IFI27, a potential candidate molecular marker for primary Sjogren's syndrome

The etiology of primary Sjogren's syndrome (pSS) is complex and not completely clear. This study was to identify key genes in pSS based on Gene Expression Omnibus (GEO).

We downloaded the GSE40568, GSE80805, GSE127952, and GSE164885 mRNA expression profiles from GEO. Differentially expressed genes (DEGs) analyses were carried out by using the online analysis tool GEO2R and R. Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to elucidate the biological processes, molecular function, cellular component, and KEGG signaling pathways for the DEGs in salivary glands (SGs) and peripheral blood mononuclear cells (PBMCs). Genes co-expressed were found in PBMCs and SGs of pSS patients. RT-qPCR was performed for validation. Finally, clinical correlation analysis and receiver operator characteristic (ROC) curve analysis were performed.

A total of thirty-nine up-regulated and one down-regulated genes were identified in pSS SGs. GO and KEGG pathway revealed that these DEGs were related to response to virus, and type I interferon signaling pathway. It was verified that fourteen genes were up-regulated in the SGs of pSS by RT-qPCR. Twenty up-regulated genes were identified in pSS patients PBMCs. Two genes were up-regulated in SGs and PBMCs of pSS patients, including IFI27 and IFI44L. The mRNA level of IFI27 was positively correlated with the disease activity of pSS patients. Furthermore, ROC analyses proved IFI27 may have diagnostic value for pSS.

IFI27 might serve as a potential biomarker for the early diagnosis and therapy of pSS. Key Points • IFI27 expression was significantly increased in PBMCs and SGs of pSS patients. • IFI27 was positively correlated with disease activity in pSS patients. • IFI27 might have a good diagnostic value for pSS.