Long term effects of Rituximab on the adaptive immune system in MS patients

Abstract

Rituximab (RTX) is a monoclonal antibody that binds to the CD20 surface antigen on cells and is widely used in the treatment of autoimmune diseases, including multiple sclerosis (MS). The drug induces targeted depletion of B cells and has demonstrated good clinical efficacy; however, despite its widespread use, the long-term effects of RTX on the immune system are not fully understood. This study aimed to investigate the long-term impact of RTX treatment on T and B cells and their subpopulations in patients with MS, and to compare these findings with those of healthy control groups. Blood samples were collected from 80 MS patients undergoing RTX treatment and from 61 healthy individuals aged 18-70 and were analyzed by flow cytometry. Patient results were compared both with results from the same assays obtained earlier in the disease course and with results from healthy individuals, to assess changes in the distribution and reconstitution of T and B cell populations following treatment. The results demonstrated significant alterations in several T cell subpopulations in patients with MS compared with healthy individuals. In addition, the study provided insight into patterns of B cell subpopulations reconstitution following RTX treatment. These findings indicate that RTX induces long-lasting alterations in immune homeostasis, not only through direct effects on B cells but also via indirect effects on T cells. The results may have clinical relevance for the long-term management of patients with MS receiving RTX therapy. Further studies are needed to understand better the clinical consequences of these immunological changes and their potential associations with treatment response and adverse effects.