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Abstract Background Measurement of exhaled nitric oxide (FeNO) is a potentially useful diagnostic test for asthma. However, no study has explored the relationship between FeNO and respiratory symptoms of nontuberculous mycobacterial pulmonary disease (NTM-PD) complicated with asthma. The objective of this study was to assess the utility of measuring FeNO levels in patients with NTM-PD complicated by asthma. Methods In this single-center retrospective cohort study, 140 NTM-PD patients with FeNO measured were enrolled. We selected NTM-PD patients who complicated with asthma as the NTM+BA group, defined using the following criteria: NTM patients with symptoms consistent with asthma, and NTM patients with symptomatic improvement after diagnostic therapy with ICS ± a long-acting beta 2-agonist (LABA). We then calculated a diagnostic cutoff point to distinguish between the NTM+BA groups and the NTM groups (all others). High-resolution computed tomography (HRCT) images were evaluated using the CT scoring system and their association with FeNO was examined. Results A total of 89 patients were included in the study. (31 in the NTM+BA group and 58 in the NTM group). Compared with the NTM group, the NTM+BA group had higher rates of allergic disease (51.6% vs. 22.4%; p=0.0085) and higher FeNO values (median, 23 [interquartile range {IQR}, 15.0-43.0] ppb vs. median, 17 [IQR, 11.8-23.0] ppb; p=0.015). With diagnostic asthma care using mainly ICS/LABA with reference to the FeNO, most patients (91.0%, 20/22) in the NTM-preceding subgroup in the NTM+BA group demonstrated a prompt improvement of their symptoms and AFB culture findings did not worsen (Culture positive rate (%): Pre-treatment: 59.1% vs. Post-treatment: 40.9%, p=0.3660) at 6 months after starting diagnostic therapy. The optimal diagnostic cutoff point of FeNO to distinguish between the two groups was calculated as 21.5 ppb by the ROC curve (sensitivity 75%, specificity 71.93%, p

Abstract Tetracyclines exhibit anti-viral, anti-inflammatory, and immunomodulatory activities via various mechanisms. The present study investigated the efficacy and safety of demeclocycline in patients hospitalized with mild-to-moderate COVID-19 via an open-label, multicenter, parallel-group, randomized controlled phase 2 trial. Primary and secondary outcomes included changes from baseline (day 1, before the study treatment) in lymphocytes, cytokines, and SARS-CoV-2 RNA on day 8. Seven, seven, and six patients in the control, demeclocycline 150 mg daily, and demeclocycline 300 mg daily groups, respectively, were included in the modified intention-to-treat population that was followed until day 29. A significant change of 191.3/μL in the number of CD4+ T cells from day 1 to day 8 was observed in the demeclocycline 150 mg group (95% CI 5.1/μL–377.6/μL) (p = 0.023), whereas that in the control group was 47.8/μL (95% CI − 151.2/μL to 246.8/μL), which was not significant (p = 0.271). The change rates of CD4+ T cells negatively correlated with those of IL-6 in the demeclocycline-treated groups (R = − 0.807, p = 0.009). All treatment-emergent adverse events were of mild-to-moderate severity. The present results indicate that the treatment of mild-to-moderate COVID-19 patients with demeclocycline elicits immune responses conducive to recovery from COVID-19 with good tolerability. Trial registration: This study was registered with the Japan Registry of Clinical Trials (Trial registration number: jRCTs051200049; Date of the first registration: 26/08/2020).

Unidentified Mycobacterium species are sometimes detected in respiratory specimens. We identified a novel Tsukamurella species (Tsukamurella sp. TY48, RIMD 2001001, CIP 111916T), Tsukamurella toyonakaense, from a patient given a misdiagnosis of nontuberculous mycobacterial pulmonary disease caused by unidentified mycobacteria. Genomic identification of this Tsukamurella species helped clarify its clinical characteristics and epidemiology.

