Research Letters

Subclinical coeliac disease in schoolchildren from northern Sardinia

Early exposure to complex dietary proteins, such as cow milk and cereal proteins, or to fruit, berries, roots, or short-term breastfeeding have all been implicated as environmental factors affecting the risk for developing type 1 diabetes (T1D). Gluten proteins from wheat, rye, and barley have several distinct properties, which distinguish them from other cereal proteins, and are partly resistant to enzymatic degradation in the intestine. The proteins are a disease-initiating factor in celiac disease; moreover, gluten intake affects the development of T1D. In animal models of T1D, the pathogenesis is also influenced by diet, and a gluten-free diet largely prevents diabetes onset in contrast to a cereal-based diet that promotes diabetes development. Furthermore, two large, human prospective cohort studies have established a connection between early infant diet containing gluten and the development of autoantibodies against the pancreatic islets. Finally, there is evidence for a primary role of the intestinal immune system in the pathogenesis of T1D and intake of dietary gluten influences both the innate and the adaptive immune system and has a direct effect on pancreatic β cells.

To study the prevalence of autoimmune thyroiditis (AT) in Sardinian children with celiac disease (CD) and the effects of a gluten-free diet (GFD) on thyroid function.

Children with biopsy-proven CD (n = 324; female:male 2:1; mean age, 6.6 years) followed from 1 to 15 years, were retrospectively evaluated for AT at onset of CD and during GFD. Serum thyroid peroxidase and thyroglobulin antibodies (AbTPO, AbTG), thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and thyroid ultrasonography were considered. Age-matched Sardinian schoolchildren (n = 8040), previously evaluated for antithyroid antibodies and thyroid function, were used as controls.

Thirty-four patients with CD (10.5%) developed AT (female:male 4,5:1; mean age, 10.5 years), 11 at onset of CD and 23 during GFD, with a higher prevalence than controls (P = 2.9⁻¹³). Twenty-eight patients were euthyroid and 6 hypothyroid. AbTPO and/or AbTG persisted elevated for 2 to 9 years despite the GFD in 9 of 11 patients with AT at onset of CD.

AT is strongly associated with CD in Sardinian children, has an age of onset of 10.5 years, and appears to be gluten-independent. In children with CD with AT, the female:male bias reported in adult AT is present before puberty.

Several European studies have suggested a higher prevalence of celiac disease (CD) among infertile women (4% to 8%) compared with the general population (<1%). We screened a cohort of women with unexplained infertility in Northern California for the serum markers of CD, tissue transglutaminase and endomysium antibodies (EMA). Given that only one woman out of 121 (0.8%) screened positive for CD, it appears that CD is about as prevalent in this cohort of infertile women as in the general U.S. population (<1%).

Celiac disease is an immune-mediated enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. The major predisposing genes are located on the HLA system on chromosome 6, namely the HLA-DQ2 and DQ8 genes found in at least 95% of patients. Gluten is a complex mixture of storage proteins of wheat, a staple food for most populations in the world, and other cereals. Celiac disease is one of the most common lifelong disorders on a worldwide basis. The condition can manifest with a previously unsuspected range of clinical presentations, including the typical malabsorption syndrome (chronic diarrhea, weight loss, abdominal distention) and a spectrum of symptoms potentially affecting any organ or body system. It is a common disorder in children as well as in adults. The spectrum of clinical presentations is wide, and currently extraintestinal manifestations (e.g. anemia or short stature) are more common than the classical malabsorption symptoms. A high degree of awareness among healthcare professionals and a “liberal” use of serological celiac disease tests can help to identify many of the non-classic cases. The primary care doctor has therefore a central role in this process of case finding. Many key questions about this unique autoimmune condition remain unanswered. The answer to some of these questions may provide a better understanding of the pathophysiological mechanisms involved in the pathogenesis of celiac disease and, possibly of other autoimmune diseases, so paving the way to innovative treatment strategies.