Analysis of the relationship between comorbid obstructive sleep apnea and clinical outcomes in patients with asthma in Japan.

BACKGROUND: Asthma and obstructive sleep apnea (OSA) are prevalent chronic respiratory disorders, which often coexist and interact with each other. Obesity is an important risk factor shared by them. The rate of obesity is lower in Japan versus Western countries. Hence, the co-existence of asthma and OSA has not been investigated in Japan. METHODS: Ninety-seven outpatients with asthma were recruited. Patients wore a portable monitor for sleep study. Background data, pulmonary function, blood tests, and patient-reported outcomes including gastroesophageal reflux disease, sleepiness, sleep quality, asthma control, cough and respiratory symptoms, and health status, were assessed. RESULTS: Of the patients, 19 (19.6 %), 40 (41.2 %), 24 (24.7 %), and 14 (14.4 %) were classified into non-, mild, moderate, and severe OSA groups. Non-OSA patients were younger than those in other groups (p < 0.05). The BMI of patients with moderate and severe OSA, was higher than that of non-OSA patients (p < 0.05). Pulmonary function, FeNO, serum IgE, and the number of peripheral eosinophils were not significantly different between groups. Nonetheless, compared with the other groups, treatment step was the highest, and the Asthma Control Test, Leicester Cough Questionnaire, COPD Assessment Test, and Asthma Health Questionnaire-33 yielded worst scores in the severe OSA group, and predicted the severe OSA after adjustment by BMI. CONCLUSIONS: Moderate and severe OSA are highly prevalent among patients with asthma in Japan. Pulmonary function did not differ between groups. However, patients with asthma and severe OSA were linked to more asthma treatment, worse asthma control, more symptoms and cough, and worse health status.

Predictive value of serum high-mobility group box 1 levels for checkpoint inhibitor pneumonitis.

BACKGROUND AND OBJECTIVE: Checkpoint inhibitor pneumonitis (CIP), caused by the anti-programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) antibody, can be a fatal adverse event in cancer patients. However, no predictive biomarkers for CIP have been identified. Because high-mobility group box 1 (HMGB1) can aggravate lung injury and potentially increase the immune response, it was investigated as a predictive blood marker. METHODS: Blood samples, prospectively stored before anti-PD-1/PD-L1 monotherapy between December 2015 and October 2020, were obtained at two university hospitals from 87 and 43 non-small cell lung cancer (NSCLC) patients (discovery and validation cohorts, respectively). We retrospectively evaluated the association of serum HMGB1 levels with the incidence of CIP developed within 3 months of initiating anti-PD-1/PD-L1 therapy. RESULTS: CIP was observed in 9 (10.3%) and 6 (14.0%) patients in the discovery and validation cohorts, respectively. In each cohort, serum HMGB1 levels were significantly and reproducibly higher in patients with CIP. In the discovery cohort, an HMGB1 cut-off level of 11.24 ng/ml was identified by receiver operating characteristic analysis. CIP incidence in the HMGB1high subgroup was significantly higher than that in the HMGB1low subgroup in the discovery (41.2% vs. 2.9%) and validation cohorts (36.4% vs. 6.3%). In an exploratory pooled analysis, three patients died of grade 5 CIP; a 19.29 ng/ml HMGB1 cut-off level detected grade 5 CIP with 100% sensitivity and 96.85% specificity. CONCLUSION: Our results suggest that HMGB1 may be a potential blood marker to predict the development and severity of CIP in NSCLC patients.

Development of a Communication Tool between Patients and Physicians for Recognizing COPD Exacerbations in Japan.

