GI Function Test: Intestinal Disaccharidase
Biochemistry Overview / Directory
Purpose of the test
The intestinal disaccharidase test utilises the breakdown of lactose/sucrose in the intestine by lactase/sucrase present in the villi of the duodenum and jejunum. Lactulose cannot be broken down by these enzymes. In lactase/sucrase deficiency the disaccharide, which is usually hydrolysed instead is absorbed via the same pathway as lactulose. A rise in the lactose/lactulose or sucrose/lactulose ratio to >0.3 is indicative of disaccharidase deficiency, which if combined with reduced rhamnose and xylose indicates villous atrophy e.g. coeliac disease, but in isolation represents inherited disaccharidase deficiency.
Each adult dose contains lactulose 5 grams, lactose 10 grams, sucrose 10 grams and rhamnose 1 gram. This solution is ready for use, it should be stored frozen and thawed on the evening before the test day and stored overnight in the refrigerator. Test Solution and instructions must be obtained from the Clinical Biochemistry Dept.
(Dietary restrictions: separate diet sheet provided with test instructions – must be followed for 12 hours prior to and during test period).
Sample Requirements
Universal container for baseline urine sample, two urine collection bottles with special preservative (methiolate). Send 25 mL aliquots with record of the two 5 hour urine volumes.
Storage and Transport
First class post within 4 days.
Turnaround Time
1 - 2 Weeks
Price
Price available on application - please contact adrian.turner@kch.nhs.uk. Discounts could be available for significant workloads.
Contacts
Ms Audrey Duffy
T 020 3299 4133
Dr Joanne Marsden
T 020 - 3299 3856
References
Takeuchi K, Smale S, Premchand P, Maiden L, Sherwood R, Thjodleifsson B, Bjornsson E, Bjarnason I. (2006) Prevalence and mechanism of non-steroidal anti-inflammatory drug-induced clinical relapse in patients with anti-inflammatory bowel disease Clin Gastroenterol & Hepatol4: 196-202
Taylor C, Hodgson K, Sharpstone D, Sigthorsson G, Coutts M, Sherwood R, Menzies I, Gazzard B, Bjarnason I (2000) The prevalence and severity of intestinal disaccharidase deficiency in HIV infected subjects Scand J Gastroenterology 35, 599-606
