13C-labeled mixed triglyceride breath test (13C MTG-BT) in healthy children and children with cystic fibrosis (CF) under pancreatic enzyme replacement therapy (PERT): a pilot study.

The MTG-BT estimates the hydrolysis of triacyl-glycerols by pancreatic lipase, and appears attractive for monitoring exogenous lipase requirements in patients with exocrine pancreatic insufficiency. To assess the test's discrimination capacity and repeatability, 9 CF patients with PERT and 10 healthy children underwent the (13)C-MTG-BT twice, at a 2- to 4-week interval. The test distinguished well between patients with severe exocrine pancreatic insufficiency (SEPI) and healthy subjects. However, within-subject variability for postprandial per thousand(13)C-enrichment and postprandial % dose recovery (PDR) was high in both groups. Therefore, the (13)C-MTG-BT seems useful to distinguish between SEPI and normal exocrine pancreatic function, but requires further development to improve its repeatability.