J is for Jelly Bean!: Investigations, Treatment and the Infamous Gluten Free Diet

Investigations for Coeliac disease

Because CD is considerably under-diagnosed in Primary Care,consider the diagnosis and perform serological testing in all patients who present with:
•chronic or intermittent diarrhoea
•failure to thrive or faltering growth in children
•persistent or unexplained gastrointestinal symptoms including nausea and vomiting
•prolonged fatigue ('tired all the time')
•recurrent abdominal pain, cramping or distension
•sudden or unexpected weight loss
•unexplained iron-deficiency anaemia, or other unspecified anaemia

Serology – make sure they have been on a gluten diet for at least 6 weeks
•IgA anti-tissue transglutaminase antibodies (tTGAs) is the preferred investigation. Endomysial antibodies (EMAs) are used if tTGA) test is not available or equivocal.
•False negatives occur if the patient has selective IgA deficiency, as occurs in ~0.4% of the general population14 and in 2.6% of patients with CD (laboratories should test for IgA deficiency on negative samples). Use IgG tTGA and/or IgG EMA serological tests for people with confirmed IgA deficiency.
•Antibodies frequently become undetectable after 6-12 months of a GFD and thus can be used to monitor the disease.
Antigliadin antibodies are no longer recommended - they are less specific, but can be either IgA (AGA) or IgG (AGG). They can be positive in other gastrointestinal conditions such as Crohn's disease

Biopsy
Patients with positive serological tests should be offered referral to local gastroenterologist for endoscopic or enteroscopic distal duodenal or jejunal biopsy to confirm diagnosis. They need to stay on gluten until after the biopsy. Referral should also be made where the serology is negative but there is still clinical suspicion of CD.
•The diagnosis of CD is made when biopsy shows villous atrophy while the patient is eating adequate amounts of gluten, followed by full clinical remission on excluding gluten.
•Under these circumstances, tTGA or EMA antibodies found at the time of diagnosis and their disappearance after gluten exclusion, means that it is only necessary to perform a further biopsy (and even a further gluten challenge and more biopsies) if there are still doubts. The further gluten challenge should always be performed if CD is diagnosed in children less than 2 yrs because of a high incidence of other causes of flat mucosa.

Other investigations
•FBC shows anaemia in 50%; iron and folate deficiency are both common (microcytes and macrocytes), hypersegmented leucocytes and Howell-Jolly bodies (splenic atrophy). Also check B12, folate, ferritin, LFT, calcium and albumin.
•Small bowel barium studies are occasionally needed to exclude other causes of malabsorption and diarrhoea, and diagnose rare complications such as obstruction or lymphoma.

Treatment

Starting a GFD rapidly induces clinical improvement, which is mirrored by the mucosa. The diet consists of no wheat, barley, rye, or any food containing them (e.g. bread, cake, pies). Moderate quantities of oats (free from other contaminating cereals) can be consumed as recent studies suggest that they do not damage the intestinal mucosa. Rice, maize, soya, potatoes, sugar jam, syrup and treacle are all allowed. Gluten-free biscuits, flour, bread and pasta are NHS prescribable. Coeliac UK produces a prescribing guide. When making GFD, must make sure cross contamination doesn’t occur, as a person with celiac can only take 0.02% of gluten in a product safely and even a little cross contamination with wheat (12% gluten) may result in return of symptoms.

Arrange dietitian appointment (with regular reviews). Even minor dietary lapses may cause recurrence. GFD should be lifelong, as relaxation of diet generally brings a return of symptoms and increased incidence of complications. Add supplements as necessary (e.g. folic acid, iron, calcium and vitamin D).
Serial tTGA or EMA antibodies can be used to monitor response to diet.

Oats - there was originally some concern about including oats in a GFD, but recent research has emphasised that oats can be given to almost all patients with coeliac disease.

Oral proteases are being developed (which digest gluten) and these may offer therapeutic options in the future.

Why follow up patients with coeliac disease?
 Patient compliance with a GFD is poor, ranging from 45-87%. The long-term health risks for patients who comply poorly with a GFD include nutritional deficiency and reduced bone mineral density.
About a quarter of patients with CD have osteoporosis of the lumbar spine compared to 5% of matched controls. Bone mineral density improves significantly with a GFD.
 Dietary compliance positively correlates with regular follow-up and knowledge of the condition.
 Half of all coeliac patients have an inadequate energy intake, and 10% have inadequate intake of calcium and vitamin B6. 80% of elderly patients have inadequate intake of vitamin D.
 GPs are responsible for the appropriate prescription of gluten-free products.20
 Regular follow-up is an opportunity to provide patient-centred care that is sensitive to the individual's life circumstances.
How often should patients be reviewed?
 Patients should be followed up throughout their lifetime.
 After diagnosis, the patient should be reviewed at the gastroenterology clinic after 3 months and 6 months to ensure they are making satisfactory progress and managing the diet.
 If well, they should be reviewed annually or sooner if problems arise - follow-up assessments are currently being carried out by dietitians, nurses, general practitioners and gastroenterologists in primary and secondary care.

GFD
- Jewish holiday Passover contains mostly gluten free food (except Maztah); usually stocked in early spring in stores catering to Jews.