Comparison of the analytical and clinical performances of four anti-cyclic citrullinated peptide antibody assays for diagnosing rheumatoid arthritis

Abstract

Introduction/Objectives Anti-cyclic citrullinated peptide antibody (anti-CCP) is one of the most important serologic markers for diagnosing rheumatoid arthritis (RA). This study aimed to compare the analytical and clinical performances of the second- and third-generation anti-CCP assays. Methods Four automated anti-CCP assays were evaluated: Chorus anti-CCP (Diesse Diagnostica), Elecsys anti-CCP (Roche Diagnostics), Atellica (R) IM anti-CCP IgG (Siemens Healthineers), and Quanta Flash (R) CCP3 (Inova Diagnostics Inc.). Analytical performance included the precision, linearity, correlation, and concordance rate. For evaluating the clinical performance, 240 patient samples (120 positive and 120 negative samples, determined by the Chorus anti-CCP assay) were used, including those with a diagnosis of RA (n= 132) and non-RA (n= 108). Using receiver operating characteristic (ROC) curve analysis, the sensitivity and specificity were evaluated. Results All four assays that were evaluated showed good precision and linearity, and their correlation and concordance rates were in acceptable ranges. The area under the curve (AUC) values ranged from 0.888 to 0.914, showing a good diagnostic performance. The sensitivity and specificity of all assays were similar (88.0-97.2%). Conclusions All four anti-CCP assays showed good analytical and diagnostic performances for diagnosing RA. After adjusting the cutoff values, these assays are expected to show enhanced sensitivity and specificity.