Background: Systemic lupus erythematosus (SLE) is an autoimmune disease that involves multiple organs. However, the current SLE-related biomarkers still lack sufficient sensitivity, specificity and predictive power for clinical application. Thus, it is significant to explore new immune-related biomarkers for SLE diagnosis and development.Methods: We obtained seven SLE gene expression profile microarrays (GSE121239/11907/81622/65391/100163/45291/49454) from the GEO database. First, differentially expressed genes (DEGs) were screened using GEO2R, and SLE biomarkers were screened by performing WGCNA, Random Forest, SVM-REF, correlation with SLEDAI and differential gene analysis. Receiver operating characteristic curves (ROCs) and AUC values were used to determine the clinical value. The expression level of the biomarker was verified by RT‒qPCR. Subsequently, functional enrichment analysis was utilized to identify biomarker-associated pathways. ssGSEA, CIBERSORT, xCell and ImmuCellAI algorithms were applied to calculate the sample immune cell infiltration abundance. Single-cell data were analyzed for gene expression specificity in immune cells. Finally, the transcriptional regulatory network of the biomarker was constructed, and the corresponding therapeutic drugs were predicted.Results: Multiple algorithms were screened together for a unique marker gene, MX2, and expression analysis of multiple datasets revealed that MX2 was highly expressed in SLE compared to the normal group (all P < 0.05), with the same trend validated by RT‒qPCR (P = 0.026). Functional enrichment analysis identified the main pathway of MX2 promotion in SLE as the NOD-like receptor signaling pathway (NES=2.492, P < 0.001, etc.). Immuno-infiltration analysis showed that MX2 was closely associated with neutrophils, and single-cell and transcriptomic data revealed that MX2 was specifically expressed in neutrophils. The NOD-like receptor signaling pathway was also remarkably correlated with neutrophils (r >0.3, P < 0.001, etc.). Most of the MX2-related interacting proteins were associated with SLE, and potential transcription factors of MX2 and its related genes were also significantly associated with the immune response.Conclusion: Our study found that MX2 can serve as an immune-related biomarker for predicting the diagnosis and disease activity of SLE. It activates the NOD-like receptor signaling pathway and promotes neutrophil infiltration to aggravate SLE.

Neutrophil extracellular traps (NETs) are reticular fiber structures released by neutrophils in response to various stimuli. Although NETs have antibacterial defense functions, their excessive formation has been proven to accelerate the progression of autoimmune diseases. Increasing studies have shown that NETs play an important role in the pathogenesis of autoimmune diseases. The pathogenesis of recent advances in autoimmune disease research, with a focus on the role of NETs in the etiology and pathogenesis of these disorders, and summarizes the current treatment strategies targeting NETs, aiming to provide new directions for the treatment of autoimmune diseases.

Rheumatic diseases are characterized by immune dysfunction, chronic inflammation and tissue damage, in which neutrophils play a pivotal role. As a heterogeneous subset of neutrophils, low-density neutrophils (LDNs) are present at extremely low levels in healthy individuals, whereas they are abnormally expanded in patients with rheumatic diseases and closely correlated with disease activity. This review summarizes the biological characteristics of LDNs, as well as their roles and potential therapeutic values in various rheumatic diseases. These cells exhibit a dual origin with distinct phenotypic and functional features and exert their pathogenic effects primarily through the release of neutrophil extracellular traps (NETs) and pro-inflammatory cytokines, as well as their involvement in the immune regulatory network. LDNs are implicated in the pathogenesis of multiple rheumatic diseases. Targeting LDNs or their key pathogenic pathways may provide novel insights into the precision therapy of rheumatic diseases. Further investigations into the subpopulations and underlying mechanisms of action of LDNs are therefore warranted to advance the development of targeted therapeutic strategies for these diseases.

Background: Systemic Lupus Erythematosus patients (SLE) are at a higher risk of cardiovascular events than the general population. This study aimed to investigate the risk perception of cardiovascular disease (CVD) and to analyze its influence factors among Chinese SLE patients. Methods: This was a cross-sectional study. Convenience sampling was used to select 201 patients with SLE who had attended the outpatient and inpatient departments of the Department of Rheumatology and Immunology at the First Affiliated Hospital of the University of Science and Technology of China from November 2022 to March 2023. The following were used in the study: the Chinese version of the Attitudes and Beliefs about Cardiovascular Disease Risk Questionnaire, the Social Support Rating Scale, the Connor–Davidson Resilience Scale, the General Self-Efficacy Scale, the Hospital Anxiety and Depression Scale, the Health Literacy Management Scale, and sociodemographic and disease-related data. Results: The mean (standard deviation) risk perception score of CVD patients with SLE was 57.18 ± 13.02. A Pearson correlation analysis showed that CVD risk perceptions were positively correlated with health literacy ( r = 0.152, p < .05) and depression ( r = 0.277, p < .05), and negatively correlated with social support ( r = −0.393, p < .05) and psychological resilience ( r = −0.374, p < .05). A multiple linear regression analysis showed that body mass index (BMI), family history, health literacy, depression, social support, and psychological resilience were the main factors influencing CVD risk perceptions among Chinese SLE patients ( p < .05). Conclusions: Body mass index, family history, health literacy, depression, social support, and psychological resilience influenced CVD risk perceptions among Chinese SLE patients. Healthcare workers should objectively and accurately assess the levels of CVD risk perception among SLE patients, identify the risk factors of CVD, adopt effective health risk communication strategies to help patients develop appropriate risk perceptions, and raise risk awareness to adopt active coping approaches to reduce risk.