The only way to confirm a celiac disease diagnosis is to have an endoscopic biopsy. A pathologist will assign a Modified Marsh Type to the biopsy findings. A Type of 3 indicates celiac disease.
Why an Endoscopic Biopsy?
An endoscopic biopsy will tell you (1) if you have celiac disease, (2) if your symptoms improve on a gluten-free diet due to a placebo effect (you feel better because you think you should) or (3) if you have a different gastrointestinal disorder or sensitivity which responds to change in your diet.
If the results of the antibody or genetic tests are positive, your doctor may suggest an endoscopic biopsy. An endoscopy is a procedure that allows your physician to see what is going on inside your GI tract. A scope is inserted through the mouth and down the esophagus, stomach and small intestine, giving the physician a clear view and the option of taking a sample of the tissue.
This is usually an outpatient procedure. Samples of the lining of the small intestine will be studied under a microscope to look for damage and inflammation due to celiac disease. It is recommended that the doctor take at least 4-6 duodenal samples from the second part of duodenum and the duodenal bulb, in order to obtain an accurate diagnosis.
IMPORTANT: For biopsy results to be accurate, adults must be eating gluten for at least 4 weeks (e.g., two pieces of toast daily).
What To Expect During An Endoscopy
This procedure takes a little less than thirty minutes and, for adults, sedatives and local anesthetics are used. Children are usually put under general anesthesia. During the biopsy, the gastroenterologist will insert a small tube with a camera through the patient’s mouth and into the digestive tract to the small intestine. Once there, the physician will examine the duodenum (entryway into the small intestine) and take multiple tissue samples due to the “patchy” nature of villous atrophy. The tissue samples will then be examined by a pathologist under a microscope and assigned a Marsh classification.
Since there are no nerve endings in the lining of the intestine, the procedure is not painful – though some patients may experience a sore throat.
Patients who cannot or will not tolerate an endoscopy may be given the option to undergo video capsule or “pill” endoscopy where a capsule the size of a large vitamin pill is swallowed and takes thousands of pictures of the small intestine. However, there is no conclusive evidence that this can substitute for traditional endoscopy and biopsy.
Modified Marsh Classification of Histologic Findings in Celiac Disease (Oberhuber)
|Marsh Type||IEL / 100 enterocytes – jejunum||IEL / 100 enterocytes – duodenum||Crypt hyperplasia||Villi|
- IEL/100 enterocytes, intraepithelial lymphocytes per 100 enterocytes
- Type 0: Intestinal lining is normal; celiac disease highly unlikely.
- Type 1: Seen in patients on gluten free diet (suggesting minimal amounts of gluten or gliadin are being ingested); patients with dermatitis herpetiformis; family members of celiac disease patients, not specific, may be seen in infections.
- Type 2: Very rare, seen occasionally in dermatitis herpetiformis.
- Type 3: Spectrum of changes seen in symptomatic celiac disease.
Is Endoscopy Really Necessary if My Blood Test is Positive or I Feel Better on a Gluten-Free Diet?
The endoscopic biopsy is necessary to confirm a celiac disease diagnosis. The blood tests indicate whether there is a possibility of celiac disease but you cannot confirm the diagnosis until an endoscopic biopsy is taken, with two exceptions:
For individuals with dermatitis herpetiformis (DH), a skin biopsy is sufficient for diagnosis of both DH and celiac disease. This biopsy involves collecting a small piece of skin near the rash and testing it for the IgA antibody. It is not necessary to perform an endoscopic biopsy to establish the diagnosis of celiac disease in a patient with DH; the skin biopsy is definitive.
For children with symptoms and signs of malabsorption, a very high tTG-IgA titer (>10 time upper limit of normal), and a positive EMA (antiendomysial) in a second blood sample, some physicians may recommend avoiding endoscopic biopsy, and directly starting a gluten-free diet. Others may recommend genetic testing for additional confirmation. Resolution of symptoms while on a gluten-free diet may be used to confirm the diagnosis.
Currently, the only treatment for celiac disease and non-celiac wheat sensitivity is lifelong adherence to a strict gluten-free diet. People living gluten-free must avoid foods with wheat, rye and barley, such as bread and beer. Ingesting small amounts of gluten, like crumbs from a cutting board or toaster, can trigger intestinal damage.
Once diagnosed, annual follow-up with your physician is necessary to monitor nutritional deficiencies and your compliance with a gluten-free diet, as well as assess for associated conditions.
Finding the Right Doctor
Celiac Disease Foundation can help you find the right doctor to discuss symptoms, diagnose, and treat celiac disease. Our nationwide Healthcare Practitioner Directory lists primary care physicians and specialists,and dietitians and mental health professionals, experienced in celiac disease and non-celiac wheat sensitivity.