Gluten Immunochemistry - HLA-DQ Recognition of Gluten - HLA-DQ8

HLA-DQ8

HLA-DQ8 confers susceptibility to coeliac disease but in a fashion somewhat similar to DQ2.5. Homozygotes of DQ8, DQ2.5/DQ8 and DQ8/DQ2.2 are higher than expected based on levels in the general population.(see: Understanding DQ haplotypes and DQ isoforms). HLA-DQ8 is generally not as involved in the most severe complications, and it does not recognize the "33mer" of α-2 gliadin to the same degree as DQ2.5. There are a smaller number of gliadin (prolamin) peptides presented by HLA-DQ8. A few studies have been done on the adaptive immune response for DQ8/DQ2- individuals. DQ8 appears to rely much more on adaptive immunity to the carboxyl half of alpha gliadins. In addition, it appear to react with gamma gliadin to a degree comparable to DQ2.5. T-cell responses to the high molecular weight glutenin may be more important with DQ8 mediated than DQ2.5 mediated celiac disease.