Diagnosing IBD by Evaluating Epigenetic Markers in Blood

Symptoms are similar in Crohn's disease, ulcerative colitis, and other inflammatory bowel conditions, which makes it difficult for doctors to diagnose which of the illnesses a patient has.

In an effort to develop better diagnostic tools for IBD, investigators at the University of Edinburgh (United Kingdom) used Illumina (San Diego, CA, USA) instruments and microarray technology to determine differentially methylated sites in whole blood and in immunomagnetically separated leucocytes (CD4+ and CD8+ lymphocytes and CD14+ monocytes) from 240 newly-diagnosed IBD cases and 190 controls.

The investigators reported that they had identified differentially methylated positions (DMPs) and regions (DMRs) in whole-blood DNA samples from 240 newly diagnosed IBD cases (121 Crohn's disease and 119 ulcerative colitis) and 191 controls. Technical validation and detailed characterization of DMRs was performed in a small cohort of six cases (three Crohn's disease and three ulcerative colitis) and three controls using whole-genome bisulphite sequencing. Independent validation of methylation results was performed using bisulphite pyrosequencing in a further cohort of 240 patients with established IBD and 98 controls.

Senior author Dr. Jack Satsangi, professor of gastroenterology at the University of Edinburgh, said, "Our findings bring fresh insights to the underlying causes of inflammatory bowel diseases, which could eventually lead to new treatments. Characterizing epigenetic signatures in the DNA of patients could help us to devise better tests for diagnosing these diseases, so that patients can be given the best possible care."

The study was published in the November 25, 2016, online edition of the journal Nature Communications.

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