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Pneumocyte injury and ubiquitin‐positive pneumocytes in interstitial lung diseases
Author(s) -
Yamada Tsutomu,
Kawabata Yoshinori
Publication year - 2015
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.12528
Subject(s) - pathology , lung , immunostaining , hyaline , usual interstitial pneumonia , granulation tissue , ubiquitin , biology , fibrosis , bronchiole , immunohistochemistry , interstitial pneumonia , medicine , immunology , biochemistry , wound healing , gene
Pneumocyte injury is a characteristic of pulmonary interstitial pneumonias ( IP s). Histological markers of pneumocyte injury and inflammation include pneumocyte necrosis, erosion, hyaline membrane and fibrin exudation with subsequent intraluminal granulation tissue formation. We found that intracytoplasmic inclusions in pneumocytes are ubiquitin‐positive (Ub + ) and that the number of Ub + pneumocytes shows positive correlation with the extent of diffuse alveolar damage ( DAD ). To determine the role of Ub + pneumocytes and inclusions in IP s, we studied their relationship with pathological and clinical features of DAD , usual interstitial pneumonia ( UIP ) and organizing pneumonia ( OP ), including airspace enlargement with fibrosis ( AEF ). We analysed Ub + pneumocytes, inclusions, erosions and intraluminal granulation tissue in relation to pneumocyte injury. The numbers of immunohistochemically identified Ub + inclusions in each IP were higher than the number of inclusions detected by light microscopy. The inclusions detected by Ub + immunostaining were identical to the inclusions observed by light microscopy. UIP and DAD had many Ub + inclusions, while OP and AEF had fewer Ub + inclusions. These results suggest that the extent of Ub + inclusions reflects the severity of pneumocyte injury among IP s. Thus, Ub + inclusions are a histological marker of pneumocyte injury that may be helpful in determining the severity and prognosis of IP s.