Biopsy Often Unnecessary for Celiac Disease Diagnosis in Children, Study Confirms
Dr. Sibylle Koletzko of Ludwig-Maximilian’s University in Munich and her colleagues found that in children with symptoms of CD and concentrations of antibodies to tissue transglutaminase (tTGA-IgA) 10 times the upper limit of normal (ULN), celiac disease could reliably be confirmed with endomysium antibody testing (EMA), with no need for HLA testing.
“More than 50% of children presenting with any symptom suggestive of CD and a positive auto-antibody test against tissue-transglutaminase will benefit from this approach saving a lot of burden, risks and costs for the patients, their families and the health care system,” Dr. Koletzko told Reuters Health by email.
She and her colleagues conducted the study to validate guidelines from the European Society of Pediatric Gastroenterology, Hepatology, and Nutrition, which state that CD can be diagnosed without biopsy in children who have symptoms and are tTGA-IgA positive if the results are confirmed by EMA testing and the patient is positive for HLA-DQ2/DQ8.
Study participants with a positive TGA result were recruited from 33 pediatric gastroenterology units in 21 countries. The analysis included 707 children, 645 of whom were diagnosed with CD, 46 who did not have CD, and 16 who had inconclusive results.
As reported online June 15 in Gastroenterology, a tTGA-IgA concentration 10 times the ULN or higher and a positive EMA had a positive predictive value of 99.75, which was 100.00 when the researchers limited symptoms to malabsorption. Adding HLA testing did not improve diagnostic accuracy.
“The non-biopsy approach suggested by ESPGHAN is reliable and adequate under clinical practice conditions and is more reliable than histology only,” Dr. Koletzko said. “HLA testing is not needed for this approach.”
When patients have elevated tTGA-IgA that is not 10 times higher than normal, they should have endoscopy and biopsies to confirm the diagnosis, and an EMA test is not required, the researcher added.
“We need further harmonization between the different tests,” she said. “Tests with different quality are on the market. Those TGA-IgA tests included in the study (10 used locally and 8 head to head centrally) did work for this purpose. But we cannot generalize this for every test. In many countries the manufacturers do not need to provide validation data in order to produce and sell a test. Only tests with a linear calibration curve are appropriate.”
“Our results do not mean that the diagnosis should be made by a GP or general pediatrician,” Dr. Koletzko said. “Because of the complexity and possible pitfalls it is highly advisable that a pediatric gastroenterologist or a pediatrician with a special knowledge in celiac disease is involved at some point in the diagnostic process. This applies for both the diagnosis with and without biopsies. Certain knowledge is needed to judge on the tests used and the results, and to explain this life-long disease and the consequences to the patient and the care givers. This has been also suggested in the ESPGHAN guidelines.”
SOURCE: https://bit.ly/2ujDWYO Gastroenterology 2017.