PURPOSE: Bronchoalveolar lavage (BAL) is generally regarded as a safe, well established, non-invasive diagnostic procedure. However, development of 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). The purpose of this study is to investigate the temporal relationship between BAL procedures and onset of AE-IPF.
METHODS: This was a retrospective cohort study. Patients with IPF diagnosed from April 1995 to December 2007 and subsequently followed at Tosei General Hospital were eligible. 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 on BAL-induced AE-IPF.
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). All patients except one underwent BAL procedures at the beginning of observation. 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: About a 4-fold increased risk of AE within 30 days after BAL was observed during the follow-up of 112 IPF patients.
CLINICAL IMPLICATIONS: These results suggest that IPF patients should be carefully monitored after BAL, especially those with functional impairment or active inflammation.
DISCLOSURE: The following authors have nothing to disclose: Koji Sakamoto, Hiroyuki Taniguchi, Yasuhiro Kondoh, Kenji Wakai, Tomoki Kimura, Kensuke Kataoka, Naozumi Hashimoto, Osamu Nishiyama, Yoshinori Hasegawa
No Product/Research Disclosure Information