HLA DQ and DP in Finnish families with celiac disease.

We studied DQA1, DQB1, and DPB1 alleles in 31 Finnish families with celiac disease (CD). All healthy first-degree relatives underwent clinical investigation, including in most cases biopsy, to establish whether clinically silent CD was present. Our results indicate that all patients, having either full clinical CD or its silent form, had the susceptibility alleles DQA1*0501 and DQB1*0201. The different clinical outcomes of CD were therefore not directly determined by the DQ alleles. The frequency of DPB1*0101 was also higher in CD patients, but the association appeared secondary to those of DQA1*0501 and DQB1*0201 (DQ2). The primary association of CD with the DQA1*0501 and DQB1*0201 alleles, rather than with HLA haplotypes, was confirmed in multiplex families.