Key learning points:
– Coeliac disease is one of the most common autoimmune conditions in the UK, affecting 1% of the population
– The disease remains undiagnosed, therefore nurses should be aware of the wide variety of presentations of coeliac disease
– The only treatment for coeliac disease is a strict lifelong gluten free diet which should be curative for the vast majority of patients
Coeliac disease is a common autoimmune condition characterised by an abnormal immunological response to ingested gluten. This abnormal reaction leads to small intestinal damage, termed villous atrophy, which in turn leads to the clinical symptoms of coeliac disease. The umbrella term, gluten is used to describe a group of similar proteins found in the cultivated grains of wheat (gliadin), barley (hordein) and rye (secalin) that are ubiquitous in the western diet.
Until the early 1980s coeliac disease was considered a rare condition, with estimated prevalence rates of one-in-4000.1 However, data from large scale screening studies in both adult and paediatric populations now estimate the prevalence of coeliac disease in western populations to be around one-in-100.2 Furthermore, modern studies suggest that the prevalence of coeliac disease may be increasing.3 Meta-analysis studies combining data from multiple studies from early in the 21st century, estimated that for every patient identified as having coeliac disease seven to eight individuals with the disease remained undiagnosed.4 However, diagnostic rates for coeliac disease are improving with a recent UK study estimating the prevalence of diagnosed coeliac disease now being 0.24%. Nonetheless this would still suggest that 75% of patients with coeliac disease remain undiagnosed.5
Who gets coeliac disease?
Historically coeliac disease was considered a disease affecting white western populations, however it is now apparent that coeliac disease is a global problem. Clinicians from both China and India amongothers are now recognising patients with coeliac disease. This change may be due to the introduction of wheat into these ethnic groups as their diet becomes more westernised, an increasing trend in all autoimmune diseases in these populations as the impact of infectious disease is reduced or improving healthcare systems detecting more cases.3
In common with other autoimmune diseases, patients are at increased risk of coeliac disease if they have another autoimmune condition, particularly type 1 diabetes mellitus and autoimmune thyroid disease. There is also a strong genetic component to coeliac disease and patients with a first degree relative (parent or sibling) with coeliac disease having roughly a 10% chance of being affected.6 Patients with a more distant relative affected may also appear to be at a slightly increased risk, although there is uncertainty as to the exact prevalence in these patients.7 Identical twins have a 75% chance of being affected if their twin is diagnosed with coeliac disease.
What are the symptoms of coeliac disease?
The presentation of coeliac disease can be extremely variable from gross malabsorption (inability to absorb nutrients from the diet) to mild non-specific abdominal symptoms and asymptomatic patients picked up on family screening or for investigation of asymptomatic anaemia. Until relatively recently the majority of patients were children presenting with symptoms of malabsorption: weight loss, chronic diarrhoea, or failure to thrive.1 However, it is now recognised that coeliac disease is common, usually presenting in adulthood in the 30s and 40s and more commonly without frank malabsorption symptoms.7 These so called “non-classical” presentations include irritable bowel syndrome (IBS) type symptoms, abdominal pain, altered bowel habit and anaemia (most commonly iron deficiency). However, it must be noted that coeliac disease is under-diagnosed and clinicians need to be aware of the variable manifestations of coeliac disease that may not include abdominal symptoms or signs of malabsorption.
Who should be tested for coeliac disease?
Case-finding in patient groups at risk of coeliac disease is the approach to diagnosis and is recommended by current national and international guidelines as the best method of case detection.8,9 The aim of case-finding is to identify patients at an early stage of their disease which may reduce the risks of developing intractable symptoms or the serious complications of coeliac disease such as osteoporosis or anaemia or more rarely lymphoma. The best evidence for testing for abdominal symptoms comes from 2 meta-analyses in patients with symptoms consistent with IBS. IBS symptoms are very common in patients with coeliac disease, affecting 38% of patients,10 and the prevalence of coeliac disease is 4.1% in patients presenting with IBS type symptoms.11 Identification of patients without intestinal symptoms at increased risk is also important to avoid missed diagnoses.8 Case finding is justified in these groups as there may be an improvement in the extra-intestinal manifestations on a gluten free diet as well as potentially reducing the risk of other known coeliac complications. Examples of this already discussed include patients with anaemia or osteoporosis who may have subclinical malabsorption. Guidelines recommend that patients with a first-degree relative with coeliac disease and patients with newly diagnosed type 1 diabetes should also be offered testing. The National Institute for Health and Care Excellence realeased clinical guidance (CG86) in 2009 to help healthcare professionals recognise and assess patients who are suspected to have coeliac disease.12
How should I test for coeliac disease?
