Anti-cyclic citrullinated peptide antibody is a good indicator for the diagnosis of rheumatoid arthritis

ABSTRACT

Anti-cyclic citrullinated peptide [CCP] antibody has recently been used in the classification of rheumatoid arthritis [RA]. This antibody is more specific than rheumatoid factor [RF] for the diagnosis of RA. The study objectives were to determine the sensitivity, specificity, positive and negative predictive values of anti-CCP in RA diagnosis. Eighty RA patients and 80 non-RA individuals were included in the study. Blood was collected from both arms of study subjects and tested for anti-CCP and RF antibodies. Relevant clinical information and laboratory profiles of the RA patients were evaluated using patients' medical records and Integrated Laboratory Management System [ILMS], respectively. The sensitivity and specificity of anti-CCP were 35% and 100% respectively. The positive and negative predictive values were 100% and 61%, respectively. Positive anti-CCP was found significantly associated with multiple joint pain [p < 0.001] and hand's joints pain [p=0.01], symmetrical joints involvement [p=0.015] and high CRP value [p < 0.001]. Anti-CCP was also found to have positive association with RF [p < 0.001]. Anti-CCP is highly specific for the diagnosis of RA. High positive predictive value should be taken into consideration for effective treatment