Serum calreticulin in rheumatoid arthritis and its relation with disease activity and severity.

Objectives: To assess the serum level of CRT in RA patients and its association with disease activity and severity. Methods: this case-control study was carried out at Rheumatology and Rehabilitation Department, Zagazig University Hospitals on 80 subjects. The subjects were divided into two groups: RA group: Forty patients with rheumatoid arthritis who were randomly selected. The patients fulfilled the 2010 American Collage of Rheumatology (ACR) / European League Against Rheumatism Classification (EULAR) criteria for rheumatoid arthritis. Control group: Forty apparently healthy subjects age and sex matched with the patients. Assessment of disease activity in RA patients was done by Disease Activity Score 28 ( DAS 28). Also VAS of pain was recorded, Modified Sharp Score and Hochberg Functional status were also assessed . Assessment of disease severity in RA patients was done by Rheumatoid Arthritis Severity Scale (RASS). The concentration of CRT in all collected serum was detected by sandwich ELISA. Results: There was a highly significant difference between RA group and control group as regards serum CRT (MW=49.5, p < 0.001). The correlations of serum CRT with DAS 28 and RASS were highly significant (P< 0.001), and correlations with disease duration, VAS, and Modified Sharp Score were significant (p < 0.01), while correlations with age & other activity parameters were non significant (p > 0.05). Conclusion: we concluded that serum CRT levels are elevated in RA patients, providing further evidence for a role of CRT in RA. Furthermore, serum CRT levels parallel the degree of activity and severity of the disease.