Respiratory investigation最新文献

{"title":"Diagnostic utility of standardized assessment of ciliary ultrastructure by transmission electron microscopy in primary ciliary dyskinesia: a Japanese perspective","authors":"Akiko Miyabayashi ,&nbsp;Keiko Wakabayashi ,&nbsp;Hiroyuki Yamada ,&nbsp;Masashi Ito ,&nbsp;Kozo Morimoto ,&nbsp;Minako Hijikata ,&nbsp;Naoto Keicho","doi":"10.1016/j.resinv.2025.10.006","DOIUrl":"10.1016/j.resinv.2025.10.006","url":null,"abstract":"<div><h3>Background</h3><div>Primary ciliary dyskinesia (PCD) is a rare genetic disorder associated with structural or functional ciliary defects. Its diagnosis usually requires a combination of tests, including observation of the cilium structure by transmission electron microscopy (TEM). In Japan, when TEM was previously the primary method for diagnosing PCD, there were no standardized methods for evaluating TEM findings, and the correlations with PCD-causing genes remained unclear.</div></div><div><h3>Methods</h3><div>Here, we evaluated 101 patients with suspected PCD using a standardized assessment of ciliary ultrastructure by TEM, based on the international guidelines that classify defects into Class 1 and Class 2.</div></div><div><h3>Results</h3><div>Class 1 or 2 ciliary defects on TEM were identified in 27 patients (26.7 %); Class 1 defects (n = 19) correlated well with the genotypes in Japanese patients with PCD, most commonly caused by <em>DNAH5</em> and <em>CCDC39/40</em>. TEM proved valuable as a complementary tool, when genetic testing failed to yield a definitive diagnosis, particularly in cases where two heterozygous variants of unknown phase were identified in a single PCD-causing gene. It was especially informative in PCD patients with situs inversus. However, in cases involving homozygous <em>DRC1</em> variants, which are most frequently identified among Japanese patients with PCD, only subtle ultrastructural defects were observed, highlighting the limitations of TEM as a standalone diagnostic method. Our study also demonstrated the need for and effectiveness of standardizing the assessment of ciliary ultrastructure by TEM.</div></div><div><h3>Conclusions</h3><div>The results of this study provide a crucial foundation for establishing a better TEM-based diagnostic system in Japan.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"63 6","pages":"Pages 1268-1273"},"PeriodicalIF":2.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145313547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent advances in lung function standard value prediction equations: Comparison with the Global Lung Initiative prediction equation based on GAMLSS","authors":"Toshitaka Shomura,&nbsp;Yosuke Wada,&nbsp;Masayuki Hanaoka","doi":"10.1016/j.resinv.2025.09.010","DOIUrl":"10.1016/j.resinv.2025.09.010","url":null,"abstract":"<div><div>To accurately interpret lung function test (LFTs) results, it is necessary to appropriately select the lung function reference value prediction equation implemented in the measuring equipment of each medical institution.</div><div>The American Thoracic Society (ATS) and European Respiratory Society (ERS) task force, known as the Global Lung Function Initiative (GLI), recommends the use of a lung function standard value prediction equation that can calculate continuous standard values across a wide age range. Generalized additive models for location, scale, and shape (GAMLSS) are statistical techniques used to create accurate percentiles for a wide age range. This prediction equation was created using the lambda, mu, and sigma (LMS) method, a subtype of a statistical method known as generalized additive models for location, scale, and shape (GAMLSS). Lung function equations created using the LMS method can be used to calculate the z-score, which can contribute to a more accurate interpretation of the results. As for the contents of this review, an overview of the development of equations for predicting lung function using GAMLSS, such as spirometry, diffusion capacity, and static lung volume, is provided in the first portion of this review. The second section of this review compiles the statistical knowledge required to develop lung function reference-value prediction algorithms based on GAMLSS. This section briefly explains how to calculate the z-score and provides advice on addressing ethnic diversity in the lung function standard value prediction equations.