This new guideline from the British Society for Gastroenterology (BSG) gives advice on the diagnosis and management of coeliac disease (CD). The diagnosis bits are useful for us as they widen the advice on who to do testing on. It is also useful to be aware of the ongoing management as there are some patients who are not under secondary care.
It is worth noting that 1% of the population have CD - so it is common.
There is a NICE guideline on this too, which is very similar in the advice it gives on testing.
I've summarised the bits that I found useful and I hadn't appreciated, even though this BSG guideline probably doesn't add much to the previous NICE guideline.
Who should we be doing serological tests on?
- Anyone with symptoms (including IBS type symptoms - NB NICE advises doing it for people with prolonged fatigue or weight loss, which I certainly haven't been doing)
- Iron deficiency anaemia
- Dermatitis Herpetiformis
- Down's Syndrome
- Type 1 DM
- First Degree relatives (if symptomatic) as 10% of first degree relatives will also have CD.
They aren't advocating 'screening' but do suggest a 'case finding' approach, because of how common CD is.
How good are the various tests?
Serology - tissue transglutaminase (TTG).
6 - 22% of people newly diagnosed with CD are seronegative, so the test isn't perfect. This means that if you have a strong suspicion of CD (eg malabsorption symptoms or other symptoms in someone who is a first degree relative of someone with CD), then it is worth referring them.
IgA deficiency - 2% of people with CD (and 0.2% of the population) have IgAdeficiency. Affected people are likely to have a false negative TTG.
Pretty good, though can still get false negatives depending on how the biopsies are done. This guideline suggests doing them in all patients having upper GI endoscopy because of the high prevalence of CD.
HLA DQ2 and DQ8 are associated with CD. Fewer than 1% of people with CD are negative for both. They are commonly found in the general population, so they are no good as a rule in test for CD. They can be useful in 2 circumstances: Patients still symptomatic on a gluten free diet. If they are both negative, it puts the diagnosis in doubt. People with a family history to avoid further unnecessary testing. If they are both negative, CD is very unlikely.
- Fasting glucose
- TTG (useful if not sure how well they are adhering to diet - if positive it means that they probably aren't, but a negative result doesn't necessarily mean that they are adhering).
Pneumococcus Vaccine - all should have at diagnosis.
Support groups. Ensure they are aware of local / National support groups
Food on Prescription. Ensure that they have adequate foods on prescription. Useful advice on amounts to prescribe is available to download here.
Any patient still symptomatic should be seen in secondary care.
Ca / Vit D should be measured at diagnosis and replaced as needed.
Ca intake should be 1000mg or more each day and may need supplementing if their diet is inadequate.
At risk patients may need DEXA scan, eg if 2 or more of the below (though beware other risk factors too):
- Persisting symptoms on gluten-free diet for 1 year or poor adherence to gluten-free diet
- Weight loss >10%
- BMI < 20
- Age >70