Despite a growing awareness of celiac disease, most people still don’t know they have it.
When a pediatrician phoned Marilyn Geller with test results indicating her 15-year-old son probably had celiac disease, Geller did not understand what the physician was saying.
With a master’s of science in public health and experience as a hospital administrator, Geller considered herself well educated in the health field. But she knew little about the disease.
While Geller has since learned a lot and now serves as head of a national support group, many people still know little about celiac disease. Although it is one of North America’s most common health problems, affecting close to one in 100 people, celiac disease is widely undiagnosed.
When the pediatrician mentioned celiac disease, Geller says she heard, “The animal at the zoo, you know, like S-E-A-L.”
She did not know what gluten was, either. Her husband, a trained clinician, was similarly bewildered. Their son did not have the classic symptoms he knew about: skinny limbs, swollen belly and diarrhea. In fact, he was overweight and constipated and had suffered for years with nasal problems.
Since then — now her son is healthy and attending college — Geller has become chief executive officer of the Celiac Disease Foundation in Los Angeles. Correcting the under-diagnosis of this condition is a project near to her heart.
Although the gluten-free diet and celiac disease have gained widespread attention in mainstream and social media in recent years, the rate of diagnosis has stubbornly remained nearly unchanged, with less than a paltry 20 percent aware they have the disease.
Untreated celiac disease presents health risks. A study from Columbia University in 2013 found that the intestinal damage brings a four times greater risk of developing a type of lymphoma, or blood cancer. Celiac disease is also linked to osteoporosis, thyroid problems, type 1 diabetes and malabsorption of nutrients.
To estimate long-term health risk, a group of celiac disease experts led by Joseph Murray, M.D., of the Mayo Clinic, in 2009 analyzed blood samples collected a half century earlier, between 1948 and 1954, from more than 9,000 healthy young men at an Air Force base. Using current technology, researchers identified who had undiagnosed celiac disease. According to records traced up to 1997, these individuals faced a fourfold greater risk of death.
Early diagnosis and adoption of a gluten-free diet can eliminate or reduce health risks.
“It is a simple blood test. It is a simple biopsy,” Geller says. “There is no reason anybody should suffer.”
The most recent nationwide study, conducted by Murray and colleagues in 2012 and appearing in theAmerican Journal of Gastroenterology, estimated that 1.8 million Americans have celiac disease and 83 percent remain undiagnosed.
Another study by Murray’s team a year earlier used a volunteer blood draw at a Wyoming health fair to estimate that undiagnosed celiac disease affects 1 in 126 Americans. Most participants whose blood tests indicated they likely had celiac disease reported no symptoms or atypical ones.
About 40 percent of North Americans are thought to possess the genes for celiac disease, but few of them will ever develop it. Scientists are still investigating what environmental factors cause a healthy person with these genes to develop celiac disease. A study last year from the Norwegian Institute of Public health found that introducing food grains to infants between 5 and 6 months of age while still breastfeeding may help protect against childhood onset. Stresses such as surgery and pregnancy seem to trigger the disease in adults.
Besides genetics and environmental factors, celiac disease is an autoimmune condition that also involves a reaction to gluten, a protein found in wheat, barley and rye. When a patient’s gut digests gluten, the immune system attacks the lining of the small intestine. This damages the tissues that absorb nutrients, eroding the villi, tiny finger-like projections that line the gut. This process is called villous atrophy.
However, in some people this tissue damage occurs without any obvious symptoms. Murray, a professor of medicine and consultant to the department of immunology at the Mayo Clinic in Rochester, Minn., calls people with no symptoms “silent patients.” This is the first reason he suggests why so many cases remain undiagnosed.
Confusion of symptoms
Even if symptoms occur, Murray says patients and doctors can miss diagnosis for several reasons. Symptoms are often vague and may be attributed to other common conditions such as irritable bowel syndrome.
The classic signs of celiac disease include digestive disturbances, pain and fatigue. In children it can cause failure to thrive. Completely different sets of symptoms can manifest, such as itchy skin, anemia, osteoporosis, infertility and miscarriage. Uncharacteristic symptoms can distract patients and doctors from a connection to celiac disease.
