Study calls for testing of all first-degree relatives after finding 44 percent also have celiac disease
By Amy Ratner, Medical and Science News Analyst
Many parents, siblings and children of celiac disease patients do not have symptoms or have atypical symptoms, making it unlikely they will be diagnosed even though they are at greater risk of having celiac disease, a recent Mayo Clinic study found. The study, published in the journal Mayo Clinic Proceedings, lead the researchers to conclude screening of all first-degree relatives of those with celiac disease is justified.
A review of medical records of patients with celiac disease and their first-degree relatives found that 44 percent of screened relatives had celiac disease. Of those, about 28 percent had no symptoms, 68 percent had symptoms not typically associated with celiac disease and 6 percent had classic symptoms.
The diagnosis rate found in the study is much higher than that 5 to 11 percent typically reported for first-degree relatives. The study was based on electronic health records from the Mayo Clinic and data from 1983 to 2017 in its celiac disease registry. The researchers noted that the higher prevalence of diagnosed first-degree relatives might stem from the fact that relatives are more likely to be tested at the clinic. But they note that other studies have found an increasing incidence of celiac disease in those with a genetic risk, which they said “supports the high prevalence noted in [their] study.”
The records of 477 first-degree relatives reviewed by researchers revealed that 360, or about 80 percent, had been screened, and 160 were diagnosed. All had positive anti-tissue transglutaminase (TTG) blood test results. Those with high levels of TTG antibodies usually also had damage to the lining of the intestine found through a biopsy regardless of whether or what kind of symptoms they had.
Classic symptoms include weight loss and diarrhea in adults, plus failure to thrive in children. Atypical symptoms include nonspecific abdominal pain, bloating, constipation, headache, anemia and osteoporosis.
“Research has shown that family members of celiac disease patients are at higher risk, and we used our Mayo Clinic data to show that proactive screening of first-degree relatives, regardless of whether they showed symptoms, resulted in diagnoses that would have been missed,” said Imad Absah, MD, a Mayo Clinic pediatric gastroenterologist and the study’s lead author.
In 2017, the US Preventive Health Services Task Force, an independent panel of national experts in disease prevention that makes evidence-based recommendations about clinical preventive services, concluded there was not enough evidence to recommend widespread celiac disease screening of those who have no symptoms. The task force called for more research before it could recommend screening of targeted populations at increased risk, including those with family members who have celiac disease and those with other autoimmune conditions.
“Gastroenterologists and general practitioners should ask about family history of celiac disease among their patients’ first degree relatives and consider screening them for celiac disease,” the authors wrote.
More screening for celiac disease among family members could prevent long-term complications, such as nutritional deficiencies, development of new autoimmune conditions, and small bowel malignancy, according to the Mayo Clinic study. Other studies also have shown higher prevalence of celiac disease in family members, the Mayo clinic study said. It also noted that other research has found an increasing incidence of celiac disease among those with genetic risk.
In recognition of the increased risk of celiac disease among family members and the need for testing, Beyond Celiac created a video, Seriously, Celiac Disease, that encourages a one-on-one conversation. Other resources are available here and here.
You can read the Mayo Clinic study here.