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

Background: Feline 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.

Objectives: To compare the results of the Spec fPL and the DGGR assays with a standardized histologic assessment of the pancreas.

Animals: Sixty client-owned cats presented for necropsy.

Prospective 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.

Results: The 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 importance: Both lipase assays performed similarly well, but their agreement with histologic pancreatic inflammation was limited.

Keywords: Feline; Feline pancreas-specific lipase; Histopathology; Lipase; Pancreas.

Figure 1

A specimen of feline pancreas that has been fixated in formalin and cut transversely every 0.5 cm.

Figure 2

Small nests of lymphocytes located predominantly perivascularly in the pancreas of a cat. The overall grade of lymphocytic inflammation in the corresponding slide was graded as 0–10%.

Figure 3

ROC curve for the histopathologic diagnosis of pancreatitis by use of the Spec fPL assay (solid line) and the DGGR assay (dashed line). The gold standard was an AI with up to 10% lymphocytic inflammation defined as normal.