Association of Presence of Band Cells and Toxic Neutrophils with Systemic Inflammatory Response Syndrome and Outcome in Horses with Acute Disease

Abstract

BackgroundBand cells and toxic neutrophils are thought to indicate acute and severe systemic illness but no studies have investigated their importance in adult equine emergency admissions.ObjectivesThe objective of this study was to evaluate the association of band cells and toxic neutrophils with systemic inflammatory response syndrome (SIRS) and outcome in horses.AnimalsOne hundred and five adult horses admitted on emergency basis to a private primary referral practice.MethodsProspective observational study with sample collection. All horses admitted on emergency basis over the study period were included in the study if they had a CBC and a blood smear collected on admission.ResultsThe detection of band neutrophils on admission was associated with the SIRS status of the horse (RR = 2.80; 95% CI = 1.57–4.99; P < .001) and with poor outcome (RR = 1.88; 95% CI: 1.05–3.37; P = .038). Similarly, the presence of a neutrophil toxic grade higher than 3 was associated with SIRS (RR = 1.71; 95% CI: 1.03–2.82; P = .034) and death (RR = 2.34; 95% CI: 1.22–4.50, P = .007). The information gained from the blood smear review could not be captured by looking at only the WBC or neutrophil count.Conclusions and Clinical ImportanceThe microscopic review of blood smears from critically ill horses to detect band cells or neutrophil toxic change is valuable and could help in assessing disease severity and prognosis in adult equine emergency admissions.

Effect of time and storage on toxic or pseudo‐toxic change in canine neutrophils

“…In cats, the presence of toxic change in neutrophils is associated with longer hospitalizations, higher treatment costs, and, when combined with a left shift and neutrophilia or neutropenia, a higher risks of mortality . Similar findings are reported for dogs and horses . Therefore, blood smear evaluation for toxic change and other neutrophil abnormalities yields valuable prognostic information.…”

“…Although other, more sensitive inflammatory biomarkers (eg, acute phase proteins) are available, the presence of toxic neutrophil change is still a widely used clinical indicator of inflammation in dogs. Indeed, the presence of neutrophil toxicity has been associated with a poorer prognosis in numerous species . Therefore, it is essential to be aware of preanalytical variables that can affect the presence of toxic change.…”

“…Even though these observations seem to be common knowledge among trained veterinary clinical pathologists, we could not find any evidence of these in the scientific literature. Given the clinical importance of toxic change (including DBs) in the neutrophils of dogs and other species, it is essential that veterinarians are aware of any preanalytical variables that could cause artifactual change, which might be misidentified as true toxic change.…”

Prognostic Value and Development of a Scoring System in Horses With Systemic Inflammatory Response Syndrome

“…However, band neutrophils are indicators of acute and severe inflammatory response in horses, and we showed, in a previous smaller study, that band neutrophils and neutrophil toxic change are associated with outcome in adult equine emergency admissions. 35 Whether including band neutrophils in the equine SIRS definition would improve its clinical performance in defining SIRS in horses is unclear; however, this addition should likely be considered.…”

Highlights of recent clinically relevant papers

“…In this study J.L. Lambert and colleagues in Canada evaluated the association of band cells and toxic neutrophils with systemic inflammatory response syndrome (SIRS) and outcome in horses .…”