Anti-citrullinated fibronectin peptide antibodies in early arthritis patient sera. A. Sera from anti-CCP2-negative (n = 23) and anti-CCP2-positive (n = 24) early arthritis patients were analyzed in the FN-Cit1035,1036 ELISA. B. Sera from anti-CCP2-positive early arthritis patients (n = 278) were analyzed in the FN-Cit1035,1036 ELISA. The broken line indicates the cut-off value (mean + 2*SD of data obtained with normal human control sera); OD450 = optical density at 450 nm.
van Beers et al. Arthritis Research & Therapy 2012 14:R35 doi:10.1186/ar3744