Identification and verification of inflammatory biomarkers for primary sjögren’s syndrome

Background: Primary Sjögren’s syndrome (pSS) is an autoimmune disease characterized by inflammatory infiltration and dysfunction of the salivary and lacrimal glands. This research aimed to explore the disease pathogenesis and improve the diagnosis and treatment of pSS by mining inflammatory biomarkers. Methods: Five pSS-related datasets were retrieved from the Gene Expression Omnibus (GEO) database. Inflammatory biomarkers were determined by Least absolute shrinkage and selection operator (LASSO) and support vector machines recursive feature elimination (SVM-RFE). Single sample gene set enrichment analysis (ssGSEA) was implemented to profile the infiltration levels of immune cells. The expression of biomarkers in clinical samples was verified by Real-Time Quantitative PCR. Results: Four genes (LY6E, EIF2AK2, IL15, and CXCL10) were confirmed as inflammatory biomarkers in pSS. Functional enrichment suggested that the biomarkers were involved inimmune and inflammation-related pathways. Immune infiltration analysis revealed that biomarkers were notably connected with some differential immune cells between pSS and control. Also, the RT-qPCR results of clinical samples further affirmed the results of the public database. Conclusion: Four inflammatory biomarkers (LY6E, EIF2AK2, IL15, and CXCL10) were defined and regulatory mechanisms and targeted drugs were investigated in pSS, which provided a basis for understanding the pathogenesis and improving clinical diagnosis and treatment for the disease.