The HLA-DRB1 polymorphism is associated with atopic dermatitis, but not egg allergy in Korean children

Purpose: We investigated whether particular HLA-DRB1 polymorphisms contribute to egg allergy development in Korean children with atopic dermatitis (AD). Methods: HLA-DRB1 alleles were determined by PCR-sequence-specific oligonucleotide (SSO) and PCR-single-strand conformation polymorphism (SSCP) methods in 185 patients with AD and 109 normal control (NC) subjects. AD patients were divided into two groups: 1) AD with egg allergy, consisting of 96 patients with egg allergies as determined by egg-specific immunoglobulin E (IgE) reactivity; and 2) AD without egg allergy, consisting of 89 patients without egg allergies. HLA-DRB1 alleles were classified into functional groups (A, De, Dr, E, Q, R, a). HLA-DRB1 phenotype and functional group frequencies in the AD, AD with egg allergy, and AD without egg allergy groups were compared with those in the NC group. Results: The frequency of DRB1*08:02 was decreased in the AD with egg allergy group compared with the AD without egg allergy group (2.1% vs. 10.1%, P=0.021), and DRB1*15:01 was increased in the AD with egg allergy group compared with the AD without egg allergy group (22.9% vs. 11.2%, P=0.036). However, significance was lost after Bonferroni correction. HLA-DRB1*11:01 had a significantly higher frequency in AD patients compared with NCs (12.4% vs. 1.8%, corrected P=0.048) and was regarded as a susceptibility factor associated with AD. DRB1*08:03 was decreased in AD patients compared with NCs (10.8% vs. 19.3%, P=0.043). HLA-DRB1 functional group 'a', which includes DRB1*15:01, seemed to be associated with the development of egg allergy in AD (P=0.033), but this result was not significant after Bonferroni correction. Conclusions: HLADRB1 polymorphism is not associated with egg allergy, but HLA-DRB1*11:01 is associated with AD in Korean children.