Respiratory investigation最新文献

{"title":"A proposed pathological diagnosis flowchart for adult interstitial lung disease with transbronchial lung cryobiopsy: Position paper from the Japanese research group on diffuse lung disease","authors":"Yoshiaki Zaizen ,&nbsp;Ryoko Saito-Koyama ,&nbsp;Koji Okudela ,&nbsp;Yasuhiro Terasaki ,&nbsp;Tomonori Tanaka ,&nbsp;Kazuhiro Tabata ,&nbsp;Mikiko Hashisako ,&nbsp;Shinobu Kunugi ,&nbsp;Kaori Ishida ,&nbsp;Mai Matsumura ,&nbsp;Masashi Kitani ,&nbsp;Tomoe Sawazumi ,&nbsp;Tomohisa Baba ,&nbsp;Takashi Ogura ,&nbsp;Tamiko Takemura ,&nbsp;Akira Hebisawa ,&nbsp;Junya Fukuoka","doi":"10.1016/j.resinv.2026.101393","DOIUrl":"10.1016/j.resinv.2026.101393","url":null,"abstract":"<div><div>Transbronchial lung cryobiopsy for interstitial lung disease is described in guidelines as an “acceptable alternative” to surgical lung biopsy. However, the pathological diagnosis of interstitial lung disease by transbronchial lung cryobiopsy is difficult compared with surgical lung biopsy because of the small sample size, leading to diagnostic disagreement not only in pathological diagnosis but also in multidisciplinary discussion diagnosis. Therefore, a standardized approach for the pathological diagnosis of ILD using transbronchial cryobiopsy is necessary. We developed a diagnostic flowchart for the pathological diagnosis of ILD using transbronchial cryobiopsy based on the consensus reached by the Pathology and Cryobiopsy Subcommittee within the Study Group on Diffuse Pulmonary Disorders, Scientific Research/Research on Intractable Diseases of the Ministry of Health, Labour, and Welfare of Japan. This study reports the diagnostic flowchart.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"64 2","pages":"Article 101393"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147348975","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":"Oxygenation deterioration and computed tomography findings in acute exacerbation of interstitial lung diseases: a prospective observational study","authors":"Toru Arai ,&nbsp;Junji Otsuka ,&nbsp;Shinobu Akagawa ,&nbsp;Yoriyuki Murata ,&nbsp;Hidetoshi Yanai ,&nbsp;Ryoji Ito ,&nbsp;Takuo Shibayama ,&nbsp;Toshihiko Ii ,&nbsp;Toshiyuki Kita ,&nbsp;Yoshifusa Koreeda ,&nbsp;Takayasu Watanabe ,&nbsp;Isoko Owan ,&nbsp;Atsuko Hara ,&nbsp;Kentaro Wakamatsu ,&nbsp;Akihiro Yoshii ,&nbsp;Shiro Ohshima ,&nbsp;Shin Sasaki ,&nbsp;Susumu Oguri ,&nbsp;Naoki Arai ,&nbsp;Eiji Yatsuyanagi ,&nbsp;Hiromitsu Sumikawa","doi":"10.1016/j.resinv.2025.101361","DOIUrl":"10.1016/j.resinv.2025.101361","url":null,"abstract":"<div><h3>Background</h3><div>Acute exacerbation (AE) is a critical prognostic event in interstitial lung diseases (ILDs), initially recognized in idiopathic pulmonary fibrosis (IPF). Current AE diagnostic criteria do not account for oxygenation deterioration, and evidence of new computed tomography (CT) findings alone is insufficient to diagnose AE-ILD. We investigated a CT-based criterion for distinguishing AE from acute deterioration (AD)-ILD and assessed the prognostic significance of oxygenation deterioration in AE-ILD.</div></div><div><h3>Methods</h3><div>Patients with AD-ILD, defined by worsening shortness of breath and new lung abnormalities within 1 month, were prospectively enrolled. AD-ILD included both AE-ILD and other acute conditions, non-AE-AD-ILD. Oxygenation deterioration was assessed using modified Blancal criteria. CT-based AE criteria were developed through receiver operating characteristic (ROC) curve and multivariate logistic regression analyses based on CT findings suggestive of AE.</div></div><div><h3>Results</h3><div>Overall, 394 patients were analyzed, including 303 diagnosed with AE and 91 with non-AE-AD-ILD. The underlying ILDs included IPF (n = 177) and non-IPF ILDs (n = 217). The presence of at least two of three CT-based parameters, including bilateral shadows, ground-glass opacity predominance, and diffuse pattern, was identified as predictive of AE diagnosis in AD-ILDs using logistic and ROC analyses. Ninety-day survival was significantly lower in patients with AE-ILD with oxygenation deterioration than in those without deterioration and in patients with non-AE-AD-ILDs. Oxygenation deterioration independently predicted poor survival in multivariate Cox proportional hazard regression analysis.