Immunoglobulin Levels May Aid in the Prediction of Treatment Response in Anti-CD20 Treatment of Multiple Sclerosis

Background: Anti-CD20 therapies are an emerging treatment strategy in multiple sclerosis (MS). Objective: Retrospective analysis of efficacy and safety in an MS cohort treated with rituximab (RTX) with identification of potential treatment response predictors. Methods: This retrospective study describes a monocentric cohort of 30 MS patients treated with RTX in a routine clinical setting. Patient characteristics, disease course, clinical and magnetic resonance imaging (MRI) treatment response markers, and laboratory assessments were analyzed. Logistic regression analysis corrected for demographic characteristics was used to identify treatment response predictors. Results: The RTX-treated cohort (mean age at RTX initiation 48 years (SD 14)) comprised patients with relapsing-remitting MS (n = 9), primary progressive MS (n = 11), and secondary progressive MS (n = 10). Two-thirds of patients had at least one MS medication prior to RTX; 27.6% of patients improved on the Expanded Disability Status Scale during RTX, whereas 72.4% of patients were stable or worsened. Based on this classification, we identified the presence of gadolinium enhancement in MRI before RTX as a predictor of response (odds ratio (OR) 12.2, confidence interval (CI) 1.02–144.55). After receiver operating characteristic curve definition of immunoglobulin (Ig) class cutoffs and creation of a sum score, the latter also predicted RTX response (OR 5.15, CI 1.21–21.88). Infectious complications were seen in three patients under RTX treatment. Conclusion: With the limitation of the retrospective approach and small sample size, this study confirms gadolinium enhancement before treatment initiation as a predictor of anti-CD20 response in MS. Lower Ig levels were associated with RTX response; however, these will have to be further investigated for a potential role for infectious complications.