Rheumatoid factor isotypes in relation to antibodies against citrullinated peptides and carbamylated proteins before the onset of rheumatoid arthritis

• Main Authors: Brink, Mikael, Hansson, Monika, Mathsson-Alm, Linda, Priyantha Wijayatunga, Verheul, Marije, Trouw, Leendert, Holmdahl, Rikard, Rönnelid, Johan, Klareskog, Lars, Rantapää-Dahlqvist, Solbritt
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Figshare 2016
• Subjects: Medicine; Physiology; FOS Biological sciences; Biotechnology; Ecology; Immunology; FOS Clinical medicine; Developmental Biology; Hematology; 60506 Virology; Cardiology; Elia; Northern Sweden
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.3607499.v1; https://figshare.com/collections/Rheumatoid_factor_isotypes_in_relation_to_antibodies_against_citrullinated_peptides_and_carbamylated_proteins_before_the_onset_of_rheumatoid_arthritis/3607499/1

Abstract Background The presence of rheumatoid factor (RF), anti-carbamylated protein antibodies (anti-CarP) and antibodies against citrullinated protein and peptides (ACPA) precedes the onset of symptoms of rheumatoid arthritis (RA) by several years. Relationships between the development of these antibodies are not obvious. Methods Three isotypes [immunoglobulin A (IgA), IgG and IgM) of RF were analysed in 321 pre-symptomatic individuals who provided 598 samples collected a median of 6.2 (interquartile range 7.2) years before the onset of symptoms, and in 492 population control subjects. All samples were donated to the Biobank of Northern Sweden. RF isotypes were analysed using the EliA system (Phadia GmbH, Freiburg, Germany) with 96 % specificity according to receiver operating characteristic curves. Ten ACPA specificities were analysed using the ImmunoCAP ISAC system, and anti-CCP2 and anti-CarP antibodies were evaluated using enzyme-linked immunosorbent assays. Results The frequencies of RF isotypes in pre-symptomatic individuals were significantly increased compared with control subjects (p