Blockade of BAFF reduces autoantibodies and immune complexes. Mdr2−/− mice were administered anti-mouse BAFF (SANDY-2) mAb or sterile PBS as described above. (A) Serum samples collected from animals were serially diluted (1:50, 1:100, and 1:200), and ANA titers were detected using an immunofluorescence staining of human epithelioid cell line (HEp-2) as shown. (B) Serum ANA titers in PBS- and anti-BAFF-treated Mdr2−/− and WT animals are shown. (C) Serum samples collected from animals were processed for determination of total IgG by a standard ELISA. (D) Serum samples were serially diluted (1:30, 1:60, 1:120, 1:240, 1:480, and 1:960 etc.), and serum titers for immune complexes were detected using C1q ELISA. Statistical significance was determined by a two-tailed Mann-Whitney Test. **P<.001, ***P<.0001. Error bars reflect SEM.