Neutrophil function in septic dogs.
BACKGROUND
Leukocytes appear to enter a hypo-inflammatory state in human patients with a severe bacterial infection, whereas, in swine, intra-abdominal sepsis produces an initial increase and subsequent decrease in neutrophil Fc receptor mediated phagocytosis.


OBJECTIVE
Impaired neutrophil function (hypo-inflammatory state) develops in dogs with sepsis.


METHODS
Thirteen adult client-owned dogs that developed clinical signs consistent with sepsis were assessed for evidence of neutrophil dysfunction. These results were compared with those of 12 healthy dogs.


METHODS
Flow cytometry combined with the appropriate fluorescent markers allowed for quantification of the phagolysosomal oxidative burst after Fc receptor-mediated phagocytosis of immune complexes, neutrophil phagocytosis of opsonized Escherichia coli, and the intracellular concentration of reduced glutathione as a measure of oxidative stress.


RESULTS
The phagolysosomal oxidative burst after Fc receptor-mediated phagocytosis was significantly lower in neutrophils from septic dogs (mean fluorescence intensity +/- standard deviation; 118 +/- 13 and 165 +/- 27 for septic and control dogs, respectively, p = 0.001), although the phagocytosis of opsonized E. coli was significantly increased (155 +/- 74 and 77 +/- 44 for septic and control dogs, respectively, p = 0.004). Intracellular reduced glutathione was not significantly different in neutrophils from septic and healthy control dogs.


CONCLUSIONS
An important component of neutrophil function is decreased in septic dogs. The diminished oxidative burst after Fc receptor-mediated phagocytosis in neutrophils from septic dogs could hinder the ability of the innate immune system to clear bacterial infections or it might help protect these patients from the systemic consequences of infection.
Webb
Craig
C
Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Ft Collins, CO 80523, USA. cbwebb@colostate.edu
McCord
Kelly
K
Dow
Steven
S
D000818:Animals; D004283:Dog Diseases / Q000097:blood / Q000276:immunology* / Q000628:therapy; D004285:Dogs; D005260:Female; D005434:Flow Cytometry / Q000662:veterinary; D005978:Glutathione / Q000097:blood; D008297:Male; D009504:Neutrophils / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology; D016897:Respiratory Burst / Q000276:immunology; D018805:Sepsis / Q000276:immunology / Q000628:therapy / Q000662:veterinary*
D005978:Glutathione