Table 1.

Epigenetic studies in patients with AITD.

Endpoint	Tissue	Disease	Findings	Reference
DNA methylation	PBMC	GD	Genome-wide screening revealed 82 hypermethylated and 103 hypomethylated genes	(31)
DNA methylation	CD4+ and CD8+ T cells	GD	Genome-wide screening revealed 365 and 3,322 differentially methylated sites in CD4+ and CD8+ T cells, respectively	(32)
DNA methylation	Thyroid gland	AITD	Impaired methylation and increased expression of the ICAM1 gene	(33)
Histone tail modifications	PBMC	GD	Global reduction of histone 4 acetylation	(36)
Histone tail modifications	CD4+ and CD8+ T cells	GD	Reduction of histone 3 lysine 4 trimethylation (H3K4me3) and histone 3 lysine 27 acetylation (H3K27ac)	(32)
MicroRNA (miRNA) expression	PBMC	GD	No expression of miR-154*, miR-376b, and miR-431*in early disease stages	(39)
MiRNA expression	Serum	HT	Increased levels of miR-22, miR-375, and miR-451	(40)
MiRNA expression	Serum	GD	Increased levels of miR-16, miR-22, miR-375, and miR-451	(36)
MiRNA expression	CD4+ and CD8+ T cells	HT and GD	Differential expression of miR-200a and miR-155	(40)
MiRNA expression	Serum	GD	Correlation between circulating levels of miR-155 and miR-146a and Grave’s ophtalmopathy	(42, 43)
MiRNA expression	Plasma and CD4+ T cells	GD	Upregulation of Bcl-6 and downregulation of miR-346	(44)
MiRNA expression	PBMC and thyroid gland	HT	Downregulated miR-125a-3p expression resulting in upregulation of interleukin-23 receptor levels	(45)
MiRNA expression	PBMC	HT	Increased let-7e expression regulates interleukin 10 expression	(46)
MiRNA expression	Thyroid gland	HT	Increased miR-142-5p expression regulates claudin-1 expression	(47)
MiRNA expression	Thyroid gland	GD	Altered expression of 23 miRNAs with resulting deregulated expression of more than 2,000 messenger RNAs	(48)

AITD, autoimmune thyroid diseases; GD, Graves’ disease; HT, Hashimoto’s thyroiditis; PBMC, peripheral blood mononuclear cells.