IL-8 and IL-23 Levels in Peripheral Blood Mononuclear Cells of Patients with Cutaneous Leishmaniasis Caused by Leishmania major: A Case-Control Study

Abstract

Background: Several cytokines contribute to cutaneous leishmaniasis outcomes. IL-23 is a key cytokine in inflammation and a central cytokine in controlling Th17. IL-8, also known as a neutrophil chemotactic factor in the lesion site of cutaneous leishmaniasis, indicates disease promotion. Objectives: This study aimed to evaluate the relationship of Leishmania major with IL-8 and IL-23 expression. Methods: This case-control study was performed on 25 healthy individuals and 25 cutaneous leishmaniasis patients who lived in Southwestern Iran, in 2017. Peripheral blood mononuclear cells (PBMCs) were first isolated. Total RNA was extracted and reverse-transcribed into cDNA. The expression levels of IL-8 and IL-23 were measured by the real-time PCR. The data were statistically analyzed using SPSS version 16. Results: Our findings indicated that the expression of IL-8 was significantly higher in the leishmaniasis group than in the control group with the median (IQR) of 0.39 (0.92) and 0.03 (0.11), respectively (P = 0.02). The expression of IL-23 was higher in the leishmaniasis group than in the control group with the median (IQR) of 0.13 (0.43) and 0.11 (0.61), respectively (P = 0.48). The increased IL-8 expression accompanied the location sites in face and hand and the increased number of skin lesions. Conclusions: The expression of IL-8 in patients with cutaneous leishmaniasis is an index of increased activity of local neutrophils that can contribute to leishmaniasis survival or inflammation increase. However, IL-23 appears to be less important in the inflammatory reaction than IL-8.