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"63 6","pages":"Pages 1139-1145"},"PeriodicalIF":2.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Daikin air purifiers on asthma control and pulmonary function: A multicenter, single-arm, observational pilot study","authors":"Satoshi Hamada ,&nbsp;Susumu Sato ,&nbsp;Shota Hori ,&nbsp;Shiqi Yu ,&nbsp;Hironobu Sunadome ,&nbsp;Kimihiko Murase ,&nbsp;Toyohiro Hirai","doi":"10.1016/j.resinv.2025.08.008","DOIUrl":"10.1016/j.resinv.2025.08.008","url":null,"abstract":"<div><h3>Background</h3><div>While numerous studies, including systematic reviews, have investigated the effects of air purifiers on asthma control in Western countries, there is a paucity of research conducted in Japan. This multicenter, single-arm, observational pilot study examined the effect of air purifiers on asthma control in Japanese patients.</div></div><div><h3>Methods</h3><div>This study was conducted at the Kyoto University Hospital and the Ayabe City Hospital. The air purifiers (MCK704ABK: Daikin Industries, Ltd., Osaka, Japan) were equipped with electrostatic high-efficiency particulate air filters, capable of capturing 99.97 % of particles ≥0.3 μm. We examined changes in particulate matter (PM) 2.5 levels and forced expiratory volume in 1 s (FEV₁) before and after one month of air purifier use.</div></div><div><h3>Results</h3><div>Eighteen patients (median age: 64 [58, 70] years, 66.7 % female) participated in the study. The median PM2.5 concentration significantly decreased from 4.6 (3.4, 6.9) μg/m³ to 1.4 (0.7, 2.7) μg/m³ after using the air purifiers (p = 0.00042). FEV₁ significantly increased from 2.0 (1.7, 2.6) L to 2.1 (1.7, 2.6) L (p = 0.041). The median change in FEV₁ after air purifier use was 40 (−22.5, 112.5) mL. Patients with improved FEV₁ (ΔFEV1 &gt;0 mL) had a significantly higher frequency of allergen sensitization compared to those without improvement (75.0 % vs. 16.7 %, p = 0.019).</div></div><div><h3>Conclusion</h3><div>The Daikin air purifiers demonstrated the potential to reduce PM levels and improve pulmonary function and asthma symptoms.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"63 6","pages":"Pages 1078-1084"},"PeriodicalIF":2.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Artificial intelligence for diagnosis in interstitial lung disease and digital ontology for unclassified interstitial lung disease","authors":"Tomohisa Baba ,&nbsp;Tsubasa Goto ,&nbsp;Yoshiro Kitamura ,&nbsp;Tae Iwasawa ,&nbsp;Koji Okudela ,&nbsp;Tamiko Takemura ,&nbsp;Akira Osawa ,&nbsp;Takashi Ogura","doi":"10.1016/j.resinv.2025.09.007","DOIUrl":"10.1016/j.resinv.2025.09.007","url":null,"abstract":"<div><h3>Background</h3><div>Multidisciplinary discussion (MDD) is the gold standard for diagnosis in interstitial lung disease (ILD). However, its inter-rater agreement is not satisfactory, and access to the MDD is limited due to a shortage of ILD experts. Therefore, artificial intelligence would be helpful for diagnosing ILD.</div></div><div><h3>Methods</h3><div>We retrospectively analyzed data from 630 patients with ILD, including clinical information, CT images, and pathological results. The ILD classification into four clinicopathologic entities (i.e., idiopathic pulmonary fibrosis, non-specific interstitial pneumonia, hypersensitivity pneumonitis, connective tissue disease) consists of two stages: first, pneumonia pattern classification of CT images using a convolutional neural network (CNN) model; second, multimodal (clinical, radiological, and pathological) classification using a support vector machine (SVM). The performance of the classification algorithm was evaluated using 5-fold cross-validation.</div></div><div><h3>Results</h3><div>The mean accuracies of the CNN model and SVM were 62.4 % and 85.4 %, respectively. For multimodal classification using SVM, the overall accuracy was very high, especially with sensitivities for idiopathic pulmonary fibrosis and hypersensitivity pneumonitis exceeding 90 %. When pneumonia patterns from CT images, pathological results, or clinical information were not used, the SVM accuracy was 84.3 %, 70.3 % and 79.8 %, respectively, suggesting that pathological results contributed most to MDD diagnosis. When an unclassifiable interstitial pneumonia was input, the SVM output tended to align with the most likely diagnosis by the expert MDD team.