One reason for increased awareness of the variable presentation of coeliac disease is the availability of appropriate screening blood tests. These tests have excellent sensitivity and specificity when used correctly. All patients with suspected coeliac disease should be offered serological testing in the first instance. It is of vital importance that patients should remain on a normal gluten containing diet for testing. There are several tests available. Endomysial antibody (EMA) was the first widely available accurate serological test. However, EMA does have some drawbacks. Firstly it is a subjective test and ‘weak positive’ results may be less accurate than ‘strong positive’ results; secondly the substrate required for the test is based on monkey oesophagus and has limited availability; and finally it may be less sensitive than tissue transglutaminase antibodies (tTG) that have become more widely available. The screening test of choice is now tTG as it has several advantages over EMA. Firstly, a quantitative result and cut-off value are provided which reduces the subjective nature of the assay; tTG is usually cheaper and is generally more sensitive, with a higher negative predictive value than EMA, making it an ideal screening test.
Adult patients with a positive serological test, or a high suspicion of coeliac disease should be offered a duodenal biopsy, taken by endoscopy, to confirm the presence of villous atrophy. Recent European paediatric guidelines suggest an algorithm for avoiding biopsy in a small proportion of paediatric patients.13 This may be understandable in children where biopsy may require a general anaesthetic and all paediatric patients should be referred to a paediatrician for further evaluation. Duodenal biopsy to confirm diagnosis is still required in adults, however, for several reasons. Firstly although the performance of serology appears to be excellent (generally both above 90%), the studies into each test are invariably performed in high prevalence populations. When the disease prevalence within the tested population is lowered the positive predictive value of the test will also fall. For example in a recent large study the positive predictive value of tTG was only 28.6%, despite sensitivity and specificity of greater than 90%.14 Meaning if a patient was diagnosed on the basis of serology alone over 70% of patients would be placed on a lifelong gluten free diet when they do not have coeliac disease. Secondly a clinical response to a gluten free diet is not diagnostic of coeliac disease particularly in patients with IBS symptoms which may be gluten sensitive in the absence of coeliac disease and Crohn’s disease that can be pseudo improved by a gluten free diet. Also the presence of villous atrophy on a duodenal biopsy gives concrete evidence of coeliac disease which is helpful for counselling patients, ensuring prescription of gluten free foods and assessing improvement on a gluten free diet. If patients do not respond to a gluten free diet as expected, any uncertainty in the initial diagnosis can make subsequent evaluation problematic. Finally the emerging entity of non-coeliac gluten sensitivity may also improve on a gluten free diet – thus it is imperative to make a positive diagnosis of coeliac disease.
Managing coeliac disease
Currently the only known treatment for coeliac disease is a lifelong gluten free diet. Removing gluten from the diet should allow the small bowel to heal and improve symptoms and reduce malabsorption. However, patients do find a gluten free diet difficult to adhere to and many find it a less than satisfactory treatment. Efforts are under way into investigating novel treatments for coeliac disease such as enzymes capable of digesting gluten and a potential therapeutic vaccine, although none of these have yet reached fruition.
Quality of life in patients with coeliac disease is improved when patients feel they are able to adhere to their gluten free diet. As a result all patients with biopsy confirmed coeliac disease should be referred to an expert dietician for further advice on the gluten free diet. Patients should also be encouraged to consider joining a support charity such as Coeliac UK as this has also been shown to improve adherence.
Nutrient deficiency including folate, ferritin and B12 as well as anaemia is common in coeliac disease and levels should be checked annually with appropriate replacement. Patients with coeliac disease are also at risk of reduced bone mineral density due to malabsorption and should have vitamin D and calcium levels checked at diagnosis. If levels are low or there are other risk factors, they should then be referred for bone mineral density measurement with DEXA scanning.
