Regulatory T-cell Changes in Patients with Steroid-Resistant Nephrotic Syndrome after Rituximab Therapy

The aim of this study was to investigate the effect of rituximab (RTX) treatment on serum immunoglobulin (Ig) A, G, M levels, and B and CD4+CD25+FoxP3+ [T regulatory (Treg)] cell numbers in children who received RTX therapy with steroid-resistant nephrotic syndrome (SRNS). Twenty-three SRNS children who received RTX and 20 healthy children in the control group were included. In this cross-sectional cohort study, 23 children with SRNS levels were determined before and one month after RTX treatment by serum IgA, IgG, IgM, and percentages of CD4+CD25+ FoxP3+ cells and B CD19+ cells by flow cytometry (FASCalibur). RTX was administered at a total of four doses of 375 mg/m2/week. Before RTX treatment, percentages of Treg and IgG values were significantly lower in the SRNS group compared to the control group, respectively (P = 0.001). B-cells were significantly lower one month after RTX treatment than before RTX treatment, respectively (P = 0.001). One month after RTX treatment percentages of Tregs, it was found to be significantly higher than before treatment level (P = 0.001). Seventy percent (11/23) remission was achieved with RTX treatment. RTX treatment not only depletes the number of B-cells in SRNS patients but also causes an increase in the number of percentages of Treg cells.