Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with unknown etiology. Nowadays, several long noncoding RNAs (lncRNAs) have been reported as molecular alterations involved in SLE. This study aimed to reveal the function of TNF‐related and HNRNPL‐related immunoregulatory lncRNA (THRIL) in SLE. Human epithelial HK‐2 cells were exposed to lipopolysaccharide (LPS) to mimic an in vitro SLE model. Then, the functions of THRIL, miR‐34a, and monocyte chemoattractant protein‐1 (MCP‐1), as well as their correlations were detected. LncRNA THRIL was highly expressed in the LPS‐stimulated cells, and THRIL overexpression aggravated LPS‐induced cell damage as cell viability was decreased, and apoptosis and the release of proinflammatory cytokines were increased. THRIL worked as a sponge of microRNA‐34a (miR‐34a) and it could directly target MCP‐1. Furthermore, MCP‐1–activated JNK and Wnt/β‐catenin signaling pathways. In conclusion, this study suggested that lncRNA THRIL might be a key regulator participating in LPS‐induced injury in HK‐2 cells. THRIL overexpression aggravated LPS‐induced injury possibly via sponging miR‐34a, and thus preventing MCP‐1 from degradation by miR‐34a. The THRIL/miR‐34a/MCP‐1 axis might play critical roles in SLE.

Screened DEGs including VIMP, NDUFAB1, SEC61G, PSMC2 might be potential targets for lupus nephritis treatment by involving in different functions and pathways, such as metabolic process and immune process.

<b><i>Introduction:</i></b> Anti-phospholipase A2 receptor antibody (PLA2R-Ab) is highly specific for primary membranous nephropathy (PMN). Here, we compare the diagnostic value of different circulating PLA2R-Ab cutoff titers in multicenter cohorts, with particular focus on determining the optimal cutoff value for Chinese patients. <b><i>Methods:</i></b> In total, 288 patients with PMN and 301 with other nephropathies were recruited retrospectively from five hospitals in China between September 2011 and October 2018. PLA2R-Ab in serum obtained at renal biopsy was determined by enzyme-linked immunosorbent assay. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristic (ROC) curve of PLA2R-Ab in diagnosing PMN were assessed. Diagnostic efficiency was evaluated by internal validation. <b><i>Results:</i></b> The sensitivity, specificity, PPV, NPV, and Youden index for PMN diagnosis were 71%, 90%, 88%, 75%, and 0.61 at the cutoff of 3.8 RU/mL; 74%, 86%, 84%, 76%, and 0.60 at 2.7 RU/mL; 68%, 92%, 90%, 73%, and 0.60 at 5.2 RU/mL; 64%, 95%, 93%, 72%, and 0.59 at 9.0 RU/mL; 57%, 96%, 94%, 68%, and 0.54 at 14.0 RU/mL; 51%, 97%, 95%, 66%, and 0.49 at 20.0 RU/mL; 47%, 98%, 96%, 64%, and 0.45 at 40.0 RU/mL, respectively. The area under the ROC curve was 0.83. <b><i>Conclusion:</i></b> By comprehensively considering specificity and sensitivity, we show that 3.8 RU/mL is the optimal cutoff of PLA2R-Ab in Chinese PMN patients, with a sensitivity of 71% and a specificity of 90%. The cutoff values were 5.2 RU/mL and 9.0 RU/mL when the diagnostic specificity was increased to 92% and 95%, respectively.