From the Guidelines
To test for gluten intolerance, the most reliable approach is to undergo blood tests that screen for celiac disease, including tissue transglutaminase antibodies (tTG-IgA) and total IgA antibodies, as recommended by the most recent study 1. The diagnosis of gluten intolerance, particularly celiac disease, has evolved with advancements in serological testing and intestinal biopsy techniques. When testing for gluten intolerance, it is crucial to continue consuming gluten before undergoing blood tests to ensure accurate results 1. If blood tests suggest celiac disease, an intestinal biopsy may be recommended for confirmation, although some guidelines now suggest biopsy-avoidance strategies for certain patients 1. Some key points to consider when testing for gluten intolerance include:
- The importance of serological tests, including tTG-IgA and total IgA antibodies, in diagnosing celiac disease 1
- The role of intestinal biopsy in confirming the diagnosis, particularly in cases where serological tests are inconclusive or negative 1
- The potential for seronegative enteropathies, where patients may have negative serological tests but still exhibit symptoms of gluten intolerance 1
- The need for careful interpretation of genetic testing results, such as HLA-DQ2 and HLA-DQ8 genes, in the context of gluten intolerance 1 It is essential to consult with a healthcare provider to determine the best course of testing and treatment for individual cases of suspected gluten intolerance, taking into account the latest evidence and guidelines 1. Common gluten intolerance symptoms include digestive issues, fatigue, headaches, joint pain, and skin problems, which can significantly impact quality of life if left undiagnosed or untreated 1. By prioritizing the most recent and highest-quality evidence, healthcare providers can ensure that patients receive accurate diagnoses and effective treatment for gluten intolerance, ultimately improving morbidity, mortality, and quality of life outcomes 1.
From the Research
Testing for Gluten Intolerance
To test for gluten intolerance, the following steps can be taken:
- Screening for celiac disease must occur before a gluten-free diet is implemented, as once a patient initiates a gluten-free diet, testing for celiac disease is no longer accurate 2
- Immunoglobulin A tissue transglutaminase serologic testing is the recommended initial screening for all age groups 3
- Esophagogastroduodenoscopy with small bowel biopsy is recommended to confirm the diagnosis in most patients, including those with a negative serologic test for whom clinical suspicion of celiac disease persists 3
- Biopsies may be avoided in children with high immunoglobulin A tissue transglutaminase (i.e., 10 times the upper limit of normal or more) and a positive test for immunoglobulin A endomysial antibodies in a second serum sample 3
- Genetic testing for human leukocyte antigen alleles DQ2 or DQ8 may be performed in select cases 3
Differential Diagnosis
It is essential to differentiate between celiac disease and nonceliac gluten sensitivity, as both conditions have similar symptoms 2
- Celiac disease is a gluten-induced immune-mediated enteropathy characterized by a specific genetic genotype (HLA-DQ2 and HLA-DQ8 genes) and autoantibodies (antitissue transglutaminase and antiendomysial) 2
- Nonceliac gluten sensitivity is diagnosed in individuals who do not have celiac disease or wheat allergy but who have intestinal symptoms, extraintestinal symptoms, or both, related to ingestion of gluten-containing grains, with symptomatic improvement on their withdrawal 2
Importance of Accurate Diagnosis
Accurate diagnosis is crucial, as patients with celiac disease require a strict lifelong gluten-free diet, while patients with nonceliac gluten sensitivity may also benefit from a gluten-free diet, but the treatment approach may differ 4, 2