Antigen avoidance and outcome of nonfibrotic and fibrotic hypersensitivity pneumonitis
- Takashi Nishida1⇑,
- Eriko Kawate1,
- Takashi Ishiguro1,
- Tetsu Kanauchi2,
- Yoshihiko Shimizu3 and
- Noboru Takayanagi1
- 1Department of Respiratory Medicine
- 2Department of Radiology
- 3Department of Pathology, Saitama Cardiovascular and Respiratory Center
- Takashi Nishida (nishida.takashi{at}saitama-pho.jp)
Abstract
Background Hypersensitivity pneumonitis (HP) is classified into nonfibrotic and fibrotic phenotypes. Patients with nonfibrotic HP often experience recurrence and develop fibrosis, whereas those with fibrotic HP have a poor prognosis. Although antigen avoidance has long been the first line of treatment for HP, its impact on prognosis has been poorly reported.
Methods Medical records of 121 patients with HP diagnosed by new diagnostic criteria of ATS/JRS/ALAT guidelines and treated at our institution in Saitama, Japan, were retrospectively analysed. HP was classified into nonfibrotic and fibrotic phenotypes and 6 HP subtypes: summer-type, bird-related, home-related, and occupational HP, humidifier lung, and hot tub lung. Achievement of reduced exposure to inciting agents was divided into complete antigen avoidance (CAA) and incomplete antigen avoidance (IAA) by HP subtype.
Results Of the 74 patients with nonfibrotic HP, 30 achieved CAA and experienced no recurrence or development of fibrosis. In the remaining 44 patients with IAA, 24 (54.5%) experienced recurrence and/or development of fibrosis. The all-cause 5-year mortality rate in the 47 patients with fibrotic HP was 47.8%. Negative prognostic factors of HP-related mortality in these patients were <50% lymphocytes in bronchoalveolar lavage (BAL) and honeycombing. Multivariate analysis showed a tendency for IAA to be related to poorer survival (hazard ratio: 3.452, 95% CI, 0.964-12.359, p=0.057).
Conclusions In the patients with nonfibrotic HP, CAA resulted in no recurrence or development of fibrosis and longer survival. In the patients with fibrotic HP, <50% lymphocytes in BAL and honeycombing were negative prognostic factors for mortality.
Footnotes
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Conflict of interest: Dr. Nishida has nothing to disclose.
Conflict of interest: Dr. Kawate has nothing to disclose.
Conflict of interest: Dr. Ishiguro has nothing to disclose.
Conflict of interest: Dr. Kanauchi has nothing to disclose.
Conflict of interest: Dr. Shimizu has nothing to disclose.
Conflict of interest: Dr. Takayanagi has nothing to disclose.
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- Received July 22, 2021.
- Accepted October 13, 2021.
- Copyright ©The authors 2021
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