From the Guidelines
For diagnosing celiac disease, upper endoscopy with duodenal biopsies is the gold standard and necessary, while lower endoscopy is not routinely required unless there are specific concerns about other gastrointestinal conditions. The diagnostic process for celiac disease typically begins with blood tests for celiac-specific antibodies (tTG-IgA, EMA, DGP) while the patient is on a gluten-containing diet, followed by the confirmatory upper endoscopy with biopsies if antibody tests are positive 1. During the upper endoscopy procedure, multiple biopsies (typically 4-6) should be taken from the duodenum, including the duodenal bulb, to ensure adequate sampling, as the villous atrophy may be patchy in celiac disease 1. It's also important not to start a gluten-free diet before completing the diagnostic process, as this can heal the intestinal damage and lead to false-negative results 1. Genetic testing for HLA-DQ2 and DQ8 may be helpful in certain situations but cannot alone diagnose celiac disease 1. Some key points to consider in the diagnosis of celiac disease include:
- The endoscopic appearance of the duodenum should not determine whether biopsy is performed, as a normal endoscopic appearance may occur in the presence of villous atrophy 1
- The taking of at least four biopsy specimens is associated with a doubling of the diagnostic rate compared with patients undergoing a lower number of biopsies 1
- Video capsule endoscopy may support a celiac disease diagnosis in certain settings, such as in patients with persistently positive coeliac serology but a normal mucosa 1
- Upper endoscopy is generally well tolerated by adults and can usually be readily performed with mild or even no sedation 1.
From the Research
Celiac Disease Diagnosis
- The diagnosis of celiac disease typically involves upper endoscopy with duodenal biopsies, as this is considered the gold standard for diagnosis 2, 3.
- Lower endoscopy is not typically necessary for the diagnosis of celiac disease, as the disease primarily affects the small intestine, which can be accessed through upper endoscopy 3.
- However, in some cases, such as refractory or complicated celiac disease, lower endoscopy or other techniques like capsule endoscopy or balloon-assisted enteroscopy may be useful for evaluating the entire small bowel 3, 4.
Endoscopic Findings
- Endoscopic findings in celiac disease can include villous atrophy, which is a hallmark of the disease, as well as other abnormalities such as erosive reflux esophagitis, gastric erosions, and suspicion of esophageal metaplasia 5.
- However, the absence of characteristic endoscopic features does not exclude celiac disease, and random biopsy of normal-appearing mucosa is necessary for diagnosis 2.
- In patients with celiac disease, upper endoscopy may also reveal comorbid conditions, although the prevalence of these findings is relatively low, especially in younger patients 5.
Diagnostic Tools
- Several endoscopic tools and procedures have been developed to aid in the diagnosis of celiac disease, including chromoendoscopy, Fujinon Intelligent Chromo Endoscopy, Narrow Band Imaging, Optical Coherence Tomography, Water-Immersion Technique, confocal laser endomicroscopy, high-resolution magnification endoscopy, capsule endoscopy, and I-Scan technology 4.
- Serum tests, such as those for tissue transglutaminase and endomysial antibodies, can also be used to monitor patients with celiac disease, but have low sensitivity for detecting persistent villous atrophy on a gluten-free diet 6.