Specificity of, and influence of hemolysis, lipemia, and icterus on serum lipase activity as measured by the v-LIP-P slide.

BACKGROUND: Measurement of pancreatic lipase in serum is being used for the diagnosis of pancreatitis.

OBJECTIVES: The aims of this study were to measure serum lipase activity by the v-LIP-P slide and serum canine pancreatic lipase immunoreactivity (cPLI) concentration by Spec cPL in dogs with exocrine pancreatic insufficiency (EPI) and in serum samples that were hemolyzed, lipemic, or icteric.

METHODS: Serum samples from 50 dogs with EPI, 8 samples spiked with canine hemoglobin, Intralipid, or ditaurobilirubin, and 8 samples from dogs with severe hypertriglyceridemia were evaluated using v-LIP-P and Spec cPL assays.

RESULTS: Serum lipase activity (v-LIP-P) was in the lower 20% of the RI in 58% of EPI dogs, while serum cPLI (as measured by Spec cPL) was in the lower 20% of the RI in 98% of EPI dogs. The mean (±SD) observed-to-expected ratios for serum samples spiked with canine hemoglobin, Intralipid, or ditaurobilirubin were 63.0 ± 25.1%, 489.2 ± 469.7%, and 80.2 ± 11.6% for the v-LIP-P slide, respectively, and 99.3 ± 6.8%, 96.9 ± 9.4%, and 98.7 ± 11.0% for Spec cPL, respectively. However, naturally occurring hypertriglyceridemia did not appear to have a significant effect on serum lipase activity as measured by the v-LIP-P slide.

CONCLUSIONS: These results show that Spec cPL is specific for pancreatic lipase, while the v-LIP-P slide is not. In addition, hemolysis and lipemia had no effect on Spec cPL, while severe icterus resulted in a slight decrease in Spec cPL. Hemolysis and icterus had a significant effect on the v-LIP-P slide. The effect of lipemia on the v-LIP-P slide cannot be conclusively established based on this study.