</div></div><div><h3>Conclusions</h3><div>The developed CT-based AE criteria effectively predicted AE and oxygenation deterioration in AD-ILD. Additionally, oxygenation deterioration predicted worse survival in AE-ILD.</div><div>This study was registered with the University Hospital Medical Information Network (UMIN000027844; registered 1 July 2017).</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"64 2","pages":"Article 101361"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146011672","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":"Serum soluble ST2: An effective prognostic biomarker for mortality in patients with severe acute exacerbation of chronic obstructive pulmonary disease requiring invasive mechanical ventilation","authors":"Yunxiang Lv ,&nbsp;JianLing Huang ,&nbsp;Kexing Han ,&nbsp;Beilei Gong ,&nbsp;Guiyun Jiang","doi":"10.1016/j.resinv.2026.101391","DOIUrl":"10.1016/j.resinv.2026.101391","url":null,"abstract":"<div><h3>Background</h3><div>For severe acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients unresponsive to initial treatment and at high mortality risk, early biomarker-based risk stratification may refine therapies and boost survival.</div></div><div><h3>Methods</h3><div>A total of 84 patients with severe AECOPD were prospectively enrolled. Serum soluble ST2 (sST2) levels were measured at baseline (day 0, diagnosis) and on days 3 and 7 after systemic therapy was initiated. The primary goals were to evaluate the prognostic value of sST2 for predicting all-cause in-hospital mortality and to determine its additive predictive effect when integrated with the DECAF score (Dyspnoea, Eosinopenia, Consolidation, Acidaemia, and atrial Fibrillation).</div></div><div><h3>Results</h3><div>Elevated sST2 levels on days 0, 3, and 7 demonstrated strong predictive value for in-hospital mortality, with area under the receiver operating characteristic curve (AUC) values of 0.799 (95% CI: 0.697–0.878), 0.856 (95% CI: 0.762–0.923), and 0.912 (95% CI: 0.831–0.963), respectively. In univariate Cox regression analysis, patients with higher sST2 levels at these time points exhibited significantly increased 60-day non-survival (hazard ratios [HRs]: 12.4 [95% CI:4.4–35.0], 11.9 [95% CI: 4.4–31.7], and 37.8 [95% CI: 12.7–113.0] for days 0, 3, and 7, respectively; <em>P</em> &lt; 0.001). Multivariate analysis revealed that combining sST2 levels ≥718 pg/mL on day 3 with the DECAF score enhanced mortality prediction accuracy (AUC: 0.920 vs. 0.654 for DECAF alone; <em>P</em> &lt; 0.001 for difference).</div></div><div><h3>Conclusions</h3><div>Early serum sST2 levels independently predict mortality in patients with severe AECOPD, and their integration with the DECAF score improves prognostic accuracy.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"64 2","pages":"Article 101391"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146228477","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":"Clinical characteristics of respiratory syncytial virus and human metapneumovirus pneumonia in adults: A multicenter retrospective cohort study in Japan","authors":"Ryota Takao ,&nbsp;Takahiro Takazono ,&nbsp;Kiyoyasu Fukushima ,&nbsp;Nobuyuki Ashizawa ,&nbsp;Masataka Yoshida ,&nbsp;Kazuaki Takeda ,&nbsp;Naoki Iwanaga ,&nbsp;Shotaro Ide ,&nbsp;Asuka Umemura ,&nbsp;Norihito Kaku ,&nbsp;Kosuke Kosai ,&nbsp;Akira Kondo ,&nbsp;Tsutomu Kobayashi ,&nbsp;Noriho Sakamoto ,&nbsp;Toyomitsu Sawai ,&nbsp;Yoji Futsuki ,&nbsp;Kohji Hashiguchi ,&nbsp;Katsunori Yanagihara ,&nbsp;Hiroshi Mukae","doi":"10.1016/j.resinv.2026.101392","DOIUrl":"10.1016/j.resinv.2026.101392","url":null,"abstract":"<div><h3>Background</h3><div>Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are increasingly being recognized as important viral pathogens in adults, particularly in advanced age and high-risk populations. However, epidemiological and clinical data on RSV and hMPV pneumonia in Japan are limited.</div></div><div><h3>Methods</h3><div>We conducted a retrospective cohort study of adult patients diagnosed with RSV, hMPV, or influenza virus pneumonia at eight institutions in Nagasaki. Clinical information, including the Charlson Comorbidity Index (CCI), laboratory and radiological findings, were collected from medical records. Pneumonia severity was assessed using the A-DROP and Pneumonia Severity Index (PSI).