Study of Peptidyl Arginine Deiminases 4 (PAD 4) Antibodies in Rheumatoid Arthritis Patients

Abstract

Rheumatoid arthritis (RA) is one of the most commonly occurring form of inflammatory polyarthritis. If untreated,20%–30% of RA patients become debilitated within the first three years following initial diagnosis. The clinical examinationoften fail to identify patients with early RA partly due to heterogeneity of disease presentation and course. To meet the needfor improved diagnostic and prognostic tests, various serum biomarkers are being assessed, including a wide range ofautoantibodies. Autoantibodies against peptidyl arginine deiminase type 4 (PAD-4) have recently been described as a specificbiomarker in subjects with clinically apparent RA. In this study, we tested the presence of anti-PAD4 antibodies in 40Egyptian subjects with RA and their first degree relatives in order to determine whether these autoantibodies play a role inearly disease evolution. In addition, we aimed to describe the Anti-PAD4 relation to anti-CCP autoantibodies, and potentialassociations with a more severe RA phenotype. The study was carried out on total of 100 subjects divided into; 40 RApatients, 40 of first degree relatives (sister or brother) of RA patients and 20 matched controls. Results: The resultsindicated that the serum level of Anti-PAD 4 is increased in Egyptian RA patients and their relatives and has a positiveassociation with disease activity. Also its level together with Anti-CCP provides a good diagnostic tool of RA. Conclusion:The serum level of Anti-PAD4 may provide diagnostic information of RA and may be considered as an early marker of thedisease among the first degree relatives of RA patients. [Egypt J Rheumatology & Clinical Immunology, 2016; 4(1): 59-66]