Evaluation of Clinicopathological Data, the Specific Feline Pancreatic Lipase Assay, and Abdominal Ultrasound as Severity Determinants in Cats with Pancreatitis.

Limited data exist to predict the severity of pancreatitis in cats. In this retrospective case series, we reviewed the medical records of 45 cats with SP from June 2014 to June 2019. Case definition was based on an internist's review of clinopathologic data, Spec fPL concentration, and AUS findings. Information extracted from the medical records included signalment, history, physical examination findings, selected clinicopathological data (total bilirubin, glucose, ALP, ALT, and total calcium), Spec fPL concentration, AUS images/clips, length of hospitalization, and survival data. Hazard ratios were used to evaluate the association between clinicopathological data, the Spec fPL assay, AUS findings, and the length of hospitalization. Clinicopathological abnormalities, the Spec fPL, and AUS abnormalities were not statistically associated with the length of hospitalization. Despite a lack of statistical significance, the hazard ratios suggest the potential that an elevated total bilirubin (hazard ratio (HR): 1.19), hypocalcemia (HR: 1.49), and an elevated Spec fPL concentration (HR: 1.54) could be associated with prolonged hospitalization, although additional studies would be needed to verify this. Additionally, hazard ratios suggest that AUS evidence of concurrent gallbladder (HR: 1.61) and gastric abnormalities (HR: 1.36) could be associated with prolonged hospitalization.

Analytical validation of an ELISA for the measurement of feline pancreas-specific lipase and re-evaluation of the reference interval and decision threshold for diagnosing pancreatitis.

BACKGROUND: The diagnosis of feline pancreatitis can be challenging. The clinical presentation often includes mild, nonspecific clinical signs, such as vomiting, anorexia, and weight loss. Measurement of feline pancreatic lipase immunoreactivity (fPLI) concentration in serum has been reported to be sensitive and specific for a diagnosis of pancreatitis in cats. However, analytical validation for a widely available commercial assay for the measurement of fPLI concentration has not been published. OBJECTIVE: We aimed to analytically validate the Spec fPL assay (IDEXX Laboratories, Westbrook, ME), a commercial ELISA for the measurement of fPLI concentration, and re-evaluate its reference interval and decision threshold for diagnosing pancreatitis in cats. METHODS: Dilutional linearity, accuracy, precision, and the effect of interfering substances were assessed. The upper limit of the reference interval was calculated based on the 95th percentile of results from clinically healthy cats (n = 107), and a decision threshold for diagnosing pancreatitis was calculated with an expected specificity of 99%. RESULTS: Analytical validation demonstrated good linearity, accuracy, and precision, as well as the absence of interference from lipemia, hemolysis, or icterus. The upper limit of the reference interval for Spec fPL was determined to be 4.4 µg/L, and the decision threshold (a theoretical cut-off) for diagnosing pancreatitis was determined to be 8.8 µg/L based on a desired specificity of 99%. CONCLUSIONS: The Spec fPL assay is analytically valid, and results suggest that a decision threshold of 8.8 µg/L would have high diagnostic specificity for excluding clinically healthy cats.

Specificity of a pancreatic lipase point-of-care test and agreement with pancreatic lipase immunoreactivity in cats without clinical evidence of pancreatitis.

OBJECTIVES: The aim of this study was to determine the specificity of a rapid point-of-care test for the estimation of feline pancreatic lipase (SNAP fPL) in healthy and sick cats without clinical evidence of pancreatitis. A second objective was to evaluate the agreement between SNAP fPL and serum pancreatic lipase immunoreactivity (fPLI), as measured by Spec fPL. METHODS: A total of 150 cats were prospectively enrolled into this study. Of them, 82 cats were healthy while 68 cats had various diseases but no clinical signs (eg, anorexia, depression, vomiting) raising a suspicion of pancreatitis. RESULTS: SNAP fPL was normal in 133/150 cats (specificity 89%) without obvious clinical pancreatitis. SNAP fPL was normal in 74/82 healthy cats (specificity 90%) and in 59/68 cats that were sick but without typical signs of pancreatitis (specificity 87%). The agreement between SNAP fPL and Spec fPL was substantial (k = 0.64) in healthy cats and almost perfect (k = 0.93) in sick cats. The overall agreement between SNAP fPL and Spec fPL was almost perfect (k = 0.81). CONCLUSIONS AND RELEVANCE: The specificity of SNAP fPL in this group of cats was high. There was a substantial and almost perfect agreement between the SNAP fPL and Spec fPL in healthy cats and sick cats without suspected pancreatitis, respectively. In the small percentage of cats with abnormal SNAP fPL and/or Spec fPL results, the possibility of subclinical pancreatitis cannot be excluded.

