Diagnosing Celiac Disease (Gluten Intolerance)
Many people suffer from stomach pain and diarrhea. Anyone who has to deal with these symptoms frequently though should take them seriously and see a doctor. Celiac Disease can only be diagnosed by a doctor. Under no circumstances you should alter their diet independently based only on a suspicion, if no reliable diagnosis is available. This can cause more harm than good.
Blood test for suspected Gluten Intolerance
The first step when a doctor suspects Celiac Disease is a blood test. Converting one’s diet before the blood test will lead to an inaccurate result. It’s possible that the antibodies in the blood will be below the determination threshold. In this case, the doctor has no chance to make the correct diagnosis.
If the blood test delivers typical antibodies (tissue transglutaminase IgA antibodies or endomysium IgA antibodies) in an increased concentration, the small intestine is biopsied.
The second step in detecting Celiac Disease: Biopsy of the small intestine
The biopsy is performed by means of gastroscopy. A small piece of the small intestinal mucous membrane is removed and microscopically examined. These microscopic images show clearly whether the small intestine is inflamed and the intestinal villi are re-formed - depending on the degree of damage to the intestinal villi, these are classified according to the so-called Marsh Criteria. The pathologist Michael N. Marsh has defined these categories. They range from Marsh Type 0 (no abnormalities) to Marsh Type 3c, a completely flattened mucosal surface.
Here, too, it is important that the affected individual continue consuming gluten until the time of the biopsy. In most cases, the intestinal mucous membranes are repaired rapidly. People suffering from celiac disease, who are already gluten-free, the pathologist may not be able to provide evidence of the damaged intestinal wall.
Unnecessary diagnostic procedures for Celiac Disease
For children, a biopsy is only performed in exceptional cases as long as the appearance and the symptoms are clear and the specific antibodies are at least 10 times the upper limit.
A genetic test cannot positively diagnose Celiac Disease, but can rule it out. Those who suffer from Celiac Disease have a certain gene variant, HLA-DQ2 or HLA-DQ8. However, in addition to individuals with Celiac Disease, about 25 percent of the population also carries this gene. A genetic test can therefore show that an individual is a HLA-DQ2 or HLA-DQ8 carrier and thus has the genetic prerequisite to develop Celiac Disease. However, such a result does not say whether the affected person is actually suffering from Celiac Disease. Conversely, this means that a genetic test may well rule out Celiac Disease. That is, if the results show that the person does not carry HLA-DQ2 or HLA-DQ8, then the genetic prerequisite for Celiac Disease (Gluten Intolerance) has not been met.
Rapid tests which are intended to provide clarity when suspected of food intolerances, as well as saliva and stool tests, are unreliable diagnostic methods for Celiac Disease.
Please see also:
What is Celiac Disease (Gluten Intolerance)?
Symptoms and concurrent disorders of Celiac Disease (Gluten Intolerance)
Therapy and treatment for Celiac Disease (Gluten Intolerance)