Differential diagnosis of Crohn’s disease (CD) and intestinal tuberculosis (ITB) is still difficult in clinical pratice. DNA methylation has been considered as a favorable area for biomarker exploration and identification.
The purpose of the current study was to evaluate DNA methylation changes between CD and ITB.
We performed a genome-wide association study to identify differentially methylated positions (DMPs), including 8 CD patients (before the initial of biologics or immunomodulators), 6 ITB patients, and 8 healthy controls (HCs), in whole blood DNA using the Infinium HumanMethylation850 BeadChip.
Patients in the CD group and ITB group were all observed with hypo-methylated changes compared with HCs. However, the CD group overlaps with the ITB group in DNA methylation, suggesting a stable epigenetic profile between the two diseases. The pathway enrichment analysis showed the alternation in inflammation-related pathway, immune system, and signal transduction. Focused on the DMPs located in the promoter region, further analysis indicated hypermethylation of cg03122532 (5’UTR of KCNJ15) could be a potential CD-specific biomarker.
We identified specific differential methylation loci related to CD and ITB in blood DNA. DNA metylation as a important epigenetic modification could contribute to the pathogenesis study and biomarker exploration of the diseases.

© 2022. The Author(s) under exclusive licence to The Genetics Society of Korea.