Hypersensitivity Pneumonitis: Radiologic Phenotypes Are Associated With Distinct Survival Time and Pulmonary Function...

Area of Science:

• Pulmonology
• Radiology
• Interstitial Lung Diseases

Background:

• Hypersensitivity pneumonitis (HP) is an interstitial lung disease.
• HP generally has a better prognosis than idiopathic pulmonary fibrosis (IPF).
• Radiologic phenotypes may influence prognosis in HP and IPF.

Purpose of the Study:

• To compare survival time and pulmonary function trajectories in patients with HP and IPF.
• To analyze survival and FVC% predicted trajectories based on distinct radiologic phenotypes.

Main Methods:

• 117 HP patients and 152 IPF patients were analyzed.
• Diagnosis was based on biopsy, BAL, exposure history (HP) or clinical/histopathological findings (IPF).
• High-resolution CT (HRCT) scans were used to define radiologic phenotypes: honeycomb, non-honeycomb fibrosis, and nonfibrotic.

Main Results:

• Nonfibrotic HP showed the longest survival (>14.73 years) and improving FVC% predicted.
• HP with non-honeycomb fibrosis survived longer than IPF with non-honeycomb fibrosis (>7.95 vs 5.20 years).
• Both HP and IPF with honeycombing had poor survival (around 2.8 years) and declining FVC% predicted.

Conclusions:

• Three prognostically distinct radiologic phenotypes exist for HP.
• Distinguishing HP from IPF is crucial in non-honeycomb fibrosis cases.
• Radiologic honeycombing suggests a uniformly poor prognosis, potentially limiting the value of invasive diagnostic testing.