Leishmania braziliensis guyanensis dermal leishmaniasis: cell-mediated immunity related to clinical features

The non-specific and specific cellular immune responses in vitro were investigated in 26 patients infected with Leishmania braziliensis guyanensis and compared with those of 12 healthy donors. An absence of marked suppression of lymphocyte proliferation in vitro to Con A, PHA and PWM mitogens, and a high variability in the cellular responsiveness to Leishmania antigens were detected in the infected patient group. The occurrence of relapses seemed to be associated with a lower lymphocyte transformation assay and a high number of lesions. The influence of delayed type hypersensitivity responses on the pattern of infection is considered.