Celiac Disease

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DESCRIPTION

Celiac disease (CD) is a systemic immune-mediated disorder caused by a permanent sensitivity to gluten in genetically susceptible individuals.

  • “Gluten” is the collective term for specific alcohol-soluble proteins (called prolamins) that are found in wheat, rye, and barley.
  • “Classic CD” refers to children who present predominantly 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, many 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” is a rare but serious manifestation of CD that consists of severe, watery diarrhea, electrolyte disturbances, dehydration, hypotension, and lethargy.
  • “Potential CD” refers to patients with positive serologic testing but no duodenal villous atrophy. Some of these “potential CD” patients progress to develop CD over time on a gluten-containing diet and should be monitored.

EPIDEMIOLOGY

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

RISK FACTORS

Genetics

  • There is an increased prevalence in patients with 1st-degree relatives with CD (10%).
  • Human leukocyte antigen (HLA)-DQ2 and HLA-DQ8 are permissive of CD but are not sufficient.
    • Having the DQ2/DQ8 antigens does not mean one has or will have CD.
    • If negative for DQ2/DQ8, it is unlikely that one has or will develop CD.
    • >90% of CD patients carry HLA-DQ2; 8–10% carry HLA-DQ8.
    • DQ2.5 homozygosity carries the highest risk.
    • Low positive predictive value (40% of the 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

  • For 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 (sIgAD): 8% have CD; 1–2% of CD patients have sIgAD.
  • Williams syndrome
  • Down syndrome
  • Turner syndrome
  • Juvenile idiopathic arthritis

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