Is periodic screening for coeliac disease in a high-risk group of patients worth it?

We present a young girl with Down syndrome and West syndrome who was referred to a paediatric gastroenterologist due to the suspicion of gastroesophageal reflux disease and coeliac disease. 

She was born in a family of healthy parents and has two older siblings, of which one has atopic dermatitis, and one has Gilbert’s syndrome. There is no coeliac disease in the family. After being born from a maintained pregnancy, she was breastfed for one month, and then milk formula was introduced. Supplementation of solid foods was introduced from 6 months, which she accepted, but prefers mixed or crushed food. She eats gluten regularly. Stools are regular, once daily. She is followed by geneticists and paediatric neurologists for Down and West syndrome and pulmonologists due to refractory bronchitis. 

In another institution, the diagnosis of gastroesophageal reflux disease was suspected by the presence of symptoms, which included occasional vomiting and regurgitation of food. In addition, according to the recommendation of geneticists, coeliac disease screening was performed with the following results: IgA 0.7 g/L (normal levels), anti tTG 0.1 U/ml (negative <7), IgG DGP 30 U/ml (positive > 10). Because of increased DGP antibodies, she was referred to our department.

When she was seen for the first time in our Department, she was 2 years and eight months. She was in an excellent general condition, bodyweight is 13.4 kg (81. percentile, 0.86 z score; adjusted for Mb. Down data), with phenotypic characteristics of Down syndrome, with regular, soft abdomen, painless on palpation, with no resistance. She was eating gluten with no restrictions. The laboratory values of total IgA levels and anti-tTG levels were interpreted as normal, and the elevation of IgG DGP levels as non-specific. However, since Down syndrome is more often associated with coeliac disease, it was necessary to determine the genetic predisposition for coeliac disease (HLA DQ heterodimer). The recommendation to continue giving gluten in the diet was given to parents, and the recommendation to repeat coeliac disease-specific serology in six months. 

Before the next visit, the mother presented the child’s results of HLA heterodimer, and she has HLA DQ heterodimer 2.5 – a positive genetic predisposition for coeliac disease, which means that it is necessary to periodically determine antibodies specific to coeliac disease because the coeliac disease can develop at any time in life.

At three years and five months, on a regular appointment, the child was in good general condition, with no symptoms or feeding problems, with standard, regular stools. She was thriving, with a bodyweight of 14.8 kg (80. percentile, 0.84 z score) and body height of 91.2 cm (77. percentile, 0.73 z); adjusted for Mb. Down data. Her coeliac-specific serology was normal, with anti-tTG levels of 0.1 U/ml and a total IgA of 0.7 g/L. It was concluded that the clinical and laboratory findings so far do not indicate coeliac disease, but further monitoring is needed due to a positive genetic predisposition. The continuation of an age-appropriate diet was advised, without any restrictions. The next appointment was scheduled for a year with new anti-tTG serology tests. 

At the scheduled appointment, our patient was still in good clinical condition. She is now four years and six months old, gaining on bodyweight with 16.6 kg (72. percentile, 0.57 z), but less on height, 96 cm (52. percentile, 0.06 z), which can be attributed to her diagnosis of Down syndrome. She is in good general condition, with no abdominal pains, regular stools, and no feeding problems. However, her laboratory values of coeliac-specific serology reveal anti-tTG levels of > 128 U/ml (>10 = positive), which is more than ten times the upper limit of normal. Endomysial antibodies (EMA) from the second blood sample were ordered and they came back positive. Coeliac disease was diagnosed with no biopsy approach, according to ESPGHAN 2020 guidelines and gluten-free diet was started.

Conclusion: 

Patients with autoimmune diseases and developmental diseases such as diabetes mellitus type I, autoimmune liver disease, autoimmune thyroid disease, Down syndrome, Turner syndrome, William’s syndrome, and patients with IgA deficiency as well as patients who have a first-degree relative with CD also have a higher risk of developing CD and should be screened periodically¹.

Coeliac disease is still underdiagnosed due to the varied presentation of clinical signs and symptoms. European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) provides new and updated summary guidance on diagnosing children and adolescents with CD².

What is new in the 2020 guidelines?³

• For initial testing, the combination of total IgA and IgA class antibodies against transglutaminase 2 (TGA-IgA) is recommended as this is most accurate and cost-effective. Testing for EMA, DGP or AGA antibodies (IgG and IgA) as initial screening in clinical practice is not recommended.
• Normal IgA – interpret only IgA antibodies
• In groups at risk (Syndrome Down included) the screening for coeliac disease should be started by HLA-DQ2 and HLA-DQ8 typing if the test is available.
• If an IgA-competent subject is negative for all of the IgA class CD antibodies but has IgG class anti-TG2 or EMA or anti- DGP positivity, a decision on additional testing should be made after considering all of the laboratory and clinical parameters, including the clarification of a previous reduction of gluten intake
• The no-biopsy approach for CD diagnosis is confirmed to be safe in children with high TGAIgA values ≥10 times the upper limit of normal with accurate, appropriate tests and positive endomysial antibodies (EMA IgA) in a second serum sample.
• Children with positive TGA-IgA but lower titers (<10 times upper limit of normal) should undergo biopsies to decrease the risk of a false-positive diagnosis. CD can be diagnosed without duodenal biopsies in asymptomatic children, using the same criteria as in patients with symptoms.

You can access the diagnostic algorithm here.

References:

1. Husby S, Koletzko S, Korponay-Szabó IR, et al. European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines for the diagnosis of coeliac disease. J Pediatr Gastroenterol Nutr. 2012;54(1):136-160. doi:10.1097/MPG.0b013e31821a23d0

2. Husby S, Koletzko S, Korponay-Szabó I, et al. European Society Paediatric Gastroenterology, Hepatology and Nutrition Guidelines for Diagnosing Coeliac Disease 2020. J Pediatr Gastroenterol Nutr. 2020;70(1):141-156. doi:10.1097/MPG.0000000000002497

3. https://www.espghan.org/knowledge-center/publications/Clinical-Advice-Guides/2020_New_Guidelines_for_the_Diagnosis_of_Paediatric_Coeliac_Disease