Revisiting the Diagnostic Marker: Oligoclonal Band Positivity is Not Associated with Early Disability or Cognitive Performance in Relapsing-Remitting Multiple Sclerosis

Abstract

Background: Oligoclonal bands (OCBs) in the cerebrospinal fluid (CSF) are a hallmark diagnostic biomarker for multiple sclerosis (MS), found in over 80 % of patients. While their role in diagnosis and disease conversion from clinically isolated syndrome (CIS) to MS is well-established, their relationship with baseline clinical, physical, and cognitive characteristics in relapsing-remitting MS (RRMS) remains less clear. Objective: To investigate whether OCB positivity is associated with differences in demographic variables, physical disability, and cognitive performance in patients with RRMS at disease onset. Methods: In this retrospective observational study, 2324 treatment-na & iuml;ve patients diagnosed with RRMS were stratified into OCB-positive and OCB-negative groups based on CSF analysis performed at diagnosis. Baseline assessments included demographic data, Expanded Disability Status Scale (EDSS) scores, and cognitive and motor performance measured by the Brief International Cognitive Assessment for MS (BICAMS), Timed 25-Foot Walk Test (T25FW), and 9-Hole Peg Test (9-HPT). Group comparisons were conducted using t-tests and chisquare tests; multivariate analyses controlled for confounders. Results: OCBs were detected in 82.4 % (n = 1915) of patients. No significant differences were observed between OCB+ and OCB- groups in terms of age at onset, sex, initial symptom type, or baseline EDSS. Similarly, cognitive scores (SDMT, CVLT-II, BVMTR) and physical test performance (T25FW, 9-HPT) did not differ significantly between the two groups. Multivariate regression confirmed no independent association between OCB status and clinical, cognitive, or motor variables at diagnosis. Additional follow-up data: At the 2-year follow-up, no significant differences were observed between OCB-positive and OCB-negative groups regarding EDSS, ARR, or SPMS conversion (all p > 0.05). At the 5-year follow-up, EDSS and relapse rates remained similar, but a significantly higher proportion of OCB-positive patients had converted to SPMS (p < 0.05). Conclusion: Although OCB positivity remains a crucial diagnostic tool and a known prognostic factor for conversion from CIS to MS, our findings suggest that it does not significantly influence early cognitive or physical performance in patients with established RRMS. Further longitudinal studies are needed to determine the prognostic utility of OCBs in relation to disease progression and neurodegeneration.