In vitro and skin lesion cytokine profile in Brazilian patients with borderline tuberculoid and borderline lepromatous leprosy.

OBJECTIVE We investigated the in vitro and skin lesions production of cytokines in non-treated borderline tuberculoid (BT) and borderline lepromatous (BL) patients. PATIENTS AND METHODS Seven untreated, non-reactional BT patients and 12 untreated, non-reactional BL patients were studied. Levels of the cytokines IFN-gamma, IL-10, TGF-beta1 and TNF-alpha were measured in supernantant of peripheral blood mononuclear cells (PBMC) cultures, stimulated with specific M. leprae antigen (sonicated and whole). The cytokines iNOS, IL-10 and TGF-beta1 were detected by immunohistochemistry in skin biopsies. RESULTS BT patients produced higher levels of IFN-gamma than BL patients; iNOS expression in skin lesions was also higher in BT patients. TGF-beta1 was detected in more cells in BL patients; IL-10 expression was similar in both groups. There was a negative correlation between iNOS and TGF-beta1 expression in skin biopsies, positive correlation between TGF-beta1 in skin lesions and bacillary index, as well as positive correlation between iNOS detected in skin biopsies and PBMC IFN-gamma production. CONCLUSIONS The BT patients had a mainly a Th1-profile of cytokines in their skin lesions and BL patients had a Th2 profile.