Summary: Despite the rise of celiac disease, it remains widely under-diagnosed. An American and Lebanese study found that certain readily available medical information could help endoscopists improve the diagnosis rate.
Endoscopy is a procedure used to investigate a variety of digestive problems such as indigestion, nausea, ulcers and celiac disease. The stomach and small intestine are visually inspected during an endoscopy. Diagnosis of celiac disease requires endoscopy plus an additional, more expensive and invasive procedure, called a biopsy, during which tissue samples are taken.
Most patients referred for endoscopies do not receive prior blood tests that could indicate celiac disease. Lacking evidence of celiac disease, the endoscopist may not recognize the importance of also performing a biopsy. So endoscopies often overlook celiac disease, delaying diagnosis. Performing a biopsy on every patient sent for endoscopy would significantly increase the cost of diagnosis and subject many people to an unnecessary procedure. On the other hand, undiagnosed celiac disease also leads to long-term health care costs.
To find a cost-effective strategy, researchers associated with American University of Beirut followed 1,000 Lebanese volunteer patients scheduled for endoscopy who had not already received blood tests. Each participant answered a questionnaire, provided blood samples, and underwent endoscopy. The interview included questions about ethnicity, chief complaint, and details of family and medical history that may be associated with celiac disease, such as diabetes, skin diseases and anemia. Based on medical information available on referral, the endoscopists were asked whether they suspected celiac disease prior to the procedure, and whether they observed any tissue damage leading to a suspicion during the procedure.
Biopsies were then performed on all patients to ensure accurate diagnosis. Labs tested the blood samples for several indicators and analyzed tissue samples for features of celiac disease. To avoid bias, specialists looking at either blood or tissue samples received no other information about the patients.
Celiac disease was common in patients referred for endoscopy; 15 cases were diagnosed. But prior suspicion was not always an accurate predictor. Many of the 50 patients the endoscopists suspected might have celiac disease actually did not. Meanwhile, half the diagnosed cases of celiac disease had not been suspected beforehand.
Conclusion: Patient medical information available to endoscopists can help predict diagnosis of celiac disease with greater accuracy.
A positive blood test for tissue transglutaminase (tTg), an enzyme that appears in most patients with celiac disease, was a powerful predictor and should prompt a biopsy, say the authors. However, one-quarter of the celiac disease patients in this study tested tTg-negative. Consequently, endoscopists should not require a positive tTg test when deciding to perform a biopsy.
The study found three other factors that strongly predict celiac disease in the absence of blood test results. Besides a positive tTg test, the authors recommend that endoscopists take tissue samples if the patient has anemia or history of eczema or if the endoscopy reveals tissue damage suggesting flattening of the villi. This protocol could improve diagnosis rates while limiting the number of costly, unnecessary biopsies.
[1] “Prediction of celiac disease at endoscopy”, Barada K, Habib RH, Malli A, Hashash JG, Halawi H, Maasri K, Tawil A, Mourad F, Sharara AI, Soweid A, Sukkarieh I, Chackachiro Z, Jabbour M, Fasano A, Santora D, Arguelles C, Murray JA, Green PH, #Endoscopy# (2014) 46:110-119, doi: 10.1055/s-0033-1359200.
