The Effects of Chronic Intermittent Hypoxia in Bleomycin-Induced Lung Injury on Pulmonary Fibrosis via Regulating the NF-κB/Nrf2 Signaling Pathway / 결핵및호흡기질환

Background@#Obstructive sleep apnea (OSA) is associated with pulmonary fibrosis. Chronic intermittent hypoxia (CIH) is considered to be a surrogate of OSA. However, its exact role in pulmonary fibrosis remains uncertain. Therefore, we investigated the mechanism underlying CIH-induced pulmonary fibrosis and the role of the anti-fibrotic agent in bleomycin (BLE) induced lung injury. @*Methods@#Mice were divided into eight groups: the normoxia (NOR), CIH, NOR plus BLE, CIH plus BLE, NOR plus pirfenidone (PF), CIH plus PF, NOR plus BLE and PF, and CIH plus BLE and PF groups. BLE was administered intratracheally on day 14 following CIH or NOR exposure. Subsequently, the mice were exposed to CIH or NOR for an additional 4 weeks. PF was administered orally on day 5 after BLE instillation once daily for 3 weeks. @*Results@#In the BLE-treated groups, CIH-induced more collagen deposition in lung tissues than NOR, and significantly increased hydroxyproline and transforming growth factor-β expression. The CIH and BLE-treated groups showed increased lung inflammation compared to NOR or CIH groups. Following CIH with BLE treatment, nuclear factor-κB (NF-κB) protein expression was significantly increased, whereas nuclear factor-erythroid-related factor 2 (Nrf2) and heme oxygenase-1 protein levels were decreased. After PF treatment, NF-κB and Kelch-like ECH-associated protein 1 expression were suppressed, and Nrf2 expression was increased. @*Conclusion@#CIH accelerated lung fibrosis in BLE-induced lung injury in mice, potentially by regulating the NF-κB/Nrf2 signaling pathway. Our results implicate PF as a potential therapeutic agent for treating pulmonary fibrosis in individuals with OSA and idiopathic pulmonary fibrosis.

The Effects of Chronic Intermittent Hypoxia in Bleomycin-Induced Lung Injury on Pulmonary Fibrosis via Regulating the NF-κB/Nrf2 Signaling Pathway / 결핵및호흡기질환

Background@#Obstructive sleep apnea (OSA) is associated with pulmonary fibrosis. Chronic intermittent hypoxia (CIH) is considered to be a surrogate of OSA. However, its exact role in pulmonary fibrosis remains uncertain. Therefore, we investigated the mechanism underlying CIH-induced pulmonary fibrosis and the role of the anti-fibrotic agent in bleomycin (BLE) induced lung injury. @*Methods@#Mice were divided into eight groups: the normoxia (NOR), CIH, NOR plus BLE, CIH plus BLE, NOR plus pirfenidone (PF), CIH plus PF, NOR plus BLE and PF, and CIH plus BLE and PF groups. BLE was administered intratracheally on day 14 following CIH or NOR exposure. Subsequently, the mice were exposed to CIH or NOR for an additional 4 weeks. PF was administered orally on day 5 after BLE instillation once daily for 3 weeks. @*Results@#In the BLE-treated groups, CIH-induced more collagen deposition in lung tissues than NOR, and significantly increased hydroxyproline and transforming growth factor-β expression. The CIH and BLE-treated groups showed increased lung inflammation compared to NOR or CIH groups. Following CIH with BLE treatment, nuclear factor-κB (NF-κB) protein expression was significantly increased, whereas nuclear factor-erythroid-related factor 2 (Nrf2) and heme oxygenase-1 protein levels were decreased. After PF treatment, NF-κB and Kelch-like ECH-associated protein 1 expression were suppressed, and Nrf2 expression was increased. @*Conclusion@#CIH accelerated lung fibrosis in BLE-induced lung injury in mice, potentially by regulating the NF-κB/Nrf2 signaling pathway. Our results implicate PF as a potential therapeutic agent for treating pulmonary fibrosis in individuals with OSA and idiopathic pulmonary fibrosis.

