Abstract
Epigenetic modifications play a central role in the cellular programming of gene expression. Two of the most characterized epigenetic modifications are DNA methylation and histone modification. Recent observation that a number of GWAS SNP for immunological diseases localize to immune enhancers suggests the importance of epigenetic modifications that control enhancer activity. Epigenome-wide analysis of DNA-methylation in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) revealed differential DNA methylation in a number of disease-related gene pathways. With regard to histone mark, the requirement of millions of cells for established protocol prevents application to clinical samples. However, recent technical advances enable us to capture open chromatin in small amount of patient samples. As epigenetic modifications function as an integrator of environmental stimulation and the underlying genetic variant, detailed epigenetic analysis combined with genetic and environmental factors may facilitate the understanding of the progression of human immunological diseases.
