The role of Th17 cells in patients with relapsing-remitting multiple sclerosis: Interleukin-17A and interleukin-17F serum levels

Abstract Background and aims Multiple sclerosis (MS) is an inflammatory condition of the central nervous system, with genetic and environmental factors having a role in its etiology. The condition is characterized by demyelination, acute inflammation, and chronic and acute lesions in the central nervous system. Human and experimental studies have shown that T-helper cells, and pro-inflammatory cytokines have a major role in the pathogenesis of MS. Recent researches have shown that IL-17 secreting T (Th17) cells have a role in inflammation and demyelination of the central nervous system. In the present study, the role of Interleukin-17A (IL-17A) and Interleukin-17F (IL-17F) in the immunopathogenesis and follow-up of the MS disease was evaluated. Materials and methods Thirty-five relapsing remitting (RR) form of MS patients were included in the present study. Blood samples were taken from 35 MS patients and 35 healthy individuals as controls. Enzyme-Linked Immunosorbent Assay (ELISA) was used to determine IL-17A and IL-17F serum levels. Results A statistically significant increase was noted in the serum levels of IL-17A and IL-17F in MS patients compared to the controls ( P < 0.001). There was a significant positive correlation of IL-17F serum levels with the number of relapses (rs = 0.717, P < 0.001). However, there was no significant relationship between the serum levels of these cytokines and Expanded Standard Disability Stated Scale (EDSS) and disease Progression Index (PI). Conclusion The data of the present study revealed a significant increase in the serum levels of IL-17A and IL-17F in MS patients compared with healthy controls and a significant positive correlation of IL-17F serum levels with the number of relapses. It appears that increased serum levels of IL-17 and especially IL-17F may lead to a raised risk of MS.