Our study demonstrates that VCE can be used to diagnose celiac disease in patients with suspected celiac disease who have either a non-diagnostic EGD with biopsy or who are unable or unwilling to undergo EGD. Although VCE is used to diagnose celiac disease in clinical practice, previous guidelines have not recommended this approach and our study is the first to support its role in diagnosing celiac disease. It is unclear what proportion of patients that have positive celiac disease serologies, but a normal EGD (these patients may be classified as having latent celiac disease and are usually not advised to commence a gluten-free diet), will have a VCE that is diagnostic for celiac disease. One small series did not find celiac disease in this situation [7
], but there is growing evidence that celiac disease may sometimes vary in distribution, appearing more distally and patchy in nature [6
]. However, before embarking on additional testing with VCE, it is important to first confirm the adequacy of the initial diagnostic work up, starting from a meticulous endoscopic evaluation, to taking a sufficient number biopsies, and finally having an experienced gastrointestinal pathologist interpret the pathology. Additionally, a trial of a gluten-free diet as a diagnostic method should be avoided as it can negatively impact quality of life, is difficult to adhere to, and overall more expensive, particularly in the United States where there is limited availability of gluten-free foods.
Traditionally celiac disease is diagnosed by biopsy of the duodenum in individuals with positive serological tests. Negative biopsies in this setting result in a consideration that the serological tests were false positives, or the patient has potential or latent celiac disease. This result could however be the result of either an inadequate number of biopsies [2
] or that the duodenal bulb was not biopsied [9
]. Our results would suggest that when the index of suspicion is high, VCE may confirm the diagnosis of celiac disease in this setting. This is based on the high specificity for the mucosal abnormalities associated with the presence of villous atrophy. However, a negative VCE in which the characteristic endoscopic appearance of villous atrophy is not appreciated does not exclude celiac disease, as villous atrophy may be present in the setting of a normal endoscopic appearance (low sensitivity).
Our findings were limited by our small cohort size and retrospective study design. Ideally we would have also confirmed mucosal recovery in addition to symptomatic and laboratory improvement with a repeat VCE while on a gluten-free diet. Although we were unable to obtain a tissue diagnosis of celiac disease in our series, the vast majority of the patients developed clinical improvement after starting a gluten-free diet, which was able to confirm the diagnosis of celiac disease. Patients with suspected celiac disease that do not improve on a gluten-free diet should be followed closely by a nutritionist experienced with celiac disease, and may possibly benefit from a repeat VCE with or without a gluten challenge.