title: Alveolar fibrocyte percentage is an independent predictor of poor outcome in patients with acute lung injury.
abstract: OBJECTIVE
  Fibrocytes are mesenchymal progenitors involved in normal and pathologic repair. The aims of this study were: 1) to quantify fibrocytes in bronchoalveolar lavage fluid from patients with or without acute lung injury and acute respiratory distress syndrome; and 2) to evaluate the prognostic value of bronchoalveolar lavage fibrocyte percentage in patients with acute lung injury and acute respiratory distress syndrome.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Three intensive care units of a large tertiary referral center.
  
  
  METHODS
  One hundred twenty-two ventilated patients requiring bronchoalveolar lavage were enrolled (62 acute respiratory distress syndrome, 30 acute lung injury, 30-ventilated patients without acute lung injury and acute respiratory distress syndrome).
  
  
  METHODS
  After bronchoalveolar lavage collection during standard care, the patients were followed up for 28 days and clinical outcome was recorded. Fibrocytes (CD45+/collagen 1+) were quantified in bronchoalveolar lavage by flow cytometry. Comparison of bronchoalveolar lavage fibrocyte percentage from patients with or without acute lung injury and acute respiratory distress syndrome was performed using a Wilcoxon test. A multivariate analysis using a Cox model was performed to study the independent predictors of survival.
  
  
  RESULTS
  Fibrocytes were detected in 90 of 92 (98%) bronchoalveolar lavages from patients with acute lung injury and acute respiratory distress syndrome. The median percentage of bronchoalveolar lavage fibrocytes was significantly higher in patients with acute lung injury and acute respiratory distress syndrome (5.0%) in comparison with ventilated control subjects (0.9%, p < .0001). After adjustment for age, comorbidity of malignancy, and severity of illness, a bronchoalveolar lavage fibrocyte percentage >6% was independently associated with a higher 28-day mortality in patients with acute lung injury and acute respiratory distress syndrome (hazard ratio [95% confidence interval] 6.15 [2.78-13.64], p ≤ .0001). Addition of bronchoalveolar lavage fibrocyte percentage in a clinical model predicting mortality in patients with acute lung injury and acute respiratory distress syndrome improved global fit and discriminatory capacity (c-statistic, 0.78-0.85; p = .007).
  
  
  CONCLUSIONS
  Fibrocytes are detectable in bronchoalveolar lavage during acute lung injury and acute respiratory distress syndrome. A bronchoalveolar lavage fibrocyte percentage >6% provides an additive prognostic value to clinical predictors and may be useful to identify patients with acute lung injury and acute respiratory distress syndrome at highest risk of an adverse outcome.
authors.affiliation: Inserm, Unité 700, Université Paris 7 Denis Diderot, Paris, France. christophe.quesnel@tnn.aphp.fr
authors.forename: Christophe
authors.initials: C
authors.lastname: Quesnel
authors.forename: Pascale
authors.initials: P
authors.lastname: Piednoir
authors.forename: Julien
authors.initials: J
authors.lastname: Gelly
authors.forename: Laurent
authors.initials: L
authors.lastname: Nardelli
authors.forename: Marc
authors.initials: M
authors.lastname: Garnier
authors.forename: Véronique
authors.initials: V
authors.lastname: Leçon
authors.forename: Sigismond
authors.initials: S
authors.lastname: Lasocki
authors.forename: Lila
authors.initials: L
authors.lastname: Bouadma
authors.forename: Ivan
authors.initials: I
authors.lastname: Philip
authors.forename: Carole
authors.initials: C
authors.lastname: Elbim
authors.forename: France
authors.initials: F
authors.lastname: Mentré
authors.forename: Paul
authors.initials: P
authors.lastname: Soler
authors.forename: Bruno
authors.initials: B
authors.lastname: Crestani
authors.forename: Monique
authors.initials: M
authors.lastname: Dehoux
mesh_terms: D055371:Acute Lung Injury / Q000175:diagnosis* / Q000473:pathology; D000367:Age Factors; D000368:Aged; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011650:Pulmonary Alveoli / Q000166:cytology* / Q000473:pathology; D012121:Respiration, Artificial; D012128:Respiratory Distress Syndrome / Q000175:diagnosis / Q000473:pathology; D016896:Treatment Outcome