How useful is fecal pancreatic elastase 1 as a marker of exocrine pancreatic disease?

Objectives: To evaluate the role of fecal elastase 1 (E1) as a marker of exocrine pancreatic insufficiency (PI). Study design: Fecal El was measured in patient groups with (1) failure to thrive but no pancreatic or intestinal disease (disease control patients); (2) PI; (3) pancreatic sufficiency; and (4) steatorrhea caused by a variety of intestinal diseases. Results: Fecal El in all disease control patients exceeded 200 mug/g stool. Only 1 (2%) of 50 patients with PI exceeded the minimum reference value of 100 mug/g stool. In contrast, 3 (11%) of 28 patients with pancreatic sufficiency (with Shwachman-Diamond syndrome) had fecal E1 concentrations <100 mug/g stool, as did 5 (20%) of 25 patients with steatorrhea from intestinal causes, all of whom had diluted feces caused by short gut. Conclusions: Fecal El is a useful noninvasive screening test of PI in childhood. A negative test (>100 mug/g stool) had 99% predictive value for ruling out PI. However, a positive test in those with short gut or Shwachman-Diamond syndrome must be interpreted with caution. (J Pediatr 2002;141:84-90).