Pancreolauryl test

Fluorescein-Ldsung 1 0 % Thilorbin (Alcon) I Pancreolauryl Test... 

The test principle of the NBT-PABA (N-b enz oyl-L-tyro sy 1-P-a m i n o b c n z o i c acid, bentiromide) test very much resembles the Pancreolauryl test (Fig. 26-4). Again, the unsplit molecule NBT-PABA cannot be absorbed, and absorption of its metabolite PABA depends on prior hydrolysis by chymotrypsin within the intestinal lumen. Subsequently, PABA undergoes conjugation in the liver and is excreted in the urine. In healthy subjects, at least 50% of the administered dose is excreted in the urine during 6 h postprandially. 

AH of the other noninvasive tests are based on the reduction in the secretion of pancreatic enzymes with direct measurement of enzymes in feces (chymotrypsin or elastase) or detection of products of their catalytic reactions, after oral administration of synthetic substrates, in urine (NBT-PABA or pancreolauryl test) or in breath ( C-mixed chain triglyceride breath test). 

The specificity of the test was significantly improved by abandoning the nonspecific colorimetric procedures in favor of high-performance liquid chromatography (HPLC)." NBT-PABA has advantages over the pancreolauryl test in that the patient procedure can be completed in a single day but the synthetic peptide is not now easily available, and the test has a lower diagnostic sensitivity and specificity for pancreatic insufficiency than does fecal elastase (see Table 48-8). 

The pancreolauryl test (fluorescein dilaurate test, Temmler Pharma, Germany) is similar in its principle to the NBT-PABA test. Fluorescein dilaurate (FDL) is poorly water-soluble. It is given orally in the middle of a standard breakfast (50 g white bread, 20 g butter, and one cup of tea) and is specifically hydrolyzed by pancreatic cholesterol esterase, which requires bile salts for its activity. The released... 

Pecal osmotic gap , fecal Na, K Pancreolauryl test, fecal. . ... 

Green MR, Austin S, Weaver LT. Dual marker one day pancreolauryl test. Arch Dis Child 1993 68 649-52,... 

Trewick AL. Glucose interference in the pancreolauryl test. Ann Clin Biochem 1998 38 274-8. 

Figure 9 The pancreolauryl test allows an indirect assessing of exocrine pancreatic function. Orally administered fluorescein dilaurate is hydrolyzed by carboxylester lipase (identical to cholesterol esterase) liberating lauric acid and free, water-soluble fluorescein. The latter is readily absorbed in the small intestine, partly conjugated in the liver, and excreted in urine mainly as fluorescein glucuronide. By measuring the concentration of fluorescein in the urine over a period of, for instance, 10 hours, the total quantity of this dye is determined. (From Ref. 52.)...

Figure 12 Degree of exocrine pancreas insufficiency in various clinical conditions evaluated by the indirect pancreolauryl test. N is the number of patients studied. (From Ref. 52.)...

Figure 26-4. Principle of the Pancreolauryl and the NBT-PABA (V-benzoyl-i.-tyrosyl-P-aminobenzoic acid, bentiromide) test. The composite molecule consisting of a substrate and a marker molecule cannot be absorbed but can be cleaved intraduodenally by pancreatic enzymes (cholesterol esterase and chymotrypsin, respectively), leading to release of an absorbable marker substance. Following absorption and hepatic conjugation, the marker is excreted in urine. In pancreatic-insufficient patients, decreased secretion of pancreatic enzymes results in incomplete cleavage of the composite molecule. This results in decreased absorption and subsequent excretion of the marker, which can be measured photometrically.

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