Table 2.

Epigenetic modifications identified in SS.

Gene/Target	Alteration in SS	Functional significance	Reference
MicroRNA
mir-17-92	Downregulated in MSG	Lymphoproliferation	[118]
miR-574	Downregulated in MSG	miR-768-3p increases, miR-574 decreases with increasing focus scores
miR-768-3p	Upregulated in MSG
miR-146a/b	Upregulated in MSG	Promotes phagocytosis and negative regulator of TLR signalling	[119]
miR-146a/b	Upregulated in PBMC
miR-155	Upregulated in PBMC	Increases Th1/Th17 subsets
DNA methylation
CD70	Hypomethylated	Overexpression of CD70 in pSS CD4+ Tcells	[120]
Global DNA methylation in SGEC, peripheral T cells and B cells	Demethylation in SGEC from SS but not in T and B cells Demethylation in SGEC may be due to PKC inhibition	Decrease in DNA methyl transferase and increase in Gadd45-alpha expression ICAM1 overexpression	[121]
FOXP3	Hypermethylated	Decreased FOXP3expression	[122]
LTA	Hypomethylated	Promotes IFN production, lymphoid structure formation TCR zeta chain	[123]
CD247		T cell proliferation
TNFRSF25		T- and B-cell receptor signalling
PTPRC
GSTM1		Detoxification of electrophilic compounds
PDCD1		Negative regulator of immune system
STAT1 IFI44L USP18 IFITM1	Hypomethylated	Interferon signature
RUNX1	Hypermethylated	Lymphoma risk
SLC11A1 SLC11A2 SLC22A23 SLC25A25 SLC25A3 SLC25A33 SLC6A20	Hypomethylated	Solute carrier proteins-may be relevant for exocrine function, renal tubular acidosis
SLC9A1	Hypermethylated

LTA -lymphotoxin α.

TNFRSF25

PTPRC -Protein tyrosine phosphatase, receptor type, C/CD45 antigen/leukocyte common antigen (LCA)

GSTM1- Glutathione S-transferase Mu 1

PDCD1- Programmed cell death protein 1