Enrichment analysis of systemic lupus erythematosus susceptible loci identified by genome-wide association studies.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease. Genome-wide association studies (GWAS) have identified several loci associated with susceptibility to the disease. For the current analysis, enrichment analysis was performed using predicted SLE loci. SLE-associated loci were retrieved from the GWAS database. Gene ontology functional annotation and Reactome pathway analysis were performed using the Enrichr online server. A total of 293 loci encoding susceptible SLE proteins were identified. The analysis revealed that genes associated with SLE were primarily involved in cytokine signaling in the immune system, as demonstrated by the Reactome pathway analysis. In addition, gene ontology analysis suggested that SLE-associated genes were primarily involved in the immune system and its functions. Statistical analysis revealed that 9 segments of the human chromosome had a significantly higher number of SLE-associated genes. Specifically, the 6p21.31-p22.2 and 19p13.2-p13.3 contained 34 and 12 SLE-associated genes, respectively. This study showed that rheumatoid arthritis and multiple sclerosis share 33 and 42 genes, respectively, with SLE, and among the shared genes, four genes CD40, STAT4, TYK2, and IL2RA are involved in the cytokine signaling pathway in the immune system. It might suggest that positive regulation of cytokine production pathway is a common pathway among autoimmune diseases.