NEUTROPHIL TO LYMPHOCYTE RATIO IN CANINE SYSTEMIC INFLAMMATORY RESPONSE SYNDROME

Introduction: The neutrophil to lymphocyte ratio (NLR) has been proposed as a readily accessible and independent predictor parameter of poor survival in human patients with tumors, cardiovascular diseases, and critically illness. As far as we know NLR has been evaluated only in oncological veterinary patients. Objective: To evaluate NLR in dogs with systemic inflammatory response syndrome (SIRS) and its association with the severity of illness, outcome, and sepsis. BLR (band neutrophil-to-lymphocyte ratio) and BLNR (band-to-neutrophil-to-lymphocyte ratio) were evaluated as well. Methods: Data were retrospectively collected and enrolled animals subsequently divided in 3 groups: 90 with SIRS, 50 healthy, and 50 with chronic diseases as control groups. A SIRS grading was obtained based on how many criteria were fulfilled. The APPLEfast score was applied to the SIRS group. The survival rate was assessed at day 7 and 15 after their admission. Dogs with cytology or positive culture for active bacterial infections were recorded as septic. Mann–Whitney U-test, Kruskal–Wallis test, and Dunn’s multiple comparison test were used to compare groups using statistical software. Results: In the SIRS group, 39 dogs (43%) died during the study period. APPLEfast score > 25 (P = 0.03) and SIRS grading > 2 (P = 0.001) were associated with poor outcome. NLR was higher in the SIRS group compared to the control groups (P < 0.0001 and P < 0.0001, respectively) and not associated with outcome. NLR was not statistically different between SIRS grading groups or APPLEfast score groups. NLR was lower in septic dogs than in nonseptic group (P = 0.016). Dogs with SIRS grading > 2 showed a higher BLR than dogs with SIRS grading = 2 (P = 0.04). Any association of BLR and BLNR with outcome, sepsis and APPLEfast groups was found. Conclusions: Our results demonstrate the utility of NLR evalua- tion in dogs with SIRS (higher) and in septic dogs (lower). Further prospective, large-scale studies investigating the role of BLR and BLNR in canine SIRS are warranted.