HLA class II antigen associations help to define two types of alopecia areata.

BACKGROUND: Multiple HLA class I and class II antigen associations have been described for alopecia areata (AA). As in other immune-mediated diseases, the HLA antigens associated with AA could influence the patient's ability to respond to immune challenge from both self- and non-self-antigens and may offer clues to the cause and prognosis of and potential therapy for the disease.

OBJECTIVE: Our purpose was to determine which HLA class II antigens are associated with two forms of long-standing AA, which we define to be long-standing patchy AA and long-standing alopecia totalis (AT) and alopecia universalis (AU). We also examined other factors such as age at onset of disease and familial and patient histories of autoimmune disease for correlation with the two groupings.

METHODS: Patients were typed for HLA class I and class II antigens by serologic methods and were typed by molecular methods for the subtypes of the HLA class II antigens.

RESULTS: HLA-DR11 (DRB1*1104) and HLA-DQ7 (DQB1*0301) were found to be highly significantly increased in frequency in patients with long-standing AT/AU (group III) but not in patients with long-standing patchy AA (group II); both patient groups showed increased frequencies of HLA-DQ3 (DQB1*03). Group III patients were unique in their early age at onset of disease. Familial incidence of AA was 37% in patients who had their first patch by 30 years of age and 7.1% with the first patch after 30 years of age.

CONCLUSION: The data support the differential association of two well-defined clinical forms of AA, namely long-standing AT/AU and long-standing patchy AA, with specific HLA antigens and age at onset; they also suggest that the broad antigen HLA-DQ3, DQB1*03, is a likely candidate for general susceptibility to AA. Our findings also suggest a bimodal pattern of disease with an early-onset form associated with greater severity, long duration, and family history of the disease and a late-onset form characterized by milder severity, shorter duration, and low family incidence.