</div></div><div><h3>Results</h3><div>A total of 301 patients were included: 215 with influenza, 34 with RSV, and 52 with hMPV pneumonia. The median ages were 75, 82, and 69 years, respectively. Female predominance was observed in RSV and hMPV cases compared with influenza. RSV cases were more frequently associated with residence in long-term care facilities, lower BMI, and higher prevalence of chronic cardiopulmonary disease. Lower respiratory tract symptoms, particularly cough and sputum production, were significantly more frequent in patients with RSV infections. hMPV cases exhibited lower CCI scores and milder severity profiles. The A-DROP and PSI scores did not differ significantly between RSV and influenza, and the in-hospital mortality was comparable across the groups.</div></div><div><h3>Conclusions</h3><div>RSV and hMPV are clinically important causes of pneumonia in advanced aged Japanese population. RSV pneumonia is associated with prominent respiratory symptoms and radiological findings, with severity comparable to that of influenza. These findings underscore the need for increased awareness and large-scale, prospective studies.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"64 2","pages":"Article 101392"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146228429","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":"Clinical characteristics and systemic treatment in patients with elderly-onset sarcoidosis: A retrospective single-centre study in Japan","authors":"Hitokazu Tsukao ,&nbsp;Michiru Sawahata ,&nbsp;Yoshitaka Yamanouchi ,&nbsp;Noritaka Sakamoto ,&nbsp;Masayuki Nakayama ,&nbsp;Koichi Hagiwara ,&nbsp;Makoto Maemondo","doi":"10.1016/j.resinv.2026.101381","DOIUrl":"10.1016/j.resinv.2026.101381","url":null,"abstract":"<div><h3>Background</h3><div>The mean age at diagnosis of sarcoidosis has been increasing worldwide, yet the clinical characteristics and treatment patterns of elderly-onset cases remain insufficiently defined, particularly in Asian populations.</div></div><div><h3>Methods</h3><div>We retrospectively investigated 187 consecutive Japanese patients newly diagnosed with sarcoidosis at Jichi Medical University Hospital between 2006 and 2018 who fulfilled the 2015 diagnostic criteria. Patients were classified as elderly (≥65 years, n = 49), middle-aged (45–64 years, n = 82), or younger (&lt;45 years, n = 56). Organ involvement was assessed based on the 2023 Japan Society of Sarcoidosis and Other Granulomatous Disorders standards and the 2014 WASOG criteria. The frequency and distribution of systemic therapy (corticosteroids, methotrexate, other immunosuppressants) and treatment indications were compared across age groups.</div></div><div><h3>Results</h3><div>The proportion of women was significantly higher in the elderly than in the younger group (81.6% vs. 41.1%, p &lt; 0.01), as was the frequency of cardiac involvement (12.2% vs. 3.6%, p &lt; 0.05). Systemic therapy was initiated less often in the elderly than in the middle-aged group (10.2% vs. 25.4%, p = 0.026), and all indications involved extrapulmonary lesions (cardiac, n = 3; neurological, n = 1; ocular, n = 1). Most treated patients received systemic corticosteroids, with a median duration of 7.0 months.</div></div><div><h3>Conclusion</h3><div>Elderly-onset sarcoidosis in Japan was characterised by a predominance of women and a higher frequency of cardiac involvement. Systemic therapy was infrequently initiated and only for extrapulmonary disease. These findings underscore the need for systematic evaluation of extrapulmonary organs—particularly the heart—and age-adapted multidisciplinary management.