B-cell Infiltration and Frequency of Cytokine Producing Cells Differ between Localized and Disseminated Human Cutaneous Leishmaniases

Biopsies from human localized cutaneous lesions (LCL n = 7) or disseminated lesions (DL n = 8) cases were characterized according to cellular infiltration,frequency of cytokine (IFN-γ, TNF-α) or iNOS enzyme producing cells. LCL, the most usual form of the disease with usually one or two lesions, exhibits extensive tissue damage. DL is a rare form with widespread lesions throughout the body; exhibiting poor parasite containment but less tissue damage. We demonstrated that LCL lesions exhibit higher frequency of B lymphocytes and a higher intensity of IFN-γ expression. In both forms of the disease CD8⁺ were found in higher frequency than CD4⁺ T cells. Frequency of TNF-α and iNOS producing cells, as well as the frequency of CD68⁺ macrophages, did not differ between LCL and DL. Our findings reinforce the link between an efficient control of parasite and tissue damage, implicating higher frequency of IFN-γ producing cells, as well as its possible counteraction by infiltrated B cells and hence possible humoral immune response in situ.