Association between anti-collagen type II autoantibodies and the acute rheumatoid arthritis phenotype in a cohort of rheumatoid arthritis patients

Background: This study aims to evaluate serum concentrations of anti-collagen type II (anti-CII) antibodies in Iraqi patients with a severe rheumatoid arthritis (RA) phenotype and investigate the relationship between higher concentrations of anti-CII antibodies and higher levels of inflammation. Methods: This study was conducted with 100 patients with RA who were admitted to the Arthritis Consulting Clinic, Baghdad Teaching Hospital, Iraq. The patients selected were patients diagnosed with RA about 2 to 3 years ago. Data on the patients were collected, including the results of tests for anti-CII concentrations, and were compared with data from 30 healthy subjects. Healthcare workers aspirated 5 ml of blood from each control and patient subject, divided into two parts. The workers transferred the first one (3 ml) into a plain tube, allowed 30 minutes for it to clot, and then isolated the serum by centrifugation at 2500 rpm for 10 minutes for measurement of the anti-collagen type II antibodies by enzyme-linked immunosorbent assay (ELISA). The workers transferred the second part (2 ml) to the tube containing EDTA for hematological measurement of the erythrocyte sedimentation rate (ESR). Results: This study found that the levels of anti-collagen type II antibodies were significantly higher in patients with RA than in healthy controls (p-value > 0.05). The study found a statistically significant positive moderate correlation with ESR (r = 0.56, p-value = 0.000) and a statistically significant positive strong correlation between disease activity score-28 (DAS28) and anti-collagen type II antibodies (r = 0.65, p-value = 0.000) in RA patients. Conclusions: Anti-CII antibodies can be considered an important parameter for the early detection of RA and can be used to determine the activity of RA.