Baff human instant elisa kit

Serum BAFF concentrations were measured at the baseline and at 6 months of TNFi treatment using the BAFF Human Instant ELISA Kit (R&D Systems, Minneapolis, MN, USA) following the manufacturer’s instructions. Serum RF concentrations were measured by nephelometry using the BNII System and N Latex RF Kit (Siemens Healthcare Diagnostics Inc., Newark, DE, USA) according to the instruction manual. Serum ACPA was determined by ELISA as anti-CCP2 with the Immunoscan CCPlus kit (Svar, Malmö, Sweden).

Serum BAFF levels were measured using the BAFF Human Instant ELISA Kit (R&D Systems, MN, USA) following the manufacturer's instructions. Briefly, an ELISA with an anti-human BAFF monoclonal coating antibody adsorbed onto microwells was used. Standards and samples were pipetted into the wells and any BAFF present was bound by the immobilized antibody. After washing away any unbound substances, an enzyme-linked polyclonal antibody specific for human BAFF was added to the wells. Following a wash to remove any unbound antibody-enzyme reagent, a substrate solution was added to the wells and colour developed in proportion to the amount of BAFF bound in the initial step. The reaction was terminated by addition of acid and absorbance was measured at 450 nm. A standard curve was prepared from seven human BAFF standard dilutions and human BAFF sample concentration was determined.