Abstract Background Allergic bronchopulmonary aspergillosis (ABPA) and chronic eosinophilic pneumonia (CEP) both display peripheral eosinophilia as well as pulmonary infiltration, together described as pulmonary eosinophilia, and differentiation is sometimes problematic. This study therefore examined the distinctions between ABPA with and without CEP-like shadows. Methods This retrospective cohort study from a single center included 25 outpatients (median age, 65 years) with ABPA diagnosed between April 2015 and March 2019, using criteria proposed by the International Society of Human and Animal Mycology (ISHAM), which focuses on positive specific IgE for Aspergillus fumigatus. Patients were assigned to either the eosinophilic pneumonia (EP) group or Non-EP group, defined according to findings on high-resolution computed tomography (HRCT). The EP group included patients with HRCT findings compatible with CEP; i.e., the presence of peripheral consolidation (p-consolidation) or ground-glass opacities (GGO), with no evidence of high-attenuation mucus. The Non-EP group comprised the remaining patients, who showed classical findings of ABPA such as mucoid impaction. Differences between the groups were analyzed. Results Baseline characteristics, frequency of a history of CEP (EP, 50% vs. Non-EP, 26%) and tentative diagnosis of CEP before diagnosis of ABPA (67% vs. 16%) did not differ significantly between groups. Although elevated absolute eosinophil count and Aspergillus-specific immunoglobulin E titers did not differ significantly between groups, the Non-EP group showed a strong positive correlation between these values (R = 0.7878, p = 0.0003). The Non-EP group displayed significantly higher levels of the fungal marker beta-D glucan (median, 11.7 pg/ml; interquartile range, 6.7–18.4 pg/ml) than the EP group (median, 6.6 pg/ml; interquartile range, 5.2–9.3 pg/ml). Both groups exhibited frequent recurrence of shadows on X-rays but no cases in the EP group had progressed to the Non-EP group at the time of relapse. Conclusions The ABPA subgroup with imaging findings resembling CEP experienced frequent recurrences, as in typical ABPA. In pulmonary eosinophilia, even if there are no shadows indicating apparent mucous change, the Aspergillus-specific immunoglobulin E level is important in obtaining an accurate diagnosis and in the selection of appropriate therapies for this type of ABPA.

Abstract The combination of rifamycin (RFP), ethambutol (EB), and macrolides is currently the standard regimen for treatment of Mycobacterium avium complex pulmonary disease (MAC-PD). However, poor adherence to the standardized regimens recommended by current guidelines have been reported. We undertook a single-centred retrospective cohort study to evaluate the long-term outcomes in 295 patients with MAC-PD following first line treatment with standard (RFP, EB, clarithromycin [CAM]) or alternative (EB and CAM with or without fluoroquinolones (FQs) or RFP, CAM, and FQs) regimens. In this cohort, 80.7% were treated with standard regimens and 19.3% were treated with alternative regimens. After heterogeneity was statistically corrected using propensity scores, outcomes were superior in patients treated with standard regimens. Furthermore, alternative regimens were significantly and independently associated with sputum non-conversion, treatment failure and emergence of CAM resistance. Multivariate cox regression analysis revealed that older age, male, old tuberculosis, diabetes mellitus, higher C-reactive protein, and cavity were positively associated with mortality, while higher body mass index and M. avium infection were negatively associated with mortality. These data suggest that, although different combination regimens are not associated with mortality, first line administration of a standard RFP + EB + macrolide regimen offers the best chance of preventing disease progression in MAC-PD patients.

