If you have undergone an endoscopy to diagnose or follow celiac disease, you may be wondering if there is anything on the horizon that might replace this type of test. Capsule endoscopy (CE) is a new way to look inside the intestines. A tiny camera near the size of a large vitamin is swallowed, and it records thousands of pictures as it passes through the intestinal tract. These images are sent to a device strapped around the waist or across the chest and are retrieved later.
CE can be used to view the entire small intestine. It is non-invasive and not painful. Researchers are trying to determine where CE can best be used in the diagnosis of celiac disease. It may be especially useful in cases of refractory celiac disease, which means CD that has not improved on a gluten-free diet.
Capsule endoscopy is something to add to the other ways of diagnosing and following celiac disease. The tools most used now are blood tests for screening and intestinal biopsies for diagnosis. Blood tests find specific antibodies that people with CD make. These tests have gotten better over the years, and are good as a first step.
Biopsies require what is called endoscopy, in which a tube is passed into the stomach and small intestine. This may involve anesthesia, usually takes place in a surgery center, and has small but real risks. A gastroenterologist looks at the intestine through the endoscope, and takes samples. Enough samples must be taken so as not to miss an area of CD. The way the intestine looks under the microscope makes the diagnosis, gives an idea of its severity, and may also tell something about the risk for refractory celiac disease and cancer, although this is far from certain.
Sometimes plain endoscopy can be supplemented or replaced by enteroscopy, which uses a different kind of tube and can get to the small intestine more easily visible. Enteroscopy can be used when the entire small bowel needs to be seen. It is more difficult and a bit more risky.
CE gathers information in a different way. It potentially can view the entire small intestine more thoroughly than what a doctor sees looking through an endoscope. Those that are trained in looking at these images can tell what areas look like celiac disease as well as how severe it appears, which goes along with how well a person is absorbing what they need from food. It may also allow a prediction as to which type of refractory celiac disease may develop and as well as finding very early cancers, called lymphomas.
A recent study used data from patients with symptomatic celiac disease and refractory celiac disease who had blood tests, intestinal biopsies and capsule endoscopy, comparing the results of these tests with each other, as well as with results in people who had the same tests looking for problems other than celiac disease, like small amounts of intestinal bleeding coming from an unknown source.
Nine patients with celiac disease and symptoms were in this study, as were 29 patients with refractory celiac disease (RCD). There were 11 with RCD type I and 18 with RCD type II. All the results from these patients were compared with those from 45 people who were tested for other things and had some type of endoscopy as well as a CE. Many patients had more than one test.
The diagnosis of CD was made by the biopsy findings, graded in the normal way. For those patients, CE was more effective at showing areas of villous atrophy than endoscopy. CE was also more effective at detecting how severe the celiac disease was and how many areas were involved.
CE was able to detect differences between patients with celiac disease and refractory celiac disease, as well as between the two types of refractory celiac disease in many cases. The number of significant abnormalities seen with CE was associated closely with how malnourished a patient was.
Also, in this study, 7 patients with RCDII developed lymphomas, 2 of which were found by CE which indicated where the doctors needed to take biopsies. A third patient was found to have a completely different disease requiring other treatment; CE determined the biopsy site.
The researchers pointed out that CE studies that were either normal or unchanged could have prevented 17 endoscopies or enteroscopies in this group of patients.
CE is not perfect. There is also a small chance the camera will not come out in the stool, but there were no problems of this kind in this study, even if the CE was not seen to exit.
CE will not replace biopsies via endoscopy or enteroscopy to diagnose CD, or even to diagnose refractory celiac disease. It may be used to follow patients with RCD, help determine which type of RCD they have, and observe the progression of RCDII. If biopsies are needed, the CE images may help determine where they need to be taken.
More study is being done. Right now, capsule endoscopy gives doctors one more way to keep an ‘eye’ on patients with CD who are not doing well on a gluten-free diet.