Unveiling oxidative stress in multiple sclerosis phenotypes: Exclusion of confounding variables for accurate...

In this study, we examined oxidative stress (OS) markers in various multiple sclerosis (MS) phenotypes during remission and assessed their correlation with patients' disability status. Potential confounding variables that could influence OS development were considered exclusion criteria in our investigation.

The present study was a matched case-control study of MS patients in Bojnourd, Iran. Detailed demographic and clinical information were collected using structured questionnaires and medical records. Disability was evaluated using the Expanded Disability Status Scale (EDSS). Potential risk factors for OS development, including active infection, medications, supplements, and comorbidities, were included as exclusion criteria for participants. Healthy controls were matched with the participants based on sociodemographic factors. Blood samples were collected to determine the serum levels of OS markers using a colorimetric assay.

MS patients showed elevated serum levels of malondialdehyde (MDA) and nitric oxide (NO) and reduced serum catalase activity and total antioxidant capacity (TAC) compared to controls. There was no significant difference in superoxide dismutase (SOD) activity between MS and control groups. Higher EDSS scores correlated with increased MDA and NO levels and decreased catalase, SOD, and TAC levels in MS. However, there were no significant differences in OS markers among MS phenotypes or relapsing-remitting MS patients with different EDSS scores.

Our study revealed elevated MDA and NO levels, reduced catalase activity and TAC in both RRMS and Non-RRMS MS phenotypes versus controls, with no differences between phenotypes. These markers correlated with EDSS, indicating potential as prognostic biomarkers for progression.