ABSTRACT
Background: Rheumatoid arthritis (RA) is characterized by synovial joint inflammation, which often leads to progressive joint destruction and disability. Several other auto-antibodies specific to RA have been found .Among them, antibodies against cyclic citrullinated peptides (CCP) are useful for diagnosing RA. Antibodies to mutated citrullinated vimentin (MCV) were described recently in RA. The aim of this study was to determine the diagnostic values of ACCP compared to anti-MCV and Rheumatoid Factor in rheumatoid arthritis patients. Methods: This study included 92 patients with Rheumatoid arthritis (RA) and 35 matching healthy controls. Blood samples were obtained from patients and controls for Erythrocyte Sedimentation Rate (ESR), C Reactive Protein (CRP), Rheumatoid factor (RF). Anti-CCP2 and anti-MCV were determined using ELISA technique. Results: RA group was significantly higher than control group as regard ESR, CRP, RF, Anti-CCP, and Anti- MCV. Conclusion: It was concluded, compared to ACCP, anti-MCV has approximately the same accuracy for the diagnosis of rheumatoid arthritis but higher than Rheumatoid Factor. Level of Evidence: Level II, prospective study, as per guidelines for authors.
ABSTRACT
BACKGROUND: Rheumatoid arthritis (RA) is the most common autoimmune rheumatic disease, but sensitive and specific test for its diagnosis is lack. This study evaluated the analytical performance and diagnostic role of a new automated ELISA anti-cyclic citrullinated peptide (anti-CCP) antibody test. METHODS: Anti-CCP antibody test was done with the enzyme-linked immunosorbent assay (ELISA) in serum samples from 49 RA patients and 104 non-RA patients, and 51 healthy subjects. Serum pools were used to determine its precision and linearity. The optimal cut-off values were determined by the receiver-operator characteristics (ROC) curve. The rheumatoid factor (RF) by turbidimetry was also assayed in every samle and the results were compared to anti-CCP for sensitivity and specificity. RESULTS: The total imprecision (CV%) was 4.8%, 7.6% for serum pools with low (mean concentration: 2.7 U/mL) and high (mean concentration :82.2 U/mL) concentration, respectively. Linearity data were acceptable (R2=0.9907). At each optimal cut-off value, the sensitivity of anti-CCP was higher than that of RF (81.6 % vs 69.4%), but statistical significance was not defined. Specificity of anti-CCP was higher than that of RF (95.5% vs 75.5%, p<0.001). A combination of anti-CCP and RF increased sensitivity and specificity to 87.7%, 98.0%, respectively. Nine of 15 (60.0%) sera from RF negative RA patients were positive for anti-CCP. CONCLUSIONS: Anti-CCP ELISA antibody test, we examined on a fully automated enzyme immunoassay, is easy to assay in routine laboratory, and showed good analytical performance. And anti-CCP antibody test also showed higher diagnostic specificity than RF. So, anti-CCP antibody may be useful serologic marker for diagnosis and monitoring of RA, if performed concomitantly with RF assay.