'Silent' celiac disease common in patients' close relatives

When a family member has celiac disease, Mayo Clinic researchers recommend parents, siblings and children also be tested, after a new study suggests first-degree relatives frequently have the condition, too - often without typical symptoms.

Celiac disease is an autoimmune disorder that damages the small intestine when patients consume gluten, a protein in wheat, barley and rye and in any foods that contain those grains or their by-products. The only treatment is a gluten-free diet.

The study, published in Mayo Clinic Proceedings, found that 44% of close relatives who had blood tests for celiac disease turned out to have the condition. Nearly all of them had atypical symptoms or no symptoms at all.

Senior study author Dr. Imad Absah told Reuters Health this rate was higher than his team had expected.

But Dr. Ritu Verma, medical director of the University of Chicago Celiac Disease Center, said the data validate what she sees in the clinic.

In fact, in 2004, two of her own children were diagnosed with celiac disease. “One of them had the symptoms and the other one did not, and she was picked up on a screen, just like in this particular study,” Verma, who was not involved in the study, said in a phone interview.

Doctors are comfortable with the idea of testing symptomatic people for celiac disease, she added, “but the asymptomatic ones - I think that’s the surprise in terms of data.” At present, guidelines say that when children are diagnosed with celiac disease, their family members should be tested, but when an adult is diagnosed, testing is only necessary for close relatives who show symptoms.

But Absah notes that in recent years, a fair number of patients have been diagnosed who didn’t have classic symptoms, which include weight loss and chronic diarrhea in adults, or stunted growth in children.

When the small intestine is damaged in celiac disease, the body can’t absorb the nutrients in food. “You’re eating but you’re not making use of what you’re eating because of damage to your small bowel,” Absah explained.

If celiac disease goes undetected, patients risk developing other conditions like nutritional deficiencies, anemia, osteoporosis and even lymphoma.

Absah and colleagues studied 104 patients with celiac disease, who altogether had 477 first-degree relatives. Of the 360 relatives who agreed to have the blood test, 160 were diagnosed with the disease, at an average age of 32.

Diagnoses are typically confirmed with a small bowel biopsy.

Absah notes that blood tests are cheaper than genetic tests, which only tell whether someone’s at risk for developing the disease, not whether they actually have it.

He recommends children related to celiac disease patients get screened every three to five years, and more often if they develop symptoms.

Verma recommends annual screening till children reach puberty, to make sure their growth is not affected.

However, doctors advise against following a gluten-free diet merely because a family member has been diagnosed.

Dr. Peter Green, director of the Celiac Disease Center at Columbia University in New York City, told Reuters Health low gluten diets increase the risk of heart disease and type 2 diabetes, “probably because of the low intake of whole grains.” Absah said gluten-free diets in patients who have not been diagnosed could skew screening results. If you’ve been gluten-free for a long time, blood tests and biopsies won’t be reliable, he said.

Verma said the data represent a good starting point to answer bigger questions, such as how often family members should be screened for celiac disease.

“I would’ve loved to see if those relatives who were not diagnosed with celiac disease in the study developed the disease later in life,” she said.

“This study will encourage more studies to be done and hopefully increase support for more testing of asymptomatic people, who often slip under the radar.”