Tehran University of Medical Sciences Current Journal of Neurology 2717-011X 16 1 2017 01 04 15 25 EN Seyed Ali Ghaffari Neurology Research Center, Department of Neurology, Kerman University of Medical Sciences, Kerman, Iran Department of Laboratory Sciences, School of Paramedicine, Kerman University of Medical Sciences, Kerman, Iran Maryam Nemati Neurology Research Center, Department of Neurology, Kerman University of Medical Sciences, Kerman, Iran Hossain Hajghani Neurology Research Center, Department of Neurology, Kerman University of Medical Sciences, Kerman, Iran Hossainali Ebrahimi Neurology Research Center, Department of Neurology, Kerman University of Medical Sciences, Kerman, Iran Abdolkarim Sheikhi Department of Immunology, School of Medicine, Dezful University of Medical Sciences, Dezful, Iran Abdollah Jafarzadeh Molecular Medicine Research Center, Department of Immunology, School of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran Department of Immunology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran 2015 10 31 2016 11 25 Background: Interleukin (IL)-17/IL-23 axis performs a prominent role in the pathogenesis of several autoimmune disorders. This study aimed to investigate the concentrations of IL-17 in patients with multiple sclerosis (MS) and its relationship with gender, medication, disease forms and single nucleotide polymorphisms (SNP) in IL-23R gene, including rs11209026 and rs1004819. Methods: The blood specimens were obtained from 135 healthy individuals and 135 MS patients. The patients exhibited relapsing-remitting (RRMS; n = 65), primary progressive (PPMS; n = 19), secondary progressive (SPMS; n = 35) or progressive relapsing (PRMS; n = 14) MS. The DNA was analyzed for SNPs using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and IL-17 concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Results: We have observed elevated serum IL-17 concentrations in MS patients compared with healthy individuals (P < 0.001). The men with MS had higher IL-17 concentrations than women patients (P < 0.050). Untreated patients had significantly higher IL-17 concentrations than healthy individuals and treated patients (P < 0.001 and P < 0.010, respectively). The IL-17 concentrations were significantly decreased in patients treated with interferon-β (IFN-β), methylprednisolone or both drugs as compared with untreated MS patients (P < 0.050, P < 0.020 and P < 0.050, respectively). The IL-17 concentrations were also significantly higher in patients with RRMS and PRMS compared with healthy individuals (P < 0.005 and P < 0.010, respectively). The genetic variations at SNPs rs11209026 and rs1004819 were not significantly different between healthy individuals and patients. The IL-17 concentrations were not influenced by genetic variations at investigated SNPs. Conclusion: These results indicated higher levels of IL-17 in MS patients that may be influenced by disease patterns, medication and gender. No association was observed between investigated SNPs and MS. https://ijnl.tums.ac.ir/index.php/ijnl/article/view/874 https://ijnl.tums.ac.ir/index.php/ijnl/article/download/874/332