Oral neutrophils are an independent marker of the systemic inflammatory response after cardiac bypass

Mary Elizabeth Wilcox,Claudia Dos Santos,Michael Glogauer,Abhijit Duggal,Susan Sutherland,Ruxandra Pinto,Pablo Perez D’Empaire,Wayne Conrad Liles,Emmanuel Charbonney,Ashkan Javid,Gordon David Rubenfeld

doi:10.1186/s12950-014-0032-5

Abstract

BackgroundCardiopulmonary 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).MethodsWe 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.ResultsCPB 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: 1.6×105, Interquartile range [IQR], 1.1×105 - 4.8×105, and group 2, median: 1.9×106, IQR, 8.7×105 - 4.0×106).ConclusionsCPB 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.

Highlights

The innate immune system provides the host with an immediate but non-specific response to infection
Cardiopulmonary bypass (CPB) is an immunoreactive state, where polymorphonuclear (PMN) cells are activated through contact with the synthetic surfaces of the bypass circuit, mechanical shear stress and hemodilution, [3,4,5,6] and as a result accumulate in different tissues
Oral and blood neutrophil counts increased immediately after CPB, oral neutrophil counts return to baseline by day 3 whereas peripheral circulating neutrophil counts remained elevated at day 7

Summary

Introduction

The innate immune system provides the host with an immediate but non-specific response to infection. The systemic inflammatory response system (SIRS) is a complex clinical syndrome involving complement activation, Coronary artery bypass grafting (CABG) is a wellestablished treatment for ischemic heart disease. It is traditionally performed using cardiopulmonary bypass (CPB), termed “on-pump CABG”. Similar such studies have shown a significant and persistent increase in lymphocytes and neutrophils postoperatively in on-pump CPB patients when compared to off-pump CPB patients [8] This widespread PMN activation generates an abundance of oxygen and hydroxyl free radicals that can exacerbate the release of granular constituents such as elastase and myeloperoxidase into surrounding tissues. 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)

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Conclusion