Spot urine pancreolauryl test for use in infancy.

Abstract

As a simple non-invasive test of possible pancreatic insufficiency 10 healthy infants, 13 infnts with cystic fibrosis, and nine infants with unexplained diarrhoea and failure to thrive were given an emulsion containing fluorescein dilaurate and mannitol by mouth. A spot urine specimen was collected and results expressed as urinary fluorescein to mannitol ratios. Sensitivity of the test was 96% and specificity was 95%. (Arch Dis Child 1995; 72: 233-234) Nine infants with unexplained diarrhoea and failure to thrive (six boys, three girls) aged 2-42 months (median 16 months) were studied each on one occasion. Two children had steatorrhoea, two children chronic diarrhoea, one had juvenile chronic arthritis with failure to thrive, and four children had unexplained failure to thrive with weights below the third centile. TEST PROCEDUREThe studies were made in the morning after an overnight fast unless the infants were still receiving regular milk feeds in which case the fast did not exceed four hours. Fluorescein dilaurate (0-134 mmol) and mannitol (6-7 mmol) in 10 ml of emulsion were given by mouth followed by a milk feed. The emulsion was formed of the water insoluble fluorescein dilaurate ester dissolved in a medium chain triglyceride, using a soya bean based lecithin as emulsifier. Ultrasonication or microfluidisation produced an extremely fine dispersion of the triglyceride in the aqueous phase, which contained the second marker, mannitol. The emulsion was physically stable, resistant to heat sterilisation, and readily dispersible in infant milk formulas by simple shaking.Feeds were given thereafter as desired with or without pancreatic supplements as required. The two 5 year old children studied were allowed breakfast of tea, toast, and cereal two hours after taking the test substrates. Specimens of urine were collected as voided, into a urine bag, or using cotton wool balls enclosed in the napkins in infants,5 including in each study a specimen produced after two, but before five, hours after substrate ingestion. Urine was frozen at -20°C until analysis. BIOCHEMICAL MEASUREMENTSFluorescein concentration was measured spectrophotometrically. An aliquot of 0 5 ml urine was added to 4-5 ml 0-1 M sodium hydroxide and incubated at 70°C for 10 minutes to hydrolyse any fluorescein glucuronide (which is colourless) to free fluorescein. After centrifugation the absorbance (A) of the supernatant was measured at 492 nm against water. Fluorescein concentration was calculated from the equation:(((A492X 100)/35) x (50 42/100)) X 50The denominator and multiplication factors were determined from the dose administered, the dilution, and the absorption coefficient. Mannitol concentration was measured enzymatically using a method previously described. 1 4 The test result was expressed as a ratio of 233 on 7 May 2018 by guest. Protected by copyright.

ESPGHAN and NASPGHAN Report on the Assessment of Exocrine Pancreatic Function and Pancreatitis in Children

“…The results are reported as a fluorescein/mannitol ratio. A spot urine test was developed for infants, and the reference value for EPI is a ratio of <30 (52). In comparison with the FE‐1, however, the pancreolauryl test is less accurate (53).…”

Detection and follow up of exocrine pancreatic insufficiency in cystic fibrosis: a review

“…The test sensitivity is approximately 96%, the speci®city 95%. This non-invasive test is well tolerated, but will not discover some isolated enzyme de®ciencies [7].…”

Indirect Pancreatic Function Tests in Children

“…1) Assessment of the absorption of markers that are hydrolyzed from conjugates by pancreatic enzymes and subsequently appearing in the urine or serum (NBT‐PABA test, pancreolauryl test) (18–23),…”