Geller’s son had suffered for years from unexplained post-nasal drip, she says, and was undergoing an expensive battery of tests prior to sinus surgery when the pediatrician identified his celiac disease.
Murray says, “Other patients at risk — with type 1 diabetes, premature osteoporosis, or iron deficiency anemia — should be tested, but again awareness of that association is not obvious” and is unfamiliar to many doctors.
He also points out many doctors do not recognize the importance of a family history of celiac disease. “It’s not a routine question,” he says. “It should be. And if someone has a family history, they should be tested.”
Essentially, doctors lack suspicion of celiac disease. Murray says, “People just don’t think about it.”
Closer look at biopsies
Diagnosis of celiac disease involves conducting an endoscopy, which allows visual examination of the small intestine using a flexible tube, combined with biopsies, tissue samples collected from the gut. Currently this procedure provides the best way to identify villous atrophy. It remains the gold standard for diagnosis of celiac disease.
But Benjamin Lebwohl, M.D., assistant professor of clinical medicine and epidemiology at the Celiac Disease Center at Columbia University Medical Center in New York, N.Y., has found that most gastroenterologists do not collect enough tissue samples from each patient.
Diseased tissue in the small intestine can occur in patches. For this reason, in 2006 the American Gastroenterological Association issued a guideline that from four to six biopsy samples should be collected from each patient.
Based on an analysis of all procedures conducted in the United States between 2006 and 2009 on about 93,000 different patients, a research team led by Lebwohl in 2013 found that only one-third of submissions included at least four biopsies. The most common number was two. Adherence to the guidelines increased only modestly during the late 2000s, from 35 to 38 percent.
The study also found that gastroenterologists who conducted a large volume of procedures were more likely to submit fewer biopsies per procedure. However, gastroenterologists from larger endoscopy practices with multiple physicians in the group were more likely to adhere to the guidelines. This suggests that doctors who work more closely with their peers follow the rules better.
The same study found that clinics with physicians who tested a higher volume of patients were less likely to adhere to the biopsy guidelines, perhaps because of the extra time required to collect additional samples.
An endoscopy alone can often find evidence of villous atrophy. However, unless tissue samples are also taken, the procedure can miss microscopic evidence of celiac disease. Researchers including Lebwohl in 2012 found that endoscopy procedures to investigate diarrhea, anemia and weight loss often did not include biopsy, even though those symptoms are indicative of celiac disease. Patients who were male, older or black or Hispanic were less likely to have biopsies taken.
“Men are equally likely as women to show the antibodies that indicate celiac disease — most studies have shown this,” says Lebwohl. “At the same time, most studies have also shown that the majority of patients diagnosed with celiac disease are female. I believe that this discrepancy is due to a combination of factors: Women may be more likely to seek evaluation of their symptoms, and doctors may be less likely to test for celiac disease in men, due to the erroneous belief that celiac disease is uncommon in men.”
Another study headed by Lebwohl in 2011 found that following the guidelines more than doubled the probability of finding celiac disease in tested patients from 0.7 percent to 1.8 percent. Inadequate testing may be overlooking many cases of celiac disease.
For a variety of reasons, patients themselves are prompting an unusually large proportion of celiac disease diagnoses.
“At my practice I ask all newly diagnosed patients, ‘Who thought of testing you for celiac disease first?’” Murray says. “And at least one-third of the time it was themselves or a family member.”
However, self-diagnosis without proper testing can have an unfortunate consequence: People will adopt a gluten-free diet without knowing whether they really have celiac disease.
The 2012 nation-wide survey of nearly 7,800 people, conducted by Murray’s team, found most who follow a gluten-free diet have not been diagnosed with celiac disease.
Geller’s experience talking to people echoes the research.
“They have these symptoms so they put themselves on the gluten-free diet to try it,” she says. “Then they feel better so they don’t want to do a gluten challenge to find out if they really do have celiac disease.”
On the gluten-free diet, villous atrophy and the blood levels of gluten antibodies often revert to normal, so a diagnosis is impossible unless the patient begins consuming gluten again. Most people do not want to make themselves sick through this process even if it would let them know for certain.
