Description of the blood test:

Gliadin is one of the main proteins found in gluten. In individuals with Celiac disease, the enzyme tissue transglutaminase (tTG) modifies gliadin through a process called “deamidation.” This modified version—Deamidated Gliadin Peptide (DGP)—is much more recognizable to the immune system, triggering a specific antibody response. Measuring DGP antibodies (both IgA and IgG classes) provides a highly sensitive and specific way to identify Celiac disease, especially in cases where other tests might be inconclusive.

What Does the Test Represent?

• Goal: To detect antibodies (IgA or IgG) specifically targeting deamidated gliadin peptides.
• Main Application: Diagnosing Celiac disease in young children (under 2 years old) and identifying the disease in patients with a total IgA deficiency.
• Method: Enzyme-Linked Immunosorbent Assay (ELISA).

Collection Recommendations (General)

• Timing: Best performed in the morning.
• Fasting: Overnight fasting (8–12 hours) is recommended; plain water is allowed.
• Material: Venous blood (serum).
• Specific Rules: Critical: Just like the tTG test, you must be consuming gluten regularly for several weeks before the blood draw. A gluten-free diet will cause these antibody levels to drop, potentially leading to a false-negative result.

Factors Influencing the Result

• Age: DGP antibodies are often the first to appear in very young children, making this test more reliable than tTG for toddlers and infants.
• IgA Status: Since the DGP test is commonly performed for both IgA and IgG classes, the DGP IgG version is an essential diagnostic tool for patients who are naturally deficient in IgA.
• Dietary Response: DGP levels tend to decrease faster than tTG levels once a gluten-free diet is started, making it a sensitive marker for monitoring recent gluten exposure.

When to Take This Test?

• Recommendations: If a child under 2 years old shows symptoms of malabsorption (failure to thrive, irritability, chronic diarrhea); if you have symptoms of Celiac disease but have a known IgA deficiency; or if tTG results are borderline.
• Importance: This test fills a diagnostic “gap,” ensuring that Celiac disease is caught early in life and in patients with complex immune profiles.

Medical Interpretation

• Crucial Note: Interpreting DGP results requires clinical expertise. A positive result strongly suggests Celiac disease, but it must be viewed as part of a larger diagnostic puzzle. Only a specialist can “fine-tune” these results by correlating them with your age, symptoms, and other antibody markers.
• Positive DGP (IgA or IgG): High likelihood of Celiac disease. In children, it is a very strong indicator of gluten-induced intestinal damage.
• Negative DGP: Generally suggests the absence of Celiac disease, though it does not rule out “Non-Celiac Gluten Sensitivity,” which does not produce these specific antibodies.

Possible Further Investigations

• Anti-tTG (IgA/IgG): Usually performed in tandem with DGP for a complete screening profile.
• Total IgA Level: To determine if the IgG version of the test is the primary result to follow.
• Small Bowel Biopsy: To confirm the presence and severity of villous atrophy.
• Genetic Testing (HLA-DQ2/DQ8): To assess the genetic risk of developing the condition.
• Consultation with a Pediatrician or Gastroenterologist.

When Does the Next Step Make Sense?

• If the DGP test is positive, the next step involves a specialist consultation to determine if an intestinal biopsy is necessary for a definitive diagnosis. Early diagnosis through DGP testing is vital to prevent long-term nutritional deficiencies and growth issues in children.
• All clinical decisions must be made by a healthcare professional based on the patient’s age and overall clinical presentation.

👉 If necessary, you can discuss the analysis results with a specialist such as a gastroenterologist (Doctors – TAMC), or immunologist (Doctors – TAMC).