# Not just a fad gluten-free diet
Definition: A T-cell-mediated autoimmune disease of the small bowel in which prolamin intolerance causes villous atrophy and chronic intestinal malabsorption.
Prolamin: component of gluten; alcohol-soluble proteins in wheat, barley, rye +/- oats
Gliadin is the prolamin in wheat gluten
Aetiology/ risk factors:
-Sensitivity to prolamin triggers an immunological reaction in the small intestine leading to mucosal damage and loss of villi.
-Genetic association: HLA DQ2 in 95%; the rest are HLA DQ8
-Associated with other autoimmune disease and dermatitis herpetiformis
-Family history- 10% prevalence in 1st degree relatives and a 30% risk for siblings
Prevalence = 1 in 300-1500
Commoner in the Irish, rare in East Asia
Can present at any age but peaks in infancy and 50-60 years
Symptoms: 1/3 are asymptomatic
–Anaemia: pale, tired
=Suspect coeliac in all with the above symptoms
–Steatorrhoea– pale, foul-smelling, stools that float and are difficult to flush away (excess fat in stool due to fat malabsorption)
–Nausea & vomiting
–Failure to thrive (children)
–Amenorrhoea (young adult)
–Angular stomatitis/angular cheilosis– ulceration of the side of the mouth, in iron deficiency. Also a feature of vitamin B12 and B2 deficiency.
-Signs of malnutrition: children = short stature, abdominal distension, wasted buttocks
reduced triceps skinfold thickness
–Dermatitis herpetiformis– intense, itchy blisters on elbow, knees or buttocks. Despite the name, it is not associated with herpes. The blisters just look like those of herpes.
Bloods: Low Hb (anaemia)
High RCDW (Red Cell Distribution Width)
The anaemia in Coeliac’s may be of a mixed picture. You have both iron deficiency, which causes a microcytic anaemia (small RBCs) and folate/vitamin B12 deficiency, which causes a macrocytic anaemia (large RBCs). So, overall, the MCV (Mean Corpuscular Volume- i.e. RBC size) is within normal range. But, if you look at the RCDW, it is high, indicating that there is a large distribution of sizes of red blood cells i.e. there are small RBCs and large RBCs = a mixed picture anaemia.
Antibodies: anti α-gliadin, anti-transglutaminase, anti-endomysial (IgA Ab, most specific, 95% specific unless patient has IgA deficiency)
-As IgA deficiency is common (1 in 50 with coeliac disease), Ig levels should be measured to avoid false negatives.
Endoscopy + Duodenal biopsy: GOLD STANDARD for diagnosing Coeliac’s disease
Endoscopy shows villous atrophy in the small intestine, giving the mucosa a flat, smooth appearance.
Biopsy = Subtotal villous atrophy, increased intra-epithelial white blood cells + crypt hyperplasia
Stool culture to exclude infection
-LIFELONG GLUTEN-FREE DIET (i.e. no prolamins).
= no wheat, barley, rye
=rice, maize, soya, potatoes, oats (≤50g/d) and sugar are ok
-can prescribe gluten-free biscuits, flour, bread, and pasta
And here I thought Heinz only did baked beans. (This is not an advert. I am not promoting Heinz.)
-Symptoms, duodenal changes and antibodies reverse with gluten-free diet. Diet can be verified by testing endomysial antibodies.
-Vitamin and mineral supplements can be taken if needed.
-Oral corticosteroids may be used if the disease does not subside with gluten withdrawal.
–Iron, folate & Vitamin B12 deficiency
–Secondary lactose intolerance
–GI T-cell lymphoma (rare, suspect if refractory symptoms or weight loss)
–Increased risk of malignancy- gastric, oesophageal, bladder, breast, brain
–Neuropathies, cerebellar ataxia (rare)
–Osteomalacia (softened bones, can lead to fractures, and bowing in children), Osteoporosis
Prognosis: with strict adherence to gluten-free diet, most patients make full recovery. Symptoms usually resolve within weeks. Histological changes may take longer to resolve. Gluten-free diet needs to be followed for life.
References: Cheese & Onion, Rapid Medicine