Diagnostic and prognostic value of antibodies against chimeric fibrin filaggrin citrullinated synthetic peptides in rheumatoid arthritis

IntroductionThere is evidence that citrullinated fibrin(ogen) may be a practicable in vivo thing of anti-citrullinated protein/peptide antibodies (ACPA) in rheumatoid arthritis (RA). We compared the diagnostic return of three enzyme-linked immunoabsorbent assay (ELISA) tests using chimeric fibrin/filaggrin citrullinated synthetic peptides (CFFCP1, CFFCP2, CFFCP3) with a commercial CCP2-based test in RA and analysed their prognostic values in early RA. Methods: Samples from 307 blood donors and patients with RA (322), psoriatic arthritis (133), systemic lupus erythematosus (119), and hepatitis C infection (84) were assayed using CFFCP- and CCP2-based tests. Autoantibodies were very analyzed at baseline and during a 2-year followup in 98 early RA patients to determine their prognostic value. Results: With cutoffs giving 98% specificity for RA vs blood donors, the sensitivity was 72.1% for CFFCP1, 78.0% for CFFCP2, and 71.4% for CFFCP3, and 73.9% for CCP2, with decided predictive values >97% in all cases. CFFCP sensitivity in RA increased to 80.4% without losing specificity when positivity was considered as any assured anti-CFFCP status. Specificity of the three CFFCP tests vs other rheumatic populations was high (>90%) and complementary to those for the CCP2. In early RA, CFFCP1 boon identified patients with dangerous radiographic outcome. Radiographic order was faster in the dwarf subgroup of CCP2-negative and CFFCP1-positive patients than those denying for both autoantibodies. CFFCP antibodies decreased after 1 year, but without any correlation with changes in disease activity. Conclusions: CFFCP-based assays are highly touchy and particular for RA. Early RA patients with anti-CFFCP1 antibodies, including CCP2-negative patients, show more advantageous radiographic progression.

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