Human Leukocyte Antigen Class II Alleles Are Associated with Risk of Alopecia Areata

The study explored the link between HLA class II alleles and alopecia areata (AA) risk, involving 443 American Caucasian participants, including 99 with persistent patchy AA, 163 with alopecia totalis/universalis (AT/AU), and 152 controls. It confirmed a positive association of the HLA-DQB1*0301 allele with AT/AU and a strong association of the HLA-DRB1*1104 allele with AT/AU risk. Conversely, the HLA-DQB1*0201 allele showed a negative association with AT/AU, indicating a protective effect. These findings suggested that HLA class II alleles were significant in determining susceptibility to AA and could help differentiate AA severity phenotypes.