Replicated methylation changes associated with eczema herpeticum and allergic response

Area of Science:

• Epigenetics
• Dermatology
• Immunology

Background:

• Epigenetic mechanisms, including DNA methylation, are implicated in allergic diseases.
• Limited research exists on DNA methylation in atopic dermatitis (AD), with no studies focusing on AD with eczema herpeticum (ADEH+).

Purpose of the Study:

• To investigate genome-wide DNA methylation variations in individuals with AD, with and without eczema herpeticum (EH).
• To explore associations between DNA methylation patterns and AD severity traits.

Main Methods:

• Genome-wide DNA methylation modeling in whole blood cells from ADEH+, ADEH-, and healthy control subjects.
• Replication cohorts were used to validate findings.
• Analyses adjusted for cell-type composition, employing both genome-wide and candidate-gene approaches.

Main Results:

• One CpG site was significantly differentially methylated by severity, with suggestive replication for four others.
• 490 differentially methylated CpGs were identified between ADEH+ and healthy controls.
• A significant portion (431/490) of these CpGs were associated with severity measures, notably eosinophil count.

Conclusions:

• A CpG site in IL4 was linked to serum total IgE levels, suggesting Th2 immune involvement in AD.
• Changes in eosinophil levels, a disease severity indicator, correlate with DNA methylation alterations.
• These findings offer potential mechanisms for phenotypic variations in immune response traits within AD.