Clinical Response and Pattern of B cell Suppression with Single Low Dose Rituximab in Nephrology

Background: There is no consensus regarding dose and frequency of rituximab in Nephrology with extrapolation of dose used in treating lymphoproliferative disorders. There are no guidelines on targeting initial and subsequent doses based on CD19+ B cells. Methods: 100 mg rituximab was given initially in 42 adults with steroid dependent (SDNS) and frequently relapsing nephrotic syndrome (FRNS), idiopathic membranous nephropathy (MN) and high immunologic risk kidney transplantation. Absolute and percentage CD19 B cells and clinical status were assessed at baseline, days 30, 90, 180 and 1 year. Subsequent doses of rituximab were based on CD19 B cell reconstitution and clinical response. Results: CD19 B cell percentage decreased from 16.3±7.6 to 0.3±0.3 (P=