[High frequency of DQ8 in the celiac population of Chaco province, Argentina].

Background: There is a strong association between celiac disease (CD) and certain genes of the major histocompatibility complex (HLA). The CD specifically related alleles are those coding for HLA-DQ2 heterodimer and to a lesser degree for HLA-DQ8. OBJECTVE. The aim of this study was to evaluate the frequency of HLA-DQB1* and HLA-DRB1* alleles, haplotypes, and genotypes in patients diagnosed with CD and in control population of Chaco, in order to establish its distribution and compare it with that observed in other populations.

Methods: A total of 139 samples from patients diagnosed with CD and 119 healthy controls were typed for HLA-DQ and HLA-DR, using PCR and reverse hybridization (INNO-LiPA or Dynal).

Results: Comparing patients with CD vs. controls, the DQBI*0201 (P = 0.0002), DQBJ*0202 (P = 0.0046), DQBI*0302 (P = 0. 0006), DRBl *03 (P = 0.0002), DRBl *04 (P = 0.0199) and DRB1 *07 (P = 0.0062) were significantly increased, while a decrease was observed in HLA-DQB1*0301 (P = 0.0006), HLA-DQBI*0303 (P = 0.0070), DQBI*0501 (P = 0.0023), DQB1*0604 (P = 0.0140) DRB1*01 (P = 0.0023), DRB1*08 (P = 0.0165), DRB1*09 (P = 0.0362) and DRB1*16 (P = 0.0228). Within DQB1* genotypes associated with EC, 65.4% of patients had the DQB1*02 in linkage disequilibrium with DRB1*03 or DRB1*07 (DQ2), and 43.2% presented genotype DQB1*0302 in linkage disequilibrium with DRB1*04 (DQ8). Both genotypes were shared by 15.2% of them.

Conclusions: We point out the high frequency of DQ8 associated with CD. Although the DQ2 is still the most common, this finding could be attributed to the Amerindian influence in our population.