HLA & immunogenetics

Celiac disease

HLA-DQ2 / DQ8

Celiac disease is an immune-mediated reaction to gluten associated with HLA-DQ2 and HLA-DQ8. Testing negative for both indicates a very low risk; a positive result does not confirm the diagnosis.

Key points

  • About 90 percent of patients carry HLA-DQ2, almost all the rest HLA-DQ8.
  • Many people with DQ2/DQ8 do not develop celiac disease; genotype alone cannot diagnose it.
  • When both types are absent, the risk is considered very low.

Why DQ2 and DQ8

HLA-DQ molecules present peptides from deamidated gluten to immune cells, and DQ2/DQ8 variants are particularly relevant to this process. This helps explain the genetic association, but does not by itself predict whether someone will develop the disease.

How to read the test

A positive DQ2/DQ8 result does not confirm celiac disease. Clinical assessment uses the history and serology; depending on the situation, a tissue sample may be needed. If both DQ2 and DQ8 are absent, risk is very low, but genetic typing does not replace clinical assessment.

What Genome measures. Whether HLA-DQ2 (DQA1*05:01 / DQB1*02:01) or HLA-DQ8 (DQB1*03:02) are present in the HLA typing, as risk or exclusion context.

Related topics

HLA and autoimmunityType 1 diabetesHLA typing

Sources

  1. 1Abadie et al., 2011 Integration of genetic and immunological insights into a model of celiac disease pathogenesis. Annual Review of Immunology 29:493-525. doi.org/10.1146/annurev-immunol-040210-092915
  2. 2Husby et al., 2020 European Society Paediatric Gastroenterology, Hepatology and Nutrition guidelines for diagnosing coeliac disease. Journal of Pediatric Gastroenterology and Nutrition 70:141-156. doi.org/10.1097/MPG.0000000000002497