Celiac Disease in Children

Celiac disease (CD), or gluten-sensitive enteropathy, is an immune-mediated enteropathy triggered by the ingestion of gluten-containing cereals (wheat, barley, and rye) in genetically susceptible individuals. Undiagnosed CD may cause intestinal (e.g. chronic diarrhea, failure to thrive) and/or extra intestinal (e.g. anemia, osteoporosis, dermatitis herpetiformis) manifestations. The etiology of CD is multifactorial, with both genetic and environmental factors involved in disease development. Susceptibility to CD is primarily associated with the human leukocyte antigen HLA-DQ2 allele. The heterodimer DQA1\*0501 and DQB1\*0201 is detected in up to 95% of persons with celiac disease, with the remaining 5% expressing HLA-DQ8 (DQA1\*0301, DQB1\*0302). The frequency of these alleles in the general populations in Western countries is 20% to 30%. Therefore, an individual not carrying DQ2 or DQ8 alleles is extremely unlikely to develop CD. Celiac disease is associated with a host of autoimmune diseases such as type 1 diabetes mellitus, autoimmune thyroid disease, Addison disease, autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis, and immunoglobulin (Ig) A deficiency. There is also an increased prevalence of CD in patients with genetic disorders such as Down syndrome and Turner syndrome. Serologic testing is recommended as the first step in pursuing a diagnosis of CD, however, small-bowel mucosal biopsy is currently considered the gold standard for diagnosing CD. All serologic tests and small-bowel biopsies need to be performed while the patient is on a gluten-containing diet. The characteristics of small intestine biopsies from CD include partial or complete villous atrophy, crypt hyperplasia, and intraepithelial lymphocyte infiltration. According to the modified Marsh classification, the intestinal damage is divided into four stages. Stage 0 intestinal damage is characterized by the lesion invasion in the mucous layer, the increased number of intraepithelial lymphocytes and the presence of lymphocytes in the lamina propria, whereas Stage 1 damage features microscopic enteritis with an increase of intraepithelial lymphocytes. A feature of Stage 2 intestinal damage is crypt hyperplasia along with villous atrophy while Stage 3 is characterized by a complete atrophy of the intestinal villi. Treatment of CD includes lifelong gluten-free diet. The clinical and histological benefits of a gluten-free diet (GFD) in the management of CD are well recognized showing that the degree of histological recovery is dependent upon how strict the patient adheres to the diet.