Have questions about being diagnosed with celiac disease? Although awareness has grown over the past decade as the medical community is better educated on celiac, it still takes an average of 5 years for someone to be correctly diagnosed. Below you’ll find that we’ve collected a bunch of information about celiac diagnosis for your convenience. Questions answered include an explanation of how celiac is diagnosed, the doctor’s examination, blood tests and the infamous biopsy, and of course the gluten free diet.
How is Celiac Disease Diagnosed?
When working with a physician to diagnose and/or confirm Celiac Disease (CD), three major steps are taken.
- A thorough physical examination is conducted, including a series of blood tests, sometimes referred to as a “Celiac Blood Panel”.
- A duodenal biopsy is performed with multiple samples from multiple locations in the small intestine.
- The gluten free diet is implemented. When the patient shows a positive response to the diet – symptoms subside and the small intestine returns to its normal, healthy state, confirming the diagnosis of Celiac Disease.
Note: To ensure the most accurate and timely diagnosis of Celiac Disease, the gluten free diet should be implemented only AFTER the first two steps have been completed. Otherwise doctors may be unable to confirm you have Celiac Disease via the biopsy.
When reviewing a patient’s medical history and symptoms with a physician, the following areas should be considered in the discussion:
- What are the symptoms? How long have they been present? How often do they occur?
- What is the patient’s emotional state? Is it consistent throughout the day? When and for how long do the symptoms occur?
- What else is involved? Other diseases? Other organs?
- How is the child developing? (Children only)
Note: See What are the Symptoms of Celiac Disease? for a thorough list of possible symptoms.
Depending on the presentation of symptoms, the physician may check for the following:
- Pallor (due to anemia)
- Hypotension (low blood pressure)
- Edema (due to low levels of protein, [albumin] in the blood)
- Dermatitis Herpetiformis (skin lesions associated with Celiac Disease)
- Easy bruising (lack of vitamin K)
- Bone or skin and mucosa membrane changes due to vitamin deficiencies
- Protruding or distended abdomen (intestine dysmotility)
- Loss of various sensations in extremities including vibration, position and light touch (vitamin deficiency)
Signs of severe vitamin/mineral deficiencies which may include:
- Diminished deep tendon reflexes
- Muscle spasms (magnesium and/or calcium deficiency)
- Bone tenderness and bone pain (due to osteomalacia)
There is no standardization in current tests. A number of tests, sometimes collectively referred to as the “Celiac Blood Panel”, will aid the physician in the diagnosis of Celiac Disease. The tests may include, but are not limited to:
- Serologic Tests
- EMA (Immunoglobulin A anti-endomysium antibodies)
- AGA (IgA anti-gliadin antibodies)
- DGP (Deamidated gliadin peptide antibody)
- tTGA (IgA anti-tissue transglutaminase)
- Tolerance or Measure of Digestion/Absorption Tests
- Lactose tolerance test.
- D-Xylose test.
- Deamidated gliadin peptide (DGP) antibodies tests developed in 2007 in combination with Tissue transglutaminase (TTG) antibodies and have better accuracy than native gliadin antibodies. Multiplex immunoassay (MIA) measures multiple antibodies simultaneously providing with reduced turnaround time and cost. This test for antibodies is as accurate as ELISA for the presence of celiac disease.
- Rational combination testing can help identify patients who need intestinal biopsy.
Note: A Celiac Home Test Kit was recently approved and made available throughout Canada, but is not currently available in the United States. Even if this test eventually makes it to the United States, it will not replace the biopsy. Instead, it was designed to help confirm you need to have a biopsy done.
Biopsy of the Small Intestine
In the event that clinical signs and laboratory tests indicate probable malabsorption, a biopsy of the small intestine [jejunal] is called for. In this test, a small flexible biopsy instrument is passed through a tube, down the throat, through the stomach and into the upper end of the small intestine where patchy, multiple snippets of tissue are gathered. The tube is removed and the tissue samples are examined under a microscope for signs of injury.
The difference between tissue in a normal small intestine and that found in a celiac patient is remarkable. The normal finger-like projections (villi), which increase the absorptive surface area of the small intestine, are partially or totally flattened in a person with celiac disease. Enzymes located on the brush border are also drastically reduced. Lactase, the enzyme responsible for splitting milk sugar (lactose) so it can be absorbed, is an example of one of these brush border enzymes. This decrease in lactase explains why some untreated celiac patients may not be able to tolerate milk products and will have developed lactose intolerance. Elevated numbers of T-cell lymphocytes (white blood cells) are also present. The small bowel biopsy samples of persons with dermatitis herpetiformis often show similar damage.
To view a color-coded illustration of a single villus, visit MEDLINEplus.
Note: At this time there is no standardization in either serological testing or intestinal biopsies.
Gluten Free Diet
The diagnosis of celiac disease is complete when the health of the patient improves following implementation of the gluten free (GF) diet. When gluten is removed from the diet, most of the damage that was done to the small intestine (the jejunum) is repaired. It takes only three to six days for the intestinal lining (the mucosa) to show improvement. Within three to six months, most symptoms subside as the mucosa returns to its normal (or nearly normal) state.
If, after six months on the gluten free diet, symptoms still persist, the following need to be considered:
- Has gluten been removed from every area of your diet and life?
- Do unrelated conditions exist that are causing the continued discomfort?
The good news is that the gluten free diet is a completely risk-free diet! Gluten, as a protein, is not essential to the diet and its amino acid components are replaced many times over by other foods. Adopting the gluten free diet can only result in improved health and well-being.