Ultrasonic humidifier lung with a reversed halo sign: A case report.

The reversed halo sign was initially reported as a representative computed tomography scan finding of cryptogenic organizing pneumonia. Since then, however, it has been reported in various diseases and is now considered a nonspecific finding. However, there are no cases of humidifier lung with the reversed halo sign. An 82-year-old Japanese male patient presented with moving difficulties 48 days after starting darolutamide treatment for prostate cancer. He was admitted to the hospital due to acute pneumonia, which presented as bilateral extensive nonsegmental ground-glass opacities in the peripheral regions and extensive areas of ground-glass opacity with a circumferential halo of consolidation, with the reversed halo sign on computed tomography scan. After darolutamide discontinuation with the concomitant administration of antibiotics, the patient's pneumonia improved, and he was discharged from the hospital. However, within a few days, he was again admitted to the hospital due to pneumonia. He was found to have been using an ultrasonic humidifier at home and was then diagnosed with humidifier lung based on the bronchoscopy and provocative testing findings. Hence, ultrasonic humidifier lung should be considered as a differential diagnosis in patients presenting with the reversed halo sign, and a detailed medical history must be taken.

Simultaneous diagnosis of allergic bronchopulmonary aspergillosis and Mycobacterium avium complex lung disease.

Allergic bronchopulmonary aspergillosis (ABPA) and Mycobacterium avium complex lung disease (MAC-LD) often coexist because bronchiectasis, caused by ABPA or MAC, might be an important predisposing factor for both conditions. Here, we describe a man with asthma symptoms who had centrilobular small nodules and mucoid impaction on chest CT. We diagnosed the patient with simultaneous ABPA and MAC-LD on the basis of bronchoscopy findings. Itraconazole monotherapy led to substantial clinical improvement, avoiding the adverse effects of systemic corticosteroids. Sputum culture conversion of MAC was achieved after switching from itraconazole monotherapy to combination therapy comprising clarithromycin, rifampicin and ethambutol. ABPA recurred but was controlled by reinitiation of itraconazole. Overall, corticosteroid management was avoided for 38 months. Itraconazole monotherapy may be selected as initial treatment for ABPA with chronic infection, including MAC.

Association between serum ferritin level and decreased diffusion capacity 3 months after the onset of COVID-19 pneumonia.

BACKGROUND: Coronavirus disease 2019 (COVID-19) pneumonia can have prolonged sequelae and lead to respiratory dysfunction, mainly because of impaired diffusion capacity for carbon monoxide (DLCO). The clinical factors associated with DLCO impairment, including blood biochemistry test parameters, remain unclear. METHODS: Patients with COVID-19 pneumonia who underwent inpatient treatment between April 2020 and August 2021 were included in this study. A pulmonary function test was performed 3 months after onset, and the sequelae symptoms were investigated. Clinical factors, including blood test parameters and abnormal chest shadows on computed tomography, of COVID-19 pneumonia associated with DLCO impairment were investigated. RESULTS: In total, 54 recovered patients participated in this study. Twenty-six patients (48%) and 12 patients (22%) had sequelae symptoms 2 and 3 months after, respectively. The main sequelae symptoms at 3 months were dyspnea and general malaise. Pulmonary function tests showed that 13 patients (24%) had both DLCO <80% predicted value (pred) and DLCO/alveolar volume (VA) <80% pred, and appeared to have DLCO impairment not attributable to an abnormal lung volume. Clinical factors associated with impaired DLCO were investigated in multivariable regression analysis. Ferritin level of >686.5 ng/mL (odds ratio: 11.08, 95% confidence interval [CI]: 1.84-66.59; p = 0.009) was most strongly associated with DLCO impairment. CONCLUSIONS: Decreased DLCO was the most common respiratory function impairment, and ferritin level was a significantly associated clinical factor. Serum ferritin level could be used as a predictor of DLCO impairment in cases of COVID-19 pneumonia.

The usefulness of change in CT score for evaluating the activity of Mycobacterium abscessus (Mab) pulmonary disease (Mab-PD).

