A Study of Correlation of Disease Severity with Antibody Titers in Rheumatoid Arthritis

Introduction: Rheumatoid Arthritis (RA) is one of the most frequent autoimmune diseases in the world which affects about 1% of people. Anti-Cyclic Citrullinated Peptides (Anti-CCP) is shown to be more specific than rheumatoid factor in the diagnosis of RA. This test becomes positive in early stage of disease and it has a high predictive value. Aim: To correlate the relationship between anti-CCP antibody and rheumatoid factor titers and disease activity scores. Materials and Methods: A cross-sectional study was performed in 50 patients with RA for evaluating the relation between anti-CCP antibody titer and Disease Activity Score 28 (DAS28), Simplified Disease Activity Index (SDAI) and Clinical Disease Activity Index (CDAI). A detailed examination of each patient including their demographic characteristics, duration of disease, number of tender and swollen joints, ESR and C-reactive protein, patient's and physician's global assessment by VAS (0-10) and titers of rheumatoid factor and anti-CCP antibody. Patients who fulfilled the ACR-EULAR 2010 criteria were included. The statistical analysis was done using Pearson's correlation coefficient. A p-value of less than 0.05 was considered significant. Results: Of the 50 patients which were included (mean age, 44.82 range, 18-70), 38 were females and 12 were males. Mean ESR was 54 +/- 27 mm/hr and Mean CRP was 17.277 +/- 23.41 mg/dL. Mean DAS 28 was 5.955 +/- 0.962; mean SDAI was 46.9 +/- 27.1 and CDAI 28.9 +/- 10.8. There was positive correlation (p<0.001) between DAS28 and SDAI (r=0.550) and CDAI (r=0.808). Anti-CCP level was associated with SDAI (r=0.317) and CDAI (r=0.282) (p<0.05). Conclusion: There was significant correlation in the titers of anti-CCP and disease activity indices-SDAI and CDAI. Patients with higher levels of anti-CCP antibody had greater activity.