ABSTRACT Although serum anti-glycopeptidolipid (GPL)-core IgA antibody is a highly specific test for infection with Mycobacterium avium complex (MAC), Mycobacterium abscessus, and its subspecies abscessus, subsp. massiliense, and subsp. bolletii (MAB), its use for the definitive diagnosis of MAC pulmonary disease (PD) and MAB-PD are unknown. To clarify the diagnostic accuracy of the anti-GPL-core IgA antibody test among patients with radiologically suspected MAC-PD or MAB-PD who already have a single positive sputum culture test. The first isolations of MAC and MAB from patients with radiologically suspected MAC-PD or MAB-PD at the Osaka Toneyama Medical Center between January 2006 and December 2020 were collected. Patients were enrolled when their serum anti-GPL-core IgA antibody was measured during the 3 months before and after the first isolation. We retrospectively compared the results of anti-GPL-core IgA antibody testing with the final diagnoses based on the current guidelines. We included 976 patients for analysis. The serum anti-GPL-core IgA antibody was positive in 699 patients (71.6%). The positive predictive value of anti-GPL-core IgA antibody for the diagnosis of MAC-PD or MAB-PD was 97.4%. The median time required for the second positive culture after the first isolation was 51 days (interquartile range 12 to 196 days). The positive serum anti-GPL-core IgA antibody test allowed an early and definitive diagnosis of MAC-PD or MAB-PD in those who already had a single positive sputum culture test. IMPORTANCE To satisfy the microbiologic criteria of the current diagnostic guideline for nontuberculous mycobacterial pulmonary disease (PD), at least two positive sputum cultures of the same species of mycobacteria from sputum are required to avoid the casual isolation of mycobacteria. This study showed that the positivity of a serum anti-glycopeptidolipid (GPL)-core IgA antibody test has an excellent diagnostic ability among patients with radiologically suspected Mycobacterium avium complex (MAC)-PD or Mycobacterium abscessus (MAB)-PD who already had a single positive sputum culture test. The usage of single culture isolation plus anti-GPL-core IgA antibody as another diagnostic criterion has a time, cost, and effort-saving effect. Furthermore, it will facilitate the diagnosis of MAC-PD or MAB-PD in the early stage of disease because serum anti-GPL-core IgA antibody becomes high in these patients. Therefore, we proposed adding single culture isolation plus anti-GPL-core IgA antibody as “combined microbiological and serological criteria” to the diagnostic guidelines for MAC-PD and MAB-PD.

Abstract Background Lung resection in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) has been reported to be associated with favorable outcomes. However, little is known regarding the risk and prognostic factors for refractory and recurrent cases. We aimed to evaluate the overall impact and benefit of adjuvant lung surgery by comparing NTM-PD patients who underwent adjuvant lung resection with those treated exclusively with antibiotics. We also investigated the efficacy of serum IgA antibody against glycopeptidolipid (GPL) core antigen (GPL core antibody) to monitor disease activity and predict the recurrence of disease after adjuvant lung resection. Methods We retrospectively evaluated the clinical characteristics and surgical outcomes of 35 patients surgically treated for NTM-PD. Furthermore, we compared surgically treated patients and control patients treated exclusively with antibiotics who were matched statistically 1:1 using a propensity score calculated from age, sex, body mass index, and radiologic features of disease. Results In the surgically treated patients, the median age was 58 (interquartile range, 47–65) years and 65.7% were female. Twenty-eight patients had Mycobacterium avium complex. Operations comprised four pneumonectomies, two bilobectomies, one bilobectomy plus segmentectomy, 17 lobectomies, two segmentectomies, and nine lobectomies plus segmentectomies. Postoperative complications occurred in seven patients (20%), there were no operative deaths, and 33 (94.3%) patients achieved negative sputum culture conversion. Refractory and recurrent cases were associated with remnant bronchiectasis, contralateral shadows, and positive acid-fast bacilli staining or culture. Of 28 statistically matched pairs, long-term sustained negative culture conversion was observed in 23 (82.2%) surgical group patients and in 14 (50.0%) non-surgical group patients (0.0438). The mortality rate was lower in the surgical group, but did not reach statistical significance (one in the surgical group and four in the non-surgical group, p = 0.3516). GPL core antibody was correlated with disease activity and recurrence. Conclusions NTM-PD patients who underwent adjuvant lung resection experienced overall favorable outcomes and achieved sputum culture conversion more frequently. Long-term mortality may have been reduced by this procedure, and the level of GPL core antibody was shown to be a good clinical indicator of disease activity after surgery.

Abstract Background Although cavities are an important finding in Mycobacterium avium complex pulmonary disease (MAC-PD), there is little information regarding the types of cavities that indicate disease progression. This study was performed to identify cavity characteristics that were associated with disease progression in patients with MAC-PD. Methods This retrospective cohort study included 97 patients presenting with MAC-PD with cavities between December 2006 and June 2016. We compared initial and final computed tomography (CT) findings, classified 52 and 45 patients in the progressive and non-progressive cavity groups, respectively, and examined the progression-related imaging features in initial CT images. A progressive cavity was defined by more than two-fold increase in internal diameter or emergence of a new cavity around the initial cavity. Results Patients in the progressive group were older (p