OBJECTIVES: Semi-quantitative CT score is generally used for evaluating the disease status of Mycobacterium abscessus (Mab) Pulmonary disease (Mab-PD). However, its accuracy and clinical usefulness are limited, since the CT score is largely affected by coexisting lung disease. Hence, we hypothesized that numerical change in CT score during the observation period may be useful for evaluating disease activity of Mab-PD. METHODS: Patients diagnosed with Mab-PD based on the official ATS/ERS/ESCMID/IDSA statement at Jikei University Hospital and Jikei Daisan Hospital between 2015 January 1 and 2021 July 31 were included (n = 32). We reviewed the medical records, and bacteriological and laboratory data of the patients. Chest CT was performed at diagnosis in all 32 cases. In 18 cases, chest CT images within 4 years before diagnosis were available. The numerical change in CT score between two time points was calculated and the association of the CT scores with sputum Gaffky score and serum CRP was examined. RESULTS: CT score at diagnosis was not correlated with sputum Gaffky score nor serum CRP, while the difference of absolute value and change rate in CT score between at diagnosis and immediate past CT were well correlated with both sputum Gaffky score and serum CRP. CONCLUSIONS: Chronological change in CT score may more precisely reflect the disease activity of airway mycobacterial burden and systemic inflammation in Mab-PD at the timing of diagnosis.

Impact of emphysema on the prognosis of Mycobacterium avium complex pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major comorbid disease of Mycobacterium avium complex pulmonary disease (MAC-PD). Emphysema is one of the main pathological findings in COPD, a risk factor for chronic pulmonary aspergillosis (CPA), and is associated with poor prognosis. We aimed to clarify the effect of emphysema on mortality in MAC-PD. METHODS: We retrospectively analyzed 203 patients with MAC-PD at The Jikei Daisan Hospital between January 2014 and December 2018. We investigated the mortality and CPA development rates after MAC-PD diagnosis in patients with or without emphysema. RESULTS: Multivariate Cox proportional hazards regression analysis showed the following negative prognostic factors in patients with MAC-PD: emphysema (hazard ratio [HR]: 11.46; 95% confidence interval [CI]: 1.30-100.90; P = 0.028); cavities (HR: 3.12; 95% CI: 1.22-7.94; P = 0.017); and low body mass index (<18.5 kg/m2) (HR: 4.62; 95% CI: 1.63-13.11; P = 0.004). The mortality and occurrence of CPA were higher in MAC-PD patients with than without emphysema (log-rank test, P < 0.0001 and P < 0.0001). CONCLUSION: Our study findings showed that emphysema detected by computed tomography was associated with an increased risk of CPA development and mortality in MAC-PD.

Solitary pulmonary nodule caused by pulmonary Mycobacterium lentiflavum infection.

An 82-year-old Japanese man who previously had descending colon cancer and underwent partial resection showed a growing solitary pulmonary nodule, suspected as lung cancer, on follow-up computed tomography. Thoracoscopic partial lobectomy was therefore performed. The surgical specimen showed granulomatous lesions with necrosis. Mass spectrometry was performed on the sputum specimen collected after surgery, which identified Mycobacterium lentiflavum infection. Antibiotics were not prescribed following surgery, and the patient has not experienced recurrence 2 years since the surgery. To our knowledge, this is the second case of solitary pulmonary nodule and the first case of M. lentiflavum infection treated via surgical resection.

Allergic bronchopulmonary aspergillosis in a patient with ankylosing spondylitis treated with adalimumab.

We herein report a case of allergic bronchopulmonary aspergillosis (ABPA) that occurred in a man treated with adalimumab for ankylosing spondylitis (AS). A 69-year-old man with a history of ankylosing spondylitis treated by adalimumab, an anti-tumour necrosis factor-α (TNF-α) antibody, developed cough and wheezing. Chest computed tomography showed obstruction of dilated left upper lobe bronchus by high attenuation mucus as well as central bronchiectasis. Both Aspergillus-specific immunoglobulin E (IgE) and Aspergillus precipitating antibody were positive and Aspergillus fumigatus was detected in a sputum culture. According to the new diagnostic criteria, the patient was diagnosed with ABPA. His condition rapidly improved after the withdrawal of adalimumab and initiation of prednisolone and itraconazole. Anti-TNF-α antibody might cause ABPA through both aggravation of the host's T-helper 2 immunological response and anti-fungal response.

A tumor-specific mechanism of Treg enrichment mediated by the integrin αvß8.

