Acute exacerbations of fibrotic hypersensitivity pneumonitis: a case series.
BACKGROUND
It is now recognized that a significant portion of patients with idiopathic pulmonary fibrosis (IPF) can have sudden and rapid deteriorations in disease course that cannot be explained by infection, heart failure, or thromboembolic disease. These events are often fatal and have been termed acute exacerbations (AEs) of underlying disease. While best described in patients with IPF, they have also been reported in patients with other forms of interstitial lung disease. We sought to determine if this same phenomenon occurs in patients with hypersensitivity pneumonitis (HP).


METHODS
We retrospectively reviewed our clinical experience at National Jewish Medical and Research Center for patients with surgical lung biopsy-proven fibrotic HP who had an acute decline in respiratory status and met criteria similar to those proposed for the diagnosis of an AE of IPF.


RESULTS
Over a 2-year period, we identified four patients with an AE of fibrotic HP. All patients had a clinical course similar to that most frequently described in AEs of IPF: respiratory failure requiring assisted ventilation, lack of clinical response to high-dose corticosteroid therapy, and a poor prognosis (all cases resulted in death or emergent lung transplantation). Lung biopsy at the time of the AE, explant, or autopsy revealed organizing diffuse alveolar damage superimposed on fibrotic lung disease.


CONCLUSIONS
Fibrotic HP, like other forms of fibrotic lung disease, can be associated with AEs of disease. Further investigation into similarities and pathways common in AEs of various fibrotic lung diseases may yield additional insight into this recently recognized syndrome.
Olson
Amy L
AL
Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Health Sciences Center, Section of Critical Care and Hospital Medicine, National Jewish Medical and Research Center, Denver, CO. Electronic address: amy.olson@uchsc.edu.
Huie
Tristan J
TJ
Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Health Sciences Center, Section of Critical Care and Hospital Medicine, National Jewish Medical and Research Center, Denver, CO.
Groshong
Steve D
SD
Interstitial Lung Disease Program, Section of Critical Care and Hospital Medicine, National Jewish Medical and Research Center, Denver, CO.
Cosgrove
Gregory P
GP
Interstitial Lung Disease Program, Section of Critical Care and Hospital Medicine, National Jewish Medical and Research Center, Denver, CO.
Janssen
William J
WJ
Interstitial Lung Disease Program, Section of Critical Care and Hospital Medicine, National Jewish Medical and Research Center, Denver, CO.
Schwarz
Marvin I
MI
Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Health Sciences Center, Section of Critical Care and Hospital Medicine, National Jewish Medical and Research Center, Denver, CO.
Brown
Kevin K
KK
Interstitial Lung Disease Program, Section of Critical Care and Hospital Medicine, National Jewish Medical and Research Center, Denver, CO.
Frankel
Stephen K
SK
Interstitial Lung Disease Program, Section of Critical Care and Hospital Medicine, National Jewish Medical and Research Center, Denver, CO.
D000208:Acute Disease; D000368:Aged; D000542:Alveolitis, Extrinsic Allergic / Q000150:complications* / Q000175:diagnosis* / Q000628:therapy; D015331:Cohort Studies; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000175:diagnosis* / Q000209:etiology* / Q000628:therapy; D012189:Retrospective Studies