title: Neutrophil extracellular traps in bronchial aspirates: a quantitative analysis.
abstract: Neutrophil extracellular traps (NETs) are structures composed of DNA and granular proteins, which rapidly trap and kill pathogens. The formation of NETs has been detected during infection in animal experiments, but their role in humans is unclear. The purposes of this study were to quantitatively evaluate the production of NETs during acute respiratory infection and to study the relationship between the NET length and various inflammatory mediators. We examined bronchial aspirates collected from nine intubated patients in an intensive care unit. Samples were collected at the onset of acute respiratory infection (day 0) and on days 1, 3-5, and 6-8. The NET length was visualised by immunohistochemistry and quantified using computer tracing software. The NET length was measured and compared at each time point. The length differed significantly between time points (p<0.001). NETs were significantly longer on day 1 than on day 0 (p<0.001). Neutrophils released NETs abundantly in response to respiratory infection and regression analysis showed that NET length correlated with six clinical parameters (white blood cells, platelets, lactate, CXC ligand-2, interleukin-8, and procalcitonin) as the explanatory variables. NETs in bronchial aspirates may reflect disease progression of respiratory infections. Quantification of NETs in bronchial aspirates may provide a new indicator of inflammation.
authors.affiliation: Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka Both authors contributed equally.
authors.forename: Shigeto
authors.initials: S
authors.lastname: Hamaguchi
authors.affiliation: Dept of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Osaka Both authors contributed equally.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Hirose
authors.affiliation: Dept of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Osaka.
authors.forename: Naoya
authors.initials: N
authors.lastname: Matsumoto
authors.affiliation: International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Akeda
authors.affiliation: Dept of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Osaka.
authors.forename: Taro
authors.initials: T
authors.lastname: Irisawa
authors.affiliation: Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Seki
authors.affiliation: Dept of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Osaka.
authors.forename: Hideo
authors.initials: H
authors.lastname: Hosotsubo
authors.affiliation: Dept of Medical Innovation, Osaka University Hospital, Osaka.
authors.forename: Kouji
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Dept of Emergency Medicine, and Unit of Clinical Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Tasaki
authors.affiliation: International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Oishi
authors.affiliation: Dept of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Osaka.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimazu
authors.affiliation: Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka tomono@hp-infect.med.osaka-u.ac.jp.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Tomono
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001980:Bronchi / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D002648:Child; D004247:DNA / Q000737:chemistry; D018450:Disease Progression; D065206:Extracellular Traps; D005260:Female; D006657:Histones / Q000737:chemistry; D006801:Humans; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology* / Q000378:metabolism; D012141:Respiratory Tract Infections / Q000378:metabolism; D013997:Time Factors
chemical_list: D006657:Histones; D004247:DNA