The association between type 1 diabetes (T1D) and other autoimmune diseases is well known.
The prevalence of celiac disease (CD) ranges from 1% to 10% among children and adolescents with T1D.
The risk of associated CD is inversely and independently associated with age at diagnosis, with the greatest risk in those diagnosed with T1D before the age of 5 years. Classical symptoms of CD as poor growth, weight loss, gastrointestinal symptoms, abdominal pain and anaemia are rare in children with T1D, as most of the children with T1D and CD are asymptomatic. Therefore, international guidelines recommend screening for CD in children with T1D. Screening is based on IgA antibodies (tissue transglutaminase (tTG-A) and/or endomysial (EmA). As IgA deficiency is more common in people with T1D and those with CD, IgA deficiency has to be excluded. If the child is IgA deficient, IgG-specific antibody tests (tTG or EMA IgG, or both) need to be used for screening.
Recent guidelines recommend testing for HLA-DQ2 and HLA-DQ8 because CD is unlikely if both haplotypes are negative. As a high proportion of patients with T1D carry these risk alleles, HLA testing as first line screening test for CD is not practical.
If CD specific antibodies are positive, a small bowel biopsy is needed to confirm the diagnosis by demonstrating subtotal villus atrophy using Marsh classification.
tTG positivity at the time of diabetes onset may also be transient emphasizing the need of retesting of CD specific antibodies and the the need of duodenal biopsy to verify diagnosis.
A gluten-free diet normalizes the bowel mucosa and leads to normalization of antibodies. The aim of the gluten-free diet also includes the reduction of gastrointestinal malignancy and conditions associated with malabsorption as iron deficiency and osteoporosis. Furthermore, recent studies show that patients with T1D and CD may have a higher risk for retinopathy and non-adherence to gluten-free diet may increase the risk for albuminuria. Children and adolescents with T1D, with poor adherence to a gluten-free diet, may also have worse glycemic control and reduced quality of life.
Screening for CD in children and adolescents with T1D is recommended at time of diabetes onset and at 2 and 5 years thereafter. More frequent measurements are indicated if the patients has clincal symptoms or a first-degree relative with CD.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology