Gliadin Antibodies IgA, IgG, Endomysial Antibodies, Celiac disease and Celiac Sprue
Gliadin Antibodies and Celiac disease
- Collect the venous blood to prepare the serum.
- A fasting sample is not necessary.
- An intestinal biopsy may be advised and it gives characteristic changes.
Purpose of the test (Indications)
- These antibodies are detected in gluten-sensitive enteropathy.
- This test is done to diagnose Celiac disease and sprue.
- These antibodies are done to monitor the disease.
- In successful treatment by a gluten-free diet, these antibodies will disappear from the serum.
- Other gastrointestinal diseases like colitis, Crohn’s disease, and lactose intolerance can give raised values of Gliadin antibodies.
- Get the list of foods eaten in the last 24 hours.
Definition of Celiac disease
- Celiac disease sometimes is called non-tropical sprue, celiac sprue, or gluten-sensitive enteropathy.
- Celiac disease is an autoimmune multisystem disease.
- Celiac disease is also called childhood non-tropical sprue.
- Celiac disease is cured by a gluten-free diet.
- The sprue is an infectious process that is cured by antibiotics.
- Celiac disease is an autoimmune phenomenon.
Pathogenesis of Celiac disease and sprue:
- Celiac disease is also called Gluten-sensitive enteropathy, Nontropical sprue, or idiopathic steatorrhea.
- Auto-antigens are:
- Gliadin is the complex of gluten and tissue transglutaminase.
- Gluten protein.
- The small bowel (mainly duodenum and jejunum) tissue Transglutaminase is the auto-antigen.
- Gliadin is the complex of gluten and tissue transglutaminase.
- Pathogenesis of the disease is believed to involve an interaction between transglutaminase and the gliadin peptide in genetically susceptible people.
- In both conditions (celiac disease and sprue), an immune reaction is mediated by the T-lymphocytes against gluten.
- Gluten is found in wheat, rye, barley, and maybe in oats.
- There is a genetic predisposition and it runs in the families.
- 10% of the first-degree relatives run this disease.
- There is an association in HLA DR3 in 90% of the patients and the same for dermatitis herpetiformis.
- Another reference says that a genetic component is present in the HLA chromosome 6.
- The major toxic protein of wheat is gliadin.
- There is sensitivity to Gliadin and gluten are the proteins found in:
- Wheat products.
Antibody formation in Celiac disease:
- Antibodies to gliadin are toxic agents in celiac disease.
- The patient with celiac disease cannot tolerate these proteins gliadin + gluten present in wheat or wheat products.
- Gliadin + gluten is toxic to the small intestinal mucosa and leads to characteristic pathologic changes seen on biopsy.
- These patients develop antibodies against:
- Gliadin = anti-gliadin antibody (IgA and IgG)
- Endomysial = anti-endomysial antibody.
- Tissue = anti-tissue transglutaminase
- These patients have severe intestinal malabsorption.
- The only treatment for these patients is to avoid wheat and wheat products.
- These antibodies are present in the mucosa and in the blood
- Celiac disease starts in infancy when cereals are given to the baby.
- IgG-antigliadin antibody is more sensitive but less specific than IgA.
Pathological changes in Celiac disease:
There are typical changes on the intestinal (jejunal) biopsy like:
- There is villous atrophy.
- Goblet cells are decreased or absent.
- It shows crypt hyperplasia.
- Intestinal epithelial cells show vacuoles.
- There is a lymphocytic infiltrate in the mucosa and submucosa. Also, these cells will infiltrate the lamina propria.
Signs and Symptoms of Celiac disease
- Mostly the symptoms are seen in the children when they start cereals.
- The most common presentation is:
- There is easy fatigability.
- There is abdominal bloating and pain.
- There may be vomiting.
- The patient will have chronic diarrhea.
- The stool is foul-smelling, pale, and fatty.
- Sometimes these patients will be constipated.
- The stool is hard to flush.
- There are aphthous ulcers.
- The patient will have weight loss.
- These children are irritable.
- Delay in the growth pattern.
- Sometimes it is difficult to thrive and the patient may have osteomalacia.
- There is a strong association with other autoimmune diseases like diabetes mellitus type 1 and autoimmune thyroid diseases.
Complications of Celiac disease
- There is anemia.
- 15 to 20% of patients develop intestinal lymphoma or adenocarcinoma
- There is an increased incidence of gastric and esophageal carcinoma.
- There may be neuropathy.
- These patients may have hyposplenism.
- Values are given for the child of age >2 years:
- Negative = < 25 U/L .
- weak positive = 25 to 50 U/L.
- Positive = >50 U/L.
- Gliadin IgA/IgG = 0 to 2 years = <20 EU.
- 0 to 3 years and older = <25 EU.
- Endomysial IgA = all ages = negative.
- Tissue transglutaminase IgA = all ages = <20 EU.
Diagnosis of celiac disease
- An elevated level of anti-gliadin and anti-endomysial antibodies.
- Both IgA and IgG antibodies sensitivity are 90% for the active untreated disease. when both antibodies are done then specificity is also 90%.
- These antibodies will detect :
- Celiac disease 100% will have IgA endomysial antibodies.
- Celiac sprue.
- Dermatitis herpetiformis 70% shows IgA endomysial antibodies.
- Intestinal (jejunum) biopsy shows typical changes in villous atrophy.
- On jejunal biopsy will see villous atrophy.
- Increased intra-epithelial lymphocytic infiltrate.
- There is hyperplasia of the crypts.
- These changes may reverse on a gluten-free diet. This will not occur in the sprue.
- In Celiac disease anemia may be either macrocytic or hypochromic microcytic anemia.
- Serological tests for Celiac disease
|IgA- antigliadin antibody||95%||75 to 95%|
|IgA- endomysial antibody||>99%||80 to 100%|
Diagnostic criteria of the Celiac disease
- Provisional diagnosis:
- Positive serological (anti-gliadin antibody) test.
- Typical pathological findings on biopsy of the small intestine.
- The confirmatory test is:
- When a gluten-free diet is given, then patients become symptoms free.
- Serological tests become in the normal range or negative.
- If a biopsy is done then the pathological changes will improve or disappear.
Treatment of Celiac disease
- Start a permanently gluten-free diet.
- Avoid wheat, barley, rye, and oats.
- Another reference excludes oats and is allowed in the list of eatable foods. Be sure that there is no mixing of wheat, barley, or rye.
- Or any food containing them like bread, cake, and pies.
- Rice, soya, potatoes, maize, jam, and sugar are allowed.
- Gluten-free flour, bread, and pasta are available.
- Try steroids if diet therapy is not helpful.