ASSOCIATION BETWEEN SERUM RESISTIN AND DISEASE ACTIVITY IN TREATED RELAPSING–REMITTING MULTIPLE SCLEROSIS

Introduction: Multiple sclerosis (MS) is an demiyelinating autoimmune disease and characterized with chronic inflammation and neurodegeneration. Resistin is an adipokine secreted from adipose tissue and known to be a pro-inflammatory mediator produced mainly by monocytes and macrophages in humans, has an uncertain role in MS pathogenesis. This study aims to compare serum resistin levels in patients with relapsing-remitting MS (RRMS) with those of healthy controls and to examine the relationship between these levels and key clinical disease parameters. Methods: 41 patients diagnosed with RRMS according to the 2017 McDonald criteria and 40 matched healthy controls were included to the study. Demographic data, clinical characteristics (disease duration, Expanded Disability Status Scale score (EDSS), relapse rates, and blood samples were collected. Serum resistin levels were measured by using the enzyme-linked immunosorbent assay (ELISA) method. The Mann-Whitney U test, Spearman's correlation analysis, independent samples t-test, and Chi-Square test were performed by using the data distribution. Results: Serum resistin levels were similar in MS patients (median: 658.6 pg/mL, range: 118-6000) and in the control group (median: 855.4 pg/mL, range: 182.6-3807.2), with no statistically significant difference (p=0.305). There was no significant correlation between serum resistin levels and the EDSS score (r=-0.056, p=0.728), the number of relapses in the last year (r=-0.006, p=0.968), or the number of relapses in the last two years (r=0.062, p=0.702). Conclusion: The findings suggest that systemic circulating serum resistin levels are not directly associated with the presence of MS and do not serve as a reliable biomarker for clinical activity. The potential role of resistin in MS pathophysiology may be confined to localized inflammatory processes behind the blood-brain barrier rather than systemic circulation. Keywords: multiple sclerosis, resistin, adipokine, neuroinflammation, biomarker, EDSS.