Regulatory T cells (Tregs) that promote tumor immune evasion are enriched in certain tumors and correlate with poor prognosis. However, mechanisms for Treg enrichment remain incompletely understood. We described a mechanism for Treg enrichment in mouse and human tumors mediated by the αvß8 integrin. Tumor cell αvß8 bound to latent transforming growth factor-ß (L-TGF-ß) presented on the surface of T cells, resulting in TGF-ß activation and immunosuppressive Treg differentiation in vitro. In vivo, tumor cell αvß8 expression correlated with Treg enrichment, immunosuppressive Treg gene expression, and increased tumor growth, which was reduced in mice by αvß8 inhibition or Treg depletion. Structural modeling and cell-based studies suggested a highly geometrically constrained complex forming between αvß8-expressing tumor cells and L-TGF-ß-expressing T cells, facilitating TGF-ß activation, independent of release and diffusion, and providing limited access to TGF-ß inhibitors. These findings suggest a highly localized tumor-specific mechanism for Treg enrichment.

Impact of emphysema on sputum culture conversion in male patients with pulmonary tuberculosis: a retrospective analysis.

BACKGROUND: Although cigarette smoking may have a negative impact on the clinical outcome of pulmonary tuberculosis (PTB), few studies have investigated the impact of smoking-associated lung diseases. Emphysema is a major pathological finding of smoking-related lung damage. We aimed to clarify the effect of emphysema on sputum culture conversion rate for Mycobacterium tuberculosis (MTB). METHODS: We retrospectively studied 79 male patients with PTB confirmed by acid-fast bacillus smear and culture at Jikei University Daisan Hospital between January 2015 and December 2018. We investigated the sputum culture conversion rates for MTB after starting standard anti-TB treatment in patients with or without emphysema. Emphysema was defined as Goddard score ≥ 1 based on low attenuation area < - 950 Hounsfield Unit (HU) using computed tomography (CT). We also evaluated the effect on PTB-related CT findings prior to anti-TB treatment. RESULTS: Mycobacterial median time to culture conversion (TCC) in 38 PTB patients with emphysema was 52.0 days [interquartile range (IQR) 29.0-66.0 days], which was significantly delayed compared with that in 41 patients without emphysema (28.0 days, IQR 14.0-42.0 days) (p < 0.001, log-rank test). Multivariate Cox proportional hazards analysis showed that the following were associated with delayed TCC: emphysema [hazard ratio (HR): 2.43; 95% confidence interval (CI): 1.18-4.97; p = 0.015), cavities (HR: 2.15; 95% CI: 1.83-3.89; p = 0.012) and baseline time to TB detection within 2 weeks (HR: 2.95; 95% CI: 1.64-5.31; p < 0.0001). Cavities and consolidation were more often identified by CT in PTB patients with than without emphysema (71.05% vs 43.90%; p = 0.015, and 84.21% vs 60.98%; p = 0.021, respectively). CONCLUSIONS: This study suggests that emphysema poses an increased risk of delayed TCC in PTB. Emphysema detection by CT might be a useful method for prediction of the duration of PTB treatment required for sputum negative conversion.

Integrin αvß8-expressing tumor cells evade host immunity by regulating TGF-ß activation in immune cells.

TGF-ß is a promising immunotherapeutic target. It is expressed ubiquitously in a latent form that must be activated to function. Determination of where and how latent TGF-ß (L-TGF-ß) is activated in the tumor microenvironment could facilitate cell- and mechanism-specific approaches to immunotherapeutically target TGF-ß. Binding of L-TGF-ß to integrin αvß8 results in activation of TGF-ß. We engineered and used αvß8 antibodies optimized for blocking or detection, which - respectively - inhibit tumor growth in syngeneic tumor models or sensitively and specifically detect ß8 in human tumors. Inhibition of αvß8 potentiates cytotoxic T cell responses and recruitment of immune cells to tumor centers - effects that are independent of PD-1/PD-L1. ß8 is expressed on the cell surface at high levels by tumor cells, not immune cells, while the reverse is true of L-TGF-ß, suggesting that tumor cell αvß8 serves as a platform for activating cell-surface L-TGF-ß presented by immune cells. Transcriptome analysis of tumor-associated lymphoid cells reveals macrophages as a key cell type responsive to ß8 inhibition with major increases in chemokine and tumor-eliminating genes. High ß8 expression in tumor cells is seen in 20%-80% of various cancers, which rarely coincides with high PD-L1 expression. These data suggest tumor cell αvß8 is a PD-1/PD-L1-independent immunotherapeutic target.

