Evaluation of selected cytokines in the assessment of canine Systemic Inflammatory Response Syndrome (SIRS): preliminary results

The quantification of circulating inflammatory biomarkers is relevant in the assessment of canine SIRS. The aim of this prospective study was to investigate the role of selected cytokines (IL6, IL8, IL10, IL15, MCP-1, GM-CSF; Millipore) during SIRS in dogs and their potential to differentiate sepsis from SIRS of non-infectious origin. Furthermore, a potential correlation between cytokines and other clinical and clinicopathological variables was investigated. Twenty dogs admitted to a Veterinary Teaching Hospital with a diagnosis of SIRS related to 3 different diseases (parvovirus, n=8; septic peritonitis, n=7; acute pancreatitis; n=5) were included. Ten blood donor dogs were included as healthy controls. Blood was collected upon admission by venipuncture, immediately processed at +4°C, and at least two aliquots of EDTA-plasma were stored at -80°C upon analysis. Additional laboratory analysis included measurement of C-reactive protein (CRP). Illness severity was calculated by the acute patient physiologic and laboratory evaluation fast score (APPLE). Cytokines were assayed by a multiparametric xMAP Luminex. CRP was assayed on serum using an immunoturbidimetric method on an automated chemistry analyzer. Results were analyzed by non-parametric statistic analysis. SIRS dogs have significantly higher serum CRP compared to controls (p<0.01). Among cytokines, only plasma IL6 concentrations were significantly different between SIRS and controls dogs (p<0.04). IL6 concentrations in SIRS dogs showed a significant positive correlation with APPLE (r=0.54, p=0.02) and AST (r=0.47, p=0.04), while a significant inverse correlation with Base Excess (r=-0.73, p=0.01) (n=11), serum iron (r=-0.5, p=0.03) and glucose (r=-0.48, p=0.04) was found. When comparing groups for different diseases, circulating IL6 levels were significantly higher in dogs with parvovirus and septic peritonitis compared to dogs with pancreatitis (p=0.04). Albumin, Antithrombin activity, APPLE, BE, glucose, IL10, lactate, total protein were all significantly different between survivors and non survivors (p<0.05). Preliminary results of this study indicate the potential prognostic significance of IL6 and IL10 in dogs with SIRS. Low number of cases included at present could have influenced the results which were borderline significant in case of IL8. A larger population is needed to define the prognostic values of these biomarkers and their ability to differentiate sepsis from SIRS of non-infectious origin.