PABA screening test for exocrine pancreatic function in infants and children

Area of Science:

• Biochemistry
• Gastroenterology
• Pediatrics

Background:

• Exocrine pancreatic insufficiency (EPI) affects nutrient absorption and requires accurate diagnostic methods.
• Assessing pancreatic enzyme activity is crucial for managing conditions like cystic fibrosis (CF).
• Current diagnostic tools for pancreatic function can be invasive or complex.

Purpose of the Study:

• To evaluate a new noninvasive diagnostic test for exocrine pancreatic function.
• To assess the utility of N-benzoyl-L-tyrosyl-PABA hydrolysis and P-Aminobenzoic acid (PABA) excretion as a biomarker for pancreatic insufficiency.
• To compare PABA recovery in healthy children, CF patients, and newborn infants.

Main Methods:

• Oral administration of N-benzoyl-L-tyrosyl-PABA (0.015 g/kg) to participants.
• Measurement of urinary PABA recovery over 6 hours as an indicator of pancreatic chymotrypsin activity.
• Comparison of PABA recovery percentages across control groups, CF patients, and neonates.

Main Results:

• Healthy controls showed a mean 6-hour PABA recovery of 58.5% (+/- 11.2 SD).
• Patients with cystic fibrosis exhibited significantly lower PABA recovery (P < 0.001) with no overlap with controls.
• Newborn infants had a mean 6-hour PABA recovery of 23.4% (+/- 17.7 SD), with some overlap with CF patient results.

Conclusions:

• Urinary PABA recovery after N-benzoyl-L-tyrosyl-PABA administration is a sensitive index of exocrine pancreatic function.
• The test effectively differentiates healthy individuals from those with CF-related pancreatic insufficiency.
• Further investigation is warranted to validate this promising, noninvasive test in newborns and younger infants.