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"64 2","pages":"Article 101381"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146137698","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":"Identifying high-risk smokers without airflow limitation using new COPD criteria: pooled analysis of two Japanese cohorts","authors":"Naoya Tanabe ,&nbsp;Shotaro Chubachi ,&nbsp;Kunihiko Terada ,&nbsp;Takashi Shimada ,&nbsp;Yoshinori Seri ,&nbsp;Hidetoshi Nakamura ,&nbsp;Koichiro Asano ,&nbsp;Atsuyasu Sato ,&nbsp;Susumu Sato ,&nbsp;Koichi Fukunaga ,&nbsp;Toyohiro Hirai","doi":"10.1016/j.resinv.2026.101368","DOIUrl":"10.1016/j.resinv.2026.101368","url":null,"abstract":"<div><h3>Background</h3><div>Recently proposed multidimensional chronic obstructive pulmonary disease (COPD) diagnostic criteria incorporate computed tomography (CT) findings and symptoms beyond airflow limitation. These criteria, developed using North American cohorts, require validation in Asian populations in which COPD phenotypes differ. We examined whether these criteria identify Japanese smokers at increased exacerbation risk, particularly those without airflow limitation.</div></div><div><h3>Methods</h3><div>This retrospective analysis pooled data from two prospective Japanese cohorts (Kyoto-Himeji and K-CCR) that included 517 smokers aged ≥40 years undergoing chest CT and COPD assessment test (CAT). The criteria included one major criterion (airflow limitation) and five minor criteria (emphysema [low attenuation area percent, LAA% ≥5 %], airway wall thickening [wall area percent ≥60 %], symptoms, dyspnea, and chronic bronchitis). COPD was defined as meeting the major criterion plus ≥1 minor criterion or ≥3 minor criteria alone. Negative binomial regression examined three-year exacerbation risk.</div></div><div><h3>Results</h3><div>Among 517 smokers, 364 had major criteria COPD, 26 had minor criteria-only COPD, 40 had airflow limitation without meeting COPD criteria, and 87 had neither (non-COPD group). Exacerbation rates were 0.270, 0.259, 0.161, and 0.069 per person-year, respectively. Both COPD groups had a significantly greater exacerbation risk than the non-COPD group (adjusted IRR: 4.95 [95 %CI: 1.79–14.62] for minor criteria-only; 3.95 [2.06–7.79] for major criteria). Higher CAT scores and LAA % were independently associated with a greater exacerbation risk in patients with COPD.</div></div><div><h3>Conclusion</h3><div>The new multidimensional COPD criteria successfully identified Japanese smokers at increased exacerbation risk, including those without airflow limitation, supporting their applicability across different populations. Registered at UMIN (UMIN000028387).</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"64 2","pages":"Article 101368"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941426","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":"Appreciation to reviewers in 2025","authors":"","doi":"10.1016/S2212-5345(26)00035-3","DOIUrl":"10.1016/S2212-5345(26)00035-3","url":null,"abstract":"","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"64 2","pages":"Article 101401"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147448552","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":"Handgrip strength in Japanese patients with chronic obstructive pulmonary disease: a prospective cohort study","authors":"Seiichi Kobayashi,&nbsp;Manabu Ono,&nbsp;Masatsugu Ishida,&nbsp;Hikari Satoh,&nbsp;Masakazu Hanagama,&nbsp;Koji Okutomo,&nbsp;Masaru Yanai","doi":"10.1016/j.resinv.2026.101377","DOIUrl":"10.1016/j.resinv.2026.101377","url":null,"abstract":"<div><h3>Background</h3><div>Skeletal muscle dysfunction frequently accompanies chronic obstructive pulmonary disease (COPD). Handgrip strength (HGS) is a simple, reliable measure of muscle strength. This study aimed to evaluate its prognostic significance in COPD.</div></div><div><h3>Methods</h3><div>We conducted a prospective observational study in a cohort of Japanese patients with COPD, stratified by HGS. Patient characteristics, exacerbations, and mortality were evaluated over 5 years. Low HGS was defined as &lt;28 kg in men and &lt;18 kg in women.</div></div><div><h3>Results</h3><div>Among 300 patients, 89 (29.7 %) had low HGS. Compared with patients with normal HGS, these patients had a lower body mass index, worse pulmonary function, more severe dyspnea, poorer health status, and reduced physical activity. Exacerbation rates were similar between the groups. Low HGS was associated with an increased risk of all-cause mortality (hazard ratio, 1.79; 95 % confidence interval, 1.03–3.13).</div></div><div><h3>Conclusions</h3><div>Low HGS was associated with adverse clinical outcomes in Japanese patients with COPD.