Specificity of a canine pancreas-specific lipase assay for diagnosing pancreatitis in dogs without clinical or histologic evidence of the disease.

OBJECTIVE: To evaluate the specificity of a canine pancreas-specific lipase (cPSL) assay for diagnosing pancreatitis in dogs without clinical or histologic evidence of the disease. ANIMALS: 20 dogs from another study with macroscopic evidence of pancreatitis and 44 dogs surrendered for euthanasia or expected to die. PROCEDURES: Prior to death, physical examination of each dog was performed and blood samples were collected for serum biochemical, serum cPSL, and hematologic analyses. After death, the pancreas was removed, sectioned in 1- to 2-cm slices, and evaluated by a pathologist. Dogs were classified by whether they had clinical or macroscopic pancreatitis. Each pancreatic section was histologically examined, and mean cumulative scores (MCSs) were assigned for 8 histologic characteristics. For each characteristic, comparisons were made between dogs with and without pancreatitis to establish histologic criteria for lack of evidence of pancreatitis. RESULTS: For all histologic characteristics except lymphocytic infiltration, the median MCS differed significantly between dogs with and without pancreatitis. Dogs were categorized as having no histologic evidence of pancreatitis when the MCSs for neutrophilic infiltration, pancreatic necrosis, peripancreatic fat necrosis, and edema were 0.0. On the basis of these criteria, 40 dogs were classified as having no evidence of pancreatitis. The cPSL concentration was within reference limits in 38 of these 40 dogs and was less than the cutoff value for diagnosing pancreatitis (400 µg/L) in 39 of the 40 dogs, resulting in a specificity of 97.5% (95% confidence interval, 86.8% to 99.9%). CONCLUSIONS AND CLINICAL RELEVANCE: The cutoff cPSL value used in this study may be useful for diagnosing pancreatitis in dogs with a lack of histologic lesions consistent with pancreatitis and for which pancreatitis is not considered a major differential diagnosis.

Symmetric Dimethylarginine: Improving the Diagnosis and Staging of Chronic Kidney Disease in Small Animals.

Chronic kidney disease (CKD) is a common condition in cats and dogs, traditionally diagnosed after substantial loss of kidney function when serum creatinine concentrations increase. Symmetric dimethylarginine (SDMA) is a sensitive circulating kidney biomarker whose concentrations increase earlier than creatinine as glomerular filtration rate decreases. Unlike creatinine SDMA is unaffected by lean body mass. The IDEXX SDMA test introduces a clinically relevant and reliable tool for the diagnosis and management of kidney disease. SDMA has been provisionally incorporated into the International Renal Interest Society guidelines for CKD to aid staging and targeted treatment of early and advanced disease.

Analytical validation of an ELISA for measurement of canine pancreas-specific lipase.

BACKGROUND: The diagnosis of canine pancreatitis is challenging. Clinical presentation often includes nonspecific clinical signs, such as vomiting, anorexia, and abdominal discomfort. Increased serum lipase activity can be indicative of pancreatitis; however, it can also be increased with other conditions. An immunoassay for measurement of canine pancreas-specific lipase in canine serum that would be suitable for commercial application and provide rapid results would be beneficial. OBJECTIVE: The goal of this study was to validate the Spec cPL assay, a commercially available ELISA for the quantitative measurement of canine pancreas-specific lipase. METHODS: Dynamic range, dilutional linearity, precision, interfering substances, assay stability, and reproducibility were investigated for analytical validation. The method was compared with the reference assay, canine pancreatic lipase immunoreactivity (cPLI), and included evaluation of a sample population of dogs and bias. RESULTS: Analytical validation showed a dynamic range of 36-954 µg/L; good precision (intra- and interassay coefficient of variation <12%); absence of interference from lipid, hemoglobin, or bilirubin; 12-month kit stability; and good reproducibility. Method comparison showed a positive bias relative to the cPLI reference method; however, the bias can be accommodated by adjustment of decision limits. The upper limit of the reference interval for Spec cPL was determined to be 216 µg/L based on the upper 97.5th percentile of results from 93 clinically healthy, kennel-housed dogs. CONCLUSIONS: Validation data demonstrated that the Spec cPL assay provides reproducible results for canine pancreas-specific lipase. A readily available assay for measurement of this enzyme allows broader clinical utilization of this analytical tool, generating timely results to aid in the diagnosis of canine pancreatitis.