Background Autoimmunity is still present in rheumatoid arthritis patients in sustained disease remission. In the absence of inflammation the pattern of autoimmunity against post-translationally modified proteins could potentially impact the course of disease of rheumatoid arthritis patients, espepcially their risk to experience relapse of disease when disease modifying anti-rheumatic drugs (DMARDs) are tapered or stopped
Objectives To perform a detailed analysis of the autoantibody response against post-translationally modified proteins in rheumatoid arthritis (RA) patients in sustained remission and to test whether its composition influences the risk for disease relapse when tapering DMARD therapy.
Methods Immune responses against 10 citrullinated, homocitrullinated/carbamylated and acetylated peptides, as well as unmodified vimentin (control) and cyclic citrullinated peptide 2 (CCP2) were tested in baseline serum samples from 94 patients of the RETRO study. Patients were classified according to the number of autoantibody reactivities (0–1/10, 2–5/10 and >5/10) or specificity groups (citrullination, carbamylation and acetylation; 0 to 3) and tested for their risk to develop relapses after DMARD tapering. Demographic and disease-specific parameters were included in multivariate logistic regression analysis for defining the role of autoantibodies in predicting relapse.
Results Patient varied in their anti-modified protein antibody response with the extremes from recognition of no (0/10) to all antigens (10/10). Antibodies against citrullinated vimentin (51%), acetylated ornithine (46%) and acetylated lysine (37%) were the most frequently observed sub-specificities. Relapse risk significantly (p=0.011) increased from 18% (0–1/10 reactivities) to 34% (2–5/10) and 55% (>5/10). With respect to specificity groups (0 to 3), relapse risk significantly (p=0.021) increased from 18% (no reactivity) to 28%, 36% and finally to 52% with one, two or three antibody specificity groups, respectively.
Conclusions The data suggest that the pattern of anti-modified protein antibody response determines the risk of disease relapse in RA patients tapering DMARD therapy.
Disclosure of Interest C. Figueiredo: None declared, H. Bang Employee of: Organtec Diagnostica, J. Cobra: None declared, M. Englbrecht: None declared, A. Hueber: None declared, J. Haschka: None declared, B. Manger: None declared, A. Kleyer: None declared, M. Reiser: None declared, S. Finzel: None declared, H.-P. Tony: None declared, S. Kleinert: None declared, J. Wendler: None declared, F. Schuch: None declared, M. Ronneberger: None declared, M. Feuchtenberger: None declared, M. Fleck: None declared, K. Manger: None declared, W. Ochs: None declared, M. Schmitt-Haendle: None declared, H.-M. Lorenz: None declared, H. Nuesslein: None declared, R. Alten: None declared, J. Henes: None declared, K. Krueger: None declared, J. Rech: None declared, G. Schett: None declared