Treatment with systemic corticosteroid versus placebo for exacerbations of COPD: A systematic review and meta-analysis.

BACKGROUND: For the treatment of COPD exacerbations, systemic corticosteroids are recommended in addition to short-acting bronchodilators. Although there have been several systemic reviews, many of the included studies were conducted before 2007 and a re-evaluation has not been performed since 2014. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety profile of systemic corticosteroids in patients with COPD during exacerbations. METHODS: We searched relevant randomized control trials (RCTs) and analyzed the treatment failure, relapse, lung function, improvement in PaO2 and PaCO2, dyspnea, quality of life (QOL), length of stay in hospital and adverse events including hyperglycemia and mortality as the outcomes of interest. RESULTS: We identified a total of 12 RCTs (N = 1336). Systemic corticosteroids significantly reduced the treatment failure (odds ratios; OR 0.41, 95% confidence intervals; CI 0.25 to 0.67) and hospital length of stay (mean difference; MD -1.57 days, 95% CI -2.36 to -0.78) and improved FEV1 (MD 0.18 L, 95% CI 0.08 to 0.28) and dyspnea (transitional dyspnea index; MD 1.90, 95% CI 0.26 to 3.54) in COPD exacerbations compared to placebo. However, systemic corticosteroids were associated with a significantly higher incidence of adverse events (OR 1.83, 95% CI 1.25 to 2.69) and hyperglycemia (OR 2.94, 95% CI 1.68 to 5.14). CONCLUSIONS: In patients with moderate and severe COPD and severe obstructive impairment during exacerbations, systemic corticosteroids cause more adverse events, including hyperglycemia, than placebo but significantly reduce the treatment failure and hospital length of stay and improve FEV1 and dyspnea.

Identification of Siglec-1-negative alveolar macrophages with pro-inflammatory phenotypes in chronic obstructive pulmonary disease.

Alveolar macrophages (AMs) in patients with chronic obstructive pulmonary disease (COPD) orchestrate persistent inflammation in the airway. However, sub-populations of AMs participating in the chronic inflammation have been poorly characterized. We previously reported that Siglec-1 expression on AMs, which is important for bacteria engulfment, was decreased in COPD. Here, we show that Siglec-1-negative AMs isolated from COPD lung tissues exhibit a pro-inflammatory phenotype and is associated with poor clinical outcomes in patients with COPD. Using flow-cytometry, we segregated three subsets of AMs based on the expression of Siglec-1 and their side scattergram (SSC) and forward scattergram (FSC) properties: Siglec-1+SSChiFSChi, Siglec-1-SSChiFSChi and Siglec-1-SSCloFSClo subsets. The Siglec-1-SSCloFSClo subset number was increased in COPD. RNA-sequencing revealed upregulation of multiple pro-inflammatory signaling pathways and emphysema-associated matrix metalloproteases in the Siglec-1-SSCloFSClo subset. Gene set enrichment analysis indicated that the Siglec-1-SSCloFSClo subset adopted intermediate phenotypes between monocytes and mature alveolar macrophages. Functionally, these cells produced TNF-α, IL-6 and IL-8 at baseline, and these cytokines were significantly increased in response to viral RNA. The increase in Siglec-1-negative AMs in induced sputum is associated with future exacerbation risk and lung function decline in patients with COPD. Collectively, the novel Siglec-1-SSCloFSClo subset of AMs display pro-inflammatory properties, and their emergence in COPD airways may be associated with poor clinical outcomes.

A randomized double-blind placebo-controlled trial of an inhibitor of plasminogen activator inhibitor-1 (TM5614) in mild to moderate COVID-19.

An inhibitor of plasminogen activator inhibitor (PAI)-1, TM5614, inhibited thrombosis, inflammation, and fibrosis in several experimental mouse models. To evaluate the efficacy and safety of TM5614 in human COVID-19 pneumonia, phase IIa and IIb trials were conducted. In an open-label, single-arm trial, 26 Japanese COVID-19 patients with mild to moderate pneumonia were treated with 120-180 mg of TM5614 daily, and all were discharged without any notable side effects. Then, a randomized, double-blind, placebo-controlled trial was conducted in Japanese COVID-19 patients with mild to moderate pneumonia. The number of study participants was set to be 50 in each arm. Even after extension of the enrollment period, the number of study participants did not reach the initially intended sample size, and 75 patients were enrolled in the study. The total oxygenation scale from Day 1 to Day 14 as the primary endpoint was 1.5 in the TM5614 group vs 4.0 in the placebo group (p = 0.22), and the number of days of oxygen administration required as the secondary endpoint was 2.0 days in the TM5614 group vs 3.5 days in the placebo group (p = 0.34). Further studies will be necessary to verify the efficacy of PAI-1 inhibition for the treatment of COVID-19 pneumonia.Clinical trial registration: Two studies were conducted: a prospective, multicenter, open-label phase II study at https://jrct.niph.go.jp (jRCT2021200018) (First registration date 18/08/2020) and a prospective, multicenter, randomized, double-blind, placebo-controlled, phase II study at https://jrct.niph.go.jp (jRCT2021210006) (First registration date 28/05/2021).

CYP27A1-27-hydroxycholesterol axis in the respiratory system contributes to house dust mite-induced allergic airway inflammation.

