Evaluation of anti-ds DNA antibodies in anti-nuclear antibody positive Omani patients

Objective: To study the correlation between enzyme linked immunosorbent assay (ELISA) and immunofluoresencent (IF) anti-dsDNA antibody measurement in different diseases. Patients: One hundred and forty sera from patients with systemic lupus erythematosus (SLE, n=40), rheumatoid arthritis (RA, n=30), disease control (n=40) and from healthy control subjects (n=30) were included. Results: Using the ELISA, serum anti-dsDNA was detected in 24/40 (60%) SLE, 5/30 (16.6%) RA, 9/40 (22.5%) disease controls and 1/30 (3.3%) of normal healthy controls. When IF assay was employed, anti-dsDNA antibodies were detected in 16/40 (40%) SLE, 3/30 (10%) RA, 5/40 (12.5%) disease controls but none in the normal subjects. Conclusion: These results suggest that both ELISA and IF techniques can be used for the measurement of anti-dsDNA antibodies in clinical laboratories and, these antibodies are not unique to SLE.