Diagnostic role of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis and its relation to disease activity

ABSTRACT

To determine diagnostic value of anti-cyclic citrullinated peptide antibodies [anti-CCP] in rheumatoid arthritis [RA] patients, and its association with disease activity. Thirty RA female patients were included in this study. All patients were subjected to full history taking, thorough clinical examination, laboratory investigations, assessment of disease activity using Disease Activity Score 28 [DAS28] and anti-CCP assay. Ten age and sex-matched healthy subjects were included as a control group. Twenty one out of the 30 RA patients were anti-CCP positive while 9 were anti-CCP negative. All the 10 controls were anti-CCP negative. The sensitivity of the anti-CCP test for RA was 70% and the specificity was 100%. Twenty three RA patients were rheumatoid factor [RF] positive while 7 were RF negative. One out of the 10 healthy controls was RF positive. The sensitivity of the RF was 76.67% and the specificity was 90%. Nineteen out of the 21 anti-CCP positive patients' were RE positive while 4 out of the 9 anti-CCP negative patients were RE positive. The presence of either anti-CCP or RF increased testing sensitivity to 83.33%. There were statistically nonsignificant differences between the anti-CCP positive and negative patients regarding age, disease duration and DAS28. On the other baud, there were statistically significant differences between them regarding the frequency of RF, CRP and ESR. The anti-CCP antibodies had comparable sensitivity and higher specificity than the RF. The presence of either anti-CCP or RF increased testing sensitivity. It is suggested that anti-CCP antibodies assay has a useful role in the diagnosis of RA and might have an association with the disease activity