In Japan, exacerbations are underreported compared with other countries, possibly due in part to a failure to recognize them. This study aimed to create a simple chronic obstructive pulmonary disease (COPD) Exacerbation Recognition Tool (CERT-J) specifically for Japanese patients. Patients ≥40 years with confirmed COPD or asthma-COPD overlap were included. Focus groups were held to identify words and phrases used by patients to describe symptoms associated with an exacerbation, resulting in candidate items being identified. Following cognitive debriefing, the items were refined based on item frequency, level of endorsement and effect of demographic factors. Exploratory factor analysis (EFA) was then performed to inform an expert panel's choice of items to form the new tool. A total of 41 patients were included in the focus groups and nine patients performed the cognitive debrief. Following this, the expert panel identified 26 items for testing in a further 100 patients (mean age 72 years, forced expiratory volume in 1 s 54.8% predicted and 1.8 exacerbations in the preceding 12 months). Eleven items were associated with breathlessness or activity limitation and seven of these were the most frequently endorsed. EFA identified four factors, with one (breathlessness) being dominant. The expert panel recommended that the CERT-J should include six items: breathlessness and activity limitation (3 items), cough (1 item) and phlegm (2 items). The final CERT-J should benefit patients with COPD by providing them with an increased understanding and recognition of exacerbations.Clinical Trial Registration: GSK K.K (jRCT1080224526).

CD44 is critical for the enhancing effect of hyaluronan in allergen-specific sublingual immunotherapy in a murine model of chronic asthma.

Allergen-specific sublingual immunotherapy (SLIT) is a potentially effective disease-modification treatment for patients with allergic asthma. Because CD44 signaling enhances regulatory T (Treg) cell-induction, administering CD44 ligands such as hyaluronan (HA) with allergen-specific SLIT may enhance the therapeutic effects. We evaluated the role of CD44 in Treg cell-induction in T helper type 2 (Th2)-mediated chronic airway inflammation using CD44-/- mice and the efficacy of HA on SLIT in a Dermatophagoides farinae (Df)-induced murine model of chronic asthma. Th2 responses and Treg cell induction were evaluated in CD44-/- mice. We devised a new SLIT model of Df-induced chronic asthma utilizing HA as an adjuvant. The effects of HA added to the new SLIT model were evaluated by the early asthmatic response (EAR) and airway hyperresponsiveness (AHR), eosinophilic airway inflammation, and serum Df-specific IgE levels. Th2-mediated chronic eosinophilic airway inflammation was worse in CD44-/- mice compared with Df-sensitized wild-type (WT) mice. HA enhanced the effect of Df-induced Treg cells in a CD44-dependent manner. Sublingual Df treatment in combination with HA, but not alone, normalized EAR and AHR, and significantly reduced the serum IgE levels and the bronchoalveolar lavage fluid (BALF) eosinophil number. HA also induced Treg cells in a Df-sensitized spleen cell culture in a CD44-dependent manner. The treatment-enhancing effects of HA in this SLIT model were diminished in CD44-/- mice. CD44 is a key contributor to Treg cell induction and critical for the enhancing effects of HA in a Df-induced murine model of chronic asthma.

Patient-reported dyspnea and health predict waitlist mortality in patients waiting for lung transplantation in Japan.

BACKGROUND: Waitlist mortality due to donor shortage for lung transplantation is a serious problem worldwide. Currently, the selection of recipients in Japan is mainly based on the registration order. Hence, scientific evidence for risk stratification regarding waitlist mortality is urgently needed. We hypothesized that patient-reported dyspnea and health would predict mortality in patients waitlisted for lung transplantation. METHODS: We analyzed factors related to waitlist mortality using data of 203 patients who were registered as candidates for lung transplantation from deceased donors. Dyspnea was evaluated using the modified Medical Research Council (mMRC) dyspnea scale, and the health status was determined with St. George's Respiratory Questionnaire (SGRQ). RESULTS: Among 197 patients who met the inclusion criteria, the main underlying disease was interstitial lung disease (99 patients). During the median follow-up period of 572 days, 72 patients died and 96 received lung transplantation (69 from deceased donors). Univariable competing risk analyses revealed that both mMRC dyspnea and SGRQ Total score were significantly associated with waitlist mortality (p = 0.003 and p < 0.001, respectively) as well as age, interstitial lung disease, arterial partial pressure of carbon dioxide, and forced vital capacity. Multivariable competing risk analyses revealed that the mMRC and SGRQ score were associated with waitlist mortality in addition to age and interstitial lung disease. CONCLUSIONS: Both mMRC dyspnea and SGRQ score were significantly associated with waitlist mortality, in addition to other clinical variables such as patients' background, underlying disease, and pulmonary function. Patient-reported dyspnea and health may be measured through multi-dimensional analysis (including subjective perceptions) and for risk stratification regarding waitlist mortality.

