TY - JOUR T1 - B-cell-activating factor receptor expression on naive and memory B cells: relationship with relapse in patients with rheumatoid arthritis following B-cell depletion therapy JF - Annals of the Rheumatic Diseases JO - Ann Rheum Dis SP - 2181 LP - 2188 DO - 10.1136/ard.2010.131326 VL - 69 IS - 12 AU - Inmaculada de la Torre AU - Rita A Moura AU - Maria J Leandro AU - Jonathan Edwards AU - Geraldine Cambridge Y1 - 2010/12/01 UR - http://ard.bmj.com/content/69/12/2181.abstract N2 - Objectives To examine the expression of B-cell-activating factor receptor (BAFF-R) on naive CD27− and memory CD27+ B cells in normal individuals and patients with rheumatoid arthritis (RA) undergoing B-cell depletion therapy with rituximab. Patients and Methods BAFF-R expression on B-cell subsets was determined in normal controls (NC; n=11), active patients with RA pre-rituximab (pre-RX; n=15), relapsing patients either concordant for B-cell repopulation (C-R, n=13) or discordant, with relapse more than 3 months after repopulation (D-R, n=11) and patients in remission over 3 months postrepopulation (discordant non-relapsing (D-NR), n=5). Serum BAFF was measured by ELISA and analysed using Mann–Whitney. Results There was no significant difference between NC, pre-RX and D-NR patients in %BAFF-R-positive B cells or mean fluorescence intensity (MFI) in naive and memory B cells. Relapsing patients had significantly lower MFI and %BAFF-R-positive cells in both naive and memory compartments from NC and pre-RX (C-R and D-R; p<0.01). BAFF levels in pre-RX patients were within the normal range and did not correlate with BAFF-R expression in any patient group. D-NR patients had relatively lower proportions of pre and postswitch CD27+ B cells than pre-RX patients (D-NR vs pre-RX; p<0.05 for both) and also lower numbers of postswitch B cells than D-R patients (D-NR vs D-R, p<0.05). Conclusion BAFF-R expression was significantly reduced on both naive and memory B cells in patients at relapse, regardless of the relationship with B-cell repopulation or serum BAFF levels. Re-establishment of active disease was also associated with an increase in class-switch recombination. Factors responsible for lower levels of BAFF-R may relate to altered thresholds for autoreactive B-cell generation at relapse in patients with RA. ER -