# Usefulness of Transbronchial Lung Cryobiopsy When Starting Antifibrotic Treatment and Predicting Progressive Fibrosing Interstitial Lung Disease: Descriptive Research

## TL;DR

This study shows that transbronchial lung cryobiopsy can help predict which interstitial lung disease patients may benefit from early antifibrotic treatment.

## Contribution

The study demonstrates that a TBLC-based UIP score can guide therapeutic decisions in interstitial lung disease patients.

## Key findings

- Patients with a TBLC-based UIP score ≥ 2 had steeper declines in lung function.
- Most patients with a score ≥ 2 received antifibrotic agents within six months.
- A higher UIP score suggests a progressive fibrosis course despite temporary stabilization.

## Abstract

Although transbronchial lung cryobiopsy (TBLC) is widely used in diagnostic algorithms for various interstitial lung diseases (ILDs), its real‐world utility in the therapeutic decision‐making strategy for ILD patients remains unclear, in particular, when judging the time to start antifibrotic agents.

We analyzed medical records of 40 consecutive patients with idiopathic or fibrotic hypersensitivity pneumonitis who underwent TBLC. A TBLC‐based usual interstitial pneumonia (UIP) score was used to assess three morphologic descriptors: patchy fibrosis, fibroblastic foci, and honeycombing.

In our 40 patients with ILD, the most frequent radiological feature was indeterminate for UIP (45.0%). Final diagnosis included idiopathic pulmonary fibrosis (22.5%), fibrotic nonspecific interstitial pneumonia (5.0%), fibrotic hypersensitivity pneumonitis (35.0%), and unclassifiable ILD (37.5%). Linear mixed‐effects analysis showed that declines in the slopes of %FVC and %DLCO in patients with TBLC‐based UIP “Score ≥ 2” were significantly steeper than those of patients with “Score ≤ 1.” During follow‐up of patients with Score ≥ 2 (n = 24), more than half of them (n = 17) received an antifibrotic agent, with most patients (n = 13) receiving early administration of the antifibrotic agent within 6 months after the TBLC procedure.

TBLC‐based UIP Score ≥ 2 indicated the increased possibility of a progressive fibrosis course that may prove helpful in predicting progressive pulmonary fibrosis/progressive fibrosing ILD even if disease is temporarily stabilized due to anti‐inflammatory agents. Patients may benefit from early introduction of antifibrotic agents by treating clinicians.

Although transbronchial lung cryobiopsy (TBLC) is widely used in diagnostic algorithms for various interstitial lung diseases (ILDs), its real‐world utility in the therapeutic decision‐making strategy for ILD patients remains unclear. In the present study, TBLC‐based UIP Score ≥ 2 indicated the increased possibility of a progressive fibrosis course that may prove helpful in predicting progressive pulmonary fibrosis/progressive fibrosing ILD.