Blockade of thymic stromal lymphopoietin and CRTH2 attenuates airway inflammation in a murine model of allergic asthma

Background/Aims@#Thymic stromal lymphopoietin (TSLP) is an epithelial cell-derived cytokine that plays a key role in Th2-mediated inflammation, both directly by promoting the proliferation of naïve CD4 Th2 cells, and indirectly by activating dendritic cells (DCs). TSLP-activated DCs induce the expansion of chemoattractant receptor homologous molecule expressed on Th2 (CRTH2)+ CD4+ Th2 memory cells, which undergo a Th2 response and express prostaglandin D2 (PGD2) synthase. CRTH2, a PGD2 receptor, is a selective Th2-cell surface marker. We investigated the effects of an anti-TSLP antibody (Ab) and a CRTH2 antagonist, as well as their mechanisms of action, in a mouse model of acute asthma. @*Methods@#BALB/c mice were sensitized and challenged with ovalbumin. We then evaluated the effects of the administration of an anti-TSLP Ab either alone or together with a CRTH2 antagonist on cell counts, Th2 cytokine levels in bronchoalveolar fluid, and the levels of epithelium-derived cytokines such as TSLP, interleukin (IL) 33, and IL-25 in lung homogenates, as well as airway hyper-responsiveness (AHR). @*Results@#Anti-TSLP Ab and the CRTH2 antagonist significantly attenuated eosinophilic airway inflammation, AHR, and the expression of Th2 cytokines. The expression of GATA-3 and the levels of IL-33 and IL-25 in lung tissues were affected by the combined anti-TSLP and CRTH2 antagonist treatment. @*Conclusions@#These results suggest that the dual blockade of TSLP and CRTH2 may serve as an effective treatment target for eosinophilic asthma.

Combination of carboplatin and intermittent normobaric hyperoxia synergistically suppresses benzoapyrene-induced lung cancer

BACKGROUND/AIMS: We explored the effects of intermittent normobaric hyperoxia alone or combined with chemotherapy on the growth, general morphology, oxidative stress, and apoptosis of benzo[a]pyrene (B[a]P)-induced lung tumors in mice. METHODS: Female A/J mice were given a single dose of B[a]P and randomized into four groups: control, carboplatin (50 mg/kg intraperitoneally), hyperoxia (95% fraction of inspired oxygen), and carboplatin and hyperoxia. Normobaric hyperoxia (95%) was applied for 3 hours each day from weeks 21 to 28. Tumor load was determined as the average total tumor numbers and volumes. Several markers of oxidative stress and apoptosis were evaluated. RESULTS: Intermittent normobaric hyperoxia combined with chemotherapy reduced the tumor number by 59% and the load by 72% compared with the control B[a]P group. Intermittent normobaric hyperoxia, either alone or combined with chemotherapy, decreased the levels of superoxide dismutase and glutathione and increased the levels of catalase and 8-hydroxydeoxyguanosine. The Bax/Bcl-2 mRNA ratio, caspase 3 level, and number of transferase-mediated dUTP nick end-labeling positive cells increased following treatment with hyperoxia with or without chemotherapy. CONCLUSIONS: Intermittent normobaric hyperoxia was found to be tumoricidal and thus may serve as an adjuvant therapy for lung cancer. Oxidative stress and its effects on DNA are increased following exposure to hyperoxia and even more with chemotherapy, and this may lead to apoptosis of lung tumors.

Clinical significance of serum vascular endothelial growth factor in young male asthma patients

BACKGROUND/AIMS: Vascular endothelial growth factor (VEGF) is an important mediator of angiogenesis. However, little is known about the potential use of serum levels of VEGF as a biomarker for asthma. We investigated the differences in VEGF levels among normal controls, stable asthma patients, and those with exacerbation of acute asthma. All subjects were young males. METHODS: We measured VEGF levels in each patient group, and examined any serial changes in those with acute exacerbation. RESULTS: VEGF levels were significantly higher in stable asthmatic patients and even more so in acute asthmatic patients, compared to healthy controls. However, there was no correlation between VEGF levels and forced expiratory volume in 1 second in patients with stable asthma. In addition, there were no correlations between VEGF levels and asthma control test scores. In patients with acute exacerbation, VEGF levels significantly increased during the acute period; their levels decreased gradually at 7 and 14 days after treatment. CONCLUSIONS: Compared to normal control patients, the serum levels of VEGF were elevated in stable asthma patients and even more elevated in patients with acute exacerbation. However, the role of VEGF as a biomarker in stable asthma is limited. In patients with acute exacerbation, VEGF levels were associated with clinical improvements.

