New Tests for Pancreatitis - IDEXX Laboratories

Diagnostics CONTINUEDSensitivity4ADVANTAGESThe SNAP cPL allows clinicians to rule outpancreatitis in dogs with acute gastrointestinalsigns and also to strengthen a suspicion of pancreatitiswithin minutes. Many dogs with acutegastritis, hypoadrenocorticism, renal failure, orother diseases may present with similar clinicalsigns. A negative SNAP cPL helps the clinicianquickly shift the focus of the clinical investigationto other conditions. Measurement of SpeccPL or Spec fPL often allows diagnosis even inanimals with mild or chronic disease (Figure 4).DISADVANTAGESWhile a positive SNAP cPL test helpsstrengthen a suspicion of pancreatitis, it does notdefinitively diagnose it. Other diagnostic tests,including abdominal ultrasound and measurementof Spec cPL, are necessary. In addition, nodiagnostic test is 100% sensitive and specific.Comparison of SensitivityDiagnostic Modalities for Canine Pancreatitis100%90%80%70%60%50%40%30%20%10%0%36%Serum cTLIConcentration55%Serum LipaseActivity68%AbnormalUltrasoundSerum trypsin-like immunoreactivity (cTLI) concentration,abdominal ultrasound, and serum pancreatic lipaseimmunoreactivity (cPLI) concentration have high specificityfor canine pancreatitis, whereas only approximately50% of dogs with an increased serum lipase activity havepancreatitis. 5,782%Serum cPLIConcentrationThus, it is crucial to integrate all clinical dataavailable during the diagnostic process.RELIABILITY OF RESULTSSNAP cPLAs mentioned earlier, a negative SNAP cPL testcan be used to rule out pancreatitis in patientswith acute gastrointestinal signs. While no studieshave determined the exact sensitivity of theSNAP cPL test, experience suggests that falsenegativeresults are uncommon. A positive SNAPcPL result helps confirm a suspicion of pancreatitis,but further diagnostics are crucial to confirmthe diagnosis because serum Spec cPLconcentrations in the questionable range willproduce a positive SNAP cPL test.Spec cPL & fPLSpec cPL and Spec fPL cannot differentiatebetween primary and secondary pancreatitis—some patients with an inflammatory diseaseprocess in another organ in the region may havesecondary pancreatic inflammation.The specificity for the Spec cPL and Spec fPLassays has been estimated at 96.8% and 100%,respectively. 2,3 The sensitivity of Spec cPL hasbeen estimated at 82% in 2 studies of dogs withmore severe forms of pancreatitis and at 63.6% inthose with mild pancreatitis. 4-6 In an initial studyinvolving a small number of cats, the Spec fPLwas reported to have a sensitivity of 67% in allcats with pancreatitis and 100% in cats withmoderate to severe pancreatitis. 3Several multicenter studies are underway to furtherassess the clinical utility of these tests inrelatively large patient populations.ECONOMIC IMPACTAll 3 tests discussed are economical, with pricesranging between $10 to $30, depending onwhether tests are ordered as stand-alone tests orpart of a panel.See Aids & Resources, back page, for referencesand suggested reading.Dr. Steiner discloses that he is a paid consultant for IDEXXLaboratories, Inc.09-68270-0078 ...................................................................................................................................................................................NAVC Clinician’s Brief / April 2010 / Diagnostics