Coeliac UK has funded research in this area exploring the receptors on immune cells involved in coeliac disease however this approach was not found to be suitable for coeliac disease and is instead now being further explored for cancer. Others have been exploring immune markers in blood in response to gluten and this may develop into a test where gluten can be added to a blood sample, and if positive, a person may only need to have one dose of gluten to be tested for coeliac disease. This would be a great improvement on the current 6 weeks of eating foods containing gluten but further research is needed: https://www.coeliac.org.uk/news/new-blood-test-for-coeliac-disease-could-eliminate-need-to-eat/ For internal use: A Randomized Double-Blind, Placebo-Controlled Dose-Response Study to Assess the Gluten Threshold Dose in Celiac Disease https://pubmed.ncbi.nlm.nih.gov/41903816/ Codex in limbo? Using the Interleukin-2 (IL-2) test to lower the bar for gluten in a gluten-free diet for celiac disease https://pubmed.ncbi.nlm.nih.gov/42070692/

Immunoglobulin A (IgA) is produced by the immune system and in people with IgA deficiency it is very low or absent. The blood test for coeliac disease measures IgA tissue transglutaminase antibodies (IgA tTGA) however if you have IgA deficiency, you may get a potential false negative result and so instead should be tested for: Immunoglobulin G tissue transglutaminase antibodies (IgG tTGA) This is important as people with coeliac disease are more likely to have IgA deficiency compared with the general population and need to prevent a potential false negative result.

Professor David Sanders, Royal Hallamshire Hospital, Sheffield and Dr Jeremy Woodward, Addenbrooke’s Hospital, Cambridge. For more information: https://www.coeliac.org.uk/information-and-support-coeliac-disease-about-coeliac-disease-refractory-coeliac-disease/

Today there will be very little change and you should have your annual review as scheduled. At this review the clinician or dietitian may discuss with you, in joint decision making, the need for any ongoing follow up care or whether you are well enough to adopt patient initiated follow up (PIFU) and if that is the case, provide you with contact details for how to reach out for help in the future should things change.

If you are experiencing persistent or recurrent symptoms suspected of being associated with your coeliac disease, feel persistently run down or are struggling with your gluten free diet, please speak with your local healthcare team for a review. This is what is known as Patient Initiated Follow Up (PIFU).

Apart from a gluten free diet, as a whole, adults with coeliac disease are not recommended to have any additional nutritional supplements compared with the general population but should be advised individually, based on determining and monitoring any specific nutrient deficiencies.

A specialist dietitian refers to a registered dietitian with enhanced knowledge and clinical experience in the management of coeliac disease. Such professionals play a central role in supporting adherence to a nutritionally adequate gluten free diet to reduce the risk of long-term complications, with the aim of improving quality of life and well-being.

A combined approach to assessing adherence to a gluten free diet is recommended as no single test provides adequate information in isolation. It should be centred on specialist dietitian review and symptom assessment. Dietary questionnaires may be useful where access to specialist dietitians is limited. It should be considered that symptoms in CD may be multifactorial and reflect associated conditions such as disorders of gut-brain interaction rather than gluten ingestion. A coeliac disease antibody blood test, IgA tTGA, in isolation is a poor marker of adherence to the gluten free diet. However, the trend of tTGA levels may provide some information on ongoing gluten exposure in established coeliac disease for instance, persistent tTGA levels that are not coming down may indicate gluten still creeping into the diet in the appropriate clinical context. It’s important to highlight that although the IgA tTGA test is highly predictive of gut damage in the diagnosis of coeliac disease, antibody levels provide no useful information regarding ongoing gut inflammation/damage once a gluten free diet has been started.

The tTGA blood test is very good in the diagnosis pathway for coeliac disease and some people may be asked to have a repeat test a few months or a year after they have been diagnosed to see a trend in the reduction of antibody levels since adopting a gluten free diet. Persistently positive antibody levels are associated with poor adherence to the gluten free diet. However, the use of the tTGA blood test in isolation, once a person is established on a gluten free diet is not a good indicator of gut healing or dietary adherence. It takes a few weeks to build up antibody levels and so intermittent gluten exposure in established coeliac disease and a negative tTGA test should not be considered as a marker of strict dietary gluten exclusion.

There should be regular follow up for up to two years after diagnosis for all patients, to monitor and support individuals transitioning onto a gluten free diet. Follow up should be provided by physicians and specialist dietitians with expertise in coeliac disease. Where access to specialist dietitians is limited, patients should be followed up by gastroenterologists and/or primary care clinicians with experience in coeliac disease, where possible. Both physical and psychological wellbeing should be assessed. Patients should be assessed and monitored for deficiencies in iron, folate, vitamin B12, vitamin D and calcium at diagnosis and during follow up. Supplementation should be provided in line with general guidance, where necessary. For calcium, dietary history is an important component of assessing adequate dietary calcium intake. Levels of vitamin B6, magnesium and zinc should be monitored in cases of severe malabsorption. Liver function tests should be checked at diagnosis and follow up and a baseline DEXA bone scan should be performed around a year after diagnosis, to document bone mineral density after adopting a gluten free diet. Adult patients who have adjusted to the gluten free diet and have demonstrated a good clinical response may be considered for patient initiated follow up (PIFU), whereby patients request follow up appointments based on individual need, rather than attending routinely scheduled clinics. To help facilitate this, patients should receive instructions on how to request an appointment if needed. Longer term systematic follow up may be needed for certain patient groups including those who are poorly adherent to the gluten free diet (or are at risk of poor adherence), have not responded adequately to a gluten free diet, or have developed complications associated with coeliac disease. The decision on the need and type of long term follow up care, including whether to have a repeat biopsy, should be discussed and agreed between the patient and clinician. Healthcare professionals may use a validated 5-point score to help inform on the risk of persistent gut damage, which may help with decision making regarding the need for a repeat biopsy.

