title: Comparison of fecal elastase-1 and pancreatic function testing in children.
abstract: OBJECTIVE
  The fecal pancreatic elastase-1 (FE-1) test is considered a simple, noninvasive, indirect measure of pancreatic function. We aimed to evaluate the performance of the FE-1 test compared with the direct pancreatic function test (PFT) with secretin stimulation in children.
  
  
  METHODS
  Data of 70 children (6 months-17 years of age) who had both FE-1 test and PFT were analyzed.
  
  
  RESULTS
  The average FE-1 concentration was 403 ± 142 μg/g. Eleven children had concentrations below 200  μg/g, 23 between 201 to 500 μg/g, and 36 were above 500 μg/g. The average pancreatic elastase activity measured on direct stimulation was 49.1 ± 38.6  μmol · min (-1)· ml(-1) and 11 children had activity below the established cutoff (10.5 μmol · min(-1) · ml(-1)). Among the 11 children with pathologic PFT, 7 had normal FE-1, 4 were in the intermediate range (201-500 μg/g), and none were in the low range (<200 μg/g). Among the 59 children with normal direct PFT 11 (19%) had pathologic (<200 μg/g) and 19 (32%) had intermediate FE-1 tests. Twenty-nine children had both normal FE-1 concentration and normal PFT, giving a negative predictive value of 80%. The correlation between pancreatic elastase activity and FE-1 concentration was poor (r = 0.190). The sensitivity of the FE-1 test was found to be 41.7%, whereas the specificity was 49.2%. The positive predictive value of the FE-1 test was only 14%.
  
  
  CONCLUSIONS
  The FE-1 test is a simple, noninvasive, indirect method; however, ordering physicians should be aware of its limitations. It can give false-positive results and has low sensitivity in children with mild pancreatic insufficiency without cystic fibrosis and in those with isolated pancreatic enzyme deficiencies.
authors.affiliation: Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: Prateek D
authors.initials: PD
authors.lastname: Wali
authors.forename: Beth
authors.initials: B
authors.lastname: Loveridge-Lenza
authors.forename: Zhaoping
authors.initials: Z
authors.lastname: He
authors.forename: Karoly
authors.initials: K
authors.lastname: Horvath
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D010188:Exocrine Pancreatic Insufficiency / Q000175:diagnosis* / Q000201:enzymology; D005243:Feces / Q000737:chemistry*; D006801:Humans; D007223:Infant; D010179:Pancreas / Q000201:enzymology*; D010196:Pancreatic Elastase / Q000032:analysis* / Q000378:metabolism; D010186:Pancreatic Function Tests / Q000379:methods*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012633:Secretin; D012680:Sensitivity and Specificity
chemical_list: D012633:Secretin; D010196:Pancreatic Elastase