Cigarette smoke exposure worsens acute lung injury in antibiotic-treated bacterial pneumonia in mice.

Evidence is accumulating that exposure to cigarette smoke (CS) increases the risk of developing acute respiratory distress syndrome (ARDS). Streptococcus pneumoniae is the most common cause of bacterial pneumonia, which in turn is the leading cause of ARDS. Chronic smokers have increased rates of pneumococcal colonization and develop more severe pneumococcal pneumonia than nonsmokers; yet mechanistic connections between CS exposure, bacterial pneumonia, and ARDS pathogenesis remain relatively unexplored. We exposed mice to 3 wk of moderate whole body CS or air, followed by intranasal inoculation with an invasive serotype of S. pneumoniae. CS exposure alone caused no detectable lung injury or bronchoalveolar lavage (BAL) inflammation. During pneumococcal infection, CS-exposed mice had greater survival than air-exposed mice, in association with reduced systemic spread of bacteria from the lungs. However, when mice were treated with antibiotics after infection to improve clinical relevance, the survival benefit was lost, and CS-exposed mice had more pulmonary edema, increased numbers of BAL monocytes, and elevated monocyte and lymphocyte chemokines. CS-exposed antibiotic-treated mice also had higher serum surfactant protein D and angiopoietin-2, consistent with more severe lung epithelial and endothelial injury. The results indicate that acute CS exposure enhances the recruitment of immune cells to the lung during bacterial pneumonia, an effect that may provide microbiological benefit but simultaneously exposes the mice to more severe inflammatory lung injury. The inclusion of antibiotic treatment in preclinical studies of acute lung injury in bacterial pneumonia may enhance clinical relevance, particularly for future studies of current or emerging tobacco products.

Cigarette Smoke Exposure Worsens Endotoxin-Induced Lung Injury and Pulmonary Edema in Mice.

INTRODUCTION: Cigarette smoking (CS) remains a major public health concern and has recently been associated with an increased risk of developing acute respiratory distress syndrome (ARDS). Bronchoalveolar lavage (BAL) experiments in human volunteers have demonstrated that active smokers develop increased alveolar-epithelial barrier permeability to protein after inhaling lipopolysaccharide (LPS). Here we tested the hypothesis that short-term whole-body CS exposure would increase LPS-induced lung edema in mice. METHODS: Adult mice were exposed in a Teague TE-10 machine to CS from 3R4F cigarettes at 100 mg/m3 total suspended particulates for 12 days, then given LPS or saline intratracheally. Control mice were housed in the same room without CS exposure. Post-mortem measurements included gravimetric lung water and BAL protein, cell counts, and lung histology. Cytokines were measured in lung homogenate by ELISA and in plasma by Luminex and ELISA. RESULTS: In CS-exposed mice, intratracheal LPS caused greater increases in pulmonary edema by gravimetric measurement and histologic scoring. CS-exposed mice also had an increase in BAL neutrophilia, lung IL-6, and plasma CXCL9, a T-cell chemoattractant. Intratracheal LPS concentrated blood hemoglobin to a greater degree in CS-exposed mice, consistent with an increase in systemic vascular permeability. CONCLUSIONS: These results demonstrate that CS exposure in endotoxin injured mice increases the severity of acute lung injury. The increased lung IL-6 in CS-exposed LPS-injured mice indicates that this potent cytokine, previously shown to predict mortality in patients with ARDS, may play a role in exacerbating lung injury in smokers and may have utility as a biomarker of tobacco-related lung injury. IMPLICATIONS: Our results suggest that short-term CS exposure at levels that cause no overt lung injury may still prime the lung for acute inflammatory damage from a "second hit", a finding that mirrors the increased risk of developing ARDS in patients who smoke. This model may be useful for evaluating the acute pulmonary toxicity of existing and/or novel tobacco products and identifying biomarkers of tobacco-related lung injury.

Increased levels of prostaglandin E-major urinary metabolite (PGE-MUM) in chronic fibrosing interstitial pneumonia.

