood mononuclear cells (PBMC) was measured by in situ hybridization. RESULTS: Nineteen patients with NPC at stage IV were treated with alum-precipitated 2H4 or 5D3. Neither hypersensitivity nor adverse side effects were observed. The levels of anti-anti-idiotypic antibodies (Ab3) and anti-NPC antibodies (Ab1') were increased. Human anti-mouse antibodies (HAMA) were seen in 19 patients of the experimental group; the levels of Ab1' did not increase in the control group. Serum IL-2, IFN-gamma and TNF-alpha levels were increased in most patients in the experimental group, while no differences were observed in Ab1' and cytokine levels between pre- and post-therapy in the control group. In addition, IL-2 mRNA expression in PBMCs from NPC patients was closely related to serum IL-2 (r = + 0.8829) levels by in situ hybridization. CONCLUSIONS: Anti-idiotype vaccine is safe for clinical active immunotherapy. Anti-idiotypic vaccine might be able to enhance humoral and/or cellular immunity in NPC patients receiving radiotherapy.
