Lung transplantation for hypersensitivity pneumonitis

Area of Science:

• Pulmonology
• Transplant Surgery
• Immunology

Background:

• Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) caused by inhaled antigens.
• Advanced HP may require lung transplantation.
• No prior studies have detailed lung transplant outcomes specifically for HP patients.

Purpose of the Study:

• To compare lung transplant outcomes in patients with HP versus those with idiopathic pulmonary fibrosis (IPF).
• To analyze survival rates, and acute and chronic rejection in HP and IPF lung transplant recipients.

Main Methods:

• Retrospective review of ILD lung transplant cases (2000-2013).
• Comparison of clinical data, survival, and rejection between HP and IPF cohorts.
• Analysis of explant pathology for undiagnosed HP and assessment of recurrent HP post-transplant.
• Survival analysis using Kaplan-Meier and Cox proportional hazard models.

Main Results:

• 31 HP and 91 IPF patients were analyzed among 183 ILD lung transplants.
• HP patients demonstrated superior 1, 3, and 5-year survival (96%, 89%, 89%) compared to IPF patients (86%, 67%, 49%).
• HP patients had a significantly reduced adjusted risk of death (HR, 0.25; P=.013).
• HP was unexpectedly diagnosed in 16% of cases via explant pathology.
• Two HP patients experienced recurrence in the lung allograft.

Conclusions:

• Lung transplantation offers excellent medium-term survival for HP patients.
• HP patients exhibit a lower mortality risk post-transplant compared to IPF patients.
• HP diagnosis can be challenging, sometimes revealed only after explant.
• Recurrence of HP in the allograft is a possibility that warrants consideration.