BACKGROUND: Dysregulation of the prostaglandin E2 (PGE2) signaling pathway has been implicated in interstitial pneumonia (IP) pathogenesis. Due to the unstable nature of PGE2, available detection methods may not precisely reflect PGE2 levels. We explored the clinical usefulness of measuring stable prostaglandin E-major urinary metabolite (PGE-MUM) with respect to pathogenesis and extent of chronic fibrosing IP (CFIP), including idiopathic pulmonary fibrosis (IPF), as PGE-MUM is reflective of systemic PGE2 production. METHODS: PGE-MUM was measured by radioimmunoassay in controls (n = 124) and patients with lung diseases (bronchial asthma (BA): n = 78, chronic obstructive pulmonary disease (COPD): n = 33, CFIP: n = 44). Extent of lung fibrosis was assessed by fibrosing score (FS) of computed tomography (CT) (FS1-4). Immunohistochemical evaluation of COX-2 was performed to find PGE2 producing cells in IPF. Human bronchial epithelial cells (HBEC) and lung fibroblasts (LFB) were used in in vitro experiments. RESULTS: Compared to control, PGE-MUM levels were significantly elevated in CFIP. PGE-MUM levels were positively correlated with FS, and inversely correlated with %DLCO in IP (FS 1-3). COX-2 was highly expressed in metaplastic epithelial cells in IPF, but lower expression of EP2 receptor was demonstrated in LFB derived from IPF. TGF-ß induced COX-2 expression in HBEC. CONCLUSIONS: PGE-MUM, elevated in CFIP, is a promising biomarker reflecting disease activity. Metaplastic epithelial cells can be a source of elevated PGE-MUM in IPF.

Role of IL-17A in murine models of COPD airway disease.

Small airway fibrosis is a major pathological feature of chronic obstructive pulmonary disease (COPD) and is refractory to current treatments. Chronic inflammatory cells accumulate around small airways in COPD and are thought to play a major role in small airway fibrosis. Mice deficient in α/ß T cells have recently been shown to be protected from both experimental airway inflammation and fibrosis. In these models, CD4+Th17 cells and secretion of IL-17A are increased. However, a pathogenic role for IL-17 in specifically mediating fibrosis around airways has not been demonstrated. Here a role for IL-17A in airway fibrosis was demonstrated using mice deficient in the IL-17 receptor A (il17ra) Il17ra-deficient mice were protected from both airway inflammation and fibrosis in two different models of airway fibrosis that employ COPD-relevant stimuli. In these models, CD4+ Th17 are a major source of IL-17A with other expressing cell types including γδ T cells, type 3 innate lymphoid cells, polymorphonuclear cells, and CD8+ T cells. Antibody neutralization of IL-17RA or IL-17A confirmed that IL-17A was the relevant pathogenic IL-17 isoform and IL-17RA was the relevant receptor in airway inflammation and fibrosis. These results demonstrate that the IL-17A/IL-17 RA axis is crucial to murine airway fibrosis. These findings suggest that IL-17 might be targeted to prevent the progression of airway fibrosis in COPD.

Cellular senescence and autophagy in the pathogenesis of chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF).

Aging is associated with impairments in homeostasis. Although aging and senescence are not equivalent, the number of senescent cells increases with aging. Cellular senescence plays important roles in tissue repair or remodeling, as well as embryonic development. Autophagy is a process of lysosomal self-degradation that maintains a homeostatic balance between the synthesis, degradation, and recycling of cellular proteins. Autophagy diminishes with aging; additionally, accelerated aging can be attributed to reduced autophagy. Cellular senescence has been widely implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD), a disease of accelerated lung aging, presumably by impairing cell repopulation and by aberrant cytokine secretion in the senescence-associated secretory phenotype. The possible participation of autophagy in the pathogenic sequence of COPD has been extensively explored. Although it has been reported that increased autophagy may induce epithelial cell death, an insufficient reserve of autophagy can induce cellular senescence in bronchial epithelial cells of COPD. Furthermore, advanced age is one of the most important risk factors for the development of idiopathic pulmonary fibrosis (IPF). Telomere shortening is found in blood leukocytes and alveolar epithelial cells from patients with IPF. Accelerated senescence of epithelial cells plays a role in IPF pathogenesis by perpetuating abnormal epithelial-mesenchymal interactions. Insufficient autophagy may be an underlying mechanism of accelerated epithelial cell senescence and myofibroblast differentiation in IPF. Herein, we review the molecular mechanisms of cellular senescence and autophagy and summarize the role of cellular senescence and autophagy in both COPD and IPF.

