A 2-year-old male presents with weight loss. The mother states his pediatrician first noticed impaired growth around 12 months of age. The mother also noticed his abdomen looked more distended over the last few months and he is more irritable than usual. She describes a vague history of looser stools without overt hematochezia. Pediatric gastroenterology was consulted and sent blood work which was remarkable for mild anemia and positive anti-tissue transglutaminase immunoglobulin A antibodies (TTG IgA). The patient underwent an upper endoscopy with biopsies, which was visually remarkable for erythematous duodenal mucosa with scalloping of the intestinal folds (Figures 60-1 and 60-2).
Histology demonstrated increased intra-epithelial lymphocytes (IEL) with villous blunting, confirming the diagnosis of celiac disease (Figure 60-3). The patient was placed on a gluten free diet and has had improved growth and normalization of laboratory values.
Worldwide distribution has been demonstrated despite the incorrect historical view that celiac disease was limited to the Caucasian population.1
Incidence of various countries:2
US—1:100 to 1:200.
Europe—1:88 to 1:262.
Middle East—1:87 to 1:166.
South America—1:67 to 1:681.
India—1:100 to 1:310.
True incidence likely unknown given wide variation in presentation, as illustrated by the “celiac iceberg” (Figure 60-4).
FIGURE 60-4
The “celiac iceberg” as an illustration of the various manifestations of celiac disease. The top level represents symptomatic patients with typical mucosal lesions. The middle level represents asymptomatic patients with typical mucosal lesions. The bottom level represents asymptomatic patients with normal mucosa who will likely develop celiac disease at some point in their lifetime. The common denominator is the genetic predisposition of HLA-DQ2 and DQ8. (Provided by The NASPGHAN Foundation for Children’s Digestive Health and Nutrition and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition. www.naspghanfoundation.org and www.naspghan.org.)
Celiac disease is an autoimmune disorder related to the ingestion of gluten containing foods (wheat, barley, and rye) in genetically susceptible individuals.3,4
Genetic predisposition linked to human leukocyte antigen (HLA)-DQ2 and DQ8.3,4
More than 95 percent of patients with celiac disease have the HLA-DQ2 heterodimer, with the remainder positive for the HLA-DQ8.
Presence of the HLA-DQ2 molecules does not necessarily confer disease as 30 to 40 percent of the Caucasian population possesses this genetic background, without developing celiac disease.
Upon ingestion of gluten containing foods, activation of the immune system occurs as follows:5,6
Deamidation of the gluten proteins by tissue transglutamine 2 (TG2) and formation of an antigen complex, which includes DQ2 and DQ8.
This antigen complex is presented to T cells, which become activated T cells and release antibodies to TG2 and gliadin peptides, along with pro-inflammatory cytokines.
The presence of other disorders places patients at-risk of developing of celiac disease.3,7 These disorders with associated prevalence rates are:
Type I diabetes (8%).
Autoimmune thyroiditis (2%).
Down’s Syndrome (5 to 12%).
Turner Syndrome (4.1 to 8.1%).
Williams Syndrome (8.2%).
Selective IgA deficiency (1.7 to 7.7%).
In a study by Fasano et al., the prevalence of celiac disease in a not at-risk population was 1:133 and increased to 1:22 in first degree relatives of patients with established celiac disease.8
