A recent multicenter retrospective study (MJ Gould et al. JPGN 2019; 68: 20-5) shows that deamidated gliadin peptide (DGP) is rarely helpful in screening for celiac disease when tissue transglutaminase IgA is negative. The study identified 40 patients who had a mean age of 6.5 years at time of intestinal biopsy.

Key findings:

• Of the 40 patients with DGP (IgG) positivity, only 1 patient (2.5%) had celiac disease; this patient was IgA deficient.
• Among the five IgA deficient patients, only 1 with DGP positivity had celiac disease.
• The cohort included 6 patients with DGP levels >250 U/mL (refernece <12).
• Only 5 patients in this DGP positive cohort were younger than 2 years.  None had celiac disease

My take: This retrospective study indicates that DGP is rarely helpful in patients with negative TTG IgA results. However, this study had too few patients who were  <2 years of age and/or IgA-deficient patients to determine its utility in these groups..

Related study: AK Verma et al. JPGN 2019; 68: 26-29. This study from Italy examined oral hygiene products and determined that 62 (94%) were gluten-free (gluten level <20 ppm). Among the 4 with detectable gluten, 3 were toothpastes and 1 lipstick with values between 20.7 adn 35 ppm. My take: Oral hygiene products have very low rates of gluten contamination.

Related blog posts:

• Is it Helpful to Check Celiac Serology Three Months After Gluten Free Diet?
• How Accurate is Serology at Predicting Mucosal Healing in Pediatric Celiac Disease?
• Closer followup for Celiac disease & pediatric guidelines
• Celiac serology normalization
• How Slow Do Objective Markers of Celiac Change After Treatment? | gutsandgrowth
• Celiac Disease Epidemic (High rate of celiac disease reported in Denver children)
• Vaccine for Celiac Disease
• Celiac Disease Risk –TEDDY study

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