Comparison of Serum Spec fPL^™and 1,2‐o‐Dilauryl‐Rac‐Glycero‐3‐Glutaric Acid‐(6′‐Methylresorufin) Ester Assay in 60 Cats Using Standardized Assessment of Pancreatic Histology

Abstract

BackgroundFeline pancreas‐specific lipase (Spec fPL) is considered a useful test for the antemortem diagnosis of pancreatitis in cats. A recent study found good agreement between the results of the Spec fPL and catalytic 1,2‐o‐dilauryl‐rac‐glycero‐3‐glutaric acid‐(6′‐methylresorufin) ester (DGGR) lipase assay. Prospective studies evaluating their sensitivity and specificity are lacking.ObjectivesTo compare the results of the Spec fPL and the DGGR assays with a standardized histologic assessment of the pancreas.AnimalsSixty client‐owned cats presented for necropsy.MethodsProspective study: Spec fPL concentrations and serum DGGR lipase activity were measured from the same blood sample. The pancreas was removed within 3 hours after euthanasia; serial transverse sections were made every 0.5 cm throughout the entire pancreas and reviewed using a histologic grading scheme. Sensitivity and specificity for the Spec fPL and DGGR assay results were determined.ResultsThe sensitivity and specificity for the Spec fPL assay (cutoff value ≥5.4 μg/L) was 42.1 [95% confidence interval (95% CI), 29.4–55.9%] and 100% (95% CI, 31.0–100.0%). The sensitivity and specificity for the DGGR assay (cutoff value >26 U/L) was 36.8 (95% CI, 24.7–50.7%) and 100% (95% CI, 31.0–100.0%). When lymphocytic inflammation up to 10% of a section was considered normal, the sensitivity and specificity for Spec fPL assay (cutoff value ≥5.4 μg/L) was 61.1 (95% CI, 36.1–81.7%) and 69.0% (95% CI, 52.8–81.9%) and the sensitivity and specificity for the DGGR assay (cutoff value >26 U/L) was 66.7 (95% CI, 41.2–85.6%) and 78.6% (95% CI, 62.8–89.2%).Conclusions and Clinical ImportanceBoth lipase assays performed similarly well, but their agreement with histologic pancreatic inflammation was limited.

Feline Diabetes Mellitus

“…Overall specificity was 91% (100% in healthy cats and 67% in symptomatic cats with normal pancreatic histology) (Forman et al, 2004). Another study evaluated the Spec fPL and also found 100% sensitivity for severe chronic pancreatitis; specificity, however, was only 54% (Oppliger et al, 2013a). These numbers nicely demonstrate the problems associated with the measurement of the fPLI/Spec fPL test: In cats with severe pancreatitis, the test will usually be positive, whereas it may be negative in mild disease.…”

Effects of 6 Weeks of Parenteral Cobalamin Supplementation on Clinical and Biochemical Variables in Cats with Gastrointestinal Disease

“…Serum thyroxine concentration was measured in 18 cats, and four cats were diagnosed with hyperthyroidism. All cats were evaluated for pancreatitis by the DGGR‐lipase activity assay; 4 of 20 cats had minimally elevated values (28, 32, 32, and 34 U/L; reference range, 8–26 U/L) with unclear significance, and one cat had a value of 73 U/L, which was considered diagnostic for pancreatitis . Serum trypsinogen‐like immunoreactivity (fTLI) was measured in all 20 cats, and none had values that were diagnostic (<8 μg/L) or suspicious (8–12 μg/L) of exocrine pancreatic insufficiency.…”

The 1,2‐o‐dilauryl‐rac‐glycero‐3‐glutaric acid‐(6’‐methylresorufin) ester (DGGR) lipase assay in cats and dogs is not specific for pancreatic lipase

“…Soon after it was introduced as a method to measure pancreatic lipase activity in people, the DGGR‐based assay began to be used for serum lipase activity measurements in cats 12,15 and dogs 11,16,17,33 . Few studies have evaluated the clinical utility of DGGR‐based assays for the diagnosis of feline and canine pancreatitis 11,17,33 .…”

“…Since 2005, various DGGR‐based assay validation studies for diagnosing pancreatitis in cats 12,15 and dogs 11,16,17 have been performed. These studies show good precision, linearity, and substantial agreement with Spec PL concentrations, with varying diagnostic sensitivities (cats: 36.8‐66.7% 12,15 ; dogs: 85.7‐93.0% 11,17 ) and specificities (cats: 63.0‐100.0% 12,15 ; dogs: 53.0‐74.3% 11,17 ). However, none of these validation studies investigated the effects of extrapancreatic lipases on DGGR‐based assays.…”