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"64 2","pages":"Article 101377"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038519","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":"A case of synchronous multiple primary lung cancers each harboring an EGFR mutation or an ALK fusion gene alone that responded to osimertinib with chemotherapy","authors":"Doppo Fukui ,&nbsp;Daisuke Morinaga ,&nbsp;Jun Sakakibara-Konishi ,&nbsp;Yukiko Yoshida ,&nbsp;Masahiro Kashima ,&nbsp;Shotaro Ito ,&nbsp;Megumi Furuta ,&nbsp;Yuta Takashima ,&nbsp;Zenichi Tanei ,&nbsp;Satoshi Konno","doi":"10.1016/j.resinv.2026.101375","DOIUrl":"10.1016/j.resinv.2026.101375","url":null,"abstract":"<div><div>A comprehensive pathological evaluation is useful for diagnosing synchronous multiple primary lung cancer (sMPLC). However, a consensus regarding treatment for sMPLC with different driver mutations is lacking. We present a case of sMPLC harboring an epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) fusion gene. For the advanced EGFR-positive tumor, osimertinib plus chemotherapy was initiated, the latter also covering ALK-positive tumor. A marked response and slight reduction occurred in the EGFR-positive and ALK-positive tumors, respectively. Surgical resection of the ALK-positive tumor achieved negative margins. Targeted therapy with chemotherapy may effectively treat sMPLC with different driver mutations.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"64 2","pages":"Article 101375"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146019476","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":"Clinical characteristics and severity of primary ciliary dyskinesia caused by large homozygous deletion including exons 1–4 of DRC1: A multicenter retrospective cohort study","authors":"Masashi Ito ,&nbsp;Atsuko Nakano ,&nbsp;Yukiko Arimoto ,&nbsp;Mitsuko Kondo ,&nbsp;Yusuke Matsuda ,&nbsp;Miki Abo ,&nbsp;Takashi Kido ,&nbsp;Masashi Morishita ,&nbsp;Takeshige Honma ,&nbsp;Hisashi Nishimori ,&nbsp;Yuzaburo Inoue ,&nbsp;Keisuke Iwamoto ,&nbsp;Yuichiro Hashida ,&nbsp;Kazuhiko Takeuchi ,&nbsp;Miyabayashi Akiko ,&nbsp;Keiko Wakabayashi ,&nbsp;Hiroyuki Yamada ,&nbsp;Minako Hijikata ,&nbsp;Naoto Keicho ,&nbsp;Kozo Morimoto","doi":"10.1016/j.resinv.2026.101376","DOIUrl":"10.1016/j.resinv.2026.101376","url":null,"abstract":"<div><h3>Background</h3><div>Approximately half of primary ciliary dyskinesia (PCD) patients in Japan carry a large homozygous deletion encompassing exons 1–4 of <em>DRC1</em> gene. However, the clinical manifestations of PCD patients with <em>DRC1</em> variants remain poorly characterized.</div></div><div><h3>Methods</h3><div>We conducted a multicenter retrospective cohort study at 12 hospitals across Japan. Patients with <em>DRC1</em> variants were included, and their clinical characteristics, disease severity, and radiological features were compared with those of patients with outer dynein arm (ODA) defects.</div></div><div><h3>Results</h3><div>A total of 43 patients with <em>DRC1</em> variants and 21 with ODA defects were included. The median age at PCD diagnosis was 27 years (IQR: 17–41) for patients with <em>DRC1</em> variants and 26 years (IQR: 8–31) for those with ODA defects. The median PICADAR score was significantly lower in patients with <em>DRC1</em> variants than those with ODA defects (4 vs. 8, p &lt; 0.001). The radiological severity and distribution of bronchiectasis did not differ between the two groups, while the median mucous plugging score (bronchiolitis/tree-in-bud) was significantly higher in patients with <em>DRC1</em> variants (5, IQR: 4–6 vs. 3, IQR: 2–4, p = 0.044). In patients with <em>DRC1</em> variants, the FEV₁ z score was negatively correlated with age (r = −0.37, p = 0.028), and the modified Reiff score was positively correlated with age (r = 0.47, p = 0.010).</div></div><div><h3>Conclusions</h3><div>Although the sensitivity of the PICADAR score was low in these patients, most clinical and radiological features of <em>DRC1</em>-related PCD were relatively typical of PCD. Given that <em>DRC1</em>-related PCD appears to worsen with age, early diagnosis and timely intervention are crucial.</div></div>","PeriodicalId":20934,"journal":{"name":"Respiratory investigation","volume":"64 2","pages":"Article 101376"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146030642","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}