title: Clinicopathological features of chronic hypersensitivity pneumonitis.
abstract: OBJECTIVE
  Only limited information exists concerning the clinical and pathological features of chronic hypersensitivity pneumonitis (HP) in Japan and elsewhere. We present data on clinicopathological features of chronic HP obtained through a Japanese nationwide survey.
  
  
  METHODS
  We studied the clinical and pathological findings in 10 patients with chronic HP who underwent surgical lung biopsy or postmortem examination.
  
  
  RESULTS
  There were three types of clinical course: six of the 10 patients had persistent symptoms followed by repeated acute episodes; two showed a subacute onset with persistent symptoms; and two exhibited an insidious onset. Five patients made no attempt to avoid antigen exposure and they all had progressive disease. Pathological findings indicated that lesions were mainly centrilobular with or without epithelioid cell granulomas in specimens obtained during the acute or subacute stage. In contrast, most patients in the chronic stage predominantly showed interstitial fibrosis with a usual interstitial pneumonia pattern.
  
  
  CONCLUSIONS
  The pathological findings of chronic HP depend on the stage of the disease at tissue sampling.
authors.affiliation: Department of Internal Medicine, National Tenryu Hospital, Hamakita, Japan. hayakawh@tenryuu.hosp.go.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hayakawa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shirai
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Sato
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yoshizawa
authors.forename: Akihito
authors.initials: A
authors.lastname: Todate
authors.forename: Shiro
authors.initials: S
authors.lastname: Imokawa
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suda
authors.forename: Kingo
authors.initials: K
authors.lastname: Chida
authors.forename: Ryoji
authors.initials: R
authors.lastname: Tamura
authors.forename: Kyousuke
authors.initials: K
authors.lastname: Ishihara
authors.forename: Shigeki
authors.initials: S
authors.lastname: Saiki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ando
mesh_terms: D000368:Aged; D000542:Alveolitis, Extrinsic Allergic / Q000175:diagnosis / Q000276:immunology / Q000473:pathology*; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010784:Photomicrography; D011658:Pulmonary Fibrosis / Q000473:pathology