Comparison of four methods of detection of anti-double-stranded DNA in SLE patients.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease. Anti-double stranded DNA (anti-dsDNA) detection is essential for diagnosis and assessment of disease severity and lupus nephritis. Variable laboratory tests for Anti-dsDNA detection have different qualities affecting the results and the disease diagnosis. This study aimed to compare the performance of four different methods of detection of anti-dsDNA among SLE patients in Sohag Governorate. This Case -control study was done in Sohag University Hospital during the period from March 2021 to June 2022 and included 81 cases diagnosed with SLE according to the ACR/EULAR 2019 classification criteria for SLE. We compared serum anti-dsDNA antibody levels by different commercially available kits including Crithidia luciliae indirect immunofluorescence assay (CLIFT), chemiluminescence immunoassay (CLIA), enzyme linked immunosorbent assay (ELISA) and dot immunoassay results. ELISA showed the highest positivity (75.3%), followed by CLIA (61.7%), dot immunoassay (49.4%) and CLIFT (48.1%), respectively. Combining the four methods of detection, 45.7% of the cases showed positive by all of the four detection methods. Most of the other cases were at least positive in two or three tests. Only 17.3% of the cases were negative by all of the four detection methods. None of the subjects in the control group were positive by any test. In conclusion for the detection of anti-dsDNA antibodies, ELISA showed the highest sensitivity. However, the combination of more than one method revealed higher sensitivity.