Celiac Disease

Basics

Description

  • Celiac disease (CD) is a systemic immune-mediated disorder caused by a permanent sensitivity to gluten in genetically susceptible individuals.
  • “Gluten”
    • The collective term for specific alcohol-soluble proteins (called prolamines) that are found in wheat, rye, and barley
  • “Classic CD”
    • Refers to children who present predominately with malabsorptive symptoms including diarrhea, abdominal pain, vomiting, and abdominal distention in the setting of suboptimal growth and irritability
    • The majority of children presenting with CD do not have classic symptoms. For example, the majority have constipation rather than diarrhea.
  • “Silent CD”
    • Defines a minority of people with CD who have no identifiable symptoms but have consistent intestinal mucosal lesions and elevated serum antibodies
  • “Celiac crisis”
    • A rare but serious manifestation of CD
    • Consists of severe watery diarrhea, electrolyte disturbances, dehydration, hypotension, and lethargy
  • “Potential CD”
    • Patients with positive serologic testing but normal intestinal histology
    • Some, but not all, of these “potential CD” patients develop CD over time on a gluten-containing diet

Epidemiology

  • CD is present in approximately 1% of the U.S. population, but only a small proportion have been diagnosed.
  • Average age at diagnosis of pediatric CD in the United States is approximately 9 years old.
  • Females are more affected than males.

Risk Factors

Genetics

  • There is increased prevalence in patients with 1st-degree relatives with CD (10–15%).
  • HLA-DQ2 and HLA-DQ8 haplotypes are “necessary but not sufficient” for CD.
    • >90% of CD patients carry HLA-DQ2, 5% carry HLA-DQ8.
    • High negative predictive value for negative DQ2/DQ8 testing
    • Low positive predictive value (30% of general population in North America is HLA-DQ2 positive.)
  • Numerous other genes have been identified as increasing CD susceptibility.
  • A family or personal history of autoimmune disease is also associated with CD.

Pathophysiology

  • In people with CD, ingestion of gluten leads to an enteropathy of the small intestine characterized by mucosal inflammation and villous atrophy.
  • Generation of unique serologic autoantibodies and development of a diverse spectrum of signs and symptoms also occur.
  • Elimination of gluten, via implementation of a strict gluten-free diet (GFD), leads to intestinal healing, normalization of elevated antibody levels, and resolution of related symptoms.

Commonly Associated Conditions

  • Autoimmune thyroiditis
  • Type 1 diabetes mellitus
  • Sjögren syndrome
  • Selective IgA deficiency
  • Williams syndrome
  • Down syndrome
  • Turner syndrome

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