Determination of the cytokine profile in American cutaneous leishmaniasis using the polymerase chain reaction

Abstract

SUMMARY: The lymphokine profiles were determined in the skin lesions of the three distinct clinical forms of American cutaneous leishmaniasis (ACL), using a reverse transcriptase polymerase chain reaction (RT-PCR) and primers for various lymphokines. The message for interferon-gamma (IFN-y). tumour necrosis factor-beta (TNF–β) and IL-8 was expressed in the three clinical forms of ACL. IL-lβ in RNA was expressed in most localized (LCL) and mucoeutaneous (MCL) leishmaniasis. but in only few of the diffuse cutaneous leishmaniasis (DCL). IL-2 mRNA was detected in about half of the lesions, with more prominent values for MCL. IL-4 mRNA was present in most lesions from the three clinical forms, but markedly increased in DCL. IL-5 and IL-10 mRNAs were expressed in all MCL and in half of the DCL lesions and weakly expressed in LCL lesions. IL-10 mRNA was more abundant in MCL lesions. In contrast. IL-6 and TNF-s mRNAs were expressed in a Iarge number of LCL. In MCL, IL-6 mRNA was expressed in most cases and TNF–α mRNA in all the cases. In DCL. 11,–6 mRNA was absent and TNF–α mRNA was weakly expressed. These results suggest that most T cells present in the MCL and DCL lesions secrete a mixture of type 1 and type 2 cytokine patterns, but in DCL granulomas type 2 cytokines predominate. In LCL the cytokine patterns show a mixture of type l and type o with a preponderance of IFN–γ over IL-4, and low levels of IL-5 and IL-10. The Iack of IL-6 and TNF–α mRNAs, and the low expression of IL-lβ in DCL lesions suggest a defect in the anligcn-processing cells that may account for the state of unrcsponsiveness in these patients.