Long-term B-cell depletion in peripheral blood and bone marrow in rheumatoid arthritis patients treated with a fixed regimen of 6-monthly anti-CD20 monoclonal antibodies with a follow-up of 24 months. (A) Absolute numbers of CD3-CD19+ B cells measured in peripheral blood every 3 months presented as Tukey box-and-whisker plots. (B) Percentages of CD3-CD19+ B cells in bone marrow measured at baseline, 3 and 21 months presented as Tukey box-and-whisker plots. (C) Serum B lymphocyte-activating factor (BAFF) concentrations before every rituximab course presented as Tukey box-and-whisker plots. (D) Disease Activity Score in 28 joints (DAS28) of the 11 individual patients (grey lines) and overall median DAS28 scores (black line) measured every 3 months. A DAS28 score below 3.2 (dotted line) indicates low disease activity.