Protease inhibitors, inflammatory markers, and their association with outcome in dogs with naturally occurring acute pancreatitis

Background: Acute pancreatitis (AP) presumably is associated with pancreatic protease activation, protease inhibitor (PI) depletion, and inflammatory mediator secretion. Objectives: Examine PIs and inflammatory mediator concentrations in dogs with AP and their association with death. Animals: Thirty-one dogs diagnosed with AP based on clinical signs, ultrasonographic findings, and increased canine pancreatic lipase immunoreactivity (cPLI) and 51 healthy control dogs. Methods: Antithrombin and α₂-antiplasmin activity (ATA and α₂AP, respectively) and concentrations of α₁-proteinase inhibitor (α₁PI), α₂-macroglobulin (α₂MG), C-reactive protein (CRP), interleukins (ILs)-2,6,8 and tumor necrosis factor-α (TNF-α) were prospectively measured. Severity of AP was assessed by clinical severity scoring systems. Results: Mortality rate was 19%. Antithrombin activity was lower (P =.004) and maximal CRP, IL-6, and TNF-α concentrations higher (P '.04) in the AP group compared to the controls, whereas IL-2, IL-8, α₁PI, and α₂AP concentrations did not differ between groups. Serum α₂MG concentration was not reliably detected. Serum cPLI, CRP, and IL-6 concentrations were significantly and positively correlated. The ATA was lower (P =.04), and canine acute pancreatitis severity (CAPS) scores higher (P =.009) in nonsurvivors compared to survivors. Higher CAPS scores were associated (P '.05) with decreased ATA and increased cPLI, CRP, and IL-6 concentrations. Conclusions and Clinical Importance: Systemic inflammation in dogs with AP is manifested by increased inflammatory mediator concentrations, correlating with cPLI and CRP concentrations. Hypoantithrombinemia is associated with death. Serum concentrations of α₂AP and α₁PI are less useful prognostic markers. The CAPS score is a useful prognostic marker in dogs with AP.