Patients

This retrospective study included 52 patients with interstitial lung diseases, who underwent TBLC followed by SLB at the Kanagawa Cardiovascular & Respiratory Centre between May 2017 and August 2018. In the clinical diagnostic course, the decision to proceed with SLB following TBLC depended on the physicians’ assessment or the local multidisciplinary discussion (MDD) according to the diagnostic guidelines. In this study patients diagnosed with interstitial lung disease with specific known causes, such as connective tissue diseases, hypersensitivity pneumonitis, and occupational lung diseases before TBLC were excluded (Fig. 1). No pharmacological treatment was performed between the two biopsies. Clinical information, including age at biopsy, sex, smoking history, pulmonary or extrapulmonary signs and symptoms, laboratory data including results of auto-antibody tests, and adverse events of each biopsy, was obtained from the patients’ medical records. For safety analysis, adverse events in all 383 and 97 patients who underwent TBLC and SLB, respectively, during the study period were collected.

The study flowchart. Among 383 patients who underwent TBLC, 54 underwent sequential SLB. Two patients were diagnosed with rheumatoid arthritis before TBLC. A total of 52 patients were included in this study. The samples from TBLC and SLB were randomly labelled to mask the relationship between the two samples. The diagnosis was made in a stepwise manner and the concordance between the two biopsy approaches was analyzed