Recurrent cutaneous or mucosal candidiasis is characterized by the occurrence of at least four candidiasis episodes within a one-year period. The factors involved in recurrence of infection are still unknown. In the present study the lymphoproliferative response and the IFN-gamma production by candidiasis patients were evaluated. The stimulation index of mononuclear cell cultures of candidiasis patients stimulated with Candida albicans antigen, PPD and TT were 6 +/- 8, 17 +/- 20 and 65 +/- 30, respectively. The addition of monoclonal antibody anti-IL-10 to Candida albicans antigen stimulated cultures raised the lymphoproliferative response from 735 +/- 415 to 4143 +/- 1746 cpm. The IFN-gamma production by cells of candidiasis patients stimulated with Candida albicans antigen was 162 +/- 345 pg/ml. Candidiasis patients have an impairment in the lymphoproliferative response specific to C. albicans antigen and on IFN-gamma production and the lymphoproliferative response can be partially restored, in vitro, by IL-10 neutralization.