What are the screening methods for Celiac disease (CD)?

From the Guidelines

Screening for celiac disease should be performed using serological testing, specifically tissue transglutaminase (tTG) IgA antibody along with total serum IgA, as the initial step, as recommended by the most recent and highest quality study 1. The initial screening test for celiac disease is crucial in identifying individuals with the condition, especially those who are asymptomatic or have non-specific symptoms.

• The serological tests should be performed while the patient is on a gluten-containing diet to avoid false-negative results.
• For individuals with IgA deficiency, deamidated gliadin peptide (DGP) IgG or tTG IgG should be used instead, as recommended by 1 and 1.
• If serological tests are positive, the diagnosis should be confirmed with an upper endoscopy and small intestinal biopsy, as suggested by 1.
• High-risk groups who should be considered for screening include first-degree relatives of celiac patients, those with autoimmune conditions like type 1 diabetes or thyroid disease, and patients with Down syndrome, Turner syndrome, or Williams syndrome, as highlighted by 1.
• Screening is important because untreated celiac disease can lead to nutritional deficiencies, osteoporosis, infertility, and increased risk of certain cancers, as noted by 1 and 1.
• Early detection and treatment with a strict gluten-free diet can prevent these complications and improve quality of life, as emphasized by 1. Key considerations in screening for celiac disease include:
• The use of serological tests as the initial screening step
• The importance of consuming a gluten-containing diet before testing
• The need for confirmation with upper endoscopy and small intestinal biopsy if serological tests are positive
• The identification of high-risk groups for screening
• The potential consequences of untreated celiac disease and the benefits of early detection and treatment.

From the Research

Screening Methods for Celiac Disease (CD)

The screening methods for Celiac Disease (CD) include:

• Serological tests for celiac disease-specific antibodies such as anti-endomysial antibodies, anti-tissue transglutaminase (TTG) antibodies, and anti-deamidated gliadin peptides (DGP) antibodies of both the immunoglobulin A (IgA) and immunoglobulin G (IgG) class 2, 3, 4
• Genetic tests to elucidate HLA DQ status 2, 3
• Ancillary tests such as total IgA 2, 3
• Intestinal biopsy and histological examination of the small intestine, which is still considered the gold standard for CD diagnosis 2, 3, 5, 4, 6

Serological Screening Tests

Serological screening tests are utilized primarily to identify those individuals in need of a diagnostic endoscopic biopsy. The serum levels of:

• Immunoglobulin (Ig)A anti-tissue transglutaminase (or TG2) are the first choice in screening for celiac disease, displaying the highest levels of sensitivity (up to 98%) and specificity (around 96%) 3
• Anti-endomysium antibodies-IgA (EMA) have close to 100% specificity and a sensitivity of greater than 90% 3
• Deamidated gliadin antibodies (DGP) have shown promising results as serological markers for celiac disease 3, 4

Screening Algorithm

A diagnostic algorithm for patients with suspected CD has been proposed, which includes:

• IgA anti-tissue transglutaminase antibodies as the first level of screening 4, 6
• Anti-endomysial antibodies and anti-deamidated gliadin antibodies for positive patients 4
• Intestinal biopsy for patients with positive serology 2, 3, 5, 4, 6

High-Risk Groups for CD

CD screening is recommended in individuals with:

• Autoimmune disease and accompanying symptoms suggestive of CD 5
• Diseases that may mimic CD (e.g., irritable bowel syndrome, inflammatory bowel disease, and microscopic colitis) 5
• Conditions with a high CD prevalence, such as first-degree relatives, idiopathic pancreatitis, unexplained liver enzyme abnormalities, and type 1 diabetes mellitus 5