Measurement and clinical applications of C-reactive protein in gastrointestinal diseases of dogs.

C-reactive protein (CRP) is a positive acute-phase protein, serum concentrations of which increase nonspecifically in response to inflammatory processes of the dog. As such, it can aid in the identification of inflammatory disease and, maybe more importantly, the objective monitoring of disease progression. In dogs, CRP is frequently used to evaluate dogs with gastrointestinal diseases, such as chronic inflammatory enteropathies (also termed idiopathic inflammatory bowel disease), acute pancreatitis, canine parvovirus infection, hepatic disease, acute abdomen, and protein-losing enteropathy. The diversity of the assays available to measure CRP in dogs is nearly as numerous as the diseases in which serum concentrations of this protein are increased. Assay methodologies include laser nephelometric immunoassays, enzyme-linked immunosorbent assays, immunoturbidimetric assays, and time-resolved immunofluorometric assays. While many of these assays are acceptable for clinical use in the dog, the same assay and analyzer should be used to measure a patient's CRP concentration longitudinally. By looking at the uses of CRP in human gastroenterology, including reducing the duration of antibiotic therapy, the veterinary profession can gain insight into novel ways in which serum CRP concentration measurements might be applied in veterinary medicine in the future.

Analytical validation of a point-of-care test and an automated immunoturbidimetric assay for the measurement of canine C-reactive protein in serum.

C-reactive protein (CRP) is an acute phase protein, which is used to evaluate and monitor the response of the innate immune system to a variety of inflammatory processes in the dog. The purpose of this study was to analytically validate a point-of-care assay (IDEXX Catalyst CRP Test) and an immunoturbidimetric assay (Gentian Canine CRP Immunoassay) for the measurement of serum CRP concentrations in dogs. These 2 assays (Catalyst, Gentian) were compared to a previously validated enzyme-linked immunosorbent assay (Tridelta Development EIA Canine CRP Assay). Linearity, precision, reproducibility, and accuracy were assessed using leftover serum samples. Agreement between assays was assessed using leftover serum samples and serum from clinically healthy dogs. Observed to expected ratios (O/E) for dilutional parallelism were 83.9 to 163.1% and 108.3 to 160.6% for the Catalyst and the Gentian assays, respectively. Coefficients of variation for intra-assay variability ranged from 6.4 to 9.5% for the Catalyst assay and 1.5 to 2.6% for the Gentian assay. Coefficients of variation for inter-assay variability ranged from 3.8 to 18.2% for the Catalyst assay and 4.5 to 5.8% for the Gentian assay. The mean O/E for recovery were 97.9% and 98.5% for the Catalyst and Gentian assays, respectively. Correlations between assays were as follows: Catalyst and Tridelta (R 2 = 0.76), Gentian and Tridelta (R 2 = 0.79), and Catalyst and Gentian (R 2 = 0.98). The Catalyst and Gentian assays are both acceptable for measuring CRP in dog serum, but their results are not directly comparable with the Tridelta assay.

La protéine C réactive (CRP) est une protéine de phase aiguë, qui est utilisée pour évaluer et surveiller la réponse du système immunitaire inné à une variété de processus inflammatoires chez le chien. Le but de cette étude était de valider analytiquement un test au point de service (test IDEXX Catalyst CRP) et un test immunoturbidimétrique (Gentian Canine CRP Immunoassay) pour la mesure des concentrations sériques de CRP chez le chien. Ces deux tests (Catalyst, Gentian) ont été comparés à un test immuno-enzymatique précédemment validé (Tridelta Development EIA Canine CRP Assay). La linéarité, la précision, la reproductibilité et l'exactitude ont été évaluées à l'aide d'échantillons de sérum restants. La concordance entre les tests a été évaluée à l'aide d'échantillons de sérum restants et de sérum provenant de chiens cliniquement sains. Les rapports observés/attendus (O/E) pour le parallélisme de dilution étaient de 83,9 à 163,1 % et de 108,3 à 160,6 % pour les tests Catalyst et Gentian, respectivement. Les coefficients de variation pour la variabilité intra-test variaient de 6,4 à 9,5 % pour le test Catalyst et de 1,5 à 2,6 % pour le test Gentian. Les coefficients de variation pour la variabilité inter-test variaient de 3,8 à 18,2 % pour le test Catalyst et de 4,5 à 5,8 % pour le test Gentian. L'O/E moyen pour la récupération était de 97,9 % et de 98,5 % pour les tests Catalyst et Gentian, respectivement. Les corrélations entre les tests étaient les suivantes : Catalyst et Tridelta (R 2 = 0,76), Gentian et Tridelta (R 2 = 0,79) et Catalyst et Gentian (R 2 = 0,98). Les tests Catalyst et Gentian sont tous deux acceptables pour mesurer la CRP dans le sérum de chien, mais leurs résultats ne sont pas directement comparables avec le test Tridelta.(Traduit par Docteur Serge Messier).