title: Oral neutrophils are an independent marker of the systemic inflammatory response after cardiac bypass.
abstract: BACKGROUND
  Cardiopulmonary bypass (CPB) is an immuno-reactive state where neutrophils are activated and accumulate in different tissues. Edema and tissue necrosis are the most common sequelae observed, predominantly in the lungs, kidneys, and heart, heralding significant risk for postoperative complications. No method exists to noninvasively assess in vivo neutrophil activity. The objective of this study was to determine if neutrophil recruitment to the oral cavity would correlate with specific biomarkers after coronary bypass surgery (CPB).
  
  
  METHODS
  We conducted a single site prospective observational study including non-consecutive adult patients undergoing elective, on-pump CPB. Blood and either oral cavity rinses or swabs were collected pre- and post-CPB. Absolute neutrophil counts from oral samples and serum biomarkers were measured. The association between neutrophil recruitment to the oral cavity, biomarkers and outcomes after CPB were analyzed.
  
  
  RESULTS
  CPB was associated with statistically significant increases in oral and blood neutrophil counts, as well as an increase in certain biomarkers over preoperative baseline. Peripheral blood neutrophil count were increased at all time points however statistically significant differences in median oral neutrophil counts were observed only at the time point immediately postoperative, and in what seems to be two unique patient populations (p < 0.001; group 1, median: 1.6×10(5), Interquartile range [IQR], 1.1×10(5) - 4.8×10(5), and group 2, median: 1.9×10(6), IQR, 8.7×10(5) - 4.0×10(6)).
  
  
  CONCLUSIONS
  CPB is associated with a transient increase in oral neutrophils that may correlate with the systemic inflammatory response; oral neutrophils may have the ability to discriminate and identify unique patient populations based on their tissue migration.
authors.affiliation: Interdepartmental Division of Critical Care, University Health Network, Toronto, Canada.
authors.forename: Mary Elizabeth
authors.initials: ME
authors.lastname: Wilcox
authors.affiliation: Division of Critical Care, Department of Medicine, University of Montreal, Montreal, Canada.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Charbonney
authors.affiliation: Interdepartmental Division of Critical Care, Trauma, Emergency and Critical Care Program, Sunnybrook Health Sciences Centre, Toronto, Canada.
authors.forename: Pablo Perez
authors.initials: PP
authors.lastname: d'Empaire
authors.affiliation: Interdepartmental Division of Critical Care, Trauma, Emergency and Critical Care Program, Sunnybrook Health Sciences Centre, Toronto, Canada.
authors.forename: Abhijit
authors.initials: A
authors.lastname: Duggal
authors.affiliation: Interdepartmental Division of Critical Care, Trauma, Emergency and Critical Care Program, Sunnybrook Health Sciences Centre, Toronto, Canada.
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Pinto
authors.affiliation: Faculty of Dentistry, University of Toronto, Matrix Dynamics Group, Toronto, Canada.
authors.forename: Ashkan
authors.initials: A
authors.lastname: Javid
authors.affiliation: Interdepartmental Division of Critical Care, St. Michael's Hospital, Keenan Research Centre of Li Ka Shing Knowledge Institute, Toronto, Canada.
authors.forename: Claudia
authors.initials: C
authors.lastname: Dos Santos
authors.affiliation: Interdepartmental Division of Critical Care, Trauma, Emergency and Critical Care Program, Sunnybrook Health Sciences Centre, Toronto, Canada.
authors.forename: Gordon David
authors.initials: GD
authors.lastname: Rubenfeld
authors.affiliation: Department of Dentistry, Sunnybrook Health Sciences Centre, Toronto, Canada.
authors.forename: Susan
authors.initials: S
authors.lastname: Sutherland
authors.affiliation: Division of Allergy and Infectious Disease, University of Washington, Seattle, USA.
authors.forename: Wayne Conrad
authors.initials: WC
authors.lastname: Liles
authors.affiliation: Faculty of Dentistry, University of Toronto, Matrix Dynamics Group, Toronto, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Glogauer
keywords: Biomarkers; Coronary bypass; Critical illness; Multiple organ failure; Neutrophil activation