Comparative repeatability of pancreatic lipase assays in the commercial and in‐house laboratory environments

BACKGROUND: Sensitivity and specificity for commercial and in‐house pancreatic lipase immunoreactivity (cPLI) assays have been reported, but repeatability under routine clinical conditions is unknown. OBJECTIVES: To determine: 1. Coefficient of variation (CV) between replicates of a commercial assay (Spec cPL) and 2 in‐house assays (VetScan cPL, Vcheck cPL) under routine conditions. 2. Effects of sample condition or personnel on results. 3. Potential directional bias between assays. ANIMALS: Serum from 12 canine clinical patients. METHODS: Prospective study. Serum Spec cPL, VetScan cPL, and Vcheck cPL (6 aliquots each) were measured, and CVs were calculated, effects of sample condition and personnel were assessed using a linear mixed model, and direction of bias was assessed using least square mean cPLI concentration. RESULTS: Mean %CVs for Spec cPL, VetScan cPL, and Vcheck cPL were 5.5, 17.0, and 23.7%. Three of 6 VetScan cPL samples and 5/9 Vcheck cPL samples had an unacceptably high %CV (>20%). Transportation (Spec cPL) and sample condition or personnel (VetScan cPL, Vcheck cPL) did not affect repeatability. Least square mean cPL was higher for Spec cPL (807.9 μg/L) than for VetScan cPL (558.5 μg/L) or Vcheck cPL (399.8 μg/L). CONCLUSIONS AND CLINICAL IMPORTANCE: For clinical use, the commercial Spec cPL has the highest repeatability, and Vcheck cPL has significantly lower repeatability. Both in‐house assays evaluated may provide discrepant categorical results (“pancreatitis” versus “equivocal” versus “not pancreatitis”) for the same sample. In‐house pancreatic lipase concentrations may be lower than those determined by the Spec cPL assay.