# Concordance Analysis Between Sputum and Bronchoscopic Specimens on Nontuberculous Mycobacteria Pulmonary Disease

## TL;DR

This study compares the agreement between sputum and bronchoscopy samples in diagnosing nontuberculous mycobacteria lung disease and finds high concordance.

## Contribution

The study provides new insights into the reliability of sputum versus bronchoscopic specimens for NTM diagnosis.

## Key findings

- 61 out of 100 patients showed concordant NTM species between sputum and bronchoscopic specimens.
- Only one patient had a discordant result with different NTM species identified in the two specimen types.
- Factors like BMI and radiologic type were linked to disease progression or treatment needs.

## Abstract

Background/Objectives: This study evaluated the concordance between sputum and bronchoscopic specimens in diagnosing nontuberculous mycobacteria (NTM) pulmonary disease. Methods: We retrospectively analyzed patients with NTM isolated from respiratory specimens between 2010 and 2022. Our analysis assessed species concordance across the two diagnostic methods and compared clinical outcomes between patients with multiple positive cultures and those with a single positive culture. Results: A total of 400 patients were included, 100 of whom underwent bronchoscopy. Among these, 61 demonstrated concordant NTM species between sputum and bronchoscopic specimens, while 38 had NTM cultured from only one source. One patient showed a discordant result, with Mycobacterium abscessus isolated from bronchoalveolar lavage and Mycobacterium avium from sputum. Multivariate analysis identified several factors associated with radiologic progression or the need for treatment: body mass index (HR, 0.847; 95% CI, 0.794–0.902; p < 0.001), membership in the single-isolation group (HR, 0.400; 95% CI, 0.184–0.871; p = 0.021), and fibrocavitary radiologic type (HR, 2.318; 95% CI, 1.470–3.655; p < 0.001). Conclusions: Only a small number of cases showed different NTM species identified by sputum and bronchoscopy.