Anti-Deamidated Gliadin Peptide Immunoglobulin G (DGP‐IgG)

Overview

The Anti-Deamidated Gliadin Peptide (DGP) IgG test is a diagnostic tool used to detect coeliac disease and monitor its management. This biomarker measures IgG antibodies directed against gliadin, a component of gluten. In coeliac disease, the body’s immune system mistakenly reacts to deamidated gliadin peptides, triggering inflammation and damage to the small intestine. Unlike tissue transglutaminase (tTg-IgA), which is the most common coeliac marker, DGP IgG is particularly useful in individuals with IgA deficiency - a condition where the body produces insufficient Immunoglobulin A, potentially leading to false-negative tTg-IgA results. Elevated DGP IgG levels can indicate an immune response to gluten and suggest active coeliac disease or gluten exposure. By assessing DGP IgG, healthcare providers gain valuable insights into gluten sensitivity and how well the intestinal lining is healing on a gluten-free diet.

Testing Levels:

• High ( FLU) - Elevated DGP IgG levels suggest active coeliac disease or gluten exposure. This means the body is mounting an immune response to gluten, damaging the intestinal lining. High levels often warrant further testing or a review of dietary adherence, especially in diagnosed individuals on a gluten-free diet. Persistently high levels might indicate unintentional gluten intake or incomplete dietary compliance.
  
  
• Mid - Normal DGP IgG levels indicate no significant immune response to gluten. For individuals with coeliac disease on a gluten-free diet, this is a sign of effective dietary management and healing of the intestinal lining. For those without coeliac disease, it reflects a healthy response to gluten.
  
  Levels nearing the upper limit can signal early or mild gluten sensitivity, especially in individuals with a family history of coeliac disease or mild symptoms. It’s an early warning sign that gluten may be causing harm, and a detailed dietary assessment is recommended.
  
  Low but detectable levels are generally not significant unless paired with other symptoms or a history of coeliac disease. For those with coeliac disease on a gluten-free diet, this shows adherence and recovery.
  
  
• Low ( FLU) - Undetectable levels are expected in individuals without coeliac disease or those adhering strictly to a gluten-free diet. If symptoms persist, alternative causes should be investigated, and other tests like tTg-IgA may be warranted.

Why We Test Anti-Deamidated Gliadin Peptide Immunoglobulin G (DGP‐IgG)

Testing DGP IgG is essential for diagnosing coeliac disease, particularly in individuals who may have IgA deficiency, where traditional markers like tTg-IgA might give false-negative results. It also aids in monitoring adherence to a gluten-free diet and ensuring intestinal healing. This test is valuable for anyone experiencing unexplained gastrointestinal symptoms, nutrient deficiencies, or conditions associated with coeliac disease.

What Affects It

DGP IgG levels are influenced by gluten intake, as the test measures the immune response to deamidated gliadin peptides. IgA deficiency is a key factor that makes this test especially important, as it provides an alternative pathway for diagnosing coeliac disease. Adherence to a gluten-free diet lowers DGP IgG levels, while accidental or intentional gluten exposure can cause elevations. Other autoimmune diseases and gastrointestinal conditions, though rare, might also affect results. Age and immune system function can play a role, as children and individuals with compromised immunity may exhibit varied responses.

How to Improve

For elevated or near-elevated levels, strict adherence to a gluten-free diet is the key intervention. Identifying and eliminating hidden sources of gluten in foods, beverages, and medications is essential. If levels are within or near the lower range, no further action is needed unless symptoms persist. Regular follow-ups with a healthcare provider ensure effective management and recovery.

Common Name: anti-DGP IgG