Mycolicibacterium mageritense (M. mageritense) is a rare species among rapidly growing mycobacteria, and M. mageritense pleurisy is very rare. Here, we report for the first time, an immunocompetent patient with pleurisy caused by M. mageritense. The patient had no history of immunodeficiency and no recurrence of lung cancer after surgery. However, 8 months after surgery, he developed a new lung shadow and pleurisy. Although whole-genome analysis of the colony cultured from the patient's pleural fluid revealed M. mageritense, we could not identify it in time, resulting in a poor outcome. M. mageritense pleurisy in this case might have occurred via a bulla rupture of the lung lesion because computed tomography of the patient's chest showed pneumothorax and a lung lesion in contact with thoracic cavity. This case emphasized that nontuberculous mycobacterial pleurisy should be considered in the differential diagnoses of pleural effusion even in immunocompetent patients. Advancement of comprehensive and rapid analyses of genomic data from clinical specimens will lead to better treatment strategies.

Aims: In contrast to cardiovascular disease, low rather than high ventilatory inefficiency, evaluated by the minute ventilation-carbon dioxide output (V'E-V'CO2)-slope, has been recognized as being related to greater disease severity in chronic obstructive pulmonary disease (COPD). To better care for patients with cardiopulmonary disease, understanding the physiological correlation between ventilatory inefficiency and exercise limitation is necessary, but remains inadequate. Given that oxygen uptake (V'O2) evaluated by cardiopulmonary exercise testing (CPET) depends on both the ventilatory capability and oxygen extraction, i.e., the difference between inspiratory and expiratory oxygen concentration (ΔFO2), the aim of this study was to investigate the correlations between V'E-V'CO2-slope and the ΔFO2 during exercise and their physiological implications in patients with COPD.Methods: A total of 156 COPD patients (mean age, 70.9 ± 7.2 years) with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages I–IV and 16 controls underwent CPET with blood gas analysis.Results: With the progression of COPD, mechanical ventilatory constraints together with a slower respiratory frequency led to exertional respiratory acidosis. In GOLD IV cases, (1) decrease in the dependence of reduced peak V'O2 on V'E led to an increase in its dependence on peak ΔFO2 during exercise; and (2) the ΔFO2-V'CO2-slope became steeper, correlating with the severity of exertional respiratory acidosis (r = 0.6359, p < 0.0001). No significant differences in peak exercise ΔFO2 or V'E-V'CO2-slope were observed among the various GOLD stages. In all subjects, including controls, peak exercise ΔFO2 had the strongest correlation with the V'E-V'CO2-slope (r = −0.8835, p < 0.0001) and correlated well with body mass index (r = 0.3871, p < 0.0001), although it did not correlate with the heart rate-V'CO2-relationship and V'E.Conclusions: Ventilatory efficiency related to CO2 clearance might depend on exertional oxygen extraction in the body. Measuring ΔFO2 might be a key component for identifying ventilatory inefficiency and oxygen availability. Increasing ΔFO2 would help to improve ventilatory inefficiency and exercise tolerance separately from cardiac and ventilatory capability in COPD patients.

The association between Mycobacterium avium complex pulmonary disease (MAC-PD) and pleuroparenchymal fibroelastosis (PPFE) has been reported previously, and interstitial pneumonia as a comorbidity is associated with a worse prognosis. However, no study has thoroughly reported on PPFE associated with MAC-PD. The present study investigated the prevalence, clinical characteristics, and prognostic impact of PPFE in patients with MAC-PD. A total of 224 patients, newly diagnosed with MAC-PD, were retrospectively reviewed. At the time of diagnosis, chest high-resolution computed tomography (HRCT), sputum examination, and clinical characteristics were collected. The extent of PPFE and MAC-PD was evaluated semi-quantitatively using HRCT scores. Risk factor analysis for clinical or radiological deterioration necessitating multidrug antimicrobial treatment within 3 years, and all-cause mortality within 5 years, from the initial diagnosis was performed based on the PPFE score. PPFE was observed in 59 out of 224 patients (26.3%). A higher PPFE score was a risk factor for dyspnoea, fatigue, and lower body mass index (BMI) (p

