Features of Pancreoamyl
Indications for the use of Pancreoamyl
Exocrine pancreatic insufficiency is associated with the decrease in activity of various enzymes in pancreatic juice. Lipase (involved in fat metabolism) and Amylase (which hydrolyses starch) are important components of pancreatic secretion into the small intestine. Pancreoamyl® is a ¹³C-Cornstarch breath test used to determine amylase activity in vivo and therefore a way of measuring pancreatic function. Conventional procedures involve the collection of urine or stool so an effective breath test, particularly on using a naturally occurring substrate such as cornstarch presents an attractive alternative.
A further advantage of an amylase breath test is the speed with which results can be obtained. If a mass spectrometer is available at the test site results can be obtained within four hours.
Test Principle and Protocol for Pancreoamyl
Pancreoamyl differs from most breath tests in that the substrate used is a naturally occurring material. Starch derived from corn (maize) contains more ¹³C than does starch derived from other sources such as rice or potatoes. This difference, which is related to a different photosynthetic pathway, is quite small but is large enough to allow the use of cornstarch as a naturally labelled substrate. At least this is the case in temperate areas where dietary carbon has a lower ¹³C content than corn.
The principle of Pancreoamyl, in common with most breath tests relies on the fact that when a carbon substrate is catabolised in the gut or other organs, any 13CO2 formed enters the blood bicarbonate pool and then rapidly appears in the breath. Once a rate of ¹³C-cornstarch conversion to 13CO2 is established for healthy subjects, we can attribute reduced production of 13CO2 in the exhaled air to exocrine pancreatic insufficiency.
The test is non-invasive, safe and may be repeated as often as required. INFAI have shown that the test detects pancreatic insufficiency with high sensitivity (88%) and specificity (82%).
After an over night fast two baseline breath samples are taken by blowing through a plastic straw into a 10 ml tubes. The tubes are sealed with a rubber stopper and stored for subsequent analysis.
The substrate (50 g of commercially available cornstarch in 100 ml of water) is then administered and further breath samples collected and stored at 30 minute intervals over a five hour period.
A mathematical analysis of the 13CO2 excretion curve from the naturally labelled cornstarch permits the identification of patients with impaired amylase activity and by implication exocrine pancreatic insufficiency.
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