Pre-Screening Blood Test for Celiac Disease Turning Up False Positives?

worried celiac parentsMcMaster University indicates that the DGP pre-screening blood test for celiac disease is turning up false positives in children.

  • McMaster University, 1

February 27, 2019 BRAMPTON/HAMILTON/TORONTO – A preliminary diagnosis of Celiac disease in a child can be a stressful life event for an entire family. In addition to the prospect of following a completely gluten-free diet for life, a child must also face a series of tests – some invasive – to confirm the disease. While this should be a seamless and effective process, a recent study from McMaster University, The Hospital for Sick Children (SickKids) and William Osler Health System (Osler) shows this is not always the case. An additional, costly blood test is routinely prescribed and performed as part of the screening process and results of the study show it rarely predicts the disease.

Based on this finding, researchers want to raise awareness of this issue to reduce the burden of stress and cost this test can pose for young patients and their families.

Celiac disease is a condition where the immune system attacks and flattens the intestine as a result of eating gluten, found in foods made from wheat, rye, and barley. A joint research project shows that a commonly prescribed blood test, called deamidated gliadin, is costly and ineffective in screening for Celiac disease in children.

“Celiac disease is a serious auto-immune disorder and we appreciate that even an initial positive screen for the disease will be an anxious time – particularly when it is impacting a child,” says Dr. Herbert Brill, co-author of the study, a gastroenterologist, Osler’s Chief of Paediatrics and Associate Clinical Professor of Paediatrics at McMaster University. “We know this anxiety will only mount when faced with the possibility of multiple invasive procedures to confirm the diagnosis.”

The researchers studied 40 children from three Ontario hospitals to better understand the effectiveness of blood tests in screening for Celiac disease in children. In order to confirm a diagnosis following initial blood test screens, an upper endoscopy procedure with biopsy is required. This procedure is considered to be invasive and can put stress on the patient and their family.

The children in the study had a negative result from an initial blood test called Transglutaminase (TTG) but tested positive for Celiac disease through the second blood test called deamidated gliadins (DGP). The second test is newer and is increasingly being used to screen children for potential Celiac disease. However, whether it is useful as a general screening tool for children is unknown.

None of the children who tested positive through the second blood test were diagnosed with Celiac disease following the biopsy.

“This is the first study that shows that the DGP test – the second, additional blood test – is not useful for screening children in the general population for Celiac disease,” says Dr. Catharine Walsh, senior author of the study, Staff Gastroenterologist and Scientist in the Child Health Evaluative Sciences program at SickKids.

“We hope to raise awareness of the issue so that we might change practice, preventing families from putting their child through an invasive procedure and an unnecessary expense, when it is not a predictor of the disease.”

The study entitled, In Screening for Celiac Disease, Deamidated Gliadin Rarely Predicts Disease When Tissue Transglutaminase Is Normal, has been published in Journal of Pediatric Gastroenterology and Nutrition in Vol. 68, No. 1, January 2019.

For more information, please contact:

 Cara Francis Director, Public Relations William Osler Health System (905) 494-2120 ext. 29467 

Jessamine Luck Communications Specialist – Media Relations Communications & Public Affairs The Hospital for Sick Children (SickKids) 416-813-7654 ext. 201436

Veronica McGuire Media Relations Faculty of Health Sciences 905-525-9140 x22169