Non-biopsy celiac diagnosis guidelines perform well in 'real world' children

Last Updated: 2015-04-17

By Anne Harding

NEW YORK (Reuters Health) - European guidelines on when children can be diagnosed with celiac disease (CD) without a biopsy performed well in a referral-based pediatric gastroenterology practice, according to a new report.

The study, involving 17,505 patients who had celiac serology testing, is the largest reported single-center experience with the 2012 European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) guidelines.

The ESPGHAN guidelines say children can be diagnosed with CD without a biopsy if they are symptomatic, have a tissue transglutaminase (TTG) level at least 10-fold higher than the upper limit of normal (ULN), a positive endomysial antibody (EMA) test, a positive human leukocyte antigen (HLA) DQ2 and/or DQ8 status, family consent, and respond to a gluten-free diet. Children with TTG levels less than three times the upper limit of normal may be followed to evaluate trends in serology testing, according to the guidelines.

To evaluate the performance of the guidelines, Dr. Dominica Gidrewicz of the University of Calgary in Alberta and her colleagues looked at consecutive children, at least 3.5 years old but less than 18, who underwent serology testing for CD between July 2008 and December 2011. Out of 775 with positive TTG tests, 437 underwent biopsy. Another 574 patients with negative TTG tests also underwent biopsy.

As reported online March 31 in the American Journal of Gastroenterology, 98.2% of symptomatic children with a TTG at least 10 times the ULN and a positive EMA had biopsies consistent with CD.

For patients with TTG between three- and 10-fold higher than ULN, 75.7% of those who were EMA-positive had CD, versus 40% of those who were EMA-negative. For patients with TTG one to three times ULN, 52.2% of those positive for EMA had CD, versus 13.3% of the EMA-negative patients.

Four patients who met the ESPGHAN non-biopsy criteria and were positive for HLA DQ2/DQ8 turned out not to have CD.

CD prevalence in the cohort was 34.6%. The TTG test was 98.7% sensitive, 86.4% specific, and 79.4% sensitive, the authors reported.

"Before a center applies this protocol they really need to know how their antibody test performs, because there are multiple different antibody tests out there that hospitals can be using, and not every one performs the same," Dr. Gidrewicz told Reuters Health in a telephone interview. "Greater than 10 times (the ULN) for one kit doesn't always mean the same thing for another kit."

"When we applied the protocol to our patients," she added, "there were still a small group of patients who had over 10 times the upper limit of normal but their biopsies were not positive for celiac disease."

"You can still have false positives with that high serology, and you would need to continue to follow the patient to see what happens with their serology and potentially need to biopsy them down the road if things remain persistently high," Dr. Gidrewicz said.

SOURCE: http://bit.ly/1ISyufU

Am J Gastroenterol 2015.