title: Expression of acute-phase cytokines, surfactant proteins, and epithelial apoptosis in small airways of human acute respiratory distress syndrome.
abstract: OBJECTIVE
  Recent studies suggest a role for distal airway injury in acute respiratory distress syndrome (ARDS). The epithelium lining the small airways secretes a large number of molecules such as surfactant components and inflammatory mediators. There is little information on how these small airway secretory functions are altered in ARDS.
  
  
  METHODS
  We studied the lungs of 31 patients with ARDS (Pao(2)/fraction of inspired oxygen ≤200, 45 ± 14 years, 16 men) and 11 controls (52 ± 16 years, 7 men) submitted to autopsy and quantified the expression of interleukin (IL) 6, IL-8, surfactant proteins (SP) A and SP-B in the epithelium of small airways using immunohistochemistry and image analysis. In addition, an index of airway epithelial apoptosis was determined by the terminal deoxynucleotidyl transferase-mediated deoxyuridine-triphosphatase nick-end labeling assay, caspase 3, and Fas/Fas ligand expression. The density of inflammatory cells expressing IL-6 and IL-8 within the small airway walls was also quantified.
  
  
  RESULTS
  Acute respiratory distress syndrome airways showed an increase in the epithelial expression of IL-8 (P = .006) and an increased density of inflammatory cells expressing IL-6 (P = .004) and IL-8 (P < .001) compared with controls. There were no differences in SP-A and SP-B epithelium expression or in epithelial apoptosis index between ARDS and controls.
  
  
  CONCLUSIONS
  Distal airways are involved in ARDS lung inflammation and show a high expression of proinflammatory interleukins in both airway epithelial and inflammatory cells. Apoptosis may not be a major mechanism of airway epithelial cell death in ARDS.
authors: Department of Pathology, Experimental Air Pollution Laboratory-LIM05, Sao Paulo University Medical School, 01246903 Sao Paulo, Brazil. ruy@usp.br
authors: Ruy Camargo
authors: RC
authors: Pires-Neto
authors: Maina Maria Barbosa
authors: MM
authors: Morales
authors: Tatiana
authors: T
authors: Lancas
authors: Nicole
authors: N
authors: Inforsato
authors: Maria Irma Seixas
authors: MI
authors: Duarte
authors: Marcelo Britto Passos
authors: MB
authors: Amato
authors: Carlos Roberto Ribeiro
authors: CR
authors: de Carvalho
authors: Luiz Fernando Ferraz
authors: LF
authors: da Silva
authors: Thais
authors: T
authors: Mauad
authors: Marisa
authors: M
authors: Dolhnikoff
mesh_terms: D000209:Acute-Phase Proteins / Q000378:metabolism*; D017209:Apoptosis; D016022:Case-Control Studies; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D037662:Pulmonary Surfactant-Associated Protein A / Q000378:metabolism; D037701:Pulmonary Surfactant-Associated Protein B / Q000378:metabolism; D037661:Pulmonary Surfactant-Associated Proteins / Q000378:metabolism*; D012128:Respiratory Distress Syndrome / Q000473:pathology*; D020545:Respiratory Mucosa / Q000378:metabolism*; D012189:Retrospective Studies
chemical_list: D000209:Acute-Phase Proteins; D016207:Cytokines; D015850:Interleukin-6; D016209:Interleukin-8; D037662:Pulmonary Surfactant-Associated Protein A; D037701:Pulmonary Surfactant-Associated Protein B; D037661:Pulmonary Surfactant-Associated Proteins