13C-mixed triglyceride breath test for the diagnosis of pancreatic function
- Not radioactive
13C is a stable isotope and therefore inherently safer than a test with radioisotopes.
The 13C-triglyceride test can be performed at lower costs compared to other test procedures.
Indications for use
A decrease in lipase activity is an early indicator of pancreatic dysfunction. Pancreo-Lip is a 13C mixed triglyceride breath test for the determination of pancreatic dysfunction by measuring lipase activity in vivo.
Direct pancreatic function tests such as the Secretin-Caerulein test are not suitable for routine diagnosis because they are time-consuming, expensive, invasive and not internationally standardized. Indirect tests such as the fluorescein dilaurate test, and fecal chymotrypsin activity have limited sensitivity. The determination of fecal elastase 1 is the most promising test currently in use, but all stool tests have their own disadvantages.
Vantrappen et al (Gastroenterology, Vol 96, 126-134, 1989) described for the first time a pancreatic lipase breath test using a 13C-labelled mixed triglyceride substrate. Since then a number of authors have further evaluated the test. Clinical studies in collaboration with INFAI (Löser et al. Scand. J. Gastroenterol. Vol 33, 327-334, 1998) showed that the test is a valuable diagnostic tool for the detection of pancreatic insufficiency.
INFAI is currently completing clinical studies for this test in preparation for the application for a pan-European marketing authorization. The kit is currently available on a per-patient basis and for research projects, subject to the appropriate ethical and licensing exclusions.
Test principle and protocol
13C-Mixed Triglyceride (200 mg glyceryl-1,3-dioctadecanoate-2-octanoate-1-13C in pure powder form), mixed with chocolate cream and administered with toast and butter is hydrolyzed by pancreatic lipase. One of the products of this hydrolysis, 13C-octanoic acid, is rapidly broken down in the liver to 13CO2 and released into the breath. The characteristics of the 13CO2 excretion curve can be used to distinguish between normal and abnormal levels of pancreatic lipase activity.
After six hours of fasting, the patient eats a standardized test meal consisting of 13C-mixed triglyceride (200 mg glyceryl-1,3-dioctadecanoate-2-octanoate-1-13C as a pure powder) mixed with chocolate cream (10 g) spread on a slice of toast (100 g) with butter (15 g). 150 ml of coffee, tea or water are given as a test meal.
The test protocol for Pancreo-Lip is convenient and patient-friendly and takes about 250 minutes. It is recommended that the patient sits during the test. The test begins with the sampling of the basal value. The patient breathes easily through a straw into a glass tube which is closed with a rubber stopper. Two basal values are recorded before the test meal is eaten. After consumption, another eight breath samples are taken at half-hour intervals. The sample tubes are returned to their original packaging and sent to a qualified laboratory for determination of 13CO2 concentration.
The 13CO2 excretion curve is analysed mathematically using a program developed by INFAI. This allows the identification of different levels of pancreatic insufficiency.
- EP1560603, Method for measuring pancreatic metabolism, European Patent, 07.03.2007
- US7762957, Method for measuring pancreatic metabolism, US Patent, 27.07.2010
- WO2004043498, Method for measuring pancreatic metabolism, International Patent, 27.05.2004
- Comparative clinical evaluation of the ¹³C-Mixed-Triglyceride breath test as an indirect pancreatic function test
Löser C., Brauer C., Aygen S., Hennemann O., Fölsch U.R; Scand. J. Gastroenterol. 33 (1998) 327-334