The diagnostic and monitoring value of serum anti-mutated citrullinated vimentin antibodies (anti-MCV) in juvenile rheumatoid arthritis

Background: JRA is currently diagnosed using the American College of Rheumatology (ACR) 1987 revised criteria that are primarily based on clinical parameters. The criteria may be insufficient for the diagnosis of early RA as they are based upon measurements of disease classification predominately featuring manifestations typical of later-stage disease. Measurement of serum anti-mutated citrullinated vimentin antibodies (MCV) has been shown to be a better marker for early adult RA, and it correlates well with the disease activity score (DAS). Objectives: The aim of this work is to evaluate the role of anti-mutated citrullinated vimentin antibodies (anti-MCV) in the diagnosis, and in monitoring disease activity in juvenile rheumatoid arthritis. Methods: The study included 40 children with JRA fulfilling the American College of Rheumatology criteria for diagnosis of JRA: 4 children with oligoarticular JRA, 12 with polyarticular JRA and 24 children with systemic onset JRA. Fifty healthy children, matching the patients in age and sex served as a control group. The studied children with JRA were subjected to laboratory tests including CBC, ESR, CRP, ANA and rheumatoid factor (RF). Serum samples from both patients and controls were assayed for anti-MCV levels using an ELISA technique. Results: The study showed high mean serum anti-MCV antibodies level in JRA patients when compared to controls (P= 0.00). In addition, there were no significant correlations between anti-MCV antibody levels and parameters of disease activity, namely, number of swollen joints, number of tender joints, ESR and CRP. The receiver operating characteristic (ROC) curve was drawn and it showed that the area under the curve (AUC) was (0.896). At a cutoff level >= 17 u/mL, anti-MCV antibodies had diagnostic specificity of 88%, diagnostic sensitivity of 87.5%, negative and positive predictive values of 89.8% and 85.4%, respectively and diagnostic efficacy of 87.8%. We also reported 3/40 of JRA patients to be positive for RF and 2/40 of JRA patients to be positive for ANA. Conclusion: Measurement of serum anti MCV antibody level holds promise as a diagnostic tool in JRA. However, they failed to show a significant efficacy in determining disease activity.