Antimelanoma immunity in vitiligo and melanoma patients

Cutaneous melanoma and vitiligo are diseases etiology of which evolves around melanocytes. The nature of immunological disturbances associated with these diseases is not elucidated. The experiments performed in this work were aimed to determine antimelanoma immunotoxicity in patients with melanoma and patients with vitiligo. Twelve patients with melanoma, ten patients with vitiligo and seventeen healthy volunteers were studied. The cytotoxicity of PBMC was evaluated indirectly through determination of target melanoma (Fem-x) or control tumor (HeLa) cell survival, in the presence of 15% of AB or autologous sera, by MTT test. The mean values of antimelanoma cytotoxicity in AB serum were similar in both patients groups and in controls. However, the frequency of patients with the enhanced cytotoxicity against melanoma cells, in relation to control tumor cells, was lower in both patients groups than in controls. The intensity of antimelanoma cell-mediated cytotoxicity in melanoma patients, in the presence of autologous serum, was significantly lower in comparison to that found in control subjects and vitiligo patients (p<0.014, in both cases). This indicates that some factors from melanoma patient's sera contribute to impairment of the cytotoxicity of autologous PBMC, while other factors from the serum of vitiligo patients and control subjects enhanced their PBMC antimelanoma cytotoxicity.