title: Longitudinal follow-up of exocrine pancreatic function in pancreatic sufficient cystic fibrosis patients using the fecal elastase-1 test.
abstract: BACKGROUND
  A progressive decline in pancreatic function is possible in cystic fibrosis (CF) patients with exocrine pancreatic sufficiency. The secretin-cholecystokinin test is invasive and not acceptable as a repeatable procedure for children. Steatorrhea, conversely, has low sensitivity. Therefore, the aim of the present study was to evaluate the usefulness of the noninvasive fecal elastase-1 (E1) test for the longitudinal assessment of exocrine pancreatic function (EPF) in pancreatic-sufficient (PS) CF patients.
  
  
  METHODS
  One hundred eighty-four CF patients were included in the study. In all subjects, E1 concentrations and fecal fat excretion were measured. PS patients were followed for 5 years.
  
  
  RESULTS
  At the beginning of the study, 35 (19.0%) CF patients were PS, and 32 (17.4%) had normal E1 concentrations. Longitudinal measurements of E1 concentrations in PS patients with CF demonstrated stable enzyme output in 27 and gradual decrease in 8. The decrease was rapid in five infant patients and gradual in three older patients. The decrease of E1 concentrations preceded the appearance of steatorrhea in all eight subjects.
  
  
  CONCLUSIONS
  The decline of EPF in patients with CF appears more frequently during the first months and years of life. However, late PS to pancreatic-insufficient (PI) conversion is also possible. The appearance of maldigestion is preceded by the decrease of fecal E1 concentration. Thus, the fecal E1 test is a helpful screening tool for the longitudinal assessment of declining EPF in PS patients with CF to demonstrate pancreatic deterioration. In suspected patients, fecal fat excretion should be assessed.
authors.affiliation: Department of Gastroenterology and Metabolism, Institute of Pediatrics, Karol Marcinkowski University of Medical Sciences, Szpitalna 27/33, 60-572 Poznan, Poland. jarwalk@am.poznan.pl
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Walkowiak
authors.forename: Sanda
authors.initials: S
authors.lastname: Nousia-Arvanitakis
authors.forename: Christina
authors.initials: C
authors.lastname: Agguridaki
authors.forename: Maria
authors.initials: M
authors.lastname: Fotoulaki
authors.forename: Krystyna
authors.initials: K
authors.lastname: Strzykala
authors.forename: Angeliki
authors.initials: A
authors.lastname: Balassopoulou
authors.forename: Michal
authors.initials: M
authors.lastname: Witt
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Herzig
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000235:genetics / Q000503:physiopathology*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics; D005243:Feces / Q000201:enzymology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D009154:Mutation; D010179:Pancreas / Q000503:physiopathology*; D010196:Pancreatic Elastase / Q000032:analysis*
chemical_list: C505032:CFTR protein, human; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D010196:Pancreatic Elastase