HLA-DQ and risk gradient for celiac disease

Area of Science:

• Immunogenetics
• Gastroenterology
• Pediatrics

Background:

• Celiac disease (CD) is a multifactorial autoimmune disorder with a strong genetic component.
• Specific Human Leukocyte Antigen (HLA) alleles, particularly DQ2 and DQ8, are critical for CD development.
• Genetic predisposition plays a crucial role in understanding CD pathogenesis.

Purpose of the Study:

• To investigate the clinical relevance of HLA DR-DQ gene typing in Italian children with celiac disease.
• To determine the association between specific HLA alleles and celiac disease predisposition.
• To establish a risk gradient for celiac disease based on HLA genotype.

Main Methods:

• DR-DQ gene typing was performed on 437 Italian children with celiac disease, 834 first-degree relatives, and 551 controls.
• Statistical analysis was used to assess the association between HLA alleles and disease status.
• Prevalence and risk stratification were calculated based on identified HLA genotypes.

Main Results:

• 91% of celiac disease patients carried DQ2 and/or DQ8 heterodimers.
• The presence of the beta half of the DQ2 dimer was strongly associated with CD predisposition (p = 4 x 10(-12)).
• A risk gradient was observed, from 1:7 for DQ2/DQ8 individuals to 1:2518 for those lacking predisposing factors.

Conclusions:

• HLA testing is of significant clinical relevance for predicting celiac disease risk.
• Specific HLA genotypes, including DQB1*02 and DQB1*0302 concurrence and DQB1*02/*02 homozygosity, influence genetic determination of CD.
• Individuals without susceptible HLA factors were not affected, highlighting the test's predictive power.