Evaluation of serum adenosine deaminase activity and autoantibodies in systemic lupus erythematosus

Abstract

Introduction: Systemic lupus erythematosus (SLE) is a complex autoimmune disease with no single specific and sensitive test available for its diagnosis. Adenosine deaminase (ADA) is an enzyme that can act as an indicator of cellular immunity reflecting the extent of inflammation. The aim of this study was to investigate the role of serum adenosine deaminase activity and its association with antinuclear antibodies (ANA) and anti-dsDNA (anti-double stranded deoxyribonucleic acid) in SLE patients. Material and methods: In this study, we included 36 diagnosed case of SLE as per the American Rheumatology Association (ARA) criteria and 30 healthy control. Serum ADA activity was measured by a spectrophotometric technique based on Giusti and Gallanti. ANA and Anti ds-DNA were measured by indirect Enzyme-Linked Immune Sorbent Assay (ELISA). Normal values of serum ADA activity, ANA and anti ds-DNA was < 25 IU/L, < 10 U/mL and < 25 IU/mL respectively. Results: The mean ADA activity (37.03 ± 13.03 IU/L) in SLE patients was higher as compared to control (18.23 ± 10.12 IU/L), and the difference was statistically significant (p < 0.001). Median values of ANA and anti-dsDNA in SLE patients was 16.9 (8.5, 42.8) and 24.7 (20.5, 45.0) respectively. Serum ANA was positive in 25 out of 36 cases, anti-dsDNA was positive in 17 out of 36 cases and ADA was positive in 29 out of 36 cases. We observed a weak positive correlation between ANA and anti-dsDNA (r = 0.46, p = 0.005), whereas a moderate correlation between ANA and ADA (r = 0.525, p = 0.001) in SLE patients. Conclusion: Serum ADA was significantly higher in SLE patients as compared to control and more specific than autoantibodies. Determination of ADA activity is a reliable, cost-effective, and easy test that can be used as an alternative parameter for diagnosing and evaluating disease activity in SLE patients.