Upregulation of reactive oxygen species generation and phagocytosis, and increased apoptosis in human neutrophils during severe sepsis and septic shock

• Published in: Shock (Augusta, Ga.) Ga.), 2003-09, Vol.20 (3), p.208-212
• Main Authors: Martins, Paulo Sergio, Kallas, Esper Georges, Neto, Miguel Cendoroglo, Dalboni, Maria Aparecida, Blecher, Sérgio, Salomão, Reinaldo
• Format: Article
• Language: English
• Subjects: Annexin A5 - pharmacology; Apoptosis; Coloring Agents - pharmacology; Enzyme Inhibitors - pharmacology; Fluoresceins - pharmacology; Humans; Lipopolysaccharides - pharmacology; N-Formylmethionine Leucyl-Phenylalanine - pharmacology; Neutrophils - pathology; Phagocytosis; Propidium - pharmacology; Reactive Oxygen Species; Respiratory Burst; Sepsis - pathology; Shock - pathology; Staphylococcus aureus - metabolism; Up-Regulation
• ISSN: 1073-2322
• DOI: 10.1097/01.shk.0000079425.52617.db

We evaluated neutrophil activation by measuring its phagocytic ability and oxidative burst activity in 16 patients with sepsis and 16 healthy volunteers. We also focused on neutrophil apoptosis as a regulatory mechanism of the inflammatory response. Neutrophil phagocytosis was evaluated by the detection of propidium iodide (PI)-labeled Staphylococcus aureus added to whole blood. Reactive oxygen species (ROS) formation was quantified by measuring the oxidation of 2',7' dichlorofluorescein diacetate (DCFH-DA) at baseline and after cell stimulation with phorbol myristate acetate (PMA), and bacterial cells (killed S. aureus) or products (lipopolysaccharide [LPS] and N-formyl-methionyl-leucyl-phenylalanine [FMLP]). Apoptosis was assessed in neutrophils stained with annexin V and PI. Neutrophil phagocytic ability was increased in patients with sepsis compared with healthy controls (median geometric mean fluorescence intensity [GMFI] was 101.9 and 54.7, respectively; P = 0.05). ROS formation was enhanced in patients with sepsis compared with healthy volunteers at baseline (median GMFI 275.6 and 52.1, respectively; P < 0.001), and after stimulation with S. aureus (median GMFI 2395.8 and 454.9, respectively; P < 0.001), PMA (median GMFI 1120.6 and 307.5, respectively; P = 0.003), FMLP (median GMFI 792.4 and 123.2, respectively; P < 0.001), and LPS (median GMFI 624.8 and 144.8, respectively; P < 0.001). Early neutrophil apoptosis was increased in patients with sepsis compared with healthy volunteers (median 11.3% and 9.1%, respectively; P = 0.03). These data demonstrate that neutrophil function is enhanced in patients with sepsis. Additionally, circulating neutrophils from patients with sepsis presented with increased early apoptosis, which may be consequence of a regulatory mechanism of the inflammatory response.