interleukin-17a and interleukin-17f mrna expressions in peripheral blood mononuclear cells of patients with multiple sclerosis

bakground: multiple sclerosis (ms) is a cd4+ t cell-mediated autoimmune disease affecting the central nervous system (cns). it was previously believed that th1 cells were pathogenic t cells in experimental autoimmune encephalomyelitis (eae). however, the functional role of th1 cells in eae has been reconsidered upon the discovery of il-17- producing t cells which are consider as dominant effectors for inducing autoimmune tissue inflammation. objective: the objective of this study was to assess the role of il-17a and il-17f in ms pathogenesis. methods: we evaluated mrna expression of il-17a and il-17f in thirty-five iranian patients with relapsing–remitting ms (rrms) and twenty-five healthy controls by quantitative real time pcr. results: the results of this study showed a twenty-fold increase in the expression of il-17a mrna in ms patients compared to the control group (p < 0.0001 ). il-17f mrna expression in ms patients was thirty three-times greater than control group (p = 0.0008). il-17a mrna expression in periphery was positively correlated with expression of il-17f transcripts in ms patients and controls (p < 0.01 and p < 0.05, respectively). conclusion: these results indicate the critical role of th17- mediated cytokines in development of ms which classically has been considered as a th1-mediated disorder. the results of this study showed, for the first time, the importance of il-17f in ms immunopathogenesis.