Effects of natalizumab on oligoclonal bands in the cerebrospinal fluid of patients with multiple sclerosis: a systematic review and meta-analysis

IntroductionOligoclonal bands (OCBs) in cerebrospinal fluid (CSF) are utilized for diagnosing multiple sclerosis (MS), as they are found in 95% of patients. Additionally, OCBs are linked to disease prognosis. The primary contributors to OCB production are long-lived plasma cells. This study aims to quantify the impact of natalizumab (NTZ) on OCB levels in the CSF of MS patients.MethodsA systematic search on MEDLINE, SCOPUS and Web of Science for English-written and peer-reviewed longitudinal studies on adults was performed. Methodological quality was assessed with the Newcastle-Ottawa Scale. Proportional meta-analysis was performed in R using a generalized linear mixed-effects model. We investigated heterogeneity with influence diagnostics, sensitivity analysis and meta-regression.ResultsEight eligible studies of adequate quality with a total sample of 326 relapsing-remitting MS patients were included. A summary rate of 14.07% [95% CI, 4.48%-36.36%] for complete loss of OCBs and 42.02% [95% CI, 15.23%-74.51%] for reduction in OCB number or intensity was observed, both with considerable heterogeneity. Pooled estimates dropped (11% [95% CI, 0.04%-0.29%] and 34% [95% CI, 0.11%-0.68%] respectively) after the identification of an influential study. Multivariable meta-regression identified IgG index as a factor contributing to heterogeneity (adj. p = 0.0279), regarding reduction of OCB number or intensity.DiscussionIn conclusion, our systematic review and meta-analysis showed that NTZ can lead to reduction of intrathecal OCBs in MS patients, indicating a possible effect of NTZ on memory plasma cells, which are the main source of OCBs in MS.