Development of Nuclear Antigen for Detection of Anti-Nuclear and Anti-DFS۷۰ Antibodies in Systemic Lupus Erythematosus Patients

Systemic Lupus Erythematosus (SLE) is a medical condition characterized by an abnormal immune response that affects multiple organs and tissues, resulting in a range of symptoms and potential problems. To confirm or exclude a diagnosis of systemic lupus erythematosus (SLE), it is necessary to conduct tests for anti-nuclear antibody (ANA) and anti-DFS۷۰ antibody. The most widely accepted and reliable approach for detecting antinuclear antibodies (ANA) is the indirect immunofluorescent test (IIFA), which is known for its complexity and high cost. Therefore, it is imperative to create a more cost-effective and simplified test for the detection of ANA and anti-DFS۷۰ antibodies. Our preliminary study aimed to isolate sensitive and specific antigens for the detection of ANA and anti-DFS۷۰ antibodies using the dot blot method. Nuclear antigens were isolated from leukocytes of SLE patients who underwent leukapheresis. DSF۷۰ antigens were obtained from R&D Systems (RH-LEDGF cat.no ۳۴۶۸-LE, Lot: ODX۰۸۱۹۰۷۱). Nuclear antigens and DFS۷۰ antigen were attached to the nitrocellulose membrane dot blot with a dilution of ۰.۰۱ mcg/mL and ۰.۱ mcg/mL, respectively. Furthermore, the antigens were tested for sensitivity and specificity in ۵۶ SLE patients and ۳۴ healthy controls. As a comparison for ANA and anti-DFS۷۰ antibody tests, the ELISA methods were used.  The sensitivity and specificity of dot blot methods using the nuclear antigen were ۶۱.۵% and ۸۴.۶% and the DSF۷۰ antigen were ۴۵.۵% and ۸۲.۳%, respectively. There were moderate sensitivity and good specificity dot blot methods using both nuclear and DFS-۷۰ antigens for ANA and anti-DFS۷۰ antibody detection. The method of nuclear antigen preparation still needs to be modified to improve its sensitivity.

Keywords:

Systemic lupus erythematosus , ANA , anti-DFS۷۰ , dot blot , ELISA