To explore the diagnostic significance of anti-cyclic citrullinated peptide (CCP) antibody (anti-CCP), antikeratin antibody (AKA) and rheumatoid factor (RF) for predicting articular erosions in patients with rheumatoid arthritis (RA).
One hundered and fifty eight RA patients were devided into 2 groups [limited radiographic damage group (Group 1) and severe radiographic damage group (Group 2)] based on the Larsen's score system. Enzyme linked immunosorbent assay, indirect immunofluorescence and rate naphelometry were used to measure anti-CCP, AKA and RF, respectively.
The sensitivity and specificity of Anti-CCP, AKA and RF for detecting RA were 49% and 94%, 50% and 93%, and 79% and 67%, respectively. The specificity increased when any two markers were combined. The patients with severe radiographic damage had higher positive rates of these three antibodies than the patients with limited radiographic damage. Anti-CCP had the highest OR (6.71) for predicting articular erosions in RA patients. The logistic regression analysis showed a strong correlation between anti-CCP, AKA, CRP or cutaneous nodules and the severity of articular erosions. Anti-CCP had the strongest correlation with the severe radiographic damages.
Anti-CCP has advantages over the other two antibodies in diagnosing RA. However, the diagnostic accuracy can be improved when anti-CCP is combined with AKA or RF. Anti-CCP and AKA have strong correlations with severe articular erosions, which will be helpful for predicting the outcomes of RA.