Comparison of two tubeless function tests in the assessment of mild-to-moderate exocrine pancreatic insufficiency

Faecal elastase 1 (FE1) and the pancreolauryl test (PLT) are widely used for the non-invasive diagnosis of exocrine pancreatic insufficiency (EPI). Whether one of these two tests is superior for the detection of mild-to-moderate EPI is the subject of controversy. The aim of this study was to compare the diagnostic performance of the PLT and FE1 for the detection of EPI in patients with chronic pancreatitis.

Forty consecutive patients (27 males, 13 females, 23-72 years) with chronic pancreatitis based on imaging procedures (computed tomography, endoscopic retrograde pancreatography and endoscopic ultrasound) were admitted to the study. A secretin-caerulein test (SCT) was performed after an overnight fast by giving secretin (1 U/kg/h) and caerulein (100 ng/kg/h) intravenously over 90 min. Duodenal contents were aspirated at 15 min intervals and analysed for pH, bicarbonate, amylase, lipase and elastase. EPI was graded on the basis of the results of the SCT as absent, mild, moderate or severe. A serum PLT was performed in accordance with a modified protocol previously described. A commercial ELISA was used for determination of FE1. The cut-off values were > or = 4.5 mg/l for PLT and > or = 200 microg/g for FE1. and 13 severe) on the basis of the results of the SCT. The sensitivity of the PLT for diagnosing EPI of all degrees of severity was 82% (27/33), compared with 50% for FE1 (16/ 33). In patients with severe EPI, the PLT was abnormal in 100% (13/13) and FE1 was abnormal in 85% (11/13) of the cases. The sensitivity decreases for both tests in the group of mild/moderate EPI (PLT 70% (14/20), FE1 35% (7/20)). In all seven patients with normal exocrine pancreatic function, both PLT and FE1 were also normal.

The PLT is more sensitive than FE1 for the diagnosis of mild-to-moderate EPI, and is therefore more appropriate for completing the staging of chronic pancreatitis.