Harnessing scRNA-seq and bulk RNA-seq to identify CD39+ T cell genes for rheumatoid arthritis diagnosis and therapy.

Rheumatoid arthritis is a prevalent autoimmune disorder with an elusive pathogenesis, hindering early detection and therapeutic advancements. This study focuses on CD39+ T cells, which play a significant role in rheumatoid arthritis, to identify diagnostic and therapeutic biomarkers. We analyzed single-cell RNA sequencing data from rheumatoid arthritis patients to identify differentially expressed genes associated with CD39+ T cells. We then cross-referenced these differentially expressed genes with those from normal and rheumatoid arthritis samples to extract a CD39+ T cell gene signature. Functional enrichment analysis and machine learning algorithms identified key hub genes and assessed their diagnostic efficacy. We identified 13 genes linked to crucial biological pathways, including T cell activation, leukocyte adhesion, and ferroptosis. Four genes, including PELI1, emerged as central to these processes. PELI1 showed remarkable diagnostic value and was upregulated in rheumatoid arthritis patients. We observed distinct immune cell infiltration patterns based on PELI1 expression and mapped out an lncRNA-miRNA-PELI1 network. We also identified 41 small molecule drugs as potential therapeutic candidates for rheumatoid arthritis. PELI1 is a promising diagnostic biomarker for RA, contributing to the pool of potential biomarkers for diagnosis and therapy. Our study provides new insights into the role of CD39+ T cells in rheumatoid arthritis and highlights potential therapeutic targets for future research.