Coeliac disease is an autoimmune condition which is triggered in a genetically predisposed individual by the consumption of gluten, a protein in wheat. There are similar proteins in barley and rye and some patients are also sensitive to oats. Coeliac disease characteristically causes inflammatory changes in the proximal small intestine, (duodenum and jejunum), which are exacerbated on eating foods containing gluten.

There is thought to be an under-diagnosis of coeliac disease within the population. Patient surveys indicate that it is frequently unrecognised and a diagnosis delayed. There may be prolonged periods of investigations before a diagnosis is made. Even after diagnosis, there is a wide variation in management and follow-up. Increased awareness of the condition, in conjunction with improved diagnostic methods, will have a significant impact.

Definition of coeliac disease

People with coeliac disease produce antibodies against gluten. In effect, the gut mistakes gluten to be harmful and reacts against it as if it was fighting bacteria. These antibodies lead to inflammation developing in the lining of the small intestine. The villi in the small intestine become flattened due to inflammation; therefore, there is a process of malabsorption, where food and nutrients cannot be readily absorbed from the gut. Villi return to normal upon removal of gluten from the diet. The timeframe to recovery varies between individuals, but generally, complete recovery can be expected within six to eight months of commencing a fully gluten-free diet.

Coeliac disease is unique among autoimmune conditions as removal of the extrinsic factor, that is gluten, typically resolves in clinical improvement.

Epidemiology

Screening studies suggest a prevalence in western Europe of 1:122. In Ireland, the prevalence is 1:100. This has been cited as Simmons hypothesis, which relates to Ireland and the close links we have genetically and ethnically. In first-degree relatives, this increases to 1:10 and the background prevalence is higher where there are other autoimmune diseases present.

Despite gluten ingestion from infancy, the majority of patients are aged over 40 years at diagnosis, and a first presentation in elderly people is well recognised.

Both sexes are affected but most trials report an excess of females, who are more likely to seek medical advice for symptoms and are at a greater risk of anaemia. There is a well documented delay in diagnosis from initial symptoms so it is important to keep it as a differential diagnosis. Occasionally a trigger event, such as pregnancy, gastroenteritis or viral illness can be identified before the onset of symptoms.

Diagnosis

It is crucial that diagnosis is made before starting a gluten-free diet. Duodenal biopsy remains the gold standard for diagnosis. Serological testing should be the first investigation, with duodenal biopsy for those who are seropositive. Serological testing in primary care has resulted in a considerable increase in diagnosis rates.

False positive serology occurs in 5-10% of cases with current antibody tests; therefore, biopsy testing should be performed on those patients with negative serology but a high index of suspicion and in those patients undergoing oesophagogastroduodenoscopy (OGD) for anaemia, despite a negative serology.

Serology testing: antitransglutaminase antibodies (TGA) and antiendomysial antibodies (EmA)

Coeliac disease occurs more commonly in patients with IgA deficiency than in the general population. Those patients found to be IgA deficient are now tested for TGA and EmA.

Monitoring compliance

TGA and EmA can be used for diagnosis, but can also be used to monitor dietary compliance. Seroconversion occurs rapidly with strict gluten exclusion. Conversely, at diagnosis, if serology is to be useful, the patient must be taking a gluten-containing diet for at least three months. 

NICE guidelines 2009 and the British Society of Gastroenterology guideline provide useful reference.

Patients with coeliac disease should have regular follow-up. Who provides this depends greatly on the region, but it is increasingly provided within primary care. Dietitian availability can vary across regions, but patients should be encouraged to link in with a coeliac society for information.

Potential complications

Osteoporosis

Bone mineral density has been found to be reduced in 40% of patients at the time of diagnosis. A bone scan (DXA) is recommended at diagnosis for all new patients.

Approximately 30% of patients have functional hyposplenism. The Department of Health recommends offering patients: haemophilus vaccination; five-yearly pneumococcal vaccination; annual influenza vaccination; and guidance about the increased risks attached to tropical infections, such as malaria. Life-long antibiotics are not indicated.

At diagnosis, the patient should be reviewed in a hospital gastroenterology clinic after three months and six months to ensure they are making satisfactory progress managing their diet. Pregnancy is a particularly important time for patients to be reviewed. If the patient is well, they should be reviewed annually in primary care or sooner if problems arise.

Ongoing management

Patients should see a dietitian, not just for gluten-free advice, but also to advise about iron, folate, vitamin D and calcium supplementation. Although anaemia will improve if they follow a gluten-free diet, specific deficiencies need to be corrected. Annual follow-up is recommended in primary or secondary care, and evidence shows that this encourages compliance with a gluten-free diet.

