Serum pancreatitis-associated protein 1 concentrations in dogs with acute signs of gastrointestinal disease and normal or abnormal DGGR lipase activity

Background Pancreatitis-associated protein (PAP-1) is synthesized during acute pancreatitis (AP) and chronic enteropathy in people. Serum PAP-1 concentration (PAP-1) has not been measured prospectively in dogs. Objectives Evaluate whether PAP-1 differentiates suspected AP (sAP) diagnosed by abnormal DGGR-lipase activity from non-pancreatic acute gastrointestinal disease (aGId) diagnosed by normal DGGR-lipase activity. Animals Twenty-six dogs with sAP, 48 dogs with aGId based on signs of acute gastrointestinal disease, lipase activity > 450 U/L (reference interval [RI],17-156 U/L) and maximally 20 U/L > RI, respectively. Forty healthy control dogs. Methods Prospective daily assessment included a simplified modified canine activity index (MCAI). PAP-1, lipase activity, C-reactive protein concentration (CRP) were measured daily. PAP-1 assay validation comprised precision, interferences, linearity, and RI establishment. Results Lower/upper PAP-1 quantification limits were 0.2 and 6.0 μg/mL, linearity was excellent (R2 0.999) at high, acceptable (R2 0.966) at low PAP-1 concentrations. Intra-, inter-run precision was ≤5%, ≤22%, PAP-1 remained stable for 15 days (room temperature), no interferences were found. Duration of hospitalization and clinical disease severity did not differ between groups. At admission, PAP-1 above RI in 50% and 48 % of sAP and aGId dogs, respectively (sAP median, range 1.88 μg/mL, 0.2-6.0 vs. aGId 1.57 μg/mL, 0.2-6.0; RI, <1.9 μg/mL). PAP-1 did not differ significantly between groups irrespective of observation time points. PAP-1 correlated significantly with CRP in sAP (rs = 0.623) and aGId (rs = 0.483). PAP-1 correlated significantly with lipase activity (rs = 0.474) in sAP, with MCAI (rs = 0.342) in aGId. Conclusion and clinical importance Serum PAP-1 reflects inflammation rather than underlying disease processes, and does not differentiate sAP from aGId.