Plasma Inflammatory Mediator Concentrations at ICU Admission in Dogs with Naturally Developing Sepsis

Background Identifying biomarkers to aide in the diagnosis and prognostication of sepsis in dogs would be valuable to veterinarians. Objective To compare plasma inflammatory mediator concentrations among dogs with sepsis, noninfectious systemic inflammatory response syndrome (NSIRS), and healthy dogs. Animals Dogs with sepsis (n similar to 22), NSIRS (n similar to 23), and healthy dogs (n similar to 13) presenting to the intensive care unit (ICU) at a veterinary teaching hospital. Methods Prospective observational study. Clinical parameters were recorded for each dog and plasma tumor necrosis factor (TNF) bioactivity and concentrations of interleukin (IL)-6, CXC chemokine ligand (CXCL)-8 and IL-10 were determined at ICU presentation. Results Dogs with sepsis and NSIRS were significantly more likely to have measurable TNF activity (sepsis 20/22; NSIRS 19/20; healthy 0/13) and IL-6 concentration (sepsis 12/22; NSIRS 15/23; healthy 2/13), than healthy dogs. Healthy dogs (9/13) were significantly more likely to have measurable plasma IL-10 concentrations than dogs with sepsis (4/19), but not NSIRS (7/20). None of the inflammatory mediators evaluated had optimal sensitivity or specificity for the diagnosis of sepsis. Twelve of 22 dogs with sepsis and 15/23 dogs with NSIRS survived to discharge; none of the measured biomarkers correlated with survival to discharge. Conclusions and Clinical Importance Sepsis and NSIRS are associated with increased production of the proinflammatory cytokines TNF and IL-6. In addition, sepsis is associated with decreased production of the anti-inflammatory cytokine IL-10. Despite this, plasma TNF, IL-6, CXCL-8, and IL-10 measured at ICU presentation do not appear to be valuable biomarkers to differentiate sepsis from NSIRS, or predict hospital outcome.