Firstly, IL-17A, IFN-γ and IL-10 were evaluated in conjunction with CD4<sup>+</sup> T cell staining by confocal microscopy of lesion biopsies from tuberculoid (TT) and lepromatous leprosy (LL) patients.
Skin biopsies were collected and submitted to immunohistochemistry using specific antibodies to IL-17, NGF and NGF R. Quantitative analysis of NGF, NGFR and IL-17 immunostaining showed a significant difference between the clinical forms, with higher expression of NGF and NGFR in lepromatous leprosy and IL-17 in tuberculoid leprosy.
Simultaneously, presence of Th17 related cytokines (TGF-β, IL-6, IL-17 and IL-23) decreased the number of FoxP3+ Treg cells concomitantly increasing IL-17 producing CD4+ cells in lepromatous leprosy.