There is currently no easy way to diagnose celiac disease in patients already following a gluten-free diet. In order for celiac disease blood tests to be accurate, patients on a gluten-free diet must undergo a “gluten challenge,” a temporary re-introduction of gluten into the diet, by consuming two slices of wheat-based bread daily for 6-8 weeks. A new study led by Dr. Robert P. Anderson found that a single-dose gluten challenge combined with an interleukin-2 assessment (a chemical in the body that modifies the immune system) may be a helpful tool in diagnosing and monitoring celiac disease for patients already on a gluten-free diet. A test that only requires one dose of gluten to detect celiac disease could make diagnosis much simpler.
Elevated serum interleukin-2 levels were found to correlate with the timing and severity of symptoms after a single-dose gluten challenge in patients with celiac disease. For this study, 25 celiac disease patients on a gluten-free diet and 25 healthy volunteers consumed 6 grams of gluten (equivalent to roughly 3 slices of wheat-based bread) for a gluten challenge. Symptom severity following the single-dose gluten challenge was self-reported by each participant. Symptoms were monitored up to 14 days after the gluten challenge for celiac disease patients and up to 24 hours in healthy volunteers. Serum interleukin-2 was measured before the gluten challenge, and then at 2, 4, and 6 hours after the gluten challenge.
Healthy control subjects showed no detectable levels of serum interleukin-2, while 92% of celiac patients showed no detectable levels at baseline, but levels greater than 0.5 pg/ml at 4 hours after gluten challenge. Patient-reported symptom severity remained steady for all healthy control subjects, while scores for celiac patients increased sharply after consuming gluten. The highest interleukin-2 levels correlated with the most severe symptoms, particularly nausea and vomiting.
A standardized gluten challenge and interleukin-2 measurement could be a valuable test to monitor and diagnose celiac disease in patients already on a gluten-free diet. A new diagnostic method requiring only a single dose of gluten may be especially useful for patients on a gluten-free diet who are unwilling, or unable, to maintain regular gluten consumption for the amount of time that a traditional gluten challenge requires (6-8 weeks). An easier, less painful diagnostic test such as this has the potential to increase rates of diagnosis among celiac patients and give researchers a more accurate picture of the celiac disease population.
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