Cyclosporine Treatment in Cats with Presumed Chronic Pancreatitis-A Retrospective Study.

Chronic pancreatitis (CP) is a common disease in middle-aged to older cats. Cyclosporine has been suggested as an alternative treatment when other immunosuppressive treatments are insufficient or contraindicated. However, no published studies have investigated its efficacy on feline CP. The aim of this retrospective study was to evaluate the efficacy of cyclosporine on supranormal serum feline pancreas-specific lipase (Spec fPL) concentrations in cats with presumed CP. Inclusion criteria were history and clinical signs suggestive of CP, serum Spec fPL concentrations above 5.3 µg/L (reference range 0-3.5 µg/L, equivocal range 3.6-5.3 µg/L) on at least two occasions and treatment with cyclosporine for at least three weeks. Serum Spec fPL was analyzed at Idexx Laboratories, Kornwestheim, Germany. Nineteen cats, aged 6.9-17.5 years (median 11.6), were included. No pancreatic biopsies were available. Median (range) serum Spec fPL concentration was 14.2 µg/L (6.1-43.3) at baseline and 6.7 µg/L (0.9-23.6) at follow-up. Cyclosporine treatment (5.0-7.9 mg/kg orally SID) was associated with a significant reduction in serum Spec fPL concentrations (p < 0.001) at follow-up after 23-206 days (median 35). Body weight decreased significantly between inclusion and follow-up (p = 0.013). Significant improvement of clinical signs could not be measured (p = 0.781). This study has several limitations, including unstandardized treatment length and dose, no control group and lack of pancreatic biopsies. Despite the limitations, our results suggest that cyclosporine treatment reduces supranormal serum Spec fPL concentrations in cats with presumed CP.

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.

BACKGROUND: The measurement of pancreatic lipase is important for the diagnosis of feline and canine pancreatitis. Recent studies have claimed that lipase assays using the 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester (DGGR) as a substrate are more specific for measuring pancreatic lipase than traditional lipase assays. However, the analytical specificity of this assay for pancreatic lipase has not been demonstrated. OBJECTIVES: We aimed to determine whether hepatic and/or lipoprotein lipases can interfere with the DGGR-based assay results in cats and dogs. We, therefore, compared plasma lipase activities measured using DGGR-based and pancreatic lipase immunoreactivity (PLI) assays before and after administering heparin, known to cause the release of hepatic and lipoprotein lipases, in cats and dogs. METHODS: Heparin was administered in six cats and six dogs. Blood was collected at baseline and 10, 20, 30, 60, and 120 minutes after heparin administration. Lipase activity was measured using a DGGR-based assay, and PLI concentrations were measured using the Spec fPL and cPL assays for cats and dogs, respectively. RESULTS: Plasma lipase activities, as measured using the DGGR-based assay, increased significantly 10 minutes after heparin administration in both cats (P = .003) and dogs (P = .006) and returned to baseline by 120 minutes. In contrast, PLI concentrations showed no significant changes after heparin administration. CONCLUSIONS: DGGR is not only hydrolyzed by pancreatic lipase but also by hepatic lipase, lipoprotein lipase, or both, in cats and dogs. Since these extrapancreatic lipases are also naturally present in cats and dogs, they could contribute to the lack of analytical specificity for the DGGR-based assays.

Estimates of biologic variation in specific feline pancreatic lipase concentrations in cats without clinical or ultrasonographic evidence of pancreatitis.

