Serum pancreatic lipase immunoreactivity in sick dogs after chronic administration of supraphysiologic doses of glucocorticoids

Background Glucocorticoids (GC) are commonly used for a long term to treat a multitude of immune-mediated, inflammatory, and neoplastic diseases in dogs. Conflicting results of published studies on the effects of exogenous and endogenous GCs on serum canine pancreatic lipase immunoreactivity (cPLI) raise the question of whether cPLI concentrations can be reliably interpreted in patients receiving GCs. Objective We sought to determine the effect of long-term GC administration at supraphysiologic doses on serum cPLI concentrations in sick dogs. Methods Serum samples were collected from 35 client-owned dogs. Dogs were administered prednisone at a dose of >= 0.5 mg/kg per day for >= 3 weeks. Serum cPLI was measured prior to the initiation and after >= 3 weeks of GC therapy. Results There was a significant increase in serum cPLI between baseline (median 101 mu g/L; range 30-1997 mu g/L) and following the administration of >= 0.5 mg/kg/day of prednisone (median 173 mu g/L; range 30-2000 mu g/L) in dogs (P = 0.025). However, the median change was small (31 mu g/L). There was no suspicion of pancreatitis in any of the dogs. Diagnostic interpretation changed in 6/35 dogs, with no apparent dose-response relationship. Conclusions There was a statistically significant difference from baseline in serum cPLI measurements in sick dogs receiving long-term prednisone. Although the change was small and often clinically insignificant, it could pose a clinical interpretation dilemma in some dogs. It is unknown whether these observations are coincidental due to subclinical pancreatitis or caused by another effect of GCs on pancreatic acinar cells.