Clinical significance of positive Pneumocystis jirovecii polymerase chain reaction in non-human immunodeficiency virus immunocompromised patients in a real practice

BACKGROUND/AIMS: Pneumocystis jirovecii polymerase chain reaction (PCR) can be helpful in diagnosing Pneumocystis pneumonia (PCP); however it has limitations. We evaluated the prevalence of positive P. jirovecii PCR from non-human immunodeficiency virus (HIV) immunocompromised patients and tried to determine the risk of PCP development. METHODS: Between May 2009 and September 2012, P. jirovecii PCR was performed in bronchoscopic specimens from 1,231 adult non-HIV immunocompromised patients suspected of respiratory infection. Only 169 patients (13.7%) who were tested positive for P. jirovecii PCR were enrolled. Retrospective chart review was performed. PCP was defined in patients with positive P. jirovecii PCR who were treated for PCP based on the clinical decision. RESULTS: From 169 P. jirovecii PCR-positive patients, 90 patients were in the PCP group (53.3%) and 79 patients were in the non-PCP group (46.7%). In the PCP group, 38% of patients expired or aggravated after therapy, whereas the majority of patients (84%) in the non-PCP group recovered without treatment for PCP. Independent risk factors for PCP by binary logistic regression analysis were underlying conditions- hematological malignancies, solid tumors or solid organ transplantation, dyspnea, age < 60 years, and albumin < 2.9 g/dL. CONCLUSIONS: This study suggests that not all P. jirovecii PCR-positive patients need to be treated for PCP. Among P. jirovecii PCR-positive patients, those who are less than 60 years old, with hematological malignancies, solid tumors or solid organ transplantation, low albumin, and with symptoms of dyspnea, the possibility of PCP might be higher. Treatment should also be selected to these patients.

Clinical significance of positive Pneumocystis jirovecii polymerase chain reaction in non-human immunodeficiency virus immunocompromised patients in a real practice

BACKGROUND/AIMS: Pneumocystis jirovecii polymerase chain reaction (PCR) can be helpful in diagnosing Pneumocystis pneumonia (PCP); however it has limitations. We evaluated the prevalence of positive P. jirovecii PCR from non-human immunodeficiency virus (HIV) immunocompromised patients and tried to determine the risk of PCP development. METHODS: Between May 2009 and September 2012, P. jirovecii PCR was performed in bronchoscopic specimens from 1,231 adult non-HIV immunocompromised patients suspected of respiratory infection. Only 169 patients (13.7%) who were tested positive for P. jirovecii PCR were enrolled. Retrospective chart review was performed. PCP was defined in patients with positive P. jirovecii PCR who were treated for PCP based on the clinical decision. RESULTS: From 169 P. jirovecii PCR-positive patients, 90 patients were in the PCP group (53.3%) and 79 patients were in the non-PCP group (46.7%). In the PCP group, 38% of patients expired or aggravated after therapy, whereas the majority of patients (84%) in the non-PCP group recovered without treatment for PCP. Independent risk factors for PCP by binary logistic regression analysis were underlying conditions- hematological malignancies, solid tumors or solid organ transplantation, dyspnea, age < 60 years, and albumin < 2.9 g/dL. CONCLUSIONS: This study suggests that not all P. jirovecii PCR-positive patients need to be treated for PCP. Among P. jirovecii PCR-positive patients, those who are less than 60 years old, with hematological malignancies, solid tumors or solid organ transplantation, low albumin, and with symptoms of dyspnea, the possibility of PCP might be higher. Treatment should also be selected to these patients.

