Universal celiac screening lacks evidence, U.S. panel finds
Research needed on course of the disease among people living with the condition but not showing symptoms
There is not enough evidence to encourage or discourage doctors from testing all their patients for celiac disease, according to a U.S. government-backed panel.
Even when close relatives have been diagnosed with the autoimmune condition, there isn't enough evidence to say screening should always be done.
The new statement from the U.S. Preventive Services Task Force (USPSTF) applies to adults without celiac disease symptoms, which can include abdominal pain, bloating, gas, diarrhea, anemia and weight loss.
"I think if individuals are concerned or they're having symptoms, they should talk to their doctor about it," said Dr. Alex Krist, who is a USPSTF member and an associate professor of family medicine and population health at Virginia Commonwealth University in Richmond.
In people with celiac disease, consuming the gluten protein in wheat, rye or barley triggers an autoimmune response that harms the lining of the small intestine. As a result, people with the condition are advised to go on a gluten-free diet.
The USPSTF writes in JAMA that between 0.40 and 0.95 per cent of people in the U.S. have celiac disease. The condition is more common among non-Hispanic whites, people with a family history of celiac disease and people with other autoimmune conditions, such as Type 1 diabetes.
Recommendations of other organizations vary, but some — like the American College of Gastroenterology and the North American Society of Pediatric Gastroenterology — do recommend testing certain individuals who are at an increased risk for the condition, such as those with immediate family with celiac disease.
Family doctors in Canada are also advised that since celiac disease can be present with mild or "atypical symptoms, a high index of suspicion is required."
"The term 'asymptomatic' can be tricky," said Dr. Mohsin Rashid, a gastroenterology professor at Dalhousie University in Halifax. "Many of these people once diagnosed and start a gluten-free diet realize that they were really not that 'asymptomatic.' The symptoms can be very mild and non-specific and people may not seek medical help," he added in an email to CBC News.
Testing for celiac disease starts out with a blood sample, Krist told Reuters Health. If the blood test is positive, a biopsy of the small intestine may be needed to confirm the results.
"We don't want to subject patients to that type of test if it's not going to help them," he said.
The USPSTF says more research on screening people at an increased risk of celiac disease who are not showing symptoms is needed.
Additionally, Krist said, research is needed on the course of the disease among people living with the condition but not showing symptoms — known as silent or asymptomatic celiac disease.
In an editorial, Drs. Rok Seon Choung and Joseph Murray from the Mayo Clinic in Rochester, Minnesota agree there is a lack of evidence supporting universal testing for celiac disease in people without symptoms.
"Recognizing that most celiac disease is undetected and may present with diverse symptoms, it is reasonable that clinicians should have a low threshold for testing for celiac disease, especially in high-risk populations such as those with an affected family member or Type 1 diabetes mellitus," they add.
Krist said the USPSTF regularly evaluates the evidence on its statements and recommendations. Depending on evidence, the statement may change during a future update.
Until then, he said, people should bring up their concerns to their doctors.
The new statement was previously published as a draft in May 2016.
With files from CBC News