From the Guidelines
Patients should consume a regular gluten-containing diet for at least 1-3 months before a celiac disease biopsy, with a daily intake equivalent to 1-3 slices of gluten-containing bread. This is based on the most recent and highest quality study, which emphasizes the importance of maintaining a gluten-containing diet to ensure accurate diagnosis 1. The study highlights that reducing or avoiding gluten prior to diagnostic testing can limit the accuracy of both serologic and histologic results.
Key Points to Consider
- Patients should not start a gluten-free diet before the biopsy, even if they suspect celiac disease, as removing gluten can allow intestinal healing and lead to false-negative results.
- Consuming foods that contain wheat, barley, and rye daily is essential for an accurate diagnosis.
- The daily intake should be equivalent to at least 1-3 slices of gluten-containing bread, as specified in the study 1.
- Patients should continue any regular medications unless specifically instructed otherwise by their doctor.
Importance of Gluten Consumption
The reason for maintaining gluten consumption is that celiac disease diagnosis relies on identifying characteristic damage to the small intestine caused by the immune response to gluten, and this damage may not be detectable if gluten has been removed from the diet. As stated in the study, "Patients must not avoid gluten before diagnostic testing for CeD and reducing gluten should be discouraged because these practices will limit the accuracy of both serologic and histologic results" 1.
Additional Considerations
It is essential to discuss the amount of gluten in the patient's diet at the time of testing to determine whether the results are reliable. If gluten has been reduced or removed from the diet, additional or repeat testing should be completed after the patient consumes a regular diet that contains 1 to 3 slices of gluten-containing bread daily for 1 to 3 months, as recommended in the study 1.
From the Research
Dietary Requirements Before a Celiac Disease Biopsy
To determine the dietary requirements before a celiac disease (CD) biopsy, it is essential to consider the guidelines and recommendations provided by various studies.
- The diagnosis of celiac disease is typically confirmed by duodenal mucosal biopsies, and both serology and biopsy should be performed on a gluten-containing diet 2.
- A gluten-free diet (GFD) is the primary treatment for celiac disease, but the diagnosis should be made while the patient is still consuming gluten 3, 4.
- The criteria for the diagnosis of celiac disease are changing, but in adults, diagnosis still depends on the presence of duodenal villous atrophy while the patient is on a gluten-containing diet, along with findings from serology analysis 5.
- Some studies suggest that assays that detect gluten-HLA tetramer complexes might be used in diagnosis to be made in the context of a gluten-free diet without intestinal biopsy, but this is not yet widely accepted 5.
Key Points to Consider
- Patients should be on a gluten-containing diet when undergoing a celiac disease biopsy 2, 3, 4, 5.
- A gluten-free diet should not be started until after the biopsy has been performed and the diagnosis has been confirmed 2, 3, 4.
- The amount of gluten consumed before the biopsy is not strictly specified, but it is essential to ensure that the patient is exposed to gluten to obtain an accurate diagnosis 2, 3, 4, 5.