While both chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) are multifactorial disorders characterized by distinct clinical and pathological features, their commonalities and differences have not been fully elucidated. We sought to investigate the preventive roles of tetraspanins Cd151 and Cd9 -that are involved in diverse cellular processes in lung pathophysiology- in pulmonary fibrosis and emphysema, respectively, and to obtain a deeper understanding of their underlying molecular mechanisms toward facilitating improved therapeutic outcomes. Using an integrative approach, we examined the transcriptomic changes in the lungs of Cd151- and Cd9-deficient mice using functional-enrichment-analysis, pathway-perturbation-analysis and protein-protein-interaction (PPI) network analysis. Circadian-rhythm, extracellular-matrix (ECM), cell-adhesion and inflammatory responses and associated factors were prominently influenced by Cd151-deletion. Conversely, cellular-junctions, focal-adhesion, vascular-remodeling, and TNF-signaling were deeply impacted by Cd9-deletion. We also highlighted a “common core” of factors and signaling cascades that underlie the functions of both Cd151 and Cd9 in lung pathology. Circadian dysregulation following Cd151-deletion seemingly facilitated progressive fibrotic lung phenotype. Conversely, TGF-β signaling attenuation and TNF-signaling activation emerged as potentially novel functionaries of Cd9-deletion-induced emphysema. Our findings offer promising avenues for developing novel therapeutic treatments for pulmonary fibrosis and emphysema.

Although the utility of oscillometry for predicting disease severity in idiopathic pulmonary fibrosis (IPF) had been researched, little has been reported on the mechanism of why respiratory impedance reflects disease severity. In addition, traction bronchiectasis has been considered to reduce respiratory resistance and correlate negatively with airflow obstruction, but this hypothesis has not been validated. The present study aimed to investigate the correlations between oscillometric parameters and fibrosis-related lung abnormalities in IPF and to assess the utility of oscillometry as a surrogate marker for traction bronchiectasis and airflow obstruction. Eighty Japanese patients with IPF underwent high-resolution computed tomography (HRCT), spirometry, and oscillometry and were retrospectively investigated. Fibrosis-related HRCT findings were scored regarding airspace consolidation, honeycombing, architectural distortion, traction bronchiectasis, and fibrosis. Correlations between the HRCT scores, spirometric parameters, and oscillometric parameters were analysed. Respiratory reactance correlated positively with all fibrosis-related HRCT scores. Vital capacity and forced vital capacity (FVC) correlated negatively with oscillometric parameters and HRCT scores, reflecting the severity of restrictive ventilatory deficiency. Respiratory resistance was not related to any of the HRCT scores or forced expiratory volume in 1 s/FVC. However, forced expiratory volume in 1 s/FVC correlated positively with HRCT scores, which showed that airflow obstruction became milder as the disease progressed. In conclusion, respiratory reactance reflects fibrosis and restrictive ventilatory deficiency in IPF. Moreover, respiratory resistance is independent of traction bronchiectasis and airflow obstruction in patients with IPF, which implies that respiratory resistance might reflect different properties of the airways.

Although the diagnostic value of impulse oscillometry (IOS) in bronchiectasis for the differential diagnosis of healthy subjects has been researched, the usefulness of each IOS parameter for predicting disease severity in bronchiectasis has not been thoroughly investigated. In addition, the usefulness of IOS in patients with nontuberculous mycobacteria (NTM) infection has not been reported. This study aimed to determine the predictive significance of respiratory impedance and detect the other most significant IOS parameters for predicting disease severity in bronchiectasis patients and to validate the usefulness of IOS in patients with NTM infection. A total of 206 patients with bronchiectasis who attended clinics at the National Hospital Organization Osaka Toneyama Medical Center were included. Chest high-resolution computed tomography, spirometry and IOS were performed. Hospital admissions, mortality and disease severity indices for bronchiectasis (Bronchiectasis Severity Index (BSI), FACED, and E-FACED scores) were calculated to assess disease severity. The patients were divided into subgroups with and without NTM infection, and subgroup analyses were performed. Respiratory reactance, especially resonant frequency (fres), correlated with both BSI and FACED score better than respiratory resistance. Inspiratory but not expiratory impedance was strongly correlated with BSI, FACED and E-FACED scores. Inspiratory fres was the most useful predictor, increasing as the disease became more severe. The usefulness of IOS was almost equivalent in patients both with and without NTM infection. Inspiratory reactance measured by IOS is useful for estimating disease severity in bronchiectasis. Inspiratory fres best predicts disease severity in bronchiectasis patients both with and without NTM infection.