Metformin attenuates lung fibrosis development via NOX4 suppression.

BACKGROUND: Accumulation of profibrotic myofibroblasts in fibroblastic foci (FF) is a crucial process for development of fibrosis during idiopathic pulmonary fibrosis (IPF) pathogenesis, and transforming growth factor (TGF)-ß plays a key regulatory role in myofibroblast differentiation. Reactive oxygen species (ROS) has been proposed to be involved in the mechanism for TGF-ß-induced myofibroblast differentiation. Metformin is a biguanide antidiabetic medication and its pharmacological action is mediated through the activation of AMP-activated protein kinase (AMPK), which regulates not only energy homeostasis but also stress responses, including ROS. Therefore, we sought to investigate the inhibitory role of metformin in lung fibrosis development via modulating TGF-ß signaling. METHODS: TGF-ß-induced myofibroblast differentiation in lung fibroblasts (LF) was used for in vitro models. The anti-fibrotic role of metfromin was examined in a bleomycin (BLM)-induced lung fibrosis model. RESULTS: We found that TGF-ß-induced myofibroblast differentiation was clearly inhibited by metformin treatment in LF. Metformin-mediated activation of AMPK was responsible for inhibiting TGF-ß-induced NOX4 expression. NOX4 knockdown and N-acetylcysteine (NAC) treatment illustrated that NOX4-derived ROS generation was critical for TGF-ß-induced SMAD phosphorylation and myofibroblast differentiation. BLM treatment induced development of lung fibrosis with concomitantly enhanced NOX4 expression and SMAD phosphorylation, which was efficiently inhibited by metformin. Increased NOX4 expression levels were also observed in FF of IPF lungs and LF isolated from IPF patients. CONCLUSIONS: These findings suggest that metformin can be a promising anti-fibrotic modality of treatment for IPF affected by TGF-ß.

Involvement of PARK2-Mediated Mitophagy in Idiopathic Pulmonary Fibrosis Pathogenesis.

Fibroblastic foci, known to be the leading edge of fibrosis development in idiopathic pulmonary fibrosis (IPF), are composed of fibrogenic myofibroblasts. Autophagy has been implicated in the regulation of myofibroblast differentiation. Insufficient mitophagy, the mitochondria-selective autophagy, results in increased reactive oxygen species, which may modulate cell signaling pathways for myofibroblast differentiation. Therefore, we sought to investigate the regulatory role of mitophagy in myofibroblast differentiation as a part of IPF pathogenesis. Lung fibroblasts were used in in vitro experiments. Immunohistochemical evaluation in IPF lung tissues was performed. PARK2 was examined as a target molecule for mitophagy regulation, and a PARK2 knockout mouse was employed in a bleomycin-induced lung fibrosis model. We demonstrated that PARK2 knockdown-mediated mitophagy inhibition was involved in the mechanism for activation of the platelet-derived growth factor receptor (PDGFR)/PI3K/AKT signaling pathway accompanied by enhanced myofibroblast differentiation and proliferation, which were clearly inhibited by treatment with both antioxidants and AG1296, a PDGFR inhibitor. Mitophagy inhibition-mediated activation of PDGFR signaling was responsible for further autophagy suppression, suggesting the existence of a self-amplifying loop of mitophagy inhibition and PDGFR activation. IPF lung demonstrated reduced PARK2 with concomitantly increased PDGFR phosphorylation. Furthermore, bleomycin-induced lung fibrosis was enhanced in PARK2 knockout mice and subsequently inhibited by AG1296. These findings suggest that insufficient mitophagy-mediated PDGFR/PI3K/AKT activation, which is mainly attributed to reduced PARK2 expression, is a potent underlying mechanism for myofibroblast differentiation and proliferation in fibroblastic foci formation during IPF pathogenesis.

Identification of pathogens by comprehensive real-time PCR versus conventional methods in community-acquired pneumonia in Japanese adults.

