What is the initial workup for celiac disease (CD)?

From the Guidelines

The initial workup for celiac disease involves serologic testing with tissue transglutaminase IgA antibody (tTG-IgA) and total serum IgA, as recommended by the most recent guidelines 1. This approach is based on the high sensitivity and specificity of these tests. Patients should remain on a gluten-containing diet during testing, as eliminating gluten can lead to false-negative results. If tTG-IgA is positive or if there is strong clinical suspicion despite negative serology, an upper endoscopy with multiple duodenal biopsies should be performed for definitive diagnosis. Some key points to consider in the initial workup include:

• The importance of serologic testing as the first-line approach
• The need for patients to remain on a gluten-containing diet during testing
• The role of upper endoscopy with multiple duodenal biopsies in definitive diagnosis
• The consideration of alternative tests such as deamidated gliadin peptide IgG (DGP-IgG) or tTG-IgG for patients with IgA deficiency
• The potential utility of genetic testing for HLA-DQ2 and HLA-DQ8 in certain situations, as noted in recent studies 1 Additional laboratory tests to assess for complications may include complete blood count, comprehensive metabolic panel, iron studies, vitamin B12, folate, and vitamin D levels, as many celiac patients present with nutritional deficiencies due to malabsorption. It is also important to consider the latest guidelines and research in the field, such as those published in Nature Reviews Gastroenterology and Hepatology 1 and Alimentary Pharmacology and Therapeutics 1, to ensure the most accurate and effective diagnosis and management of celiac disease.

From the Research

Initial Workup for Celiac Disease

The initial workup for celiac disease (CD) involves several steps, including:

• Serologic testing for tissue transglutaminase immunoglobulin antibody and endomysial immunoglobulin antibody, which are the most sensitive and specific serologic tests for identifying individuals who need to undergo an intestinal biopsy 2, 3
• Intestinal biopsy, which is the gold standard for the diagnosis of celiac disease, showing villous atrophy 2, 3
• Consideration of the patient's clinical presentation, including symptoms such as diarrhea, anemia, and bone disease 2, 3
• Evaluation of the patient's genetic background, including testing for HLA-DQ2 or DQ8 alleles, which are mandatory determinants of the development of the disease 3, 4

Serologic Tests

Serologic tests play a crucial role in the diagnosis of celiac disease, including:

• Tissue transglutaminase antibodies, which are highly sensitive and specific for CD 3, 4
• Endomysial antibodies, which are also highly sensitive and specific for CD 2, 3
• Deamidated gliadin peptide antibodies, which can be used in conjunction with other tests to diagnose CD 3

Biopsy and Histology

Intestinal biopsy and histology are essential for confirming the diagnosis of celiac disease, including:

• Duodenal biopsies, which should be taken from the second part of the duodenum and the bulb 4
• Histomorphological classification, which should be done according to the modified Marsh-Oberhuber classification 5
• Evaluation of villous atrophy, which is a hallmark of celiac disease 2, 3