Background Exertional prolonged expiration should be identified as a therapeutic target in COPD. The efficacy of expiratory or inspiratory pressure load training (EPT/IPT) based on the degree of prolonged expiration was investigated. Methods A total of 21 patients with COPD were divided into two groups according to the exertional change in the inspiratory duty cycle (TI/Ttot). For 12 weeks, patients whose exertional TI/Ttot decreased received EPT (EPT group, n=11, mean percentage forced expiratory volume in 1 s (%FEV1), 32.8%) and those whose exertional TI/Ttot increased received IPT (IPT group, n=10, mean %FEV1, 45.1%). Results The therapeutic responses were as follows. In both groups, endurance time (EPT, +5.7 min, p

Inspiratory muscle training (IMT) has been attracting attention as one of the useful treatments in patients with chronic obstructive pulmonary disease (COPD). IMT is reportedly effective in most patients with COPD. However, little is known about the benefits of IMT, especially in patients with advanced COPD.We reported two cases of COPD that received 12-week IMT to explore intolerance to and the limitations of IMT in advanced COPD. The effectiveness of IMT was evaluated using cardiopulmonary exercise testing (CPET), spirometry, and respiratory muscle strength testing before and after the training.A 75-year-old man with normal body mass index (BMI) and forced expiratory volume in 1 s (FEV1) of 1.63 L responded well to IMT, but a 78-year-old man with low BMI and FEV1 of 0.83 L did not. In the responder, IMT resulted in increased minute ventilation (V’E) and oxygen uptake at peak exercise in incremental load testing. Moreover, IMT increased endurance time in constant load testing and maximal inspiratory pressure. In both patients, breathing frequency (fR) increased, but tidal volume and the inspiratory-expiratory ratio were not improved during exercise. Despite the high fR obtained after IMT, V’E at peak exercise did not increase and endurance time shortened in the non-responder.In underweight patients with advanced COPD, IMT might lead to tachypnea and ventilatory inefficiency, which in turn might decrease exercise performance. Therefore, underweight patients with advanced COPD might be unable to tolerate IMT and should avoid receiving the training.

The presence of anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab) is closely associated with rapidly progressive interstitial lung disease (RP-ILD) in patients with clinically amyopathic dermatomyositis. Despite intensive immunosuppressive therapies, some of these patients still have a poor prognosis with few treatment options. Although removal of pathogenic autoantibodies and cytokines by plasma exchange (PE) could be a treatment option, its safety and efficacy have never been determined. We report a patient with anti-MDA5 Ab-positive RP-ILD who was refractory to intensive therapies including steroids, cyclosporine, and intravenous cyclophosphamide, and then treated by PE to prevent the progression of RP-ILD. Shortly after the initiation of PE therapy, however, his respiratory condition suddenly deteriorated due to acute pulmonary edema and the patient died on the following day. Transfusion-related acute lung injury (TRALI) would be the most likely cause of the acute pulmonary edema because there was no sign of circulatory overload. To the best of our knowledge, this is the first report showing a critical adverse event associated with PE therapy for these patients. This case supports the idea that the presence of ILD could increase a risk for TRALI and therefore we should carefully evaluate the eligibility for PE therapy of anti-MDA5 Ab-positive RP-ILD patients given the risk of acute lung injury. Further studies collecting more clinical data are necessary to assess the efficacy, safety, and risk factors of PE therapy for these patients. Keywords: Acute lung injury, Plasma exchange, Anti-MDA5 antibody, Interstitial pneumonia, Clinically amyopathic dermatomyositis