Prospective associations of sleep apnea, periodic limb movements, and plasma fibrinogen level.

PURPOSE: Our previous cross-sectional study showed that periodic limb movements during sleep (PLMS) were frequently found in patients with obstructive sleep apnea (OSA) and that both OSA and PLMS were associated with higher plasma fibrinogen levels. We explored the longitudinal relationships among these factors. METHODS: Plasma fibrinogen levels were measured in 333 consecutive patients who underwent polysomnography to diagnose OSA. Patients who initiated continuous positive airway pressure (CPAP) underwent follow-up polysomnography after 3 months of CPAP use. They were categorized into groups with good or poor adherence (% days with ≥ 4 h/night of CPAP use ≥ 70% or < 70%, respectively). Changes in sleep parameters and plasma fibrinogen levels during the treatment period were compared between these groups. RESULTS: The cross-sectional analysis of all reviewed 333 patients indicated that fibrinogen levels were associated with the severities of OSA and PLMS. The 60 patients (27 good and 33 poor adherence) who underwent follow-up polysomnography were included in the longitudinal analysis. The median (interquartile range) periodic limb movement index did not change significantly from CPAP titration to the 3-month follow-up (good adherence: 10.5 (0-23.8) to 10.8 (0-70.2) events/h, p = 0.21; poor adherence: 1.2 (0-14.3) to 0.8 (0-15.7) events/h, p = 0.67). However, the plasma fibrinogen level significantly decreased only in the good adherence group (good adherence: baseline 275 ± 46 to follow-up 255 ± 47 mg/dl, p < 0.01; poor adherence: 277 ± 52 to 284 ± 70 mg/dl, p = 0.48). CONCLUSIONS: These results did not support a longitudinal association between PLMS and OSA. However, good adherence to CPAP could reduce plasma fibrinogen levels, thus ameliorating elevations in plasma fibrinogen as a risk factor for future cardiovascular events.

Sleep quality and its association with health-related quality of life of patients on lung transplantation waitlist in Japan.

PURPOSE: Poor quality of sleep is a common feature in patients with various lung diseases and affects their health-related quality of life (HRQL). We evaluated sleep quality and HRQL in patients on the waitlist for lung transplantation in Japan. METHODS: In this prospective study, patient-reported and physiological data were collected from patients newly registered on the waitlist for lung transplantation in Japan. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI) and HRQL using the St. George's Respiratory Questionnaire (SGRQ). The frequency of poor sleep quality, correlations between sleep quality and various clinical parameters, and predictive factors of sleep quality were examined. RESULTS: Of 193 patients, the three most-frequent indications for lung transplantation were interstitial pneumonia (n = 96), pulmonary complications of hematopoietic stem cell transplantation (n = 25), and pulmonary hypertension (n = 17). Poor sleep quality (PSQI > 5) was observed in 102 patients (53%) and was significantly associated with worse Hospital Anxiety and Depression Score (HADS), worse SGRQ score, worse modified Medical Research Council Dyspnea score, and shorter 6-min walk distance. However, it was not associated with sex, pulmonary function, interstitial pneumonia, or arterial blood gas. Stepwise multiple regression analysis indicated that poor sleep quality was explained significantly by HADS anxiety (23%) and SGRQ Symptoms (10%). CONCLUSION: Poor sleep quality was found to be common among patients on the lung transplantation waitlist in Japan. The two most significant factors responsible for impaired sleep quality were anxiety and respiratory symptoms. Additional care should be taken to ensuring a better quality of sleep for such patients.

Role of interleukin 5-induced eosinophils in interleukin 33-triggered airway inflammation in mice.

