Table 1.

Studies on DNA methylation and histone modifications in PBC.

Study	Method	Sample	Findings
Huet al, 2011 [68]	Chromatin Immunoprecipitation (ChIP)	60 PBC patients (55 women, 5 men)	Increased H4 histone acetylation of promoters for CD40L, LIGHT, IL-17, IFNγ and deacetylation of H4 histone of TRAIL, Apo2, HDAC7A promoter in T cells.
Lleo et al., 2012 [66]	Bisulfite sequencing	20 PBC women, 20 healthy women, 9 women with psoriasis, 9 women with DM1	Hypomethylationof CD40L gene promoter
Selmi et al., 2014 [69]	DNA immunoprecipitation (MeDIP)	3 pairs of monozygotic female twins, 8 pairs of sisters discordant for PBC	Differentmethylation • twins—60 gene regions • sisters—14 gene regions Downregulation of: CXCR5, HLA-B, IFI44L, IFIT1, and SMARCA1, Upregulation of IL-6
Lleo et al., 2015 [51]	Bisulfite sequencing	30 women with PBC30 healthy women	20, 15, and 9 distinct gene promoters with a significant difference in methylation profile in CD4(+), CD8(+), and CD14(+) T cells respectively

Abbreviations: PBC: primary biliary cholangitis; DM1: diabetes mellitus type 1; LIGHT: tumor necrosis factor superfamily member 14; IL-17: interleukin 17; IFNγ: interferon γ; TRAIL: TNF-related apoptosis-inducing ligand; Apo2: apoptosis 2; HDAC7: histone deacetylase 7; CXCR5: C-X-C motif chemokine receptor 5; HLA-B: human leucocyte antigen B; IFI44L: interferon-induced protein 44 like; IFIT1: interferon-induced protein with tetratricopeptide repeats 1; SMARCA1: SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 1; IL-6: interleukin 6.