Finally all patients should be offered pneumococcal vaccination as they are at risk of functional hyposplenism.
Coeliac disease is one of the most common autoimmune conditions in the UK. However, unlike many autoimmune conditions the trigger for coeliac disease is well known and removal of gluten from the diet should result in complete recovery. The diagnosis of coeliac disease has improved greatly over the last decade and more people are now being tested and diagnosed, however, 75% of patients remain undiagnosed. Clinicians need to be aware of the wide variation in presentation of coeliac disease and have a low threshold for testing. Importantly coeliac serology tests are for screening only and a confirmatory duodenal biopsy should remain mandatory to make a diagnosis of coeliac disease in all adult patients.
1. Davidson LS, Fountain JR. Incidence of the sprue syndrome; with some observations on the natural history. British medical journal. 1950;1(4663):1157-61.
2. Mustalahti K, Catassi C, Reunanen A, Fabiani E, Heier M, McMillan S, et al. The prevalence of celiac disease in Europe: results of a centralized, international mass screening project. Annals of medicine.
3. Lohi S, Mustalahti K, Kaukinen K, Laurila K, Collin P, Rissanen H, et al. Increasing prevalence of coeliac disease over time. Alimentary pharmacology & therapeutics. 2007;26(9):1217-25.
4. van Heel DA, West J. Recent advances in coeliac disease. Gut. 2006;55(7):1037-46.
5. West J, Fleming KM, Tata LJ, Card TR, Crooks CJ. Incidence and prevalence of celiac disease and dermatitis herpetiformis in the UK over two decades: population-based study. The American Journal of Gastroenterology. 2014;109(5):757-68.
6. Esteve M, Rosinach M, Fernandez-Banares F, Farre C, Salas A, Alsina M, et al. Spectrum of gluten-sensitive enteropathy in first-degree relatives of patients with coeliac disease: clinical relevance of lymphocytic enteritis. Gut. 2006;55(12):1739-45.
7. Fasano A, Berti I, Gerarduzzi T, Not T, Colletti RB, Drago S, et al. Prevalence of celiac disease in at-risk and not-at-risk groups in the United States: a large multicenter study. Archives of internal medicine. 2003;163(3):286-92.
8. Ludvigsson JF, Bai JC, Biagi F, Card TR, Ciacci C, Ciclitira PJ, et al. Diagnosis and management of adult coeliac disease: guidelines from the British Society of Gastroenterology. Gut. 2014;63(8):1210-28.
9. Rubio-Tapia A, Hill ID, Kelly CP, Calderwood AH, Murray JA, American College of G. ACG clinical guidelines: diagnosis and management of celiac disease. The American Journal of Gastroenterology. 2013;108(5):656-76; quiz 77.
10. Sainsbury A, Sanders DS, Ford AC. Prevalence of irritable bowel syndrome-type symptoms in patients with celiac disease: a meta-analysis. Clinical gastroenterology and hepatology: the official clinical practice journal of the American Gastroenterological Association. 2013;11(4):359-65 e1.
11. Ford AC, Chey WD, Talley NJ, Malhotra A, Spiegel BM, Moayyedi P. Yield of diagnostic tests for celiac disease in individuals with symptoms suggestive of irritable bowel syndrome: systematic review and meta-analysis. Archives of internal medicine. 2009;169(7):651-8.
12. NICE. Coeliac disease: Recognition and assessment of coeliac disease. 2009. www.nice.org.uk/guidance/cg86 (accessed 24 June 2015)
13. Husby S, Koletzko S, Korponay-Szabo IR, Mearin ML, Phillips A, Shamir R, et al. European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines for the diagnosis of coeliac disease. Journal of pediatric gastroenterology and nutrition. 2012;54(1):136-60.
14. Hopper AD, Hadjivassiliou M, Hurlstone DP, Lobo AJ, McAlindon ME, Egner W, et al. What is the role of serologic testing in celiac disease? A prospective, biopsy-confirmed study with economic analysis. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2008;6(3):314-20.
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