BACKGROUND: Interleukin (IL)-5 is essential for allergen induced eosinophilic airway inflammation, but not activation of T helper type 2 (Th2) cells in the lung. Although an excessive Th2 reaction is observed without IL-5 signaling, the mechanisms have remained unknown. OBJECTIVE: To evaluate the negative-feedback mechanism in eosinophilic airway inflammation, we examined IL-33 triggered eosinophilic airway inflammation in IL-5Rα-/- mice. METHODS: Mice were administered intranasal IL-33 for 3 days. Airway hyperresponsiveness (AHR) was evaluated and bronchoalveolar lavage (BAL) was performed 24 h after the last IL-33 treatment. The number of inflammatory cells and cytokine levels in the BAL fluid (BALF) were analyzed, and histologic examination was performed. RESULTS: Compared with IL-33 treated wild-type (WT) mice, intranasal administration of IL-33 in IL-5Rα-/- mice reduced eosinophilic airway inflammation, AHR, and basement membrane thickening, while we found excessive IL-33 induced IL-5 and IL-13 production in the airway without IL-5 signaling. The numbers of eosinophils with a ringshaped nucleus (resident) and segmented nucleus (inflammatory) were increased in WT mice, but not in IL-5Rα-/- mice following intranasal administration of IL-33, and the numbers of SiglecF-positive eosinophils with (resident) or without (inflammatory) expression of CD62L were also significantly increased by IL-33 treatment in WT mice, but not in IL5Rα-/- mice. The number of ILC2 cells in the BALF was significantly higher in IL-33 treated IL-5Rα-/- mice than in IL-33 treated WT mice. CONCLUSIONS: These findings suggest the possibility that IL-5 induced eosinophils contribute to the negative-feedback mechanisms in IL-33 induced ILC2 mediated airway inflammation.

Role of serum periostin in severe obstructive sleep apnea with albuminuria: an observational study.

BACKGROUND: Periostin is a matricellular protein and is a useful marker in respiratory diseases. However, the roles of periostin in patients with obstructive sleep apnea (OSA) remain unclear. Several in vitro studies have suggested that mechanical stress, hypoxia, impaired metabolism, and kidney injury, which often accompany OSA, may upregulate the expression of periostin. Meanwhile, serum periostin level has been negatively associated with body mass index (BMI) in the general population. In this study, we hypothesized that a high level of serum periostin despite being overweight/obese may discriminate severe OSA or OSA with comorbidities from mild OSA with obesity alone. We aimed to clarify the roles of periostin in patients with OSA to assist in elucidating the heterogeneity of OSA with comorbidities. METHODS: Among patients diagnosed as OSA, we examined the associations between serum periostin levels and clinical indices, including the severity of OSA, BMI, and comorbidities, using a multifaceted approach. The serum periostin levels and clinical indices were assessed after 3 months of continuous positive airway pressure (CPAP) treatment. RESULTS: In 96 patients with OSA, serum periostin level was negatively correlated with BMI, albeit marginally, and tended to be higher in severe OSA than in others when adjusted for BMI. Cluster analysis identified four clusters, including two severe OSA clusters, one of which was characterized by high serum periostin levels and the presence of comorbidities, including albuminuria. In a comparative analysis of severe OSA cases (n = 53), the level of serum-free fatty acids and the frequency of albuminuria were higher in patients with high serum periostin level of ≥87 ng/mL, which was the highest quintile among all participants, than in those with low serum periostin levels (< 87 ng/mL, n = 41). In patients with severe OSA and high serum periostin levels, the levels of serum periostin and urinary albumin significantly decreased after 3 months of CPAP treatment. CONCLUSIONS: Elevated serum periostin in patients with OSA despite being overweight/obese may be an indicator of severe OSA with comorbidities, particularly albuminuria.

External Validation and Recalculation of the CODEX Index in COPD Patients. A 3CIAplus Cohort Study.

