title: Acute exacerbation of idiopathic pulmonary fibrosis: role of Chlamydophila pneumoniae infection.
abstract: OBJECTIVE
  Patients with idiopathic pulmonary fibrosis (IPF) may experience acute exacerbations of their illness. The actual trigger(s) of such exacerbations is unknown. Chlamydophila pneumoniae infection can cause exacerbation of asthma and COPD. A prospective study was conducted to investigate the possible role of C. pneumoniae infection in triggering acute exacerbations of IPF.
  
  
  METHODS
  A prospective observational study over 5 years of consecutive IPF patients who fulfilled the criteria for acute exacerbation. Sputum, blood cultures and acute and convalescent serology for C. pneumoniae IgG and IgA (ELISA) were performed.
  
  
  RESULTS
  Previous infection with C. pneumoniae is common. Of the 27 study patients, 15 had a C. pneumoniae IgG index of 1.10-2.99 (positive) and 3 had a C. pneumoniae IgG index of >2.99 (strongly positive) at the time of presentation with an acute exacerbation. In addition, 15 subjects had a C. pneumoniae IgA index of 1.10-2.99 (positive) and 6 subjects had a C. pneumoniae IgA index of >2.99 (strongly positive). However, only two of the 15 subjects (13%) for whom paired sera were tested exhibited a significant rise in antibody response (change in index of 1.90 for C. pneumoniae IgG and 1.54 for IgA, respectively) indicating either acute or reactivated infection with C. pneumoniae. There were 15 deaths (56%) despite supportive care that included high-dose corticosteroid therapy and oxygen supplementation.
  
  
  CONCLUSIONS
  Mortality is high with acute exacerbation of IPF. Acute infection with C. pneumoniae is uncommon at the time of presentation with acute exacerbation of IPF.
authors.affiliation: Department of Respiratory Medicine, Nishi-Kobe Medical Center, Nishi-ku, Kobe, Japan. htomy@kobe-nishishimin-hospi.jp
authors.forename: Hiromi
authors.initials: H
authors.lastname: Tomioka
authors.forename: Toshiyasu
authors.initials: T
authors.lastname: Sakurai
authors.forename: Kimio
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Hironobu
authors.initials: H
authors.lastname: Iwasaki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000032:analysis; D023521:Chlamydophila Infections / Q000150:complications* / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000401:mortality; D016993:Chlamydophila pneumoniae / Q000276:immunology; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage; D008875:Middle Aged; D011446:Prospective Studies; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D014057:Tomography, X-Ray Computed
chemical_list: D000907:Antibodies, Bacterial; D005938:Glucocorticoids; D008775:Methylprednisolone