Methodologies

• Serum canine pancreatic lipase immunoreactivity is measured with an ELISA Enzyme linked immunosorbent assay (ELISA).
• This test (Spec cPL™) is exclusively manufactured by Idexx Laboratories.
  • A microplate is coated with monoclonal antibodies against canine pancreatic lipase.
  • Sera are diluted and incubated on the plate, allowing the monoclonal antibodies to capture the pancreatic lipase, while other proteins are washed away.
  • A secondary antibody carrying a label is then incubated in the wells.
  • The amount of bound label is proportionate to the quantity of pancreatic lipase in the original serum sample.
  • A standard curve is constructed using a recombinant peptide that is part of the native canine pancreatic lipase protein.
• Other diagnostic assays for canine pancreatitis are also available (VetScan Rapid cPL and Precision PSL). The VetScan Rapid cPL is a semi-quantitative point-of-care immunoassay. The Precision PSL is a non-immunological colorimetric DGGR lipase assay DGGR lipase activity which is not specific for pancreatic lipase. A good level of agreement has been described among the assays in some studies while other studies have raised concerns regarding the precision and linearity of these assays. 
• The Idexx Spec cPL™ assay is currently the only assay for which there has been extensive validation studies and assessment of its clinical utility in dogs.

Availability

• Serum canine pancreatic lipase immunoreactivity measurement (Spec cPL™ Assay) is currently available via an Idexx Reference Laboratory or the Gastrointestinal Laboratory at Texas A&M University.
• A point of care test (IDEXX SNAP cPL™) is also available using a SNAP ELISA technology and this patient-side test has a 95% agreement with Spec cPL. It is recommended that abnormal SNAP cPL results are followed-up with SpecPL to establish a baseline cPL concentration and avoid potential false positives (SNAP cPL may be abnormal when SpecPL is between 200-400 ug/l, however, the cut-off for diagnosis of pancreatitis is 400 ug/L) (see reference ranges below).

Validity

Sensitivity

• A wide range of sensitivities have been cited in the literature dependent on the stage of disease. In one study in dogs with histopathological evidence of pancreatitis, the sensitivity for the Spec cPL (cut-off value 400 μg/L) was 21% in dogs with mild pancreatitis and 71% in dogs with moderate-severe pancreatitis. When a cut-off of 200 ug/L was used sensitivity was 43% for mild pancreatitis and 71% for moderate to severe pancreatitis. In more recent studies where history, clinical signs and ultrasonography were used to support a diagnosis of pancreatitis the sensitivity of the Spec cPL was 81.0-90.9% (using a cutoff of 400 ug/L).

Specificity

• Specificity varies depending on the cut-off used for the diagnosis of pancreatitis. Specificity ranges of 86% (where a cut off of 200 ug/L was used) to 100% (where a cut of of 400 ug/L was applied) have been reported. A more recent study using clinical criteria to support or exclude a diagnosis of pancreatitis reported a sensitivity range of 74-81% (using a cut-off for 400 ug/L).

Technique intrinsic limitations

• Avoid submission of severely lipemic or hemolyzed samples.