Diagnostic accuracy of antinuclear antibodies and anti-double stranded DNA antibodies in patients of systemic lupus erythematosus presenting with dermatological features

Abstract

Objective To determine the diagnostic accuracy of antinuclear antibodies (ANA) and anti-double stranded DNA (dsDNA) antibodies in systemic lupus erythematosus patients presenting with dermatological features.  Methods In this cross-sectional study, 82 patients diagnosed as having systemic lupus erythematosus (SLE) per American College of Rheumatology (revised criteria 1997) from October 2012 to October 2013 and fulfilling the study’s inclusion criteria were enrolled. These patients were first assessed by the dermatologist for four dermatological features, namely malar rash, discoid rash, photosensitivity and oral ulcers and were than referred to Department of Pathology for assessment of serological markers i.e. ANA and anti-dsDNA antibodies. The diagnostic accuracies of serological markers were analyzed to determine which one of the two serological markers is associated with any of the four dermatological features under observation in our study. Results Out of 82 SLE patients, 77 (93.9%) patients were females and 5 (6.1 %) were males. Male to female ratio in this study was 1:15. Mean age of patients was 34.91 years and ranged between 8-62 years. Photosensitivity, malar rash, oral ulcers and discoid rash were found in 97.5%, 85.3%, 76.8% and 46.3% patients, respectively. ANA was not found to be statistically significantly associated with any of the dermatological features under observation in our study. However, anti-dsDNA antibodies were strongly associated with photosensitivity 0.024 (p<0.05) and malar rash was 0.003 (p<0.05). Conclusion The study proves that anti-dsDNA antibodies have high diagnostic accuracy for photosensitivity and malar rash in SLE patients and can be used alone with confidence in patients presenting with these two dermatological features, without burdening the lab with a lengthy serological evaluation.