BACKGROUND: Serum concentrations of feline-specific pancreatic lipase are commonly used for diagnosis and monitoring of pancreatitis in cats, but little is known regarding biologic variation of this analyte. OBJECTIVES: The purpose of the study was to determine biologic variation, index of individuality, and reference change values (RCV) for specific feline pancreatic lipase concentrations (Spec fPL) in apparently healthy cats. METHODS: Four blood samples were collected prospectively from 12 apparently healthy cats at 2-week intervals. The Spec fPL was measured in all serum samples by a reference laboratory. RESULTS: Intra-individual variation for Spec fPL was 33.5% (95% CI 27.1-43.8%); inter-individual variation was 99.9% (69.2-169.9%) and analytic variation was 7.3% (6.1-9.2%). Reciprocal index of individuality for Spec fPL was 2.9 (2.5-3.8), the 2-sided RCV was 95.1% (77.0-123.9%). CONCLUSIONS: Due to high individuality, use of a population-based RI for Spec fPL may fail to detect clinically significant elevations in individual cats. The use of subject-based RIs for Spec fPL may have greater sensitivity for the detection of a change in pancreatic physiology in cats; however, this would require serial assessment of apparently healthy cats.

SNAP Tests for Pancreatitis in Dogs and Cats: SNAP Canine Pancreatic Lipase and SNAP Feline Pancreatic Lipase.

A clinical diagnosis of pancreatitis in dogs and cats can be challenging. Several diagnostic modalities have been evaluated over the years for the diagnosis of canine and feline pancreatitis, but most of these modalities have been shown to be of limited clinical use because of poor performance, limited availability, or because they are invasive, or all of these. Assays for the measurement of pancreatic lipase (PL) immunoreactivity [Specific canine PL (Spec cPL) in dogs and Specific feline PL (Spec fPL) in cats] were first developed approximately 15 years ago, and studies have shown that they are currently the serum tests of choice for the evaluation of canine and feline patients, respectively, suspected of having pancreatitis. This is a direct consequence of their high specificity of detecting only PL and their sensitivity for pancreatitis when compared with other serum tests. SNAP cPL and SNAP fPL are in-clinic tests that have been developed based on the Spec cPL and Spec fPL assays. As with any other test, false-positive and false-negative results do occur with PL immunoreactivity assays, and it is important to know the limitations of these assays.

Longitudinal evaluation of serum pancreatic enzymes and ultrasonographic findings in diabetic cats without clinically relevant pancreatitis at diagnosis.

BACKGROUND: Cats with diabetes mellitus can have subclinical pancreatitis but prospective studies to confirm this are lacking. Metabolic control of diabetic cats with pancreatitis is difficult. HYPOTHESIS: Subclinical pancreatitis occurs in diabetic cats at the time diabetes is diagnosed or might develop during the follow-up period, hampering diabetic remission. ANIMALS: Thirty cats with newly diagnosed diabetes without clinical signs of pancreatitis on admission. METHODS: Prospective study. On admission and 2 and 6 months later, serum Spec fPL and DGGR-lipase were measured and the pancreas underwent ultrasonographic examination. Pancreatitis was suspected if serum markers were increased or ≥2 ultrasonographic abnormalities were detected. Cats were treated with insulin glargine and diabetic remission was defined as euglycemia ≥4 weeks after discontinuation of insulin. Nonparametric statistical tests were used for analysis. RESULTS: Subclinical pancreatitis at the time of diagnosis was suspected in 33, 50, and 31% of cats based on Spec fPL, DGGR-lipase and ultrasonography, respectively; and in 60% when diagnostic criteria were combined. During the follow-up period, suspected pancreatitis developed in additional 17-30% cats. Only 1 cat had transient clinical signs compatible with pancreatitis. Seventeen of the 30 cats (57%) achieved remission. Frequency of abnormal Spec fPL and DGGR-lipase and abnormal ultrasonographic findings did not differ in cats achieving remission and those who did not. Cats achieving remission had significantly lower Spec fPL at 2 months (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: Based on laboratory and ultrasonographic measurements, many cats with diabetes might have pancreatitis, although without clinical signs. Cats with high Spec fPL might have a reduced chance of diabetic remission; however, this topic needs further studies in large cohorts of diabetic cats.