</div></div><div><h3>Conclusions</h3><div>The algorithm based on multimodal information can assist in diagnosing interstitial lung disease and is suitable for ontology diagnosis. (242 words)</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"63 6","pages":"Pages 1179-1186"},"PeriodicalIF":2.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comment on “Reduced hemoglobin-corrected diffusing capacity in pulmonary arterial hypertension with preserved pulmonary function and morphology”","authors":"Zhikun Zheng","doi":"10.1016/j.resinv.2025.09.013","DOIUrl":"10.1016/j.resinv.2025.09.013","url":null,"abstract":"","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"63 6","pages":"Page 1286"},"PeriodicalIF":2.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145346756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exacerbation and cardiopulmonary risk after prompt initiation of single-inhaler budesonide /glycopyrrolate/formoterol fumarate following COPD exacerbations: Insights from MITOS EROS (Japan) study","authors":"Koichiro Takahashi ,&nbsp;Yuri Yoshida ,&nbsp;Naoyuki Makita ,&nbsp;Kenichiro Nishida ,&nbsp;Michihiro Yoshimura ,&nbsp;Zhao Cheng ,&nbsp;Aaro Salosensaari ,&nbsp;Catarina Camarinha ,&nbsp;Reiko Yamaura ,&nbsp;Marta Cuntin ,&nbsp;Michael Pollack","doi":"10.1016/j.resinv.2025.10.015","DOIUrl":"10.1016/j.resinv.2025.10.015","url":null,"abstract":"<div><h3>Background</h3><div>Previous evidence supported prompt initiation of single-inhaler triple therapy in chronic obstructive pulmonary disease (COPD), but data specific to Japan are lacking. This study investigated the association between budesonide/glycopyrrolate/formoterol fumarate (BGF) initiation and subsequent COPD exacerbations or severe cardiopulmonary events in Japanese patients initiating BGF following previous exacerbations.</div></div><div><h3>Methods</h3><div>This was an observational cohort study among patients with COPD using IQVIA Integrated claims data. Between BGF launch (September 2019) and March 2023, patients aged ≥40 years initiating BGF following COPD exacerbations (index) were included. Patients were categorized into BGF initiation groups by treatment initiation timing following index exacerbations: prompt (≤30 days), delayed (31–180 days), and very delayed (181–365 days). Multivariable negative binomial regression models evaluated the associations between BGF initiation strategies and subsequent exacerbations or severe cardiopulmonary events.</div></div><div><h3>Results</h3><div>3402 eligible patients were included: 840 prompt, 1143 delayed, and 1419 very delayed BGF initiators. The crude COPD exacerbation event rate (95 % confidence interval [CI]) per person-year was 1.66 (1.58–1.74) for prompt, 2.36 (2.30–2.43) for delayed, and 2.60 (2.54–2.66) for very delayed initiators during follow-up. Compared to prompt initiation, delayed (adjusted rate ratio [RR]: 1.25; 95 % CI: 1.13–1.38) and very delayed (adjusted RR: 1.09; 95 % CI: 0.99–1.20) BGF initiation showed an increased risk of COPD exacerbations. No associations were observed between BGF initiation strategies and severe cardiopulmonary events.</div></div><div><h3>Conclusion</h3><div>Following COPD exacerbations, initiating BGF promptly was associated with reduction in subsequent exacerbations. Patients should receive prompt and proactive treatment to reduce COPD morbidity.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"63 6","pages":"Pages 1330-1337"},"PeriodicalIF":2.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145452926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Pseudomonas aeruginosa on the outcomes after lung transplantation: a single-center study","authors":"Takashi Kanou,&nbsp;Hideki Nagata,&nbsp;Kenji Kimura,&nbsp;Eriko Fukui,&nbsp;Toru Kimura,&nbsp;Naoko Ose,&nbsp;Yasushi Shintani","doi":"10.1016/j.resinv.2025.09.002","DOIUrl":"10.1016/j.resinv.2025.09.002","url":null,"abstract":"<div><h3>Background</h3><div>Lung transplantation (LTX) is an established treatment for end-stage pulmonary diseases. However, infections, particularly those caused by <em>Pseudomonas aeruginosa,</em> remain a major challenge, contributing to morbidity, mortality, and complications such as acute cellular rejection (ACR). This study aimed to investigate the relationship between the postoperative detection of <em>P. aeruginosa</em> in respiratory samples and post-LTX outcomes, including the incidence of ACR and overall survival.