Different anti-remodeling effect of nilotinib and fluticasone in a chronic asthma model

BACKGROUND/AIMS: Inhaled corticosteroids are the most effective treatment currently available for asthma, but their beneficial effect against airway remodeling is limited. The tyrosine kinase inhibitor nilotinib has inhibitory activity against c-kit and the platelet-derived growth factor receptor. We compared the effects of fluticasone and nilotinib on airway remodeling in a chronic asthma model. We also examined whether co-treatment with nilotinib and fluticasone had any synergistic effect in preventing airway remodeling. METHODS: We developed a mouse model of airway remodeling, including smooth muscle thickening, in which ovalbumin (OVA)-sensitized female BALB/c-mice were repeatedly exposed to intranasal OVA administration twice per week for 3 months. Mice were treated with fluticasone and/or nilotinib intranasally during the OVA challenge. RESULTS: Mice chronically exposed to OVA developed eosinophilic airway inflammation and showed features of airway remodeling, including thickening of the peribronchial smooth muscle layer. Both fluticasone and nilotinib attenuated airway smooth muscle thickening. However, only nilotinib suppressed fibrotic changes, demonstrating inhibition of collagen deposition. Fluticasone reduced pro-inflammatory cells, such as eosinophils, and several cytokines, such as interleukin 4 (IL-4), IL-5, and IL-13, induced by repeated OVA challenges. On the other hand, nilotinib reduced transforming growth factor β1 levels in bronchoalveolar lavage fluid and inhibited fibroblast proliferation significantly. CONCLUSIONS: These results suggest that fluticasone and nilotinib suppressed airway remodeling in this chronic asthma model through anti-inflammatory and anti-fibrotic pathways, respectively.

Lung Transplantation in a Patient with Pre-transplant Colonization of Extensively Drug-resistant Acinetobacter baumannii / 대한구급학회지

Colonization of the pre-transplant lung by multidrug-resistant bacteria affects short- and long-term outcomes of lung transplantation. However, there are no case reports on the colonization of a pre-transplant lung by drug-resistant Acinetobacter baumannii. We report a case of extensively drug resistant (XDR) A. baumannii colonization in the tracheobronchial tree that caused severe infectious complications after bilateral lung transplantation. A 23-year-old man diagnosed with bronchiolitis obliterans syndrome (BOS) 4 years earlier with a history of allogenic bone marrow transplantation for acute lymphoblastic leukemia was admitted to the hospital with dyspnea. Due to progressive hypercapnic respiratory failure, long-term mechanical ventilation was started after a tracheostomy was performed, and the patient underwent a bilateral lung transplantation to treat end-stage BOS. After the transplantation, the colonization of XDR A. baumannii caused severe bacterial pneumonia in the early postoperative period. Combined treatment with colistin and meropenem led to recovery from the pneumonia but caused drug-induced renal failure. Because many centers are willing to transplant candidates who are on mechanical ventilation or extracorporeal life support, the incidence of XDR A. baumannii colonization of pretransplant lungs is expected to increase. Further studies are needed to examine pre-transplant management strategies in patients colonized with XDR A. baumannii.

Successful Application of Extracorporeal Membrane Oxygenation for a Patient with Clinical Amniotic Fluid Embolism / 대한구급학회지

Amniotic fluid embolism (AFE) is a rare but potentially fatal complication that occurs acutely during pregnancy or within 12 h of delivery. The management of AFE focuses initially on supportive measures for cardiopulmonary stabilization. Extracorporeal membrane oxygenation should be considered in patients who are unresponsive to medical treatment in order to prevent additional hypoxia and subsequent organ failure. We present a 41-year-old woman with clinical AFE who developed acute respiratory distress syndrome and was treated successfully with extracorporeal membrane oxygenation.

Barotrauma after Manual Ventilation in a Patient with Life-Threatening Massive Hemoptysis / 대한구급학회지

A 36-year-old female patient with aplastic anemia developed massive hemoptysis and was placed on ventilator support. However, airway obstruction by blood clots triggered desaturation and ventilator malfunction. Manual ventilation was initiated to improve oxy-genation, and emergency flexible bronchoscopy was performed to clear the airway. Nevertheless, the patient developed extensive subcutaneous emphysema, pneumothorax, and pneumomediastinum.