For over a decade, some children have been able to have a diagnosis of coeliac disease based on two separate, positive blood test results and without an endoscopy and biopsy. Adults have always required an endoscopy and biopsy until Covid. During Covid interim guidance allowed for some adults to be diagnosed with coeliac disease from a blood test, if their antibody levels were more than ten times the upper limit of normal and some other criteria were met. Additional research has further supported this position so that the revised BSG Guideline now formally recognises that some symptomatic adults (~20-30%) may be diagnosed with coeliac disease from a single blood test when assessed by a gastroenterologist in secondary care and in discussion with the patient. Essentially, they should have no red flag symptoms and there should be no suspicion of other diagnoses that may need to be ruled out by endoscopy and biopsy. A second blood test may be considered for adults, but it’s been seen that people frequently reduce or eliminate gluten intake between tests causing the second test to potentially be less accurate and there is no research to suggest it is essential.

Coeliac disease is not an allergy or intolerance but a serious autoimmune condition affecting around 1 in 100 people. Left undiagnosed, and untreated it can lead to long term complications such as iron deficiency anaemia, osteoporosis, infertility, repeated miscarriage, neurological complications and in rare cases small bowel lymphoma. Improvement in health and general wellbeing after adopting a gluten free diet, on its own, does not indicate coeliac disease. Having a formal diagnosis and the appropriate follow up care is important, not only to ensure you are set up to manage your coeliac disease and gluten free diet for life but also to rule out any other conditions and prevent future complications.

An endoscopy is where a small tube with a camera on the end is passed through the mouth, into the stomach and on into the small intestine. It allows images of the lining of the gut to be seen. A biopsy is a small piece of tissue that is taken from the lining of the gut for more detailed examination e.g. the biopsy sample is stained and viewed under a microscope to look for certain types of cells and the gut damage associated with coeliac disease.

Ultra short coeliac disease (USCD) refers to someone who has a positive blood test for coeliac disease and their gut damage is limited to the first part of the small intestine referred to as D1. If there is damage only to the D1 section of the small intestine and the coeliac disease antibody blood test is negative alternative causes should be considered. Clinical response to a gluten free diet in USCD is similar to conventional coeliac disease and management of USCD should be supported in the same way as for conventional coeliac disease. It’s suggested that USCD accounts for around 8% of adult coeliac disease.

Seronegative coeliac disease is diagnosed when there is extensive gut damage, the HLA genetics associated with risk of coeliac disease, the blood tests using IgA- and IgG-based coeliac antibodies are negative and there are improvements to the lining of the gut after adopting a gluten free diet is followed. Sero negative coeliac disease accounts for around 2 – 3% of coeliac disease cases and around a third of people who have extensive gut damage but don’t have a positive coeliac disease antibody test, so it’s important to rule out other causes of the gut damage.

Potential CD is used to describe someone who has a persistently positive antibody blood test for coeliac disease, has the HLA genetics associated with coeliac disease but has normal or minimal changes to the lining of their gut and other conditions ruled out. Potential coeliac disease accounts for around 10 – 18% of coeliac disease cases and is generally considered as an early manifestation within the broad spectrum of coeliac disease. For people who are symptomatic it’s suggested that a gluten free diet could be trialled with the support of a specialist dietitian. This approach should be reconsidered if there is no clinical improvement after around 3 – 6 months and an alternative cause for symptoms should be further explored. Follow-up for individuals with potential coeliac disease who have adopted a gluten free diet should be the same as for those with a diagnosis of coeliac disease. In the case that someone with potential coeliac disease remains on a gluten containing diet, they should be counselled about their risk of developing coeliac disease. A discussion between patient and gastroenterologist should take place, regarding a repeat blood test and endoscopy and biopsy if new symptoms develop or repeat testing after 1 – 2 years if stable.

