Comparison of pro-inflammatory cytokines of non-healing and healing cutaneous leishmaniasis

Cutaneous leishmaniasis (CL) heals spontaneously within several weeks or months, but, in rare cases, CL-active lesions last for many years. In this study, we assessed cell-mediated immunity in non-healing CL through the measurement of three pro-inflammatory cytokines: Interferon-gamma (IFN-gamma), IL-17a and CXCL-11. For this, 32 patients afflicted with healing or non-healing CL were recruited in this study. Peripheral blood mononuclear cells (PBMCs) of every patient were treated with three antigens: purified protein derivative (PPD), soluble Leishmania antigen (SLA) and phytohaemagglutinin (PHA). Cytokine quantification was performed using enzyme-linked immunosorbent assay (ELISA) method. Results of our study showed that neither cytokine produced in the presence of a PPD stimulator (as an irrelevant antigen) significantly differed between the healing and non-healing groups (P-value > 0.05 for all of them). However, IFN-gamma, CXCL-11 and IL-17a levels produced in the presence of PHA or SLA were significantly higher within the healing than in the non-healing group (P-value < 0.01 for all of them). It seems that appropriate levels of IFN-gamma, as well as IL-17a and CXCL-11, contribute to the control of Leishmania infection.