CORRELATES OF IMMUNITY IN SUDANESE DERMAL AND MUCOSAL LEISHMANIASIS PATIENTS

There is a need to study the role of immune response particularly cytokines profile in persistence of Leishmania infection and the distruction observed in some forms of leishmaniasis. In this study Th1 (IFN-γ and TNF- α), Th2 (IL-4 and IL-10) and T reg (TGF-ß1) cytokines concentrations were measured in the supernatant of Crude Soluble Antigen (CSA) and live parasite stimulated and non stimulated peripheral blood mononuclear cells (PBMCs) of cutaneous Leishmaniasis (CL), mucosal Leishmaniasis (ML), post kala-azar dermal Leishmaniasis (PKDL), leishmanin skin test (LST) positive and negative reactors. Significant IFN-γ and TNF- α concentrations were detected in the CL, ML, and PKDL patients than in the LST +ve and LST –ve controls. IL-10 and IL-4 concentrations were low in the CL, ML, and PKDL patients with no significant difference between them and the LST +ve and LST –ve controls. A significant TGF-ß1 concentration was detected in the LST +ve and LST –ve controls than in the CL, ML, and PKDL patients. Cytokines levels were measured before and after Ambisome therapy for 3 ML patients and they showed a non significant increase in concentrations of IL-10, TGF-ß1, and IL-4 while significant reductions in IFN-γ and TNF- α concentrations were detected. IFN-γ increased with the duration of lesion in CL patient and it was higher in the supernatants stimulated with the homologous parasite. No correlation between LST indurations and IFN-γ production was detected in either patients or controls. Live Leishmania parasites were more efficient in stimulating PBMCs of active CL, ML, and PKDL patients while killed parasite lysates were more efficient in stimulating PBMCs of LST +ve and LST –ve controls. Leishmania antigens stimulate T reg cells as evident by induction of TGF-ß1. Sources of detected cytokines need to be investigated