Background: Pulmonary rehabilitation (PR) is a key intervention for chronic obstructive pulmonary disease (COPD); however, adherence remains suboptimal, particularly in patients with low physical activity (PA) despite preserved physical capacity (PC). This study aimed to identify factors associated with low PA, with a focus on patient-reported outcomes (PROs). Methods: In this prospective study, COPD patients were categorized according to daily moderate-to-vigorous PA measured using Fitbit devices: ≥30 minutes/day (‘Do do’) and <30 minutes/day (‘Don’t do’). Baseline characteristics, pulmonary function, and exercise capacity assessed by 6-minute walk distance (6MWD) were evaluated. PROs included the modified Medical Research Council (mMRC) dyspnea scale, COPD Assessment Test (CAT), and Patient Health Questionnaire-9 (PHQ-9). Logistic regression analysis was performed to identify factors independently associated with low PA. Results: Among 96 patients, 44 were classified as ‘Do do’ and 52 as ‘Don’t do.’ The ‘Don’t do’ group showed significantly lower 6MWD (424 m vs. 488 m, p=0.005) and lower forced expiratory volume in 1 second (46.73% vs. 54.48%, p=0.005). They also reported higher dyspnea scores (mMRC 1.77 vs. 1.30, p=0.019). Greater breathlessness measured by CAT was independently associated with low PA (odds ratio, 1.31; 95% confidence interval, 1.06 to 1.62), even after adjustment for 6MWD and pulmonary function. This association persisted in patients with preserved PC. Conclusion Low PA in COPD is influenced not only by objective physical limitations but also by subjective symptom burden, particularly dyspnea. Integrating PROs into PR assessment may facilitate identification of barriers and improve adherence to rehabilitation programs.

Bronchiectasis is a chronic respiratory disease characterized by abnormal dilation of the bronchi that causes cough, sputum, and recurrent infections. As it may be associated with various respiratory or systemic diseases, a critical aspect of managing bronchiectasis is to identify the underlying cause. Immunodeficiency is a rare but important cause of bronchiectasis, and its treatability is a significant trait for bronchiectasis management. While primary immunodeficiencies in bronchiectasis are well recognized, secondary immunodeficiencies remain under-reported and under-researched. Secondary immunodeficiencies may result from various diseases and conditions, such as hematologic malignancies, human immunodeficiency virus infection, renal transplantation, or the use of immunosuppressive drugs, and may contribute to the occurrence of bronchiectasis. Recurrent pulmonary and/or extrapulmonary infections in bronchiectasis may indicate the presence of secondary immunodeficiency in patients with these underlying conditions. For treatment, examining the underlying condition, managing bronchiectasis adequately, and prophylactic antibiotics (e.g., macrolide) and/or supplementary immunoglobulin G therapy may provide potential benefits. Considering the projected increase in the prevalence of secondary immunodeficiencies and bronchiectasis, future guidelines and research on the diagnosis and optimized treatment are needed.

Limited data are available regarding the in vitro activity of SPR719, a derivative of benzimidazole, against diverse nontuberculous mycobacteria (NTM) species. We investigated the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of SPR719 against clinical NTM isolates, including clarithromycin- and amikacin-resistant strains. NTM isolates were obtained from patients with NTM-pulmonary disease caused by various NTM species, including Mycobacterium avium complex, M. abscessus (subspecies abscessus and massiliense), M. kansasii, and M. fortuitum. Regardless of clarithromycin or amikacin resistance, the MIC and MBC values of SPR719 were comparable among these major pathogenic NTM species. In over 70% of the isolates, the MIC values were ≤ 2 µg/mL with MBC values of ≤ 4 µg/mL. The MIC and MBC values of M. kansasii were relatively lower than those of the other species with little difference between them, demonstrating the bactericidal properties of SPR719. The in vitro activity of SPR719 against major clinical NTM species suggests that SPR719 can serve as a novel treatment option for NTM-pulmonary disease.