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AB0279 Study of Peptidyl Arginine Deiminases 4 (PAD 4) Antibodies in Rheumatoid Arthritis (RA) Patients
  1. N. Mohannad1,
  2. D.A. Hallous2,
  3. M.A.E.N. Kamel3,
  4. E.S.H. Radwan4
  1. 1Alexandria University hospitals, Internal Medicine Department, Rheumatology Unit. Faculty of medicine
  2. 2Internal Medicine, Rheumatology Unit, Faculty Of Medicine
  3. 3Biochemistry Department, Medical Research Institute, Alexandria
  4. 4Internal Medicine Department, Damhour Teaching Hospital, Behera, Egypt


Background A “window of opportunity” exists in early RA. Autoantibodies against citrullinated proteins catalyzed by PADs are often detected in patients with RA. They are produced early & are more specific than rheumatoid factor (RF).Anti-PAD 4 antibodies are specific markers of RA, independently associated with more severe disease. Autoantibodies to PAD-4 are present during the preclinical phase of RA in a subset of patients (pts).

Objectives to study the presence of anti PAD-4 in early RA pts (<2 years) & first degree relatives and its relation to disease activity & extra-articular involvement

Methods BMI,CBC,kidney functions, ESR, CRP, RF, Anti-CCP, Anti-PAD4 were assessed in 40 RA pts, 20 first degree relatives & 20 matched controls. DAS 28 calculated in RA pts, pts with history of renal, cardiac or liver dysfunction were excluded

Results It was observed that: highly significant increase in anti-PAD4 in RA group (gp)than controls, & in female relatives than control females, significant increase anti-CCP in RA pts & in relatives gp than the control gp. The sensitivity of anti-CCP alone was 87.5%, anti-PAD4 alone 60%, combining the two markers the sensitivity rose to 97.5%. The specificity of anti-CCP was 95%, of anti-PAD4 was 90%, on combining the two it reached 100% in controls. No significant difference between positive and negative anti-PAD4 RA pts regarding DAS28. RF and anti-CCP show a significant increase in positive anti-PAD4 pts than the negative ones. ESR & CRP show no significant difference in both positive and negative anti-PAD4 pts. The number of tender joints (TJC) and swollen joints, morning stiffness was higher in anti-PAD 4 pts but not to the level of significance, disease duration show no significant difference between the positive and negative anti-PAD4 pts. A positive significant correlation between: anti-PAD4 and DAS 28 score (r= +0.43, P=0.006), between anti-PAD4 and anti-CCP (r=0.819, p=0.0001). between anti-PAD4 and RF (r=0.6, p=0.0001), and between Anti-PAD4 and TJC (r=0.50, p<0.001) in RA pts was observed. As most of ' pts had early RA no significant extra-articular manifestations

Conclusions Significant increase in anti-PAD4 in RA & their relatives -female ones- than controls. Sensitivity & specificity of anti-CCP increased in the presence of anti-PAD4. Anti-PAD4 was correlated with RF, anti-CCP & disease activity reflected by DAS 28 & TJC


  1. Roth EB, et al. Antibodies against transglutaminases, peptidylargininedeiminase and citrulline in RA – new pathways to epitope spreading. Clin Exp Rheumatol 2006; 24:12-8

Disclosure of Interest None declared

DOI 10.1136/annrheumdis-2014-eular.1078

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