Salivary IgA antibodies to cyclic citrullinated peptides (CCP) in rheumatoid arthritis
2013 (English)In: Immunobiology, ISSN 0171-2985, E-ISSN 1878-3279, Vol. 218, no 2, 232-237 p.Article in journal (Refereed) Published
Circulating IgG anti-cyclic citrullinated peptide antibodies (CCP) are highly specific for rheumatoid arthritis (RA) and prognostic of poor outcome. Serum IgA anti-CCP occurs in a subset of IgG-positive cases and relates to still more aggressive disease. Mucosal IgA-class antibodies, however, are generally associated with anti-inflammatory actions and systemic tolerance induction. In the present study, unstimulated salivary samples from 63 patients with established RA and 20 healthy persons were analysed by enzyme-linked immunoassay for the presence of IgA anti-CCP antibodies. To ensure antigen specificity, IgA-reactivity with the corresponding uncitrullinated antigen, cyclic arginine peptide (CAP), was analysed and anti-CCP/anti-CAP ratios calculated. Retrospective data regarding disease activity and radiological outcome were achieved via medical records. Salivary IgA anti-CCP was found in 14/63 (22%) patients and one (5%) control (positive test = anti-CCP/anti-CAP ratio andgt; 1.5). Salivary IgA reactivity was dose-dependently inhibited by pre-incubation with soluble CCP to a degree strongly correlating with anti-CCP/anti-CAP ratio. In salivary IgA anti-CCP positive patients, joint erosions within 6 years of diagnosis was significantly lower (p = 0.043), and at the time for diagnosis there was a trend towards lower erythrocyte sedimentation rate (p = 0.071) and C-reactive protein (p = 0.085). Contrasting to circulating IgG and IgA anti-CCP, our results imply that salivary IgA antibodies may be associated with a less severe outcome of RA. Hypothetically, this relates to an anti-inflammatory and protective immunomodulating role of secretory IgA-class autoantibodies against citrullinated antigens presented at mucosal surfaces.
Place, publisher, year, edition, pages
Elsevier, 2013. Vol. 218, no 2, 232-237 p.
Citrullinated peptides, IgA, Rheumatoid arthritis, Saliva, Mucosal immunity
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-90205DOI: 10.1016/j.imbio.2012.04.011ISI: 000315312000013OAI: oai:DiVA.org:liu-90205DiVA: diva2:612354
Funding Agencies|Centre for Clinical Research in Dalarna||Swedish Research Council|2008-2832|Swedish Association Against Rheumatism||King Gustaf Vth 80-Year Foundation||County Council of Ostergotland Research Foundations||Medical Research County Council of South-East Sweden (FORSS)||2013-03-212013-03-212015-08-31