Multiple basal cell carcinomas: no association with HLA-DRB, HLA-DQA1 or HLA-DQB1 in Swedish patients.

Many diseases with autoimmune features are associated with alleles of the human leucocyte antigen (HLA). However, few if any malignant disorders have reproducibly been shown to be HLA-associated. In three independent studies, using serological tissue typing techniques, an increase of the HLA class II specificity DR1 has been found in patients with multiple basal cell carcinomas. These observations prompted us to determine the frequencies of DRB1, DQA1, and DQB1 alleles by high-resolution genomic tissue-typing methods, including subdivision of the serological DR1 specificity in the four sequence-defined alleles, DRB10101 to DRB10104, in 50 unrelated Swedish patients with a history of four or more basal cell carcinomas and 250 healthy controls. The frequency of DR1 was the same in patients and controls (18%). All DR1-positive patients and controls carried the DQA10101 and DQB10501 alleles. Six of the nine DR1-positive patients and controls carried the DQA10101 and DQB10501 allels. Six of the nine DR1-positive patients were DRB10101-positive, one DRB10102 and two carried the DRB10103 allele. This distribution of DRB101 alleles did not differ from the one found in the controls. We conclude that genetic factors associated with the HLA class II region do not contribute significantly to the aetiology of multiple basal cell carcinomas.