Background Anti-drug antibodies (ADAb) and autoantibodies can be determined in the patients with some rheumatic diseases during treatment of anti-TNF drugs.

Objectives Anti-TNF drugs used in rheumatic diseases may promote formation of autoantibodies. In this study, we aimed to investigate the relationship between the formation of autoantibodies, anti-drug antibodies (ADAb), serum levels for anti-TNF drugs and disease activity in patients with treated anti-TNFs.

Methods Our cross-sectional study included 183 patients with rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis treated with anti-TNF agents (infliximab, adalimumab and etanercept), as well as 97 patients as part of the control group. Disease activity and functional status were measured in all patients using BASDAI, BASFI, HAQ, DAS28 and ASDAS (CRP). In addition, serum levels of anti-TNF drugs, anti-drug antibodies (ADAb), ANA, ANCA and anti-ds DNA were determined.

Results Anti-IFX, anti-ADA and anti-ETA were positive in 33.8%, 26.3% and 0%, respectively, in all patient groups with ANA levels of 59.7%, 39.5% and 13%, respectively. ANCA was 16.1%, 14%, 7.4% and anti-ds DNA was 7.6%, 12.5%, 2.7% positive in IFX, ADA, and ETA-treated patients, respectively. The rate of the ANA positivity was %66.7 in the patients who had pozitive ADAb, it was found %31.1 in patients who had negative ADAb. This difference was statistically significant (p<0.001).

We found negative correlations among a number of the key parameters: a. between serum levels of anti-TNF and TNF; b. between anti-ADA and ADA; c. between serum levels of all anti-TNF drugs and anti-TNF antibodies. We detail the full extent of determined correlations in the body of our study.

Disease activity and functional status indexes were corelated with both autoantibodies and ADAb formation in each type of anti-TNF treated groups. However, statistically signifcant results were only found in rheumatoid arthritis patients who had taken ADA therapy.

Conclusions Our study indicates that the patients who produce autoantibodies are likely to be more prone to developing anti-TNF antibodies and measurement of these autoantibodies can be related with ADAb formation. However, anti-TNF antibody formation does not always impact the clinical effect.

References

1. Atzeni F, Talotta R, Salaffi F, Cassinotti A, Varisco V, Battellino M, Ardizzone S, Pace F, Sarzi-Puttini PImmunogenicity and autoimmunity during anti-TNF therapy. Autoimmun Rev. 2013 May;12(7):703-8.

2. Arends S, Lebbink HR, Spoorenberg A, Bungener LB, Roozendaal C, van der Veer E, Houtman PM, Griep EN, Limburg PC, Kallenberg CG, Wolbink GJ, Brouwer E. The formation of autoantibodies and antibodies to TNF-α blocking agents in relation to clinical response in patients with ankylosing spondylitis. Clin Exp Rheumatol. 2010 Sep-Oct;28(5):661-8.

Acknowledgements We thank Pfizer for giving financial support and all those who participated in the study performed as part of this project.

Disclosure of Interest S. Ataman Grant/research support: Investigator initiated Research Grant received from Pfizer, R. Soltanalizade Grant/research support: Investigator initiated Research Grant received from Pfizer, H. Tutkak: None declared, D. Öztuna: None declared, E. Ozdemirel: None declared, Z. Surmeli: None declared

DOI 10.1136/annrheumdis-2014-eular.1848