Some people who adopt the diet have non-celiac gluten sensitivity. Ideally, they have undergone the diagnostic procedure to rule out celiac disease, then tried a gluten-free diet under a doctor’s supervision. As yet, there is no test to diagnose non-celiac gluten sensitivity, but if the diet leads to improved health, then this confirms it as the best course of action. In other cases patients reach this conclusion on their own and adopt the diet without getting tested for celiac disease.
The danger in not knowing whether celiac disease is the culprit is in the absence of appropriate follow-up health care, Geller says.
With celiac disease, “You have the risk for the other autoimmune disorders. So if you put yourself on a gluten-free diet, who is doing your regular bloods testing to make sure that you don’t now have thyroid disease, psoriasis, lupus or type 1 diabetes?”
Some patients continue to show tissue damage from unknown sources of gluten. Symptoms may vanish, but long-term health impact is hard to assess.
Murray recommends that self-treated patients pursue diagnosis under medical supervision. This might begin with a genetic test, which can rule out the possibility of celiac disease if the required genes are missing. If a patient has the genes, Murray advises an antibody test, possibly followed by a gluten challenge and duodenal biopsy.
Better to know
Geller says diagnosis can provide a strong incentive against cheating on the diet.
It helps parents such as Margaret Steen, 43, who lives near San Francisco with her husband and two sons. Her younger son, Harrison Webster, 9, has been diagnosed with celiac disease.
“When the blood tests came back positive, we took Harrison to a pediatric gastroenterologist, who recommended that we do the endoscopy and biopsies to find out for sure whether he had celiac, disease” Steen says. “Because we knew that sticking to the diet would be difficult, we wanted to know for certain.
“It would be hard for him to refuse pizza at pizza parties, cake at birthday parties and all sorts of food offered by well-meaning people. We thought it would be easier for him (and for us, when he is asking for ‘just one bagel’) to remain firm if we had a clear medical diagnosis.”
She adds, “Since he wasn’t having painful symptoms before, I don’t think he sees much of a benefit. He has been good about sticking to the diet, though.”
The pediatrician recommended testing Harrison because he was underweight and had a family history of Crohn’s disease.
“I’m glad to know he has celiac disease so we can be sure he grows as much as he is meant to and so he doesn’t have further medical problems caused by gluten later,” Steen says.
Finding lost patients
Higher rates of diagnosis require better awareness among doctors. Lebwohl says physicians can help each other.
“In our research we found that gastroenterologists who perform endoscopy with higher numbers of colleagues in the same unit tend to have greater adherence to these [biopsy] guidelines,” he explains. “This suggests that peer education is playing a positive role in adoption of these guidelines. We learn from our colleagues.”
A 2007 study from the University of Maryland School of Medicine found that providing a checklist of symptoms at primary care clinics led to a marked increase in diagnoses.
Geller argues that change starts with the public.
“The patient community needs to support celiac disease [research] just like they would support any cancer research. Just like they would support Parkinson’s disease or lupus [research]. There need to be dollars donated to advance research, period,” she says. “That’s going to be the biggest driving factor. When the community stands up for itself and takes care of itself, that will drive diagnosis.”
Geller points out that the pharmacy industry also drives health care in North America. Doctors may have been slow to gain awareness of celiac disease because of the lack of any drug treatment for the disease. Some drugs are currently in the testing phase, so this situation may change if any of them become approved. Again, funding is required.
Meanwhile, the exploding availability of gluten-free foods may have done more than anything else to spread awareness. But while that benefits those who have celiac disease, it also has some drawbacks.
“This is the double-edged sword of the gluten-free marketplace,” Geller says, “because you have so many people adopting gluten-free and vegan and paleo diets that, from a clinician’s perspective, it falls into an alternative health lifestyle as opposed to a disease.”
The tendency for people to adopt the diet without diagnosis also casts some doubt. But overall Geller sees the outcome as beneficial.
“Because of the gluten-free marketplace, consumers are aware, and because consumers are aware and asking, physicians are doing more research.”