Clinical outcomes of extracorporeal membrane oxygenation support in patients with hematologic malignancies

BACKGROUND/AIMS: The clinical outcomes of patients with hematologic malignancies who were treated with extracorporeal membrane oxygenation (ECMO) after the failu re of optimal conventional therapy were determined. METHODS: The medical records of all patients administered ECMO during their stay in a medical intensive care unit of Seoul St. Mary's Hospital between February 2010 and July 2013 were reviewed retrospectively. RESULTS: In total, 15 patients with hematologic malignancies were compared to 33 immunocompetent patients with documented cardiorespiratory failure. Underlying hematologic malignancies were significantly associated with lower overall survival (0.0% vs. 24.2%, p = 0.044). Mortality was significantly associated with a higher 24 hours ECMO inspired fraction of oxygen (0.71 +/- 0.24 vs. 0.47 +/- 0.13, p = 0.015), the development of infection after ECMO (87.5% vs. 25.0%, p = 0.001), and the presence of hyperbilirubinemia (70.0% vs. 0.0%, p < 0.001). Matching of the patients based on their Acute Physiology and Chronic Health Evaluation II scores confirmed the greater risk of mortality in patients with hematologic malignancies (survival: 0.0% vs. 40.0%, p = 0.017). The mean difference in inotropic-equivalent scores after ECMO was significantly lower in the immunocompetent patients than in those with hematologic malignancies (-59.22 +/- 97.83 vs. 53.87 +/- 164.46, p = 0.026). CONCLUSIONS: Patients with hematologic malignancies who require ECMO for respiratory support have poor outcomes. The incidence of complications in these patients did not significantly differ from that in immunocompetent patients.

Lung Transplantation in a Patient with Pre-transplant Colonization of Extensively Drug-resistant Acinetobacter baumannii / 대한중환자의학회지

Colonization of the pre-transplant lung by multidrug-resistant bacteria affects short- and long-term outcomes of lung transplantation. However, there are no case reports on the colonization of a pre-transplant lung by drug-resistant Acinetobacter baumannii. We report a case of extensively drug resistant (XDR) A. baumannii colonization in the tracheobronchial tree that caused severe infectious complications after bilateral lung transplantation. A 23-year-old man diagnosed with bronchiolitis obliterans syndrome (BOS) 4 years earlier with a history of allogenic bone marrow transplantation for acute lymphoblastic leukemia was admitted to the hospital with dyspnea. Due to progressive hypercapnic respiratory failure, long-term mechanical ventilation was started after a tracheostomy was performed, and the patient underwent a bilateral lung transplantation to treat end-stage BOS. After the transplantation, the colonization of XDR A. baumannii caused severe bacterial pneumonia in the early postoperative period. Combined treatment with colistin and meropenem led to recovery from the pneumonia but caused drug-induced renal failure. Because many centers are willing to transplant candidates who are on mechanical ventilation or extracorporeal life support, the incidence of XDR A. baumannii colonization of pretransplant lungs is expected to increase. Further studies are needed to examine pre-transplant management strategies in patients colonized with XDR A. baumannii.

An Unusual Presentation of Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma as Diffuse Pulmonary Infiltrates with Spontaneous Regression / Journal of the Korean Cancer Association, 대한암학회지

A 57-year-old woman presented with cough and dyspnea for 2 months. Computed tomography of the chest showed diffuse ground-glass opacities in both lungs. Histologic examination via thoracoscopic lung biopsy revealed atypical lymphoproliferative lesion. Her symptoms and radiologic findings of the chest improved just after lung biopsy without any treatment. Therefore, she was discharged and monitored at an outpatient clinic. Two months later, pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma was confirmed by the detection of API2-MALT1 translocation in fluorescent in situ hybridization analysis. Although the lung lesions resolved spontaneously, she received chemotherapy due to bone marrow involvement in her staging workup. Pulmonary MALT lymphoma is rare. Nodular or consolidative patterns are the most frequent radiologic findings. Although the disease has an indolent growth, it rarely resolves without treatment. We report an unusual case of pulmonary MALT lymphoma with diffuse interstitial abnormalities on image and spontaneous regression on clinical course.

Low Grade Pulmonary Lymphomatoid Granulomatosis with an Endobronchial Mass / 결핵및호흡기질환

Lymphomatoid granulomatosis (LYG) is an angiocentric and angiodestructive neoplastic proliferation of B and T lymphocytes commonly involving the lungs. Epstein-Barr virus is commonly detected in lesional cells. We report a case of a 54-year-old female with underlying monoclonal gammopathy of unknown significance who presented with a 4 week history of dyspnea and cough. Computed tomography scan of the chest showed multiple lung nodules as well as endobronchial narrowing causing atelectasis at the left upper lobe. Bronchoscopic findings revealed obstruction at the lingula segment due to endobronchial mass as a rare presentation. Bronchoscopic biopsy was diagnosed with LYG grade 1. After treatment, the endobronchial mass and lung lesions were completely resolved. However, the patient eventually evolved to malignant lymphoma after 1 year.

