Biological variability of C-reactive protein and specific canine pancreatic lipase immunoreactivity in apparently healthy dogs.

TitleBiological variability of C-reactive protein and specific canine pancreatic lipase immunoreactivity in apparently healthy dogs.
Publication TypeJournal Article
Year of Publication2011
AuthorsCarney PC, Ruaux CG, Suchodolski JS, Steiner JM
JournalJournal of veterinary internal medicine / American College of Veterinary Internal Medicine
Volume25
Issue4
Pagination825-30
Date Published2011 Jul-Aug
ISSN1939-1676
KeywordsAnimals, C-Reactive Protein, Cohort Studies, Dogs, Female, Lipase, Male, Prospective Studies, Reference Values, Statistics, Nonparametric
Abstract

BACKGROUND: C-reactive protein (CRP) and specific canine pancreatic lipase immunoreactivity (Spec cPL) are biomarkers of generalized or nonspecific inflammation and pancreatic inflammation in dogs, respectively. The extent of inter- and intraindividual variation over time of these analytes is not well defined in dogs. The minimal critical difference for sequential determinations of these markers (ie, the smallest change necessary to represent physiological change rather than biological variation), has not been defined.

OBJECTIVES: To determine the inter- and intraindividual variability (CV(G) and CV(I) ) and minimal critical difference for sequential determinations of serum CRP and Spec cPL concentrations in apparently healthy dogs.

ANIMALS: Eleven apparently healthy dogs owned by staff or students at a veterinary teaching hospital.

METHODS: Blood was collected repeatedly at varying intervals over 12 weeks. CRP and Spec cPL concentrations were determined with commercially available assays. Indices of inter-, intraindividual, and assay variability and 1-sided minimal critical differences for sequential concentrations were calculated.

RESULTS: For CRP, CV(G) was 90.8%, CV(I) was 115.5%, and the analytical variability (CV(A) ) was 6.3%; the index of individuality was 0.74, and 1-sided critical difference was 269.9%. For Spec cPL, CV(G) = 49.48%, CV(I) = 193.8%, CV(A) = 8.4%, index of individuality = 0.24, and 1-sided critical difference was 452.6%.

CONCLUSIONS AND CLINICAL IMPORTANCE: A population-based reference range is appropriate for Spec cPL, but questionable for CRP in dogs. Large changes in serial measurements of Spec cPL are necessary to infer clinical importance, more modest changes in CRP are likely to be meaningful.

DOI10.1111/j.1939-1676.2011.0729.x
Alternate JournalJ. Vet. Intern. Med.