BackgroundWith ocrelizumab another drug is available for the treatment of multiple sclerosis (MS). Little is known on the long-term use of ocrelizumab on immune cell subsets, and no surrogate markers are available. Rituximab (RTX) has been in off-label use for the treatment of MS, neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorder (NMOSD) for > 10 years.ObjectiveWe evaluated the long-term depletion and repopulation rate of peripheral CD19+ B-cells as a potential surrogate for the clinical outcome, and whether it may serve for dosage and time-to-infusion decision making.MethodsWe evaluated the CD19+ and CD4+/8+ T-cell counts in n = 153 patients treated with RTX (132 MS, 21 NMO/NMOSD). The dosages ranged from 250 to 2000 mg RTX. Depletion/repopulation rates of CD19+ B-cells as well as long-term total lymphocyte cell counts, were assessed and corroborated with EDSS, ARR (annualized relapse rate), MRI, and time to reinfusion.ResultsCD19+ B-cells’ repopulation rate significantly varied depending on the dosage applied leading to individualized application intervals (mean 9.73 ± 0.528 months). Low/absent CD19+ B-cell counts were associated with reduced ARR, EDSS, and GD+-MRI-lesions. Long-term B-cell-depleting therapy led to a transiently skewed CD4+/8+ T-cell ratio due to reduced CD4+ T-cells and absolute lymphocyte counts, which recovered after the second cycle.ConclusionOur data suggest that CD19+ B-cell repopulation latency may serve as surrogate marker for individualized treatment strategies in MS and NMO/NMOSD, which proved clinically equally effective in our cohort as evaluated by previous studies.

Background and purpose For the diagnosis of relapsing–remitting multiple sclerosis (RRMS), the revised 2017 McDonald criteria include cerebrospinal fluid specific oligoclonal bands as a new criterion for dissemination in time. Amongst other things, one expectation of the new criteria is to marginalize the diagnosis of clinically isolated syndrome (CIS), thus allowing for a faster and at the same time still reliable diagnosis of RRMS. Methods In this study, data from an unselected patient cohort with a typical CIS and dissemination in space at a large German Multiple Sclerosis Center from 2013 to 2016 were re‐analysed to compare differences in diagnosing RRMS with the 2017 versus 2010 McDonald criteria in everyday practice. Results Out of a cohort of 290 patients presenting with a typical first demyelinating event, 52% (152 patients) with the diagnosis of RRMS and 48% (138 patients) with the diagnosis of CIS according to the 2010 McDonald criteria were identified. The application of the 2017 McDonald criteria in the same patients increased the number of definite RRMS to 94% (273), thus leaving only 6% of patients with the diagnosis of CIS. The reason for this shift was the presence of cerebrospinal fluid specific oligoclonal bands which was found in 92.7% of the total population and in all patients with 2017 McDonald RRMS. Over a mean follow‐up of 1.5 years, 50% of patients formerly diagnosed with CIS who are now RRMS also fulfilled the 2010 McDonald criteria. Conclusions Our data support the use of the 2017 McDonald criteria for a more sensitive, but not that specific, diagnosis of RRMS in everyday practice.