Predicting the efficacy of anti-B-cell therapy in patients with multiple sclerosis

Introduction. Prognostic markers can be used to evaluate a response to anti-B-cell therapy in patients with multiple sclerosis (MS). Aim. The study aimed to evaluate the characteristics of peripheral blood (PB) lymphocytes and monocytes in patients with aggressive MS during the first 6 months of anti-B-cell therapy. Materials and methods. Twenty-nine patients with aggressive MS were treated with a humanized anti-CD20 monoclonal antibody (anti-CD20 mAb). A panel of MAbs to differentiation antigens of PB lymphocytes was used to assess the parameters of cellular immunity using six-color flow cytometry. The reference values were based on the similar parameters of ten apparently healthy volunteers. Results. At month 6, the initial course of anti-CD20 therapy resulted in low recovery of the PB sub-populations of B cells in 85% of patients. Significant decreases were reported in the absolute counts of T cells, T helper cells, Natural Killer (NK) cells, and relative percentage of natural killer T (NKT) cells. The study also showed low levels of activated T cells and significantly decreased percentage of memory B cells (CD27+) and B cells expressing costimulatory and activation molecules (CD40+, CD38+, and CD25+, respectively). A significant decrease in the mean fluorescence intensity of HLA-DR was observed on PB monocytes compared to normal values and those in patients receiving other disease-modifying therapies. Anti-CD20 therapy may indirectly suppress their antigen-presenting ability. Other immunological criteria for prediction of MS progression and magnetic resonance imaging activity during the first year of anti-B-cell therapy may include the following changes from baseline: increased percentages of CD3+, CD3+HLA-DR+, CD25+CD3+, and CD95+CD3+cells; significant expression of the CD40 molecule and B-cell activation markers CD38 and CD25, and decreased expression of CD95. Conclusion. Further research on changes in cellular immunity parameters during anti-CD20 therapy could allow for early adjustment of MS treatment to stabilize the patient’s condition.