B-101 Performance assessment of a newly developed chemiluminescence assay for anti-CCP determination

Abstract Background Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by painful, swollen joints with limited movement and progressive joint destruction. Approximately 70% of RA patients develop autoantibodies (AAbs) against citrullinated peptides (ACPA) which are detected using primarily cyclic citrullinated peptides (CCP). This study aimed to assess the performance of the novel EUROIMMUN Anti-CCP chemiluminescence assay (ChLIA) based on clinical data and in comparison with an anti-CCP ELISA. Methods Sera from 185 patients with clinically diagnosed RA and from 281 control patients with various autoimmune and infectious diseases were analyzed for the presence of anti-CCP AAbs. The results obtained using the EUROIMMUN Anti-CCP ChLIA (IgG), processed on the IDS-i10 (Immunodiagnostic Systems), and the EUROIMMUN Anti-CCP ELISA (IgG) were compared. Results The Anti-CCP ChLIA yielded a sensitivity of 64.9% (120/185) with a specificity of 97.9% (275/281), while the anti-CCP ELISA yielded a sensitivity of 61.6% (114/185) with a specificity of 96.1% (270/281). Assay comparison resulted in a positive, negative, and overall agreement of 93.6%, 97.4% and 96.4%, respectively. Conclusion High agreement rates were observed between the anti-CCP ChLIA and the anti-CCP ELISA, with increased sensitivity and slightly higher specificity for the anti-CCP ChLIA. Thus, the Anti-CCP ChLIA is an excellent tool to support the diagnosis of RA. Results should always be interpreted together with those of further laboratory diagnostic procedures and based on the clinical picture.