Altered DNA methylation profile in Norwegian patients with Autoimmune Addison's Disease

• Abnormal DNA methylation is frequently observed in autoimmune diseases. • We identified multiple differentially methylated regions (DMRs) in AAD patients. • We used DNA from CD4+ T cells in combination with MeDIP. • Many of the DMRs localized to genes involved in immune regulation and autoimmunity. Autoimmune Addison's Disease (AAD) is an endocrine and immunological disease of uncertain pathogenesis resulting from the immune system's destruction of the hormone producing cells of the adrenal cortex. The underlying molecular mechanisms are largely unknown, but it is commonly accepted that a combination of genetic susceptibility and environmental impact is critical. In the present study, we identified multiple hypomethylated gene promoter regions in patients with isolated AAD using DNA isolated from CD4+ T cells. The identified differentially methylated regions were distributed evenly across the 10.5-kb-promoter regions covered by the array, and a substantial number localized to promoters of genes involved in immune regulation and autoimmunity. This study reveals a hypomethylated status in CD4+ T cells from AAD patients and indicates differential methylation of promoters of key genes involved in immune responses.