RT Journal Article
SR Electronic
T1 Overlap between differentially methylated DNA regions in blood B lymphocytes and genetic at-risk loci in primary Sjögren's syndrome
JF Annals of the Rheumatic Diseases
JO Ann Rheum Dis
FD BMJ Publishing Group Ltd and European League Against Rheumatism
SP 933
OP 940
DO 10.1136/annrheumdis-2014-206998
VO 75
IS 5
A1 Miceli-Richard, Corinne
A1 Wang-Renault, Shu-Fang
A1 Boudaoud, Saida
A1 Busato, Florence
A1 Lallemand, Céline
A1 Bethune, Kevin
A1 Belkhir, Rakiba
A1 Nocturne, Gaétane
A1 Mariette, Xavier
A1 Tost, Jörg
YR 2016
UL http://ard.bmj.com/content/75/5/933.abstract
AB Background Beyond genetics, epigenetics alterations and especially those related to DNA methylation, play key roles in the pathogenesis of autoimmune diseases such as primary Sjögren's syndrome (pSS) and systemic lupus erythematosus. This study aimed to assess the role of methylation deregulation in pSS pathogeny through a genome-wide methylation approach.Patients and methods 26 female patients with pSS and 22 age-matched controls were included in this study. CD4+ T cells and CD19+ B cells were isolated from peripheral blood mononuclear cells by magnetic microbeads and their genome-wide DNA methylation profiles were analysed using Infinium Human Methylation 450 K BeadChips. Probes with a median DNA methylation difference of at least 7% and p<0.01 between patients and controls were considered significantly differentially methylated.Results Methylation alterations were mainly present in B cells compared with T cells. In B cells, an enrichment of genes with differentially methylated probes in genetic at-risk loci was observed, suggesting involvement of both genetic and epigenetic abnormalities in the same genes. Methylation alterations in B cells were more frequent in some specific pathways including Interferon Regulated Genes, mainly among patients who were autoantibody positive. Moreover, genes with differentially methylated probes were over-represented in B cells from patients with active disease.Conclusions This study demonstrated more important deregulation of DNA methylation patterns in B cells compared with T cells, emphasising the importance of B cells in the pathogenesis of the disease. Overlap between genes with differentially methylated probes in B lymphocytes and genetic at-risk loci is a new finding highlighting their importance in pSS.