Points to consider in annual review

At the annual review, BMI, weight and height should be measured. All symptoms should be assessed, including bowel functions. Laboratory investigations should include FBC, folate, vitamin D, serum iron and ferritin, LFT, B12, calcium and tTGA to assess adherence to a gluten-free diet (tTGA will be raised with ongoing gluten ingestion).

Consider risk factors for osteoporosis and discuss lifestyle, alcohol, smoking, diet and exercise. Arrange DXA if indicated and offer immunisation. Discuss concerns or issues regarding diet, symptoms and consider the need for family testing. There is a prevalence in first-degree relatives of 4-22%, so they should be offered testing.

A general practice review

The Drumalee Cross Family Practice has approximately 2,200 patients including GMS and private patients. The practice is mixed urban and rural. There are two partners, a GP registrar, two practice nurses, a practice manager and two reception staff. We decided to review the management of coeliac patients within our practice and assess the possible need for change.

Method

A list of patients with repeat prescriptions for gluten-free foodstuffs and also those patients with positive serology of tTGA was compiled by running a database search on Socrates. These patients were included into a database to facilitate recall and audit. They were coded according to ICD10 (D99). A total of 10 patients were found within our practice to have been diagnosed with coeliac disease.

A letter was sent to each patient with a questionnaire to be filled out. An appointment was made to see each patient and assessment was in accordance with NICE guidelines 2009 and British Society of Gastroenterology guidelines.^1,2

Contact was made to senior dietitian Darina Curran, who runs the coeliac clinic between Cavan and Monaghan general hospitals (CGH and MGH), in order to confirm these patients. The clinic is overseen by consultant endocrinologist Dr Muthalagu. Three of our 10 patients had not previously been referred to the clinic and this served as an opportunity to refer them for dietitian review, with their consent.

Results

Bone mineral review

Seven out of 10 patients had a DXA scan. Three of these seven have a diagnosis of osteoporosis and are on either a bisphosphonate or s/c denosumab, while the other four have a diagnosis of osteopaenia and are on calcium supplementation. The patients who had not had a DXA scan were referred to radiology in CGH.

BMI

Nine out of 10 of these patients had a documented BMI, weight and height in their chart, with two patients on a BMI < 18.

Dietary compliance

Seven out of the 10 patients feel they are ‘fully compliant’ with a gluten-free diet and their symptoms are well controlled. The remaining three are not fully compliant and note symptoms such as constipation, diarrhoea, cramping and mouth ulcers.

Understanding of coeliac disease

Seven out of 10 feel they have a good understanding of the disease, but all were interested in receiving more information. Five out of the 10 are members of the Coeliac Society of Ireland.

Dietitian review

Nine out of the 10 had been seen by the senior dietitian. These were the same nine patients who had recorded BMI readings.

Laboratory findings

Low vitamin D levels were found in six out of the 10 patients. Blood testing was otherwise normal.

Immunisations

No patient had been offered or received immunisation against influenza, haemophilus or pneumococcus at any time either from primary care or secondary care. Nine of the 10 patients said they would be interested in receiving vaccination once informed about the splenic side-effects of coeliac disease.

Steps to improve care

A database of patients with coeliac disease was created within the practice in order to facilitate audit and review. They have been linked in with secondary care and referred for dietitian input. The practice has created a template for an annual review checklist of these patients, with prompts for BMI recording, osteoporosis assessment, symptom review, laboratory investigations and screening of family members.

This patient cohort received letters regarding immunisation for the influenza season 2013 and were encouraged to attend for vaccination. They were included in the practice target population for vaccination. Patient information leaflets regarding immunisation were given during the first cycle of the audit to inform about the benefit of vaccination. A second cycle will be completed in 2014 to review uptake of vaccinations.

In conclusion, coeliac disease is relatively common in Ireland and with good knowledge of diagnosis, initial management and a structured and logical approach to annual review, can be managed effectively in general practice. The recent NICE guidelines 2009 have shown that functional hyposplenism can exist in up to 30% of patients and we, as GPs, are well placed to offer vaccinations against pneumococcus, influenza and haemophilus within the practice. 

References

1. Coeliac disease. Recognition and assessment of coeliac disease. NICE Guideline, May 2009
2. British Society of Gastroenterology Guidelines, as accessed on
3. www.bsg.org.uk/clinical/general/guidelines.html
4. Berrill JW, Ahmed H, Butt S, Sweift G. Reviewing a patient with coeliac disease. BMJ 2012; 344: d8152
5. CREST: Clinical Resource Efficiency Support Team, 2006, as accessed on www.gain-ni.org/images/Uploads/Guidelines/Coeliac%20Disease%2028pp.pdf