Genetic Variants in Interferon Regulatory Factor 2 (IRF2) Are Associated with Atopic Dermatitis and Eczema Herpeticum

Interferon regulatory factor 2 (IRF2) is a member of a family of transcriptional factors involved in the modulation of IFN-induced immune responses to viral infection. To test whether genetic variants in IRF2 predict risk of atopic dermatitis (AD) and ADEH (atopic dermatitis complicated by eczema herpeticum), we genotyped 78 IRF2 tagging single-nucleotide polymorphisms (SNPs) in both European-American (n=435) and African-American (n=339) populations. Significant associations were observed between AD and two SNPs (rs793814, P=0.007, odds ratio (OR)=0.52; rs3756094, P=0.037, OR=0.66) among European Americans and one SNP (rs3775572, P=0.016, OR=0.46) among African Americans. Significant associations were also observed between ADEH and five SNPs (P=0.049-0.022) among European Americans. The association with ADEH was further strengthened by haplotype analyses, wherein a five-SNP (CAGGA) haplotype showed the strongest association with ADEH (P=0.0008). Eight IRF2 SNPs were significantly associated with IFN-γ production after herpes simplex virus (HSV) stimulation (P=0.048-0.0008), including an AD-associated SNP (rs13139310, P=0.008). Our findings suggest that distinct markers in IRF2 may be associated with AD and ADEH, which may depend upon ethnic ancestry, and genetic variants in IRF2 may contribute to an abnormal immune response to HSV.