title: Acute exacerbation of IPF following diagnostic bronchoalveolar lavage procedures.
abstract: BACKGROUND
  Bronchoalveolar lavage (BAL) is generally regarded as a safe diagnostic procedure. However, acute exacerbation after BAL is increasingly recognized as a specific complication for patients with idiopathic pulmonary fibrosis (IPF). So far little is known about the correlation between BAL and acute exacerbation of IPF (AE-IPF).
  
  
  METHODS
  A cohort of 112 IPF patients at a single institution was analyzed retrospectively. We defined BAL-related AE-IPF as development of AE-IPF within 30 days after the procedure. The incidence rate of AE-IPF per person-month during the post-BAL period was compared with that after the post-BAL period. The relative risk was estimated as the former rate divided by the latter. We also reviewed the previous literature.
  
  
  RESULTS
  Four AE-IPF cases occurred during the 201 person-month post-BAL period. The risk of AE-IPF was significantly elevated within 30 days after BAL (rate ratio = 4.12; 95% CI = 1.03-12.2). None of the 111 initial BAL procedures were followed by AE-IPF within a month. In a post hoc analysis, the relative risk of developing AE after second or later BAL procedures was estimated to be considerably higher (rate ratio = 9.10; 95% CI = 2.27-26.98). Twelve cases of BAL-induced AE-IPF were found in our study and in the literature review. Among them, nine showed moderate to severe functional impairment, and eight had either findings of leukocytosis, positive C-reactive protein, or neutrophilia in BAL.
  
  
  CONCLUSIONS
  These results suggest that IPF patients should be carefully monitored after BAL, especially those with functional impairment or active inflammation.
authors.affiliation: Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Taniguchi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kondoh
authors.forename: Kenji
authors.initials: K
authors.lastname: Wakai
authors.forename: Tomoki
authors.initials: T
authors.lastname: Kimura
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kataoka
authors.forename: Naozumi
authors.initials: N
authors.lastname: Hashimoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Nishiyama
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Hasegawa
mesh_terms: D000208:Acute Disease; D000368:Aged; D018893:Bronchoalveolar Lavage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D013997:Time Factors