Something approaching 1 percent of people of European ancestry have celiac disease: an autoimmune intolerance to gluten, a protein found in wheat, barley and rye. That's roughly 3 million people in the United States, only 5 to 10 percent of whom have actually been diagnosed.
As in other autoimmune disorders such as type-1 diabetes, rheumatoid arthritis and multiple sclerosis, celiac disease is marked by an immune attack on the body's own cells (in this case, cells lining the small intestine) as if they were invading viral or bacterial pathogens. The way to avoid this condition's discomforting, often debilitating and potentially devastating effects is to stay away from all foods that contain gluten - a major sacrifice for most, at least until the food industry began pushing gluten-free foods in earnest not too long ago.
An estimated 1.6 million Americans follow a gluten-free diet without an established diagnosis of celiac disease. Though many folks swear by that Spartan regimen, it's safe to say that at least some of them are deriving no benefit from the sacrifice. (Let me be clear: If you tell me that since going gluten-free you're symptom-free, I'll take your word for it.)
Available tests for diagnosing celiac disease rely on measuring blood levels of circulating antibodies to gluten, or biopsying the intestine. But anyone who has been on a gluten-free diet long enough will test completely normal. Even if these individuals do have celiac disease, the tests won't show it unless they kick-start their autoimmunity by continuously eating gluten-containing foods for two to four weeks - enough time for a new round of intestinal tissue damage to occur - before being tested. That's a lot to ask of them.
Now, a team led by Stanford immunologist Mark Davis, PhD, has laid the groundwork for a way to diagnose celiac disease in a much shorter time - six days - and with a much-reduced gluten intake. In a new study published in Proceedings of the National Academy of Sciences, Davis and his colleagues asked volunteers who had previously been definitively diagnosed with celiac disease and had been on gluten-free diets for at least a month to eat four slices of white bread per day for three days in a row. Then, using extremely sophisticated techniques pioneered in Davis's lab, the investigators analyzed several classes of circulating immune cells from volunteers' blood samples. These analyses were able to detect gluten-focused, gut-ward bound immune cells in the blood by Day 6 -much sooner than telltale antibodies would appear, and a whole lot less invasive than a gut biopsy.
"This might be a very easy diagnostic to use for celiac disease, and more accurate than any out there now," Davis, the director of Stanford's Institute for Immunity, Transplantation and Infection, told me, expressing special gratitude for "these heroic volunteers, who cheerfully agreed to eat bread and experience discomfort to advance the science of their disease."
Previously: Chat with Stanford pediatric gastroenterologist on celiac disease research archived on Storify, Deja vu: Adults' immune systems "remember" microscopic monsters they've never seen before, Living the gluten-free life, From frustration to foundation: Embracing a diagnosis of celiac disease and Gluten: The "new diet villain"?
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