From the Guidelines
Diagnosis of celiac disease (CD) is based on a combination of serology, specifically tissue transglutaminase antibodies (TG2Ab), and duodenal biopsy while the patient is on a gluten-containing diet, as this approach has high sensitivity and specificity 1. The diagnostic process typically starts with serological testing, including TG2Ab and anti-endomysial antibodies (EMAs), which have high sensitivity and specificity for CD 1.
- Key points to consider in the diagnosis of CD include:
- The patient should maintain a gluten-containing diet during testing to avoid false-negative results.
- Genetic testing for HLA-DQ2 and HLA-DQ8 can be helpful in ruling out CD in uncertain cases, as nearly all CD patients carry these genetic markers 1.
- Duodenal biopsy is essential for definitive diagnosis, as it reveals characteristic intestinal damage, including villous atrophy, crypt hyperplasia, and increased intraepithelial lymphocytes 1.
- The diagnosis of CD combines clinical symptoms, such as chronic diarrhea, weight loss, fatigue, and abdominal pain, with positive serological tests and confirmatory biopsy findings 1. The most recent and highest quality study recommends that analysis of TG2Ab serum levels should be done as a first-line screening test, with high sensitivity (93%) and specificity (98%) 1. In cases where the diagnosis is uncertain, HLA typing can play a crucial role in ruling out CD when the results are negative 1.
- It is also important to note that the utility of serology versus histology in follow-up has not been definitively settled 1. Ultimately, the diagnosis of CD requires a comprehensive approach, including serology and duodenal biopsy, to ensure accurate diagnosis and effective management of the disease 1.
From the Research
Diagnosis of Celiac Disease
The diagnosis of Celiac Disease (CD) is a complex process that involves a combination of clinical, serological, and histopathological data 2, 3, 4, 5, 6.
- The diagnosis is typically made by serologic testing of celiac-specific antibodies, such as anti-endomysial antibodies, anti-tissue transglutaminase (TTG) antibodies, and anti-deamidated gliadin peptides (DGP) antibodies 4, 5.
- Duodenal mucosal biopsies are also used to confirm the diagnosis, and both serology and biopsy should be performed on a gluten-containing diet 2, 6.
- The gold standard for the diagnosis of CD is a small bowel biopsy showing villous atrophy 5.
- In some cases, the diagnosis may be made without biopsy if strict criteria are available, such as in a group of children 6.
Diagnostic Tests
Several laboratory tests are available to aid in the diagnosis and monitoring of CD, including:
- Serological tests for celiac disease-specific antibodies, such as anti-endomysial antibodies, anti-TTG antibodies, and anti-DGP antibodies of both the immunoglobulin A (IgA) and immunoglobulin G (IgG) class 4.
- Genetic tests to elucidate HLA DQ status 4.
- Ancillary tests such as total IgA 4.
Clinical Presentation
CD can present with a wide range of symptoms, including:
- Typical gastrointestinal symptoms, such as diarrhea, steatorrhea, weight loss, bloating, flatulence, and abdominal pain 2, 5.
- Non-gastrointestinal abnormalities, such as abnormal liver function tests, iron deficiency anemia, bone disease, skin disorders, and many other protean manifestations 2, 5.
- Atypical presentations, including anemia and bone disease 5.
- Some individuals with CD may have no symptoms at all 2.