The CODEX index was developed and validated in patients hospitalized for COPD exacerbation to predict the risk of death and readmission within one year after discharge. Our study aimed to validate the CODEX index in a large external population of COPD patients with variable durations of follow-up. Additionally, we aimed to recalculate the thresholds of the CODEX index using the cutoffs of variables previously suggested in the 3CIA study (mCODEX). Individual data on 2,755 patients included in the COPD Cohorts Collaborative International Assessment Plus (3CIA+) were explored. A further two cohorts (ESMI AND EGARPOC-2) were added. To validate the CODEX index, the relationship between mortality and the CODEX index was assessed using cumulative/dynamic ROC curves at different follow-up periods, ranging from 3 months up to 10 years. Calibration was performed using univariate and multivariate Cox proportional hazard models and Hosmer-Lemeshow test. A total of 3,321 (87.8% males) patients were included with a mean ± SD age of 66.9 ± 10.5 years, and a median follow-up of 1,064 days (IQR 25-75% 426-1643), totaling 11,190 person-years. The CODEX index was statistically associated with mortality in the short- (≤3 months), medium- (≤1 year) and long-term (10 years), with an area under the curve of 0.72, 0.70 and 0.76, respectively. The mCODEX index performed better in the medium-term (<1 year) than the original CODEX, and similarly in the long-term. In conclusion, CODEX and mCODEX index are good predictors of mortality in patients with COPD, regardless of disease severity or duration of follow-up.

Large-scale external validation and comparison of prognostic models: an application to chronic obstructive pulmonary disease.

BACKGROUND: External validations and comparisons of prognostic models or scores are a prerequisite for their use in routine clinical care but are lacking in most medical fields including chronic obstructive pulmonary disease (COPD). Our aim was to externally validate and concurrently compare prognostic scores for 3-year all-cause mortality in mostly multimorbid patients with COPD. METHODS: We relied on 24 cohort studies of the COPD Cohorts Collaborative International Assessment consortium, corresponding to primary, secondary, and tertiary care in Europe, the Americas, and Japan. These studies include globally 15,762 patients with COPD (1871 deaths and 42,203 person years of follow-up). We used network meta-analysis adapted to multiple score comparison (MSC), following a frequentist two-stage approach; thus, we were able to compare all scores in a single analytical framework accounting for correlations among scores within cohorts. We assessed transitivity, heterogeneity, and inconsistency and provided a performance ranking of the prognostic scores. RESULTS: Depending on data availability, between two and nine prognostic scores could be calculated for each cohort. The BODE score (body mass index, airflow obstruction, dyspnea, and exercise capacity) had a median area under the curve (AUC) of 0.679 [1st quartile-3rd quartile = 0.655-0.733] across cohorts. The ADO score (age, dyspnea, and airflow obstruction) showed the best performance for predicting mortality (difference AUCADO - AUCBODE = 0.015 [95% confidence interval (CI) = -0.002 to 0.032]; p = 0.08) followed by the updated BODE (AUCBODE updated - AUCBODE = 0.008 [95% CI = -0.005 to +0.022]; p = 0.23). The assumption of transitivity was not violated. Heterogeneity across direct comparisons was small, and we did not identify any local or global inconsistency. CONCLUSIONS: Our analyses showed best discriminatory performance for the ADO and updated BODE scores in patients with COPD. A limitation to be addressed in future studies is the extension of MSC network meta-analysis to measures of calibration. MSC network meta-analysis can be applied to prognostic scores in any medical field to identify the best scores, possibly paving the way for stratified medicine, public health, and research.

Clinical significance of radiological pleuroparenchymal fibroelastosis pattern in interstitial lung disease patients registered for lung transplantation: a retrospective cohort study.

