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Int.","Neurology International"],"abstract":"<jats:p>Background: Systemic inflammation contributes to the pathobiology of multiple sclerosis (MS), yet serum biomarker data from Middle Eastern populations remain limited. This study evaluated serum levels of IL-6, IL-16, IL-18, and IL-36 in Saudi adults with MS compared with matched healthy controls and examined associations with disease duration, phenotype, treatment, and disability. Methods: This single-center, cross-sectional, matched case\u2013control study enrolled 26 MS patients and 26 age- and sex-matched controls. Serum cytokines were measured by ELISA. Disability was assessed using EDSS and the Timed 25-Foot Walk (T25FW). Matched comparisons used Wilcoxon signed-rank tests; subgroup comparisons used Wilcoxon rank-sum or Kruskal\u2013Wallis tests; associations used Spearman\u2019s correlation. Results: No correction for multiple comparisons was applied given the exploratory design. All four interleukins were higher in MS patients than in controls (p &lt; 0.001). Age correlated with EDSS (r = 0.573, p = 0.002) and T25FW (r = 0.464, p = 0.014). Only IL-6 showed a notable correlation with disability, with T25FW (r = 0.53, p = 0.008) and, weaker, EDSS (r = 0.38, p = 0.052); IL-18 showed a weak, non-significant correlation with T25FW (r = 0.35, p = 0.126); IL-16 and IL-36 showed no relevant associations. IL-16 was higher in newly diagnosed than in long-standing cases (p = 0.012); no differences by phenotype or treatment were observed for any marker. Conclusions: Serum IL-6, IL-16, IL-18, and IL-36 were elevated in Saudi MS patients versus controls. IL-6 alone showed a modest, unadjusted association with disability, supporting its evaluation as a candidate biomarker in larger, longitudinal, covariate-adjusted cohorts. These findings are hypothesis-generating and should not be interpreted as evidence of independent or clinically actionable biomarker utility.<\/jats:p>","DOI":"10.3390\/neurolint18090168","type":"journal-article","created":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T03:19:26Z","timestamp":1788232766000},"page":"168","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Serum Levels of the Proinflammatory Cytokines IL-6, IL-16, IL-18, and IL-36 in Patients with Multiple Sclerosis from the Western Region of Saudi Arabia: Associations with Disease Duration and Disability"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7803-2078","authenticated-orcid":false,"given":"Jehan","family":"Alrahimi","sequence":"first","affiliation":[{"name":"Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia"},{"name":"Immunology Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]},{"given":"Yara","family":"Mualla","sequence":"additional","affiliation":[{"name":"Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1751-8944","authenticated-orcid":false,"given":"Alawiah","family":"Alhebshi","sequence":"additional","affiliation":[{"name":"Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6096-3667","authenticated-orcid":false,"given":"Hind A.","family":"Alnajashi","sequence":"additional","affiliation":[{"name":"Department of Neurology, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia"},{"name":"Department of Neurology, King Abdulaziz University Hospital, King Abdulaziz University, Jeddah 21589, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0909-6558","authenticated-orcid":false,"given":"Kawther","family":"Zaher","sequence":"additional","affiliation":[{"name":"Neuroscience and Geoscience Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia"},{"name":"Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"software","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1816","DOI":"10.1177\/1352458520970841","article-title":"Rising Prevalence of Multiple Sclerosis Worldwide: Insights from the Atlas of MS, Third Edition","volume":"26","author":"Walton","year":"2020","journal-title":"Mult. 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