title: Elevation of KL-6, a lung epithelial cell marker, in plasma and epithelial lining fluid in acute respiratory distress syndrome.
abstract: KL-6 is a pulmonary epithelial mucin more prominently expressed on the surface membrane of alveolar type II cells when these cells are proliferating, stimulated, and/or injured. We hypothesized that high levels of KL-6 in epithelial lining fluid and plasma would reflect the severity of lung injury in patients with acute lung injury (ALI). Epithelial lining fluid was obtained at onset (day 0) and day 1 of acute respiratory distress syndrome (ARDS)/ALI by bronchoscopic microsampling procedure in 35 patients. On day 0, KL-6 and albumin concentrations in epithelial lining fluid were significantly higher than in normal controls (P < 0.001), and the concentrations of KL-6 in epithelial lining fluid (P < 0.002) and in plasma (P < 0.0001) were higher in nonsurvivors than in survivors of ALI/ARDS. These observations were corroborated by the immunohistochemical localization of KL-6 protein expression in the lungs of nonsurvivors with ALI and KL-6 secretion from cultured human alveolar type II cells stimulated by proinflammatory cytokines. Because injury to distal lung epithelial cells, including alveolar type II cells, is important in the pathogenesis of ALI, the elevation of KL-6 concentrations in plasma and epithelial lining fluid could be valuable indicators for poor prognosis in clinical ALI.
authors.affiliation: Department of Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan. ishizaka@cpnet.med.keio.ac.jp
authors.forename: Akitoshi
authors.initials: A
authors.lastname: Ishizaka
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Matsuda
authors.forename: Kurt H
authors.initials: KH
authors.lastname: Albertine
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Koh
authors.forename: Sadatomo
authors.initials: S
authors.lastname: Tasaka
authors.forename: Naoki
authors.initials: N
authors.lastname: Hasegawa
authors.forename: Nobuoki
authors.initials: N
authors.lastname: Kohno
authors.forename: Toru
authors.initials: T
authors.lastname: Kotani
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Morisaki
authors.forename: Junzo
authors.initials: J
authors.lastname: Takeda
authors.forename: Morio
authors.initials: M
authors.lastname: Nakamura
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Fang
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Martin
authors.forename: Michael A
authors.initials: MA
authors.lastname: Matthay
authors.forename: Satoru
authors.initials: S
authors.lastname: Hashimoto
mesh_terms: D000328:Adult; D000368:Aged; D000941:Antigens / Q000097:blood*; D000951:Antigens, Neoplasm; D015415:Biomarkers; D001992:Bronchoalveolar Lavage Fluid; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D006023:Glycoproteins / Q000097:blood* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D018396:Mucin-1; D009077:Mucins; D011650:Pulmonary Alveoli / Q000378:metabolism / Q000473:pathology; D011654:Pulmonary Edema / Q000378:metabolism* / Q000473:pathology*; D012128:Respiratory Distress Syndrome / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D020545:Respiratory Mucosa / Q000378:metabolism / Q000473:pathology; D015996:Survival Rate
chemical_list: D000941:Antigens; D000951:Antigens, Neoplasm; D015415:Biomarkers; D006023:Glycoproteins; C060192:MUC1 protein, human; D018396:Mucin-1; D009077:Mucins