title: Defective efferocytosis by alveolar macrophages in IPF patients.
abstract: BACKGROUND
  Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrosing interstitial pneumonia. The pathogenicity of IPF has been widely investigated but still remains to be clarified. Efferocytosis, the specialized recognition and ingestion of apoptotic cells by phagocytes, is essential for the resolution of inflammation in the lungs and repair of injured tissues. Impaired efferocytosis contributes to the pathogenesis of chronic lung diseases such as emphysema and cystic fibrosis. We hypothesized that efferocytosis would also be reduced in alveolar macrophages isolated from subjects with IPF.
  
  
  METHODS
  Efferocytosis, was evaluated using Wright-Giemsa stained cell preparations isolated from the bronchoalveolar lavage (BAL) fluid of patients with IPF (n = 5), nonspecific interstitial pneumonitis (n = 6), cryptogenic organizing pneumonia (n = 4) and eosinophilic pneumonia (EP) (n = 5).
  
  
  RESULTS
  Uningested apoptotic cells were significantly higher in BAL fluid from patients with IPF compared to other forms of interstitial lung disease. Macrophages isolated from patients with eosinophilic pneumonia had significantly fewer phagocytic ingestions than macrophages from the other three groups.
  
  
  CONCLUSIONS
  Efferocytosis by alveolar macrophages was significantly lower in subjects with IPF compared to subjects with other interstitial pneumonia. Dysregulated efferocytosis may contribute to the pathogenesis of IPF.
authors.affiliation: Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan. komorimo@nagasaki-u.ac.jp
authors.forename: Konosuke
authors.initials: K
authors.lastname: Morimoto
authors.forename: William J
authors.initials: WJ
authors.lastname: Janssen
authors.forename: Mayumi
authors.initials: M
authors.lastname: Terada
mesh_terms: D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D018549:Cryptogenic Organizing Pneumonia / Q000473:pathology; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000473:pathology*; D016676:Macrophages, Alveolar / Q000502:physiology*; D010587:Phagocytosis / Q000502:physiology*; D011657:Pulmonary Eosinophilia / Q000473:pathology