HLA DQB1*0301 allele is involved in the susceptibility to erythema multiforme.

Erythema multiforme (EM) is an acute, episodic inflammatory disorder of the skin and mucous membranes of various etiology that could be related to immunologic hypersensitivity response. EM has been previously reported to be associated with serologically defined HLA-DRw53 and DQw3 antigens. In this report, we reevaluate the role of HLA class II alleles in EM manifestations. With use of the polymerase chain reaction, followed by sequence-specific oligonucleotide hybridization, 35 unrelated Caucasian EM patients and 80 randomly selected healthy subjects were studied, and the DRB3, DRB4, DQA1, and DQB1 alleles were analyzed. The comparison of frequencies of these alleles indicates that (i) susceptibility to EM disease is more associated with the HLA-DQ than the HLA-DR subregions and (ii) that the DQB1*0301 is the most frequent allele among EM patients. Sixty-six percent of the patients had the DQB1*0301 allele compared to 31% of the controls (RR = 4.1; p less than 0.001). An even stronger DQB1*0301 association was found in the patient group with herpes-associated EM (76%; RR = 6.5; p less than 0.001). Our data demonstrate a clear association between an HLA-DQB1 allele and susceptibility to EM.