New classification of rheumatoid arthritis based on immune cells and clinical characteristics

Abstract

Abstract Background Rheumatoid arthritis (RA) is a chronic systemic immune disease characterized by joint synovitis, but the specific etiology is unknown, and the characteristic serum diagnostic markers are also lacking. Methods First, we obtained the gene expression profile of synovium to evaluate the infiltration of immune cells in synovium, and screened the differentially expressed immune related genes for enrichment analysis. Subsequently, we classified RA into three subtypes by unsupervised clustering of serum gene expression profiles based on immune enrichment scores. Then, the enrichment and clinical characteristics of different subtypes were analyzed. Finally, according to the infiltration of different subtypes of immune cells, diagnostic markers were screened and verified by qRT-PCR. Results C1 subtype is related to the increase of neutrophils, CRP and ESR, and joint pain is more significant in patients. C2 subtype is related to the expression of CD8+T cells and Tregs, and patients have mild joint pain symptoms. The RF value of C3 subtype is higher, and the expression of various immune cells is increased. The function of this subtype is enriched in a variety of immune system diseases. T cells CD4, NK cells activated, macrophages M1 and neutrophils are immune cells significantly infiltrated in synovium and serum of RA patients. IFNGR1, TRAC, IFITM1 can be used as diagnostic markers of different subtypes. Conclusion In this study, RA patients were divided into different immune molecular subtypes based on gene expression profile, and immune diagnostic markers were screened, which provided a new idea for the diagnosis and treatment of RA.