Firstly, please check that you were including enough foods containing gluten in your diet to prevent having a false negative test. The blood test measures antibodies your body produces in response to eating gluten, even if you have only reduced the amount of gluten in your diet, this can have a negative impact on the results. Please see ‘How much gluten do I need to eat before being tested for coeliac disease?’ Secondly, please check with your local healthcare team that you don’t have IgA deficiency. The blood test for coeliac disease measures IgA antibodies but if you have IgA deficiency you will not make IgA antibodies and will need to have an IgG antibody test instead. Please see ’What is IgA deficiency and why is it important?’ If you were consuming enough gluten, you are not IgA deficient, the antibody test for coeliac disease is negative yet you continue to experience ongoing symptoms, you should have a further discussion with your local healthcare team. If there remains a clinical suspicion for coeliac disease you should be referred to a gastroenterologist for further investigation. This will likely involve an endoscopy and biopsy. It is possible for someone to have a negative blood test and still have coeliac disease. You need to have extensive gut damage typical of coeliac disease with other conditions ruled out, the genetics associated with a risk for coeliac disease and your symptoms and health improve on a gluten free diet, to achieve a formal diagnosis in this circumstance.

You should be referred to secondary care to see a specialist i.e. Gastroenterologist for assessment. After a discussion, formal diagnosis may then be determined either from a blood test or after an endoscopy and biopsy, as required. To consider a diagnosis from a blood test, the antibody levels must be ten times the upper limit of normal, the person should have no red flag symptoms and there should be no suspicion of other possible conditions that might require an endoscopy and biopsy for diagnosis. Some people may prefer a blood test diagnosis in this situation, while others may still value confirmation from an endoscopy and biopsy, before committing to a lifelong gluten free diet. Hence the need for individualised discussion between patient and gastroenterologist. Any adults with antibody levels below ten times the upper limit of normal should be offered an endoscopy and biopsy.

Some adults with symptoms associated with undiagnosed coeliac disease, around 20-30%, will have a blood test with antibody levels that are so high, ten times the upper limit of normal, that they can be diagnosed with coeliac disease without the need for having an endoscopy and biopsy. This is because the healthcare team will have previously validated the local blood test against gut biopsy results and know that if someone has antibody levels more than ten times the upper limit of normal, it’s very probable they will have coeliac disease. It should then be a joint decision between patient and a specialist, known as a gastroenterologist, regarding a diagnosis of coeliac disease without an endoscopy and biopsy. In a very few cases it is possible to have a false positive blood test which is why it is very important for the diagnosis to be carried out by the specialist gastroenterologist and not the GP. The blood test for coeliac disease is a tissue transglutaminase immunoglobulin A antibody test, you may see it abbreviated as IgA tTGA or just tTGA. There are many different manufacturers of this test which is why the results need to be locally validated. There is no evidence supporting the need for a second confirmatory blood test. It’s been reported that often antibody levels fall between a first and second blood test as people stend to naturally start to reduce their gluten intake.

If you have already removed gluten from your diet and noticed an improvement in your symptoms, you will need to re-introduce gluten, known as a gluten challenge before having the blood test for coeliac disease. In the short term this is usually safe and early acute symptoms such as nausea, vomiting, abdominal pain, diarrhoea, headache and lethargy are common but typically reduce in severity within a few days of the challenge. Please speak with your local healthcare team about your personal situation so they may support you if considering re-introducing gluten. It is recommended to check for the genes associated with coeliac disease i.e. HLA-DQ2 and HLA-DQ8 to determine risk of coeliac disease before re-introducing gluten. To improve tolerability of the gluten challenge: Commence a graded gluten challenge. For example, start with a half dose of gluten for the first two days before increasing to the full daily dose Select gluten containing foods that are lower in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) as these can produce Irritable Bowel Syndrome (IBS) type symptoms similar to those experienced in coeliac disease e.g. sourdough spelt bread is lower in FODMAP content so may be better tolerated compared to standard wheat bread. Higher doses of gluten will give more accurate results and wheat as a source of gluten is the best. Endoscopy and biopsy is the preferred diagnostic route after 6 weeks gluten challenge, as antibody production can be slow to take off. Please see ‘How much gluten do I need to eat before being tested for coeliac disease?’ for further information.

You need to include at least 3g but preferably 6g gluten every day for a minimum 6 weeks before being tested for coeliac disease and to remain on gluten throughout the diagnosis process. After six weeks, at 6g gluten per day, most people will start to show some level of gut damage or changes in cells, but antibody levels may take longer to increase so assessment by endoscopy and biopsy is preferred for diagnosis following re-introduction of gluten. Higher doses of gluten will improve diagnostic accuracy. However, doses greater than 6g per day are associated with increased symptom burden. If the gluten challenge is poorly tolerated, people can also try halving the daily gluten dose and proceeding for an additional 6 weeks. There will be individual variation. Below is a table providing examples of foods and portion sizes that contain about 3g of gluten: Gluten containing food Amount providing around 3 g gluten Sourdough Spelt Bread 60g, 1.5 – 2 slices bread / medium bread roll Wheat-based breakfast cereal e.g. Shredded wheat/ Weetabix 25g, wheat-based cereal such as two Weetabix or two fist-sized portions of cereal Wheat-based bread 60g; 1.5-2 slices bread/ medium bread roll Wheat-based cooked pasta 90g cooked pasta, a fist-size portion Wheat-based biscuits 50g, 3-5 biscuits Wheat Gluten Flour or Vital Wheat Gluten 7.5g, 1.5-2 teaspoons