Analysis of nocturnal desaturation waveforms using algorithms in patients with idiopathic pulmonary fibrosis.

PURPOSE: Sleep-disordered breathing is recognized as a comorbidity in patients with idiopathic pulmonary fibrosis (IPF). Among them, nocturnal hypoxemia has been reported to be associated with poor prognosis and disease progression. We developed a diagnostic algorithm to classify nocturnal desaturation from percutaneous oxygen saturation (SpO2) waveform patterns: sustained pattern, periodic pattern, and intermittent pattern. We then investigated the prevalence of nocturnal desaturation and the association between the waveform patterns of nocturnal desaturation and clinical findings of patients with IPF. METHODS: We prospectively enrolled patients with IPF from seven general hospitals between April 2017 and March 2020 and measured nocturnal SpO2 and nasal airflow by using a home sleep apnea test. An algorithm was used to classify the types of nocturnal desaturation. We evaluated the association between sleep or clinical parameters and each waveform pattern of nocturnal desaturation. RESULTS: Among 60 patients (47 men) who met the eligibility criteria, there were 3 cases with the sustained pattern, 49 cases with the periodic pattern, and 41 cases with the intermittent pattern. Lowest SpO2 during sleep and total sleep time spent with SpO2 < 90% were associated with the sustained pattern, and apnea-hypopnea index was associated with the intermittent pattern. CONCLUSION: We demonstrated the prevalence of each waveform and association between each waveform and sleep parameters in patients with IPF. This classification algorithm may be useful to predict the degree of hypoxemia or the complication of obstructive sleep apnea.

A case of granulomatosis with polyangiitis (Wegener's granulomatosis) presenting with marked inflamed tracheobronchial mucosa.

A 70-year-old man was admitted to our hospital because of weight loss and persistent dry cough. Chest radiograph and CT showed multiple infiltrates in the bilateral upper lobes and the remarkably thickened bronchial walls. Bronchoscopy revealed diffuse erythema and edema of the tracheobronchial mucosa without any ulcerous legions. Serum MPO-ANCA was positive (155 EU). Transbronchial biopsy was performed and revealed necrotic granulomas with multinucleated giant cells in the bronchial/bronchiolar and parenchymal lesions. Thus, we diagnosed it as a localized form of granulomatosis with polyangiitis (GPA, Wegener's granulomatosis). After treatment with corticosteroid and cyclophosphamide, the bronchial findings were entirely resolved. We report here a rare case of GPA presenting with markedly inflamed tracheobronchial mucosa.

Targeted inactivation of endothelial lipase attenuates lung allergic inflammation through raising plasma HDL level and inhibiting eosinophil infiltration.

Endothelial lipase (EL) is a novel phospholipase that determines plasma high-density lipoprotein cholesterol (HDL-C) levels. We have investigated the role of HDL-C in lung allergic inflammation by using EL knockout (EL-KO) mice that are high in HDL-C. EL-KO and wild-type control mice were sensitized and challenged with ovalbumin to evoke eosinophilic inflammation in the lung. EL was expressed in epithelial cells, alveolar type II cells, and endothelial cells in the lung, and its expression was upregulated during inflammation. Concomitant with attenuated hyperresponsiveness of the airway smooth muscles, the number of eosinophils in bronchoalveolar lavage and the expression of VCAM-1 were lower in EL-KO mice than in control mice. HDL reduced cytokine-induced VCAM-1 expression in cultured endothelial cells. When plasma HDL levels were decreased to similar levels in both mouse groups by adenovirus-mediated overexpression of EL, however, eosinophil infiltration was still lower in EL-KO mice. In vitro adhesion assays revealed that EL expression on the cell surface promoted the interaction of eosinophils through the ligand-binding function of EL. In summary, targeted inactivation of EL attenuated allergic inflammation in the lung, and the protective effects in EL-KO mice were associated with high plasma HDL levels, downregulation of VCAM-1, and loss of the direct ligand-binding function of EL. Thus EL is a novel modulator of the progression of allergic asthma.

Inhalation of urokinase-type plasminogen activator reduces airway remodeling in a murine asthma model.

The airway remodeling that occurs in asthma is characterized by an excess of extracellular matrix deposition in the submucosa, hyperplasia/hypertrophy of smooth muscle, goblet cell metaplasia, and accumulation of fibroblasts/myofibroblasts. The urokinase-type plasminogen activator (uPA)/plasmin system participates in pericellular proteolysis and is capable of directly degrading matrix components, activating latent proteinases, and activating growth factors. In a mouse ovalbumin (OVA) asthma model, we increased plasminogen activator activity in the lung by administering exogenous uPA or by using mice genetically deficient in the uPA inhibitor plasminogen activator inhibitor-1 (PAI-1) to assess the role of this system in asthma pathogenesis. After intraperitoneal OVA sensitization, mice inhaled OVA plus uPA (500 IU/mouse) or saline by ultrasonic nebulization for 3 wk. When studied 24 h after the final exposure, the groups with upregulated plasmin activity had significantly reduced subepithelial fibrosis within the airway walls and had decreased airway hyperresponsiveness (AHR) to methacholine. Morphometric analysis showed that subepithelial wall thickening of the bronchi (subepithelial area ratio) was also reduced, as were collagen and alpha-smooth muscle actin. Upregulation of plasmin activity also increased the level of hepatocyte growth factor activity in bronchoalveolar lavage fluid, whereas the release of transforming growth factor-beta was decreased. The administration of uPA 1 wk after the last OVA inhalation also significantly reduced lung hydroxyproline content and AHR. These results show that enhancing uPA/plasmin activity lessens the airway remodeling in a murine asthma model.

