Association of Anti-SS-A Antibodies with Lupus Nephritis in Patients with Glomerulonephritis

Introduction: Anti-SS-A antibodies (anti-SS-A) are the most prevalent anti-extractable nuclear antibody (ENA). Glomerulonephritis (GN), characterized by intraglomerular inflammation and cellular proliferation, is the leading cause of end-stage renal failure. The association of anti- SS-A in various types of GN is not well established in the literature. The documented role of anti- SS-A in lupus nephritis (LN) is controversial; some studies did not mention any significant association, whereas others recognized them as potentially pathogenic. This study aimed to determine the association of Anti-SS-A in patients suffering from various GN and its significance in LN patients. Methods: This cross-sectional study evaluated 200 GN patients for the presence of anti-dsDNA and anti-ENA antibodies via indirect immunofluorescence (IFA) and Immunoblot assays, respectively. All patients had anti-cell antibodies in their sera, which were evaluated with the help of IFA using the HEp-2 cell line as substrate. Data was analyzed using SPSS software version 20. Pvalue ≤ 0.05 was considered statistically significant. Results: Anti-dsDNA were found in 56(28%) whereas anti-ENA in 94(47%) patients. Anti-SS-A was the most common anti-ENA, which was isolated in 58(29%) patients. In the anti-ENA positive group, single antigen specificity was present in 55 (58.5%) patients, whereas more than one antigen specificity was seen in 39 (41.5%) patients. Out of 58 patients with anti-SS-A antibodies majority presented with nephrotic syndrome 44 (76%), and most of them 51 (88%) had a clinical diagnosis of Lupus Nephritis (LN). Majority patients 31 (53%) also had another anti-ENA along with anti-SS-A (P = 0.05). 24 (41.4%) patients also had anti-dsDNA along with anti-SS-A. In the enrolled GN patients, anti-SS-A antibodies were found to be significantly associated with anti- SS-B and anti-P antibodies. Discussion: Although anti-SS-A are most prevailing anti-ENA, however their presence in GN patients needs special consideration to rule out an underlying autoimmune disorder. Previous studies have highlighted the pathogenic potential of anti-SS-A in GN patients. The results of this study are in agreement with these studies, as most of the GN patients with anti-SS-A were later on diagnosed as LN. These findings suggest that anti-SS-A may contribute to the disease pathogenesis. However, larger studies in various ethnic populations are needed to confirm these results for adequate patient management. Conclusion: The study results predict the pathogenic potential of anti-SS-A in GN patients. As the majority of patients were diagnosed as LN, GN patients with anti-SS-A antibodies need special consideration to rule out LN for adequate management