Effect of antigen removal in hypersensitivity pneumonitis

BMC Pulm Med. 2024 Aug 20;24(1):398. doi: 10.1186/s12890-024-03098-3.

Abstract

Background: Antigen removal is a cornerstone of treatment of hypersensitivity pneumonitis (HP), but its association with transplant-free survival remains unclear. Further, HP guidelines conflict as to whether antigen removal is a recommended diagnostic test in patients with suspected HP.

Objective: The purpose of this study is to (1) evaluate the impact of antigen removal on transplant-free survival and (2) to describe the impact of antigen removal on pulmonary function testing and imaging in a retrospective cohort of patients with HP.

Methods: We retrospectively identified HP patients evaluated between 2011 and 2020. Demographic, physiologic, radiographic, and pathologic data were recorded.

Results: 212 patients were included in the cohort. Patients who identified and removed antigen had a better transplant-free survival than patients who did not identify antigen and patients who identified but did not remove antigen. Antigen removal was associated with improvement in FVC by 10% predicted in 16.9% of patients with fibrotic HP and 56.7% of patients with nonfibrotic HP.

Discussion: Our results suggest that over 50% of nonfibrotic HP patients and 16.9% of fibrotic HP patients improve with exposure removal. In addition, antigen removal, rather than antigen identification, is associated with transplant-free survival in HP.

MeSH terms

  • Adult
  • Aged
  • Alveolitis, Extrinsic Allergic* / diagnosis
  • Alveolitis, Extrinsic Allergic* / immunology
  • Alveolitis, Extrinsic Allergic* / therapy
  • Antigens / immunology
  • Female
  • Humans
  • Lung Transplantation
  • Male
  • Middle Aged
  • Respiratory Function Tests
  • Retrospective Studies
  • Tomography, X-Ray Computed

Substances

  • Antigens