BACKGROUND: Radiological pleuroparenchymal fibroelastosis (PPFE) lesion is characterized by pleural thickening with associated signs of subpleural fibrosis on high-resolution computed tomography (HRCT). This study evaluated the clinical significance of radiological PPFE as an isolated finding or associated with other interstitial lung diseases (ILDs) in patients having fibrotic ILDs and registered for cadaveric lung transplantation (LT). METHODS: This retrospective study included 118 fibrotic ILD patients registered for LT. Radiological PPFE on HRCT was assessed. The impact of radiological PPFE on clinical features and transplantation-censored survival were evaluated. RESULTS: Radiological PPFE was observed in 30/118 cases (25%): definite PPFE (PPFE concentrated in the upper lobes, with involvement of lower lobes being less marked) in 12 (10%) and consistent PPFE (PPFE not concentrated in the upper lobes, or PPFE with features of coexistent disease present elsewhere) in 18 (15%). Of these, 12 had late-onset non-infectious pulmonary complications after hematopoietic stem-cell transplantation and/or chemotherapy (LONIPCs), 9 idiopathic PPFE, and 9 other fibrotic ILDs (idiopathic pulmonary fibrosis, IPF; other idiopathic interstitial pneumonias, other IIPs; connective tissue disease-associated ILD, CTD-ILD, and hypersensitivity pneumonia, HP). Radiological PPFE was associated with previous history of pneumothorax, lower body mass index, lower percentage of predicted forced vital capacity (%FVC), higher percentage of predicted diffusion capacity of carbon monoxide, less desaturation on six-minute walk test, and hypercapnia. The median survival time of all study cases was 449 days. Thirty-seven (28%) received LTs: cadaveric in 31 and living-donor lobar in six. Of 93 patients who did not receive LT, 66 (71%) died. Radiological PPFE was marginally associated with better survival after adjustment for age, sex, %FVC, and six-minute walk distance < 250 m (hazard ratio 0.51 [0.25-1.05], p = 0.07). After adjustment for covariates, idiopathic PPFE and LONIPC with radiological PPFE was associated with better survival than fibrotic ILDs without radiological PPFE (hazard ratio 0.38 [0.16-0.90], p = 0.03), and marginally better survival than other fibrotic ILDs with radiological PPFE (hazard ratio, 0.20 [0.04-1.11], p = 0.07). CONCLUSIONS: idiopathic PPFE and LONIPC with radiological PPFE has better survival on the wait list for LT than fibrotic ILDs without radiological PPFE, after adjustment for age, sex, %FVC, and six-minute walk distance.

The Relationship Between Cephalogram Analysis and Oxygen Desaturation Index During Sleep in Patients Submitted for Mandibular Setback Surgery.

OBJECTIVES: The aim of this study was to examine the relationship between morphologic factors of mandibular protrusion patients and clinical indices of obstructive sleep apnea (OSA). METHODS: Fifty-two Japanese patients divided into 2 groups: 1 jaw surgery group (30 patients) and 2 jaw surgery group (22 patients). Morphologic changes were studied using cephalograms taken before surgery and 1 year after surgery. Functional changes studied using impulse oscillometry and pulse oximetry during sleep, both of which are clinically useful measures in assessing OSA, taken before surgery and 1 year after surgery. RESULT: Lower face cage area significantly decreased in 1 jaw group than in 2 jaw group patients. Positive significant correlation was found between changes in 3% oxygen desaturation index (ODI) and changes of tongue area and vertical position of the hyoid bone in 1 jaw surgery group. Multiple regression analysis indicates that tongue area and airway area were independently significant predictors of 3% ODI in 1 jaw group patients. CONCLUSION: In 2 jaw surgery, maxillary surgery compensated for the effect of mandibular setback surgery. Mandibular setback surgery to mandibular protrusion patients was performed within the range of adequate movement distance, but precautions for risk of postoperative obstructive sleep apnea syndrome should be considered.

A simple algorithm for the identification of clinical COPD phenotypes.

This study aimed to identify simple rules for allocating chronic obstructive pulmonary disease (COPD) patients to clinical phenotypes identified by cluster analyses.Data from 2409 COPD patients of French/Belgian COPD cohorts were analysed using cluster analysis resulting in the identification of subgroups, for which clinical relevance was determined by comparing 3-year all-cause mortality. Classification and regression trees (CARTs) were used to develop an algorithm for allocating patients to these subgroups. This algorithm was tested in 3651 patients from the COPD Cohorts Collaborative International Assessment (3CIA) initiative.Cluster analysis identified five subgroups of COPD patients with different clinical characteristics (especially regarding severity of respiratory disease and the presence of cardiovascular comorbidities and diabetes). The CART-based algorithm indicated that the variables relevant for patient grouping differed markedly between patients with isolated respiratory disease (FEV1, dyspnoea grade) and those with multi-morbidity (dyspnoea grade, age, FEV1 and body mass index). Application of this algorithm to the 3CIA cohorts confirmed that it identified subgroups of patients with different clinical characteristics, mortality rates (median, from 4% to 27%) and age at death (median, from 68 to 76 years).A simple algorithm, integrating respiratory characteristics and comorbidities, allowed the identification of clinically relevant COPD phenotypes.

