American tegumentary leishmaniasis: cytokines and nitric oxide in active disease and after clinical cure, with or without chemotherapy.

The influence of immune response on the treatment of American tegumentary leishmaniasis is pointed by several authors, and the existence of protective immunity in self-healed patients (SH) is also suggested. Thus, interferon-gamma (IFN-γ), tumour necrosis factor-alpha (TNF-α), interleukin (IL-) 10, IL-17, IL-22 and nitric oxide (NO) production was determined in PBMC culture supernatants from patients with active disease (AD) and after therapy, SH patients and healthy subjects, in response to the soluble antigen of Leishmania (Viannia) braziliensis. It was demonstrated that, during the active disease, there is a predominance of IFN-γ and TNF-α, indicating a proinflammatory phase of the response; IL-17 is also highlighted at this clinical state. Also, TNF-α was slightly increased in patients after therapy. NO secretion was noticed in SH individuals, while IL-17 appeared in low levels in these patients and seems to be regulated by NO. The presence of IL-10 was observed in all groups of patients. From this study, we can suggest that in the active disease and after clinical cure, with or without chemotherapy, specific cellular immunity takes part against Leishmania, but with some similarities between the clinical states. Thus, it indicates that the mediators herein described are necessary for the cure to occur.