Arc-welders’ pneumoconiosis (AWP) is an occupational lung disease and has nonspecific symptoms typically with the patterns of centrilobular and/or branching opacities on chest high-resolution computed tomography (HRCT) which are similar to those of hypersensitivity pneumonitis (HP) and/or respiratory tract infections. Therefore, the differential diagnosis is often difficult if they are not suspected.We report a case of AWP which was initially suspected to be pulmonary tuberculosis because of the chest HRCT findings: centrilobular opacities distributed predominantly on the right lobe. On detailed review of the work history, however, the patient was found to be involved in welding. Prussian blue staining of the lung tissues and the bronchoalveolar lavage fluid (BALF) ferritin analysis were useful for the final diagnosis and the appropriate treatment for AWP. The atypical lymphocytosis in BALF in this case suggested the involvement of HP in the pathogenesis due to the occupational sensitization to causal antigens.To the best of our knowledge, this is the first case report of AWP showing features of HP. AWP should be noted even in patients with the typical patterns of centrilobular opacities on chest HRCT. Medical history, iron staining of lung tissues, and the BALF ferritin analysis would be useful for the diagnosis of these patients. The BALF findings are sometimes indeterminate for the diagnosis because the occupational sensitization to causal antigens might be involved in some cases of AWP. Keywords: Hemosiderin-laden macrophage, Hypersensitivity pneumonitis, Iron oxide, Occupational lung disease, Welding

Abstract Background Bronchial thermoplasty (BT) is a bronchoscopic treatment that can ameliorate the symptoms of severe asthma. However, little is known about the mechanism by which BT improves exertional dyspnea without significantly changing the resting pulmonary function in asthmatics. To understand the mechanism, cardiopulmonary variables were investigated using cardiopulmonary exercise testing (CPET) in a patient with severe asthma before and after BT. Case presentation A 57-year-old Japanese man visited our hospital for consultation of the intractable asthma, which we managed with three treatment sessions of BT. Comparison of the findings pre-BT and at 1 year after BT demonstrated that (1) the resting tests for respiration showed no improvement in forced expiratory volume in 1 s, but the forced oscillation technique showed decreases in both inhalation and exhalation respiratory resistance values, and (2) the CPET results showed (i) improvement in exertional dyspnea, exercise endurance, and arterial oxygen saturation at the end of exercise; (ii) that the expiratory tidal volume exceeded the inspiratory tidal volume during exercise, which implied that a sufficient exhalation enabled longer inspiratory time and adequate oxygen absorption; and (iii) that an increase in respiratory frequency could be prevented throughout exercise. Conclusions This case report described a novel mechanism of BT in improving exertional dyspnea and exercise duration, which was brought about by ventilatory improvements related to the breathing pattern of inspiration to expiration.

Abstract Chronic obstructive pulmonary disease (COPD) has been recently characterized as a disease of accelerated lung aging, but the mechanism remains unclear. Tetraspanins have emerged as key players in malignancy and inflammatory diseases. Here, we found that CD9/CD81 double knockout (DKO) mice with a COPD-like phenotype progressively developed a syndrome resembling human aging, including cataracts, hair loss, and atrophy of various organs, including thymus, muscle, and testis, resulting in shorter survival than wild-type (WT) mice. Consistent with this, DNA microarray analysis of DKO mouse lungs revealed differential expression of genes involved in cell death, inflammation, and the sirtuin-1 (SIRT1) pathway. Accordingly, expression of SIRT1 was reduced in DKO mouse lungs. Importantly, siRNA knockdown of CD9 and CD81 in lung epithelial cells additively decreased SIRT1 and Foxo3a expression, but reciprocally upregulated the expression of p21 and p53, leading to reduced cell proliferation and elevated apoptosis. Furthermore, deletion of these tetraspanins increased the expression of pro-inflammatory genes and IL-8. Hence, CD9 and CD81 might coordinately prevent senescence and inflammation, partly by maintaining SIRT1 expression. Altogether, CD9/CD81 DKO mice represent a novel model for both COPD and accelerated senescence.