Successful Application of Extracorporeal Membrane Oxygenation for a Patient with Clinical Amniotic Fluid Embolism / 대한중환자의학회지

Amniotic fluid embolism (AFE) is a rare but potentially fatal complication that occurs acutely during pregnancy or within 12 h of delivery. The management of AFE focuses initially on supportive measures for cardiopulmonary stabilization. Extracorporeal membrane oxygenation should be considered in patients who are unresponsive to medical treatment in order to prevent additional hypoxia and subsequent organ failure. We present a 41-year-old woman with clinical AFE who developed acute respiratory distress syndrome and was treated successfully with extracorporeal membrane oxygenation.

Barotrauma after Manual Ventilation in a Patient with Life-Threatening Massive Hemoptysis / 대한중환자의학회지

A 36-year-old female patient with aplastic anemia developed massive hemoptysis and was placed on ventilator support. However, airway obstruction by blood clots triggered desaturation and ventilator malfunction. Manual ventilation was initiated to improve oxy-genation, and emergency flexible bronchoscopy was performed to clear the airway. Nevertheless, the patient developed extensive subcutaneous emphysema, pneumothorax, and pneumomediastinum.

Pneumatosis Intestinalis Complicated by Pneumoperitoneum in a Patient with Asthma / 결핵및호흡기질환

Pneumatosis intestinalis (PI) is a very rare condition that is defined as the presence of gas within the subserosal or submucosal layer of the bowel. PI has been described in association with a variety of conditions including gastrointestinal tract disorders, pulmonary diseases, connective tissue disorders, organ transplantation, leukemia, and various immunodeficiency states. We report a rare case of a 74-year-old woman who complained of dyspnea during the management of acute asthma exacerbation and developed PI; but, it improved without any treatment.

Clinical Characteristics of Asthma Combined with COPD Feature

PURPOSE: In clinical practice, some patients with asthma show incompletely reversible airflow obstruction, resembling chronic obstructive pulmonary disease (COPD). The aim of this study was to analyze this overlap phenotype of asthma with COPD feature. MATERIALS AND METHODS: A total of 256 patients, over the age of 40 years or more with a diagnosis of asthma, based on either 1) positive response to bronchodilator: >200 mL forced expiratory volume in 1 s (FEV1) and >12% baseline or 2) positive methacholine or mannitol provocation test, were enrolled. Among the asthma patients, we defined the overlap group with incompletely reversible airflow obstruction [postbronchodilator FEV1/forced vital capacity (FVC) or =70) and overlap group (38%, n=97, postbronchodilator FEV1/FVC <70). The overlap group was older, and contained more males and a higher percentage of current or ex-smokers than the asthma only group. Significantly lower FEV1 and higher total lung capacity, functional residual capacity, and residual volume were observed in the overlap group. Finally, significantly lower serum eosinophil count and higher IgE were seen in the overlap group. CONCLUSION: Our results showed that the overlap phenotype was older, male asthmatic patients who have a higher lifetime smoking intensity, more atopy and generally worse lung function.

A Case of Atypical Manifestation of Pulmonary Alveolar Proteinosis Associated with Myelodysplastic Syndrome / 대한내과학회지

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the accumulation of lipoproteinaceous material in the distal air spaces. Secondary forms of PAP are caused by underlying diseases, in particular tumorous conditions, the most common of which are hematologic malignancies, such as chronic myeloid leukemia and myelodysplastic syndrome (MDS). We herein describe a case of atypical manifestation of PAP caused by MDS, which initially mimicked military tuberculosis with severe thrombocytopenia because of radiologic features showing necrotic mediastinal lymphadenopathies and diffuse bronchiolitis. A 46-year-old male visited the hospital complaining of coughing and general weakness and was presumptively diagnosed with military tuberculosis combined with MDS. He was treated with antituberculous medication, but the lung lesions did not improve and dyspnea only progressed. Finally, he underwent lung biopsy and was diagnosed with atypical pattern of PAP associated with MDS.