Brief Report: Genetic Variation of the α1‐Antitrypsin Gene Is Associated With Increased Autoantibody Production in Rheumatoid Arthritis

• Published in: Arthritis & rheumatology (Hoboken, N.J.) N.J.), 2017-08, Vol.69 (8), p.1576-1579
• Main Authors: McCarthy, Cormac, Orr, Carl, Fee, Laura T., Carroll, Tomás P., Dunlea, Danielle M., Hunt, David J. L., Dunne, Eimear, O'Connell, Paul, McCarthy, Geraldine, Kenny, Dermot, Fearon, Ursula, Veale, Douglas J., Reeves, Emer P., McElvaney, Noel G.
• Format: Article
• Language: English
• ISSN: 2326-5191; 2326-5205
• DOI: 10.1002/art.40127

Objective To examine the prevalence of α1‐antitrypsin deficiency (AATD) in rheumatoid arthritis (RA), and to determine whether AATD is associated with higher levels of rheumatoid factor (RF), antinuclear antibodies (ANAs), and anti–citrullinated peptide autoantibodies (ACPAs). Methods RF, ANAs, and ACPAs were measured by standard immunoturbidimetry, immunofluorescence assay, and enzyme‐linked immunosorbent assay, respectively. Characterization of AAT phenotypes was performed by isoelectric focusing and immunofixation. The chi‐square test with Yates' correction and the Mann‐Whitney U test were used to assess the prevalence of alleles associated with AATD in RA and to compare mean antibody titers, respectively. Results Of 246 patients with RA, 24 who were heterozygous for AATD were identified, with no statistically significant difference in the prevalence of AATD between RA patients and the general population (P = 0.39). A positive association between heterozygosity for AATD and the production of ACPAs was observed (P