Diffuse periairway thickening in patients with Mikulicz disease.

A 70-year-old woman presented with dry mouth, bilateral swelling of the eyelids, and abnormal taste and smell sensations that had persisted for 3 years. She was diagnosed with Mikulicz disease and presented with dyspnea on exertion afterwards. Chest computed tomography and magnetic resonance imaging showed wall thickening of the trachea and bilateral bronchus. Transbronchial needle aspiration showed lymphoproliferative lesion in the tracheobronchus. The patient was treated with corticosteroid, which improved all of her clinical symptoms, computed tomography, and magnetic resonance findings. In this case, we presented a rare condition of coexistent Mikulicz disease with tracheobroncial wall thickening caused by lymphoproliferation without lesions in small airways or lung.

Adenoviral transfer of rho family proteins to lung cancer cells ameliorates cell proliferation and motility and increases apoptotic change.

Lung cancer is still a very severe disease which has a low survival rate due to local invasion and metastasis potentials in spite of many clinical challenges using anti-cancer drugs. Rho family small GTPases play pivotal roles in cell invasion and metastasis during carcinogenesis. In this study, we explored the inhibitory effect of adenoviral vector encoding dominant negative mutants of Rac, RhoA, and ROCK in human non-small cell lung carcinoma cell lines (A549 and SQ5) and mouse carcinoma cell line (Lewis lung carcinoma, LLC). These cells showed high expression of Rac, Rho, and ROCK, whereas only faint bands were detected in normal human lung epithelial cells, BET-1A. The efficiency of adenoviral vector transfer was stronger in A549 and SQ5 cells than LLC cells. Dominant negative forms of RhoA (Rho-DN) and Rac (Rac-DN) decreased cell proliferation in WST-8 assay and increased the number of apoptotic cells in both A549 and SQ5 cells by Hoechst 33258 and TUNEL staining. On the other hand, DN form of ROCK (ROCK-DN) did not show any apparent changes compared with the other proteins. Transwell chamber analysis showed that migration/invasion activity was significantly suppressed by gene transfection both in A549 and SQ5 cells and that ROCK-DN gene transfer required a higher multiplicity of infection to show effects similar to Rho and Rac. Although the effect of gene therapy is cell-dependent, these data suggest that adenoviral gene transfer with Rho family small GTPases is one good approach to lung cancer therapy.

Neutrophil elastase inhibitor (sivelestat) attenuates subsequent ventilator-induced lung injury in mice.

Mechanical ventilation can paradoxically cause acute lung injury, which is termed ventilator-induced lung injury. Neutrophil recruitment and neutrophil elastase release play a central role in the pathogenesis of ventilator-induced lung injury including cell damage, extracellular matrix degradation and alveolar-capillary hyperpermeability. We therefore speculated that neutrophil elastase inhibition ameliorates ventilator-induced lung injury. Anesthetized C57/BL6 mice received mechanical ventilation with a high tidal volume (V(T); 20 ml/kg) for 4 h. The neutrophil elastase inhibitor (sivelestat, 100 mg/kg) or saline was given intraperitoneally (i.p.) 30 min before ventilation. Sivelestat completely inhibited both neutrophil elastase and myeloperoxidase activities that were increased by ventilation, and attenuated the histopathological degree of lung damage, neutrophil accumulation and lung water content, as well as the concentration of macrophage inflammatory protein (MIP)-2, interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha in bronchoalveolar lavage fluid and serum. Moreover, mechanical ventilation increased the phosphorylation of c-Jun NH2-terminal kinase (JNK) and the expression of early growth response gene-1 (Egr-1) mRNA, and these increases were also recovered by sivelestat. The terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) staining revealed apoptotic cells mainly in alveolar epithelial cells and their numbers corresponded to histological damage. These data suggested that sivelestat could protect against ventilator-induced lung injury by suppressing apoptotic responses through mechanical stress-induced cell signaling in addition to inhibiting neutrophil chemotaxis.

Overexpression of nitric oxide synthase by the endothelium attenuates bleomycin-induced lung fibrosis and impairs MMP-9/TIMP-1 balance.