Role of mitochondrial hydrogen peroxide induced by intermittent hypoxia in airway epithelial wound repair in vitro.

The airway epithelium acts as a frontline barrier against various environmental insults and its repair process after airway injury is critical for the lung homeostasis restoration. Recently, the role of intracellular reactive oxygen species (ROS) as transcription-independent damage signaling has been highlighted in the wound repair process. Both conditions of continuous hypoxia and intermittent hypoxia (IH) induce ROS. Although IH is important in clinical settings, the roles of IH-induced ROS in the airway repair process have not been investigated. In this study, we firstly showed that IH induced mitochondrial hydrogen peroxide (H2O2) production and significantly decreased bronchial epithelial cell migration, prevented by catalase treatment in a wound scratch assay. RhoA activity was higher during repair process in the IH condition compared to in the normoxic condition, resulting in the cellular morphological changes shown by immunofluorescence staining: round cells, reduced central stress fiber numbers, pronounced cortical actin filament distributions, and punctate focal adhesions. These phenotypes were replicated by exogenous H2O2 treatment under the normoxic condition. Our findings confirmed the transcription-independent role of IH-induced intracellular ROS in the bronchial epithelial cell repair process and might have significant implications for impaired bronchial epithelial cell regeneration.

Changes in Energy Metabolism after Continuous Positive Airway Pressure for Obstructive Sleep Apnea.

RATIONALE: Disrupted energy homeostasis in obstructive sleep apnea (OSA) may lead to weight gain. Paradoxically, treating OSA with continuous positive airway pressure (CPAP) may also promote weight gain, although the underlying mechanism remains unclear. OBJECTIVES: To explore the underlying mechanism by which patients with OSA gain weight after CPAP. METHODS: A comprehensive assessment of energy metabolism was performed in 63 newly diagnosed OSA study participants (51 men; 60.8 ± 10.1 yr; apnea-hypopnea index >20 h(-1)) at baseline, CPAP initiation, and at a 3-month follow-up. Measurements included polysomnography, body weight, body composition, basal metabolic rate (BMR), hormones (norepinephrine, cortisol, leptin, ghrelin, insulin-like growth factor-1), dietary intake, eating behavior, and physical activity. MEASUREMENTS AND MAIN RESULTS: BMR significantly decreased after CPAP (1,584 kcal/d at baseline, 1,561 kcal/d at CPAP initiation, and 1,508 kcal/d at follow-up; P < 0.001), whereas physical activity and total caloric intake did not significantly change. In multivariate regression, baseline apnea-hypopnea index, Δurine norepinephrine, and CPAP adherence were significant predictors of ΔBMR. The weight gainers had higher leptin levels, lower ghrelin levels, and higher eating behavior scores than the non-weight gainers, indicating a positive energy balance and disordered eating behavior among the weight gainers. Among the parameters related to energy metabolism, increased caloric intake was a particularly significant predictor of weight gain. CONCLUSIONS: Although a reduction in BMR after CPAP predisposes to a positive energy balance, dietary intake and eating behavior had greater impacts on weight change. These findings highlight the importance of lifestyle modifications combined with CPAP. Clinical trial registered with http://www.umin.ac.jp/english/ (UMIN000012639).

Neutralization of leukotriene C4 and D4 activity by monoclonal and single-chain antibodies.

