Mean anticitrullinated peptide antibody count and anticyclic citrullinated peptide titer by years prior to rheumatoid arthritis diagnosis. Mean number of positive anticitrullinated peptide antibodies (ACPAs) and anticyclic citrullinated peptide (anti-CCP) titer by time between blood draw and rheumatoid arthritis (RA) diagnosis date in cases and index date in controls in the Nurses’ Health Study (NHS) and the Nurses’ Health Study II (NHSII). ELISA: enzyme-linked immunosorbent assay.
Arkema et al. Arthritis Research & Therapy 2013 15:R159 doi:10.1186/ar4342