</div></div><div><h3>Methods</h3><div>We retrospectively analyzed 63 patients who underwent cadaveric LTX at our institution between 1999 and 2021. Patient characteristics, perioperative factors, and microbiological data were collected, and the association of <em>P. aeruginosa</em> detection within three months post-LTX with ACR and survival outcomes was analyzed. ACR was diagnosed by surveillance bronchoscopy and histological assessment.</div></div><div><h3>Results</h3><div><em>P. aeruginosa</em> was detected in the respiratory samples of 21 patients (33 %) within three months post-LTX. Patients with the history of <em>P. aeruginosa</em> detection after LTX exhibited a significantly higher incidence of ACR (p = 0.02) and poorer 5-year overall survival rates (p = 0.03). A multivariate analysis confirmed that <em>P. aeruginosa</em> detection and older recipient age were independent risk factors for poor survival.</div></div><div><h3>Conclusions</h3><div>The detection of <em>P. aeruginosa</em> in respiratory samples was associated with an increased risk of ACR and poorer overall survival following LTX. These findings underscore the importance of vigilant monitoring for <em>P. aeruginosa</em> detection and development of targeted antimicrobial strategies to improve post-transplant outcomes. Further studies are warranted to explore the mechanisms linking <em>P. aeruginosa</em> to adverse outcomes and evaluate the efficacy of novel therapeutic interventions.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"63 6","pages":"Pages 1127-1131"},"PeriodicalIF":2.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145092392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Airway tree morphology and blood eosinophil count in past smokers without a history of lung disease: A cross-sectional analysis of lung cancer screening computed tomography","authors":"Kohei Obata ,&nbsp;Naoya Tanabe ,&nbsp;Yusuke Hayashi ,&nbsp;Tomoki Maetani ,&nbsp;Yusuke Shiraishi ,&nbsp;Katsuhiro Suzuki ,&nbsp;Susumu Sato ,&nbsp;Atsuyasu Sato ,&nbsp;Toyohiro Hirai","doi":"10.1016/j.resinv.2025.11.003","DOIUrl":"10.1016/j.resinv.2025.11.003","url":null,"abstract":"<div><h3>Background</h3><div>Native airway structures may affect the host immune response to inhaled noxious particles. We hypothesized that a distinct airway tree structure may be associated with a higher blood eosinophil count (BEC) after smoking cessation, even in the absence of lung disease.</div></div><div><h3>Methods</h3><div>This cross-sectional study retrospectively evaluated consecutive male nonsmokers and smokers with no history of lung disease or airflow limitation who underwent lung cancer screening computed tomography (CT), spirometry, and BEC measurement. Total airway count (TAC), airway tree surface area-to-volume ratio (SAV), airway-to-lung size ratio (ALR), and segmental airway wall area percentage (WA%) were quantified using computed tomography (CT).</div></div><div><h3>Results</h3><div>The study included 205 nonsmokers, 123 past smokers, and 133 current smokers. BEC, neutrophil, lymphocyte, monocyte, and basophil counts were higher in current smokers than in past smokers and nonsmokers, but there was no difference between past smokers and nonsmokers. Higher TAC and SAV, but not ALR or WA%, were associated with greater log-transformed BEC in past smokers (r = 0.25, p = 0.005 and r = 0.25, p = 0.005, respectively), but not in current smokers or nonsmokers. These associations in past smokers remained significant after adjusting for age, body size, and pack-years. In contrast, TAC and SAV were not associated with neutrophil, lymphocyte, or monocyte count in past smokers.</div></div><div><h3>Conclusion</h3><div>A higher branch count and surface area-to-volume ratio of the airway tree may be associated with persistent eosinophilic inflammation in past smokers without a history of lung disease.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"63 6","pages":"Pages 1359-1364"},"PeriodicalIF":2.