BACKGROUND: Community-acquired pneumonia (CAP) has high morbidity and mortality. Unfortunately, the pathogen detection rate using conventional culture methods is relatively low. We compared comprehensive real-time polymerase chain reaction (real-time PCR) analysis of nasopharyngeal swab specimens (NPS) and sputum samples against conventional methods for ability to detect causative pathogens of CAP. METHODS: We prospectively enrolled adult CAP patients, including those with prior antibiotic use, from December 2012 to May 2014. For each patient, causative pathogens were investigated conventionally and by real-time PCR that can identify 6 bacterial and 11 viral pathogens. RESULTS: Patients numbered 92 (mean age, 63 years; 59 male), including 30 (33%) with prior antibiotic use. Considering all patients, identification of causative pathogens by real-time PCR was significantly more frequent than by conventional methods in all patients (72% vs. 57%, p = 0.018). In patients with prior antibiotic use, identification rates also differed significantly (PCR, 77%; conventional, 50%; p = 0.027). Mixed infections were more frequent according to real-time PCR than conventional methods (26% vs. 4%, p < 0.001). By the real-time PCR, Streptococcus pneumoniae was most frequently identified (38%) as a causative pathogen, followed by Haemophilus influenzae (37%) and Mycoplasma pneumoniae (5%). PCR also identified viral pathogens (21%), with sensitivity enhanced by simultaneous examination of both NPS and sputum samples rather than only NPS samples. CONCLUSIONS: Real-time PCR of NPS and sputum samples could better identify bacterial and viral pathogens in CAP than conventional methods, both overall and in patients with prior antibiotic treatment.

Pathogens in COPD exacerbations identified by comprehensive real-time PCR plus older methods.

Respiratory infection is a major cause of exacerbation in chronic obstructive pulmonary disease (COPD). Infectious contributions to exacerbations remain incompletely described. We therefore analyzed respiratory tract samples by comprehensive real-time polymerase chain reaction (PCR) in combination with conventional methods. We evaluated multiple risk factors for prolonged hospitalization to manage COPD exacerbations, including infectious agents. Over 19 months, we prospectively studied 46 patients with 50 COPD exacerbations, collecting nasopharyngeal swab and sputum samples from each. We carried out real-time PCR designed to detect six bacterial species and eleven viruses, together with conventional procedures, including sputum culture. Infectious etiologies of COPD exacerbations were identified in 44 of 50 exacerbations (88%). Infections were viral in 17 of 50 exacerbations (34%). COPD exacerbations caused by Gram-negative bacilli, including enteric and nonfermenting organisms, were significantly associated with prolonged hospitalization for COPD exacerbations. Our results support the use of a combination of real-time PCR and conventional methods for determining both infectious etiologies and risk of extended hospitalization.

PARK2-mediated mitophagy is involved in regulation of HBEC senescence in COPD pathogenesis.

Cigarette smoke (CS)-induced mitochondrial damage with increased reactive oxygen species (ROS) production has been implicated in COPD pathogenesis by accelerating senescence. Mitophagy may play a pivotal role for removal of CS-induced damaged mitochondria, and the PINK1 (PTEN-induced putative kinase 1)-PARK2 pathway has been proposed as a crucial mechanism for mitophagic degradation. Therefore, we sought to investigate to determine if PINK1-PARK2-mediated mitophagy is involved in the regulation of CS extract (CSE)-induced cell senescence and in COPD pathogenesis. Mitochondrial damage, ROS production, and cell senescence were evaluated in primary human bronchial epithelial cells (HBEC). Mitophagy was assessed in BEAS-2B cells stably expressing EGFP-LC3B, using confocal microscopy to measure colocalization between TOMM20-stained mitochondria and EGFP-LC3B dots as a representation of autophagosome formation. To elucidate the involvement of PINK1 and PARK2 in mitophagy, knockdown and overexpression experiments were performed. PINK1 and PARK2 protein levels in lungs from patients were evaluated by means of lung homogenate and immunohistochemistry. We demonstrated that CSE-induced mitochondrial damage was accompanied by increased ROS production and HBEC senescence. CSE-induced mitophagy was inhibited by PINK1 and PARK2 knockdown, resulting in enhanced mitochondrial ROS production and cellular senescence in HBEC. Evaluation of protein levels demonstrated decreased PARK2 in COPD lungs compared with non-COPD lungs. These results suggest that PINK1-PARK2 pathway-mediated mitophagy plays a key regulatory role in CSE-induced mitochondrial ROS production and cellular senescence in HBEC. Reduced PARK2 expression levels in COPD lung suggest that insufficient mitophagy is a part of the pathogenic sequence of COPD.