N-terminal pro-C-natriuretic peptide and cytokine kinetics in dogs with endotoxemia.

BACKGROUND: Serum N-terminal pro-C-natriuretic peptide (NT-proCNP) concentration at hospital admission has sufficient sensitivity and specificity to differentiate naturally occurring sepsis from nonseptic systemic inflammatory response syndrome (SIRS). However, little is known about serum NT-proCNP concentrations in dogs during the course of sepsis. OBJECTIVE: To determine serum NT-proCNP and cytokine kinetics in dogs with endotoxemia, a model of canine sepsis. SAMPLES: Eighty canine serum samples. METHODS: Eight healthy adult Beagles were randomized to receive Escherichia coli lipopolysaccharide (LPS, 5 µg/kg) or placebo (0.9% NaCl) as a single IV dose in a randomized crossover study. Serum collected at 0, 1, 2, 4, and 24 hours was stored at -80°C for batch analysis. Serum NT-proCNP was measured by ELISA and 13 cytokines and chemokines by multiplex magnetic bead-based assay. RESULTS: Serum NT-proCNP concentrations did not differ significantly between LPS- and placebo-treated dogs at any time. When comparing serum cytokine concentrations, LPS-treated dogs had higher interleukin-6 (IL-6), IL-10, TNF-α and KC-like at 1, 2, and 4 hours; higher CCL2 at 1, 2, 4, and 24 hours; and higher IL-8 and CXCL10 at 4 hours compared to placebo-treated dogs. There were no differences in serum GM-CSF, IFN-γ, IL-2, IL-7, IL-15 or IL-18 between LPS- and placebo-treated dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Serum NT-proCNP concentration does not change significantly in response to LPS administration in healthy dogs. Certain serum cytokine and chemokine concentrations are significantly increased within 1-4 hours after LPS administration and warrant further investigation as tools for the detection and management of sepsis in dogs.

Investigation of a commercial ELISA for the detection of canine procalcitonin.

BACKGROUND: Rapid identification of sepsis enables prompt administration of antibiotics and is essential to improve patient survival. Procalcitonin (PCT) is a biomarker used to diagnose sepsis in people. Commercial assays to measure canine PCT peptide have not been validated. OBJECTIVE: To investigate the validity of a commercially available enzyme-linked immunosorbent assay (ELISA) marketed for the measurement of canine PCT. ANIMALS: Three dogs with sepsis, 1 healthy dog, 1 dog with thyroid carcinoma. METHODS: Experimental study. The ELISA's ability to detect recombinant and native canine PCT was investigated and intra-assay and interassay coefficients of variability were calculated. Assay validation including mass spectrometry of the kit standard solution was performed. RESULTS: The ELISA did not consistently detect recombinant canine PCT. Thyroid lysate yielded a positive ELISA signal. Intra-assay variability ranged from 18.9 to 77.4%, while interassay variability ranged from 56.1 to 79.5%. Mass spectrometry of the standard solution provided with the evaluated ELISA kit did not indicate presence of PCT. CONCLUSIONS AND CLINICAL IMPORTANCE: The results of this investigation do not support the use of this ELISA for the detection of PCT in dogs.