In autoantibody-mediated autoimmune diseases, pathogenic autoantibodies generated by a failure of central or peripheral tolerance, have different effects mediated by a variety of mechanisms. Interestingly, even non-autoimmune chronic diseases have a set of disease-specific natural autoantibodies that are maintained for a long time. Because most of these natural autoantibodies target intracellular proteins or long non-coding RNAs, they are speculated to be non-pathological and have some important as yet unrecognized physiological functions such as debris clearance. Recently, we revealed a set of disease-specific natural autoantibodies of chronic pulmonary diseases with unknown etiology by protein arrays that enable detection of specific autoantibodies against >8000 targets. Surprisingly, some of the targeted antigens of disease-specific autoantibodies were subsequently reported by other laboratories as strongly associated with the disease, suggesting that these antigens reflect the pathology of each disease. Furthermore, some of these autoantibodies that target extracellular antigens might modify the original course of each disease. Here, we review the disease-specific natural autoantibodies of chronic pulmonary diseases, including chronic fibrosing idiopathic interstitial pneumonias, sarcoidosis, and autoimmune pulmonary alveolar proteinosis, and discuss their utility and effects.

Background: Patients with chronic obstructive pulmonary disease (COPD) show varying mechanisms of exertional dyspnea with different exercise capacities.Methods: To investigate the pathophysiologic conditions related to exertional dyspnea, 294 COPD patients were evaluated using cardiopulmonary exercise testing (CPET) with arterial blood analyses, with the patients classified into two groups according to their exercise limitation: the leg fatigue group (n = 58) and the dyspnea group (n = 215). The dyspnea group was further subdivided into four groups based on peak oxygen uptake (V°O2 in mL/min/kg): group A (< 11), group B (11 to < 15), group C (15 to < 21), and group D (≥21).Results: In the dyspnea group, group A (n = 28) showed the following findings: (i) the forced expiratory volume in 1 s was not correlated with the peak V°O2 (p = 0.288), (ii) the arterial oxygen tension (PaO2) slope (peak minus resting PaO2/ΔV°O2) was the steepest (p < 0.0001) among all subgroups, (iii) reduced tidal volume (VT) was negatively correlated with respiratory frequency at peak exercise (p < 0.0001), and (iv) a break point in exertional VT curve was determined in 17 (61%) patients in group A. In these patients, there was a significant negative correlation between bicarbonate ion (HCO3-) levels at peak exercise and VT level when the VT-break point occurred (p = 0.032). In group D (n = 46), HCO3- levels were negatively correlated with plasma lactate levels (p < 0.0001). In all subgroups, the HCO3- level was negatively correlated with minute ventilation. The dyspnea subgroups showed no significant differences in the overall mean pH [7.363 (SD 0.039)] and Borg scale scores [7.4 (SD, 2.3)] at peak exercise.Conclusions: During exercise, ventilation is stimulated to avoid arterial blood acidosis and hypoxemia, but ventilatory stimulation is restricted in the setting of reduced respiratory system ability. These conditions provoke the exertional dyspnea in COPD. Although symptom levels were similar, the exertional pathophysiologic conditions differed according to residual exercise performance; moreover, COPD patients showed great inter-individual variability. An adequate understanding of individual pathophysiologic conditions using CPET is essential for proper management of COPD patients.

Tetraspanins organize protein complexes in tetraspanin-enriched membrane microdomains that are distinct from lipid rafts. Our previous studies suggested that reduction in the levels of tetraspanins CD9 and CD81 may be involved in the progression of inflammatory lung diseases, especially COPD. To search for agents that increase the levels of these tetraspanins, we screened 1,165 drugs in clinical use and found that statins upregulate CD9 and CD81 in RAW264.7 macrophages. The lipophilic statins, fluvastatin and simvastatin, reversed LPS-induced downregulation of CD9 and CD81, simultaneously preventing TNF-α and matrix metalloproteinase-9 production and spreading of RAW264.7 cells. These statins exerted anti-inflammatory effects in vitro in wild-type macrophages but not in CD9 knockout macrophages, and decreased lung inflammation in vivo in wild-type mice but not in CD9 knockout mice, suggesting that their effects are dependent on CD9. Mechanistically, the statins promoted reverse transfer of the LPS-signaling mediator CD14 from lipid rafts into CD9-enriched microdomains, thereby preventing LPS receptor formation. Finally, upregulation of CD9/CD81 by statins was related to blockade of GTPase geranylgeranylation in the mevalonate pathway. Our data underscore the importance of the negative regulator CD9 in lung inflammation, and suggest that statins exert anti-inflammatory effects by upregulating tetraspanin CD9 in macrophages.