Coeliac Disease Flashcards
What is coeliac disease?
An immune-mediated, permanent intolerance to gluten
Pathophys of coeliacs
Exposure to gluten results in inflammation of the small intestine and flattening of the villi, which affects the absorption of important nutrients including iron, folic acid, calcium and fat-soluble vitamins
Gluten is found in…
Wheat, rye, barley, and oats
Diagnosis is made by…
Tissue diagnosis made by gastroscopy when the patient is eating gluten
Role of coeliac serology
Serology is a screening test to indicate which patients need biopsy
Cannot make a diagnosis based on serology
Untreated coeliac disease can be associated with the development of long-term health problems, including…
Anaemia
Nutritional deficiencies, e.g. iron, folate, vitamin B12, vitamin D
Osteopenia
Malignancy
The only current, proven effective treatment for coeliac’s is…
Lifelong gluten-free diet
Symptoms of coeliacs
Nonspecific, many are asymptomatic
GI - chronic or intermittent diarrhoea, constipation, N+V
Recurrent abdo discomfort, cramping, bloating, or distension
Prolonged fatigue
Poor appetite
Recurrent aphthous ulceration
Recurrent migraine
Low mood
Weight loss
Is Coeliac’s more common if a family history?
10% prevalence in first-degree relatives, but higher if more than one relative has the disease
Consider screening if fam hx or associated conditions e.g.
Autoimmune (liver, thyroid, T1DM)
Nutrient deficiencies (iron, B12, folate)
Unexplained osteoporosis and fragility fractures
Lactose intolerance
Pancreatic insufficiency
Microscopic colitis
Gynae problems, e.g. reduced fertility, adverse pregnancy outcomes, recurrent miscarriage, amenorrhoea
Unexplained elevated transaminases
Unexplained neurological or psychiatric conditions
Down and Turner Syndrome
Sarcoidosis
Most people are diagnosed at what age
Most diagnosed as adults
Often 40-45yo
‘Classical’ presentation of coeliac disease
Diarrhoea, abdominal distension and discomfort, weight loss or in children, failure to gain weight
Is the amount of dietary intake a gluten and its relationship to symptoms predictive in terms of Coeliiacs?
Exacerbation of symptoms following gluten consumption should not be used as a diagnostic measure in the absence of other investigations as it has a very low predictive value for coeliac disease.
Conversely, dietary tolerance of gluten does not rule out coeliac disease.
Blood tests
Coeliac screen (while consuming gluten)
CBC
Ferritin
LFTs
TSH (as higher risk of autoimmune thyroid disease)
Folate
Vitamin B12
Calcium and phosphate
CRP (as indicated)
Faecal calprotectin (if inflammatory bowel disease suspected)
Important advice re diet when testing for coeliac on bloods
If the patient had been on a gluten-free or low-gluten diet, a normal diet must be resumed for at least 6 weeks before serological testing, otherwise results may be falsely negative.
The preferred initial test as part of coeliac serology is…
tTG antibodies
A tTG test detects _______ antibodies
IgA
Relationship between IgA and Coeliacs
Always be suspicious of coeliac disease in pt with an IgA deficiency. However, an elevated total IgA does not suggest coeliac disease, and is not an indication for gastroscopy.
10% of patients with IgA deficiency will have coeliac disease.
Effect of IgA deficiency on Coeliac screen results
Patients with a co-existing IgA deficiency will have a false-negative IgA tTG result and the IgG tTG should be measured
Should you order HLA DQ2 or DQ8 gene testing if Coeliac’s suspected?
No - expensive. Indicate risk susceptibility for coeliac disease. Only 5-10% of people who test positive will go on to develop coeliac disease.
Although nearly all patients with coeliac disease have these genes (HLA DQ2 or DQ8), so do ________% of the normal population.
> 50%
What to do if next if tTG elevated
Remain on gluten diet, ref gastro for gastroscopy and small bowel biopsy
If tTG is normal, consider alternative diagnosis, which will most likely be…
IBS or non-coeliac wheat sensitivity
Next steps if negative or equivocal serology, but high clinical suspicion and high risk factors (e.g. associated condition, fam hx)
Ref gastro for consideration of gastroscopy and small bowel biopsy
Can you do HLA testing to exclude Coeliac’s in people with T1DM
Not helpful as the HLA associations are the same –> will be positive by virtue of having T1DM
Testing of family members in confirmed Coeliac’s
First-degree relatives should also be checked for coeliac disease using serology
Next steps from GP perspective once patient confirmed Coeliac positive
Ensure referred to dietitian
GP r/v in 3-6 months
Check that meds/supplements are gluten‑free – suggest that the patient informs their pharmacists
Suggest all 1st degree relatives are informed +/- tested
Lifetime risk of 1st degree relative developing Coeliac’s disease
10%
What needs to be covered in GP follow up post Coeliac diagnosis
Check following a strict and nutritious gluten-free diet
Recheck tTg – a falling titre indicates compliance and effective gluten exclusion (can take 2yrs to normalise)
Recheck any previously abnormal biochemistry
Consider the need for a bone density scan – may be publicly funded.
Repeat prescriptions for gluten-free food available through the gluten-free subsidy.
Flu vax (funded)
Recommend coeliac NZ/support groups/apps
What gluten free foods are available via prescription
Gluten-free baking mix
Gluten-free bread mix
Gluten-free flour
Coeliac disease is associated with a temporary ________ intolerance that usually resolves in ________
Lactose
Resolves in 2-3 months
Coeliac disease and oats
Some people with coeliac disease do not tolerate oats + can also be cross contamination with gluten during production
No reliable source of gluten-free oats in NZ
Dermatitis herpetiformis occurs in up to ___% of people with coeliac disease
25%
Dermatitis herpetiformis is characterised by…
An itchy, blistering skin eruption predominantly affecting the knees, elbows, buttocks and back.
Malignancies associated with coeliac disease
T-cell lymphoma and GI malignancies, particularly small intestinal carcinoma
