(30-10-09) Should we screen for coeliac disease? Yes

Alessio Fasano, director
1 Mucosal Biology Research Center and Center for Celiac Research, University of Maryland School of Medicine, Baltimore, MD 21201, USA
[email protected]

Coeliac disease often goes undiagnosed. Alessio Fasano argues that screening would prevent considerable morbidity, but Kate Evans and colleagues (doi:10.1136/bmj.b3674) think we do not know enough about the effects on people without symptoms
Coeliac disease is an immune mediated enteropathy triggered by the ingestion of gluten, the major protein component of wheat, and related proteins in rye and barley, in genetically susceptible individuals.1 It is one of the most common lifelong disorders, affecting 0.5-1% of the population.2 Many of those affected are not diagnosed because of the wide spectrum of clinical presentations. People who remain undiagnosed are at risk of long term complications, including infertility, osteoporosis, and lymphoma. Therefore prompt diagnosis is important not only to enable appropriate treatment of symptoms but to prevent future complications. Since diagnosis currently takes 7-10 years,3 serological screening will increase the quality of life for many people.
Increased awareness of the disease, coupled with a low threshold for serological testing, will undoubtedly uncover a large portion of those with undiagnosed disease. What remains to be established by cost effectiveness analyses is whether we should adopt mass screening of the general population or focus resources on people who are at risk of coeliac disease, such as patients with symptoms (osteoporosis, anaemia, infertility, etc) or other conditions associated with the disease (type 1 diabetes, Hashimoto?s disease, Down?s syndrome) and first and second degree relatives of patients.4
Screening is good public health policy
The reported prevalence of coeliac disease worldwide is much higher than that of several other conditions such as congenital hypothyroidism or phenylketonuria for which mass screening programmes are accepted as proper public health policy.5 The disease also meets the World Health Organization criteria for mass screening programmes6:
Early clinical detection is difficult?Coeliac disease was initially described as a paediatric gastrointestinal condition. We now know that it can affect people at any age and can manifest in a wide range of symptoms potentially affecting any organ or body system.2 7 Many undiagnosed patients accept a state of chronic, vague, ill health as normal. Early detection based on clinical suspicion is therefore difficult, and many patients remain undiagnosed for many years and exposed to the risk of long term complications.8
Condition is common?Once considered to almost exclusively affect white Europeans, coeliac disease is now known to be widely distributed worldwide.2 Recent epidemiological studies conducted in areas supposedly free of coeliac disease, including Africa, the Middle East, Asia, and South America, show that the disease was underdiagnosed,9 providing evidence that coeliac disease is one of the commonest genetically based diseases affecting humans.
Screening tests are highly sensitive and specific?The tools for screening for coeliac disease are much more accurate than those for other chronic conditions. The discovery of tissue transglutaminase as the autoantigen target of the immune response, together with the appreciation of the key role of HLA DQ2/DQ8 in pathogenesis of the disease, led to the development of new diagnostic algorithms that reached sensitivity and specificity close to 100% in populations at risk and 70-75% in mass screening.10 11
Effective treatment is available?Since the pathogenesis of the disease is related to the interplay between genes and gluten and related proteins, the cornerstone of treatment is a strict gluten-free diet.11 12 Dietary treatment generally results in an improvement in symptoms and healing of the coeliac enteropathy within a matter of months, and this provides additional diagnostic confirmation.
Untreated disease can lead to complications?Given the undisputable role of gluten in causing autoimmunity, coeliac disease represents a unique example of an immune mediated disease for which early diagnosis and dietary treatment can prevent severe, sometimes life threatening complications. Patients with undiagnosed and untreated disease have increased morbidity and mortality from associated conditions13 and risk chronic ill health, permanent stunted growth, infertility, skeletal disorders, and malignancy.2 These patients also incur increased healthcare costs because of the multiple visits to specialists and laboratory tests required before the correct diagnosis is obtained. Mortality at every age is twofold greater in people with untreated coeliac disease than in those with treated disease and the general population.13
Screening is cost effective
Recent studies suggest that screening is also cost effective. According to Shamir and colleagues mass screening would cost $49 491 (?31 000; 35 000) per life year gained using endomysial antibodies and $572 616 using transglutaminase antibodies.14 Green and colleagues also showed that an increase in diagnosis was associated with a significant reduction in medical costs and use of selected healthcare services over time.15 Screening for coeliac disease would thus be a good return on investment for patients, public health policy makers, and healthcare systems.

Source: Published 17 September 2009, doi:10.1136/bmj.b3592
Cite this as: BMJ 2009;339:b3592

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