Transcriptomic profiling after B-cell depletion reveals central and peripheral immune cell changes in multiple sclerosis

We investigated the immunological effects of B cell depletion therapy using ocrelizumab in treatment-naive relapsing-remitting multiple sclerosis (RRMS) patients. Our primary aim was to delineate transcriptomic alterations in immune cell populations in peripheral blood before and after therapy, using single-cell RNA sequencing (scRNAseq). This study included 18 newly diagnosed, treatment-naive RRMS patients who provided matched pre- and 6-month post-treatment peripheral blood mononuclear cells (PBMCs). A secondary cohort of five patients also contributed paired cerebrospinal fluid (CSF) samples. All RRMS patients were treated with ocrelizumab, except one patient in the CSF cohort who received rituximab.