BACKGROUND: Cysteinyl leukotrienes (LTs) are key mediators in inflammation. To explore the structure of the antigen-recognition site of a monoclonal antibody against LTC4 (mAbLTC), we previously isolated full-length cDNAs for heavy and light chains of the antibody and prepared a single-chain antibody comprising variable regions of these two chains (scFvLTC). METHODS: We examined whether mAbLTC and scFvLTC neutralized the biological activities of LTC4 and LTD4 by competing their binding to their receptors. RESULTS: mAbLTC and scFvLTC inhibited their binding of LTC4 or LTD4 to CysLT1 receptor (CysLT1R) and CysLT2 receptor (CysLT2R) overexpressed in Chinese hamster ovary cells. The induction by LTD4 of monocyte chemoattractant protein-1 and interleukin-8 mRNAs in human monocytic leukemia THP-1 cells expressing CysLT1R was dose-dependently suppressed not only by mAbLTC but also by scFvLTC. LTC4- and LTD4-induced aggregation of mouse platelets expressing CysLT2R was dose-dependently suppressed by either mAbLTC or scFvLTC. Administration of mAbLTC reduced pulmonary eosinophil infiltration and goblet cell hyperplasia observed in a murine model of asthma. Furthermore, mAbLTC bound to CysLT2R antagonists but not to CysLT1R antagonists. CONCLUSIONS: These results indicate that mAbLTC and scFvLTC neutralize the biological activities of LTs by competing their binding to CysLT1R and CysLT2R. Furthermore, the binding of cysteinyl LT receptor antagonists to mAbLTC suggests the structural resemblance of the LT-recognition site of the antibody to that of these receptors. GENERAL SIGNIFICANCE: mAbLTC can be used in the treatment of inflammatory diseases such as asthma.

Matrix metalloproteinase-10: a novel biomarker for idiopathic pulmonary fibrosis.

BACKGROUND: Matrix metalloproteinases (MMPs) are believed to be involved in the pathogenesis of idiopathic pulmonary fibrosis (IPF), and MMP-7 has been described as a useful biomarker for IPF. However, little is known regarding the significance of MMP-10 as a biomarker for IPF. METHODS: This observational cohort study included 57 patients with IPF. Serum MMPs were comprehensively measured in all patients, and the relationships between these markers and both disease severity and prognosis were evaluated. Bronchoalveolar lavage fluid (BALF) MMP-7 and -10 levels were measured in 19 patients to investigate the correlation between these markers and their corresponding serum values. Immunohistochemical staining for MMP-10 was also performed in IPF lung tissue. RESULTS: Serum MMP-7 and -10 levels correlated significantly with both the percentage of predicted forced vital capacity (ρ = -0.31, p = 0.02 and ρ = -0.34, p < 0.01, respectively) and the percentage of predicted diffusing capacity of the lung for carbon monoxide (ρ = -0.32, p = 0.02 and ρ = -0.43, p < 0.01, respectively). BALF MMP-7 and -10 levels correlated with their corresponding serum concentrations. Only serum MMP-10 predicted clinical deterioration within 6 months and overall survival. In IPF lungs, the expression of MMP-10 was enhanced and localized to the alveolar epithelial cells, macrophages, and peripheral bronchiolar epithelial cells. CONCLUSIONS: MMP-10 may be a novel biomarker reflecting both disease severity and prognosis in patients with IPF.

Association between endothelial function (assessed on reactive hyperemia peripheral arterial tonometry) and obstructive sleep apnea, visceral fat accumulation, and serum adiponectin.

BACKGROUND: Visceral obesity, low adiponectin, and severe obstructive sleep apnea (OSA) are associated with cardiovascular diseases, but the interactions among these factors on endothelial dysfunction are not well known. METHODS AND RESULTS: Endothelial function in 133 patients after polysomnography was evaluated as reactive hyperemia index (RHI) on reactive hyperemia peripheral arterial tonometry. Visceral obesity was defined as visceral fat area ≥100 cm(2)on computed tomography. RHI was significantly correlated with apnea hypopnea index (AHI), visceral fat area, and serum adiponectin (r=-0.24, P=0.0055, r=-0.19, P=0.031, and r=0.20, P=0.019, respectively). RHI in patients with visceral obesity was significantly decreased in the presence of severe OSA (AHI ≥30; P=0.042). On multivariate regression analysis, only severe OSA remained as an independent predictive factor of RHI (P=0.024, R(2)=5.4%). RHI in patients with severe OSA (n=44) was significantly improved after 3 months of continuous positive airway pressure (CPAP) treatment (1.78±0.40 before CPAP vs. 2.00±0.53 after CPAP, P=0.013), similarly to those with AHI <30 (P=0.45). CONCLUSIONS: Severe OSA, but not visceral fat area or serum adiponectin, was independently associated with endothelial function according to RHI. In addition, impaired endothelial function was reversible following 3 months of CPAP treatment.