POLAR AND SUBPOLAR DIFFUSE CUTANEOUS LEISHMANIASIS IN BRAZIL - CLINICAL AND IMMUNOPATHOLOGIC ASPECTS

Background. Diffuse cutaneous leishmaniasis (DCL) is a rare manifestat ion of human leishmaniasis, characterized by multiple, slowly progress ive nodules or plaques without ulceration, involving almost the entire body. It has been suggested, that DCL results from a lack of cell-med iated immunity to leishmanial antigen, leading to uncontrolled parasit e growth. Methods. We have performed detailed clinical, histopathologi c, and immunologic investigations in six patients with DCL. Biopsies w ere taken from the nodules, processed, and examined for determination of the macrophagic pattern present, based on the intensity of vacuolat ion and the frequency of vacuolated cells, the parasite index, and the presence of eosinophils. Immunologically, patients were evaluated by their response to intradermal skin test to PPD or leishmania antigen, determination of antileishmania antibodies by immunofluorescent assay, and lymphocyte proliferation assay. Results. There seemed to be a neg ative relation between nodules and skin ulcerations, whereas the highe st number of parasites were observed in patients with the greatest num ber of vacuolated macrophages. The delayed hypersensitivity skin test to leishmanial antigen was negative, and antileishmania IgG antibodies were positive in all patients, Conclusions. Although all cases fulfil l the criteria for being classified as DCL, they present a wide spectr um. Three cases were clearly at the unresponsive pole, and three other cases belonged to the subpolar form of DCL, exhibiting varying weak s igns of antiparasite responsiveness.