BACKGROUND: Nitric oxide (NO) produced by endothelial NO synthase (eNOS) is thought to effect an anti-inflammatory response, but its mechanism is still unknown. METHODS: eNOS transgenic (eNOS-TG) mice and their littermate controls (C57/BL6) were used to clarify the role of NO derived from eNOS. Bleomycin hydrochloride (1 U/body/day) or PBS was injected intraperitoneally. RESULTS: Subpleural fibrotic changes and hydroxyproline content in the eNOS-TG mice were significantly reduced compared with those of the wild-type (WT) mice by day 56. Administration of N(omega)-nitro-L-arginine methyl ester, a potent inhibitor of NO synthase, worsened the fibrotic response in bleomycin-treated eNOS-TG mice. Gelatinolytic activity in lung homogenates, corresponding to metalloproteinase-9 (MMP-9), was significantly increased in bleomycin-injured WT mice on day 14. In contrast, the level of tissue inhibitor of metalloproteinases-1 (TIMP-1), an endogenous MMP-9 inhibitor, was increased in the bleomycin-treated eNOS-TG mice compared with WT. Immunohistochemical analysis demonstrated that MMP-9 and TIMP-1 were strongly expressed in inflammatory cells, including subpleural fibrotic lesions. CONCLUSION: These data suggested that eNOS overexpression attenuates bleomycin-induced lung injury by ameliorating the MMP-9/TIMP-1 balance.

Ventilator-induced lung injury is reduced in transgenic mice that overexpress endothelial nitric oxide synthase.

Although mechanical ventilation (MV) is an important supportive strategy for patients with acute respiratory distress syndrome, MV itself can cause a type of acute lung damage termed ventilator-induced lung injury (VILI). Because nitric oxide (NO) has been reported to play roles in the pathogenesis of acute lung injury, the present study explores the effects on VILI of NO derived from chronically overexpressed endothelial nitric oxide synthase (eNOS). Anesthetized eNOS-transgenic (Tg) and wild-type (WT) C57BL/6 mice were ventilated at high or low tidal volume (Vt; 20 or 7 ml/kg, respectively) for 4 h. After MV, lung damage, including neutrophil infiltration, water leakage, and cytokine concentration in bronchoalveolar lavage fluid (BALF) and plasma, was evaluated. Some mice were given N(omega)-nitro-L-arginine methyl ester (L-NAME), a potent NOS inhibitor, via drinking water (1 mg/ml) for 1 wk before MV. Histological analysis revealed that high Vt ventilation caused severe VILI, whereas low Vt ventilation caused minimal VILI. Under high Vt conditions, neutrophil infiltration and lung water content were significantly attenuated in eNOS-Tg mice compared with WT animals. The concentrations of macrophage inflammatory protein-2 in BALF and plasma, as well as plasma tumor necrosis factor-alpha and monocyte chemoattractant protein-1, also were decreased in eNOS-Tg mice. L-NAME abrogated the beneficial effect of eNOS overexpression. In conclusion, chronic eNOS overexpression may protect the lung from VILI by inhibiting the production of inflammatory chemokines and cytokines that are associated with neutrophil infiltration into the air space.

Localization of plasminogen activator activity within normal and injured lungs by in situ zymography.

During inflammatory lung injury, the fibrinolytic activity that is normally present within bronchoalveolar lavage (BAL) fluid (BALF) is often suppressed due to increased levels of inhibitors, including plasminogen activator inhibitor (PAI)-1. Despite this suppression, BALF frequently contains fibrin degradation products, indicating persistence of fibrinolytic activity within the lung. To address this discrepancy and determine the sites where plasminogen activation is occurring, we developed an in situ zymographic technique for frozen sections of lung tissue that localizes plasminogen activator activity at the cellular level. After validating the method using enzyme inhibitors and mice with genetic manipulations of their plasminogen system genes, we applied the technique to lungs of normal and bleomycin-exposed mice. In normal mice, plasminogen activator activity was localized to bronchial epithelial cells, cells of the alveolar walls, and alveolar macrophages. After bleomycin exposure, in situ zymography showed that, despite loss of fibrinolytic activity within BALF, abundant enzymatic activity was associated with aggregates of inflammatory cells. PAI-1-deficient mice that are protected from bleomycin-induced fibrosis had preserved plasminogen activator activity in BALF and increased tissue activity, as determined by in situ zymography. We conclude that analysis of BALF does not adequately reflect the fibrinolytic activity that persists within microenvironments of the lung during inflammation.

[A case of pneumocystis carinii pneumonia associated with low dose methotrexate treatment for rheumatoid arthritis and trimethoprim-sulphamethoxazole induced pancytopenia].

A 64-year-old man was admitted to our hospital complaining of dyspnea and fever. He had been treated with low-dose methotrexate for rheumatoid arthritis. Chest radiography showed diffuse ground-glass attenuation in both lung fields, and hypoxia was detected. Pneumosystis carinii pneumonia was demonstrated on transbronchial lung biopsy, and the serum beta-D glucan level was high. We started treatment with trimethoprim-sulphamethoxazole, but respiratory failure worsened, and drug-induced pancytopenia occurred. Although trimethoprim-sulphamethoxazole was stopped, pancytopenia persisted and the patient required ventilatory support. After we changed the medication from trimethoprim-sulphamethoxazole to pentamidine, respiratory failure improved. It was thought that pneumocystis carinii pneumonia was associated with low-dose methotrexate and that trimethoprim-sulphamethoxazole interacted with methotrexate to induce severe pancytopenia.