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145496515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Caregiver burden among caregivers of patients receiving home oxygen therapy: Insights of the Japanese White Paper on Home Respiratory Care 2024","authors":"Satoshi Hamada ,&nbsp;Jun Ueki ,&nbsp;Toyohiro Hirai ,&nbsp;Emika Sano ,&nbsp;Keiko Hino ,&nbsp;Megumi Ikeda ,&nbsp;Susumu Sato ,&nbsp;Toru Oga ,&nbsp;Tomomasa Tsuboi ,&nbsp;Hajime Kurosawa ,&nbsp;Hiroo Wada ,&nbsp;Japanese White Paper on Home Respiratory Care 2024 working group","doi":"10.1016/j.resinv.2025.10.011","DOIUrl":"10.1016/j.resinv.2025.10.011","url":null,"abstract":"<div><h3>Background</h3><div>The factors influencing caregiver burden in Japan remained understudied, particularly in nationwide surveys. Japan is among the countries experiencing the most rapid population aging and declining birth rates. Herein, we examined caregiver burden and the related factors in caregivers of patients receiving home oxygen therapy (HOT) based on data from the Japanese White Paper on Home Respiratory Care 2024.</div></div><div><h3>Methods</h3><div>Patients receiving HOT who responded to the Short Form-8 (SF-8) questionnaire comprised two summary scores (physical [PCS] and mental component summaries [MCS]) and caregivers of these patients who responded to the SF-8 questionnaire and the Burden Index of Caregiver-11 (BIC-11) questionnaire were included in the analysis.</div></div><div><h3>Results</h3><div>A total of 102 caregiver−patient pairs were included; the median age was 72 and 74 years, respectively. The BIC-11 total score in caregivers providing &lt;3 h of daily care was significantly lower than that in those providing ≥3 h (p &lt; 0.0001). Stepwise multiple linear regression analysis identified the following independent predictors of the BIC-11 total score: among caregivers, daily caregiving hours (β = 0.16, p = 0.043), PCS (β = −0.29, p = 0.0001), and MCS (β = −0.53, p &lt; 0.0001); and among patients, male sex (β = 0.22, p = 0.020), a modified Medical Research Council score of 4 (β = 0.20, p = 0.048), and daily walking and exercising (β = −0.23, p = 0.027).</div></div><div><h3>Conclusions</h3><div>This study identified key factors associated with caregiver burden in HOT.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"63 6","pages":"Pages 1300-1305"},"PeriodicalIF":2.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145401788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnostic value of nonpurulent sputum in nontuberculous mycobacterial lung disease: A cross-sectional study based on the Miller and Jones classification","authors":"Minako Hanaka ,&nbsp;Kazunori Tobino","doi":"10.1016/j.resinv.2025.10.009","DOIUrl":"10.1016/j.resinv.2025.10.009","url":null,"abstract":"<div><h3>Background</h3><div>Sputum quality is widely considered a determinant of microbiological diagnostic yield in respiratory infections. However, its significance in the context of nontuberculous mycobacterial (NTM) lung disease remains unclear. This study aimed to investigate the association between sputum quality, as assessed using the Miller and Jones classification, and the detection rates of NTM via smear microscopy, polymerase chain reaction (PCR), and culture.</div></div><div><h3>Methods</h3><div>We conducted a cross-sectional study of 54 patients diagnosed with NTM lung disease at a single institution in Japan between September 2021 and September 2022. A total of 158 sputum samples were visually classified into five categories (M1–P3). Diagnostic yield was assessed using auramine-O fluorescence staining, <em>Mycobacterium avium</em> complex–polymerase chain reaction, and mycobacterial culture. Bacterial co-detection and treatment status were also analyzed.</div></div><div><h3>Results</h3><div>Nonpurulent sputum samples (M1 and M2) comprised over 60 % of all specimens and demonstrated clinically relevant positivity rates: 33 % for M1 and over 50 % for M2 by culture. No significant association was found between sputum quality and smear, PCR, or culture positivity. Purulent sputum (P2–P3) was significantly associated with bacterial co-detection (p = 0.0008), particularly <em>Pseudomonas aeruginosa</em>.</div></div><div><h3>Conclusions</h3><div>Sputum purulence was not associated with diagnostic yield for NTM. Nonpurulent samples should not be excluded from diagnostic evaluation. These findings support current guideline recommendations and highlight the importance of repeated sputum collection and adjunctive diagnostic tools in NTM lung disease.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"63 6","pages":"Pages 1287-1292"},"PeriodicalIF":2.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145355514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}