Pathophysiology of celiac disease.

Area of Science:

• Immunology
• Genetics
• Gastroenterology

Background:

• Celiac disease (CD) is strongly associated with HLA-DQ2 and HLA-DQ8 molecules.
• These molecules present gluten-derived peptides to CD4 T cells, a key feature in CD pathogenesis.
• Tissue transglutaminase modification enhances gluten peptide binding to HLA-DQ2/8, explaining the genetic association.

Purpose of the Study:

• To explore the reasons behind the incomplete penetrance of celiac disease in genetically predisposed individuals.
• To discuss the variable age of onset and symptom presentation in celiac disease.
• To examine the role of multiple factors in celiac disease development using the multiple hit model.

Main Methods:

• Review of existing literature on celiac disease genetics and immunology.
• Discussion of the molecular mechanisms of gluten peptide presentation by HLA-DQ2/8.
• Application of the multiple hit model to explain disease variability.

Main Results:

• The genetic predisposition to celiac disease via HLA-DQ2/8 is well-established.
• The precise reasons for disease development in only a subset of HLA-DQ2/8 positive individuals remain unclear.
• Multiple extrinsic and intrinsic factors likely contribute to or protect against celiac disease development.

Conclusions:

• The strong association between celiac disease and HLA-DQ2/8 is understood at a molecular level.
• The variability in disease onset and presentation suggests a multifactorial etiology.
• The multiple hit model provides a framework for understanding the complex interplay of factors in celiac disease development.