Frequency distribution of HLA DQ2 and DQ8 in celiac patients and first-degree relatives in Recife, northeastern Brazil.

AIMS

The aim of this study was to evaluate the frequencies of the HLA genotypes DQ2 and DQ8 and the alleles A105, A10201, B10201 and B10302 in individuals with celiac disease in Recife, northeastern Brazil.

METHODS

HLA DQ2 and DQ8 genotyping was performed for 73 individuals with celiac disease and 126 first-degree relatives with negative transglutaminase serology. The alleles DQA105, DQA10201, DQB102 and DQB10302 were identified by sequencing using specific primers and the EU-DQ kit from the Eurospital Laboratory, Trieste, Italy and double-checked by the All Set SPP kit (Dynal).

RESULTS

Among the 73 cases, 50 (68.5%) had the genotype DQ2, 13 (17.8%) had DQ8, 5 (6.8%) had DQ2 and DQ8, and 5 did not have any of these genotypes. Among the 5 negative individuals, four had the B102 allele and one did not have any of the alleles studied. B102 was the most frequent allele in both groups (94% in the patients and 89% in the control relatives).

CONCLUSIONS

In this study, celiac disease was associated with the genotypes DQ2 and DQ8. DQ2 predominated, but the distribution of the frequencies was different from what has been found in European populations and was closer to what has been found in the Americas. The high frequencies of the HLA genotypes DQ2 and DQ8 that were found in first-degree relatives would make it difficult to use these HLA genotypes for routine diagnosis of celiac disease in this group.