BACKGROUND: 27-Hydroxycholesterol (27-HC) derived from sterol 27-hydroxylase (CYP27A1) has pro-inflammatory biological activity and is associated with oxidative stress and chronic inflammation in COPD. However, the role of regulation of CYP27A1- 27-HC axis in asthma is unclear. This study aimed to elucidate the contribution of the axis to the pathophysiology of asthma. METHODS: House dust mite (HDM) extract was intranasally administered to C57BL/6 mice and the expression of CYP27A1 in the airways was analyzed by immunostaining. The effect of pre-treatment with PBS or CYP27A1 inhibitors on the cell fraction in the bronchoalveolar lavage fluid (BALF) was analyzed in the murine model. In vitro, BEAS-2B cells were treated with HDM and the levels of CYP27A1 expression were examined. Furthermore, the effect of 27-HC on the expressions of E-cadherin and ZO-1 in the cells was analyzed. The amounts of RANTES and eotaxin from the 27-HC-treated cells were analyzed by ELISA. RESULTS: The administration of HDM increased the expression of CYP27A1 in the airways of mice as well as the number of eosinophils in the BALF. CYP27A1 inhibitors ameliorated the HDM-induced increase in the number of eosinophils in the BALF. Treatment with HDM increased the expression of CYP27A1 in BEAS-2B cells. The administration of 27-HC to BEAS-2B cells suppressed the expression of E-cadherin and ZO-1, and augmented the production of RANTES and eotaxin. CONCLUSIONS: The results of this study suggest that aeroallergen could enhance the induction of CYP27A1, leading to allergic airway inflammation and disruption of the airway epithelial tight junction through 27-HC production.

Addressing therapeutic inertia for asthma biologics: Lessons from the KOFU study.

Despite evidence-based guidelines and the availability of five biologics in Japan to treat severe asthma, approximately one-third of patients with severe asthma continue to have uncontrolled disease. This lack of appropriate evidence-based treatment is a complex issue resulting from therapeutic inertia, a lack of treatment intensification according to evidence-based guidelines for patients who are considered eligible but not receiving therapy, and is often driven by complex factors involving patients, physicians, and healthcare systems. The KOFU study, the largest cross-sectional Internet Survey for severe asthma in Japan, addressed potential barriers to starting biologic treatment and sought a solution for therapeutic inertia regarding asthma biologics. Although the burden of high medical costs is the largest barrier to initiating biologic treatment for patients, other important barriers were also revealed, including an incorrect perception of asthma severity or a poor recognition of the need for treatment intensification, a lack of proper communication with patients or a lack of confidence in the physicians, initiating biologics together with the complicated process of the insurance systems to ease the burden of high medical costs or strict criteria for the approval of biologics for health care insurance systems. Increased awareness and understanding of these barriers to biologic treatment may facilitate an optimal recommendation process to individualize treatment in patients with severe asthma.

Management goals and stable phase management of patients with chronic obstructive pulmonary disease in the Japanese respiratory society guideline for the management of chronic obstructive pulmonary disease 2022 (6th edition).

Chronic obstructive pulmonary disease (COPD) is characterized by airflow obstruction on spirometry and symptoms such as dyspnea on exertion and chronic cough with sputum production, thus making it a significant healthcare issue worldwide. Japanese patients with COPD have unique characteristics compared to patients in Western countries, including older age and lower exacerbation frequency. The Japanese Respiratory Society (JRS) published the 6th edition of the COPD guideline in June 2022. This article introduces the management goals of COPD and describes its management during the stable phase, as outlined in the guideline. Management goals include improving the current status, such as the symptoms, quality of life (QOL), exercise tolerance, and physical activity, and reducing future risks through prevention of exacerbation and suppression of disease progression to prevent shortening of healthy life expectancy. Management plans should include avoidance of causative substances, assessment of disease severity, and personalized treatment plans. Pharmacotherapy using inhalation bronchodilators is a key component of the treatment of stable COPD. Bronchodilators, including short- and long-acting dilators, are commonly used to relieve symptoms and improve QOL. Inhaled corticosteroids (ICSs) are used in combination with long-acting bronchodilators, especially in patients with asthma and COPD overlap, or those experiencing frequent exacerbation of eosinophilia. Combination therapy with a long-acting muscarinic antagonist (LAMA), a long-acting beta 2 agonist (LABA), and ICS is expected to improve QOL and respiratory function and reduce mortality and exacerbation compared to the LAMA + LABA combination. Non-pharmacological therapies, including smoking cessation and pulmonary rehabilitation, should also be considered.

Supersulphides provide airway protection in viral and chronic lung diseases.

Supersulphides are inorganic and organic sulphides with sulphur catenation with diverse physiological functions. Their synthesis is mainly mediated by mitochondrial cysteinyl-tRNA synthetase (CARS2) that functions as a principal cysteine persulphide synthase (CPERS). Here, we identify protective functions of supersulphides in viral airway infections (influenza and COVID-19), in aged lungs and in chronic lung diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF). We develop a method for breath supersulphur-omics and demonstrate that levels of exhaled supersulphides increase in people with COVID-19 infection and in a hamster model of SARS-CoV-2 infection. Lung damage and subsequent lethality that result from oxidative stress and inflammation in mouse models of COPD, IPF, and ageing were mitigated by endogenous supersulphides production by CARS2/CPERS or exogenous administration of the supersulphide donor glutathione trisulphide. We revealed a protective role of supersulphides in airways with various viral or chronic insults and demonstrated the potential of targeting supersulphides in lung disease.

Associations between birth weight and lung function in a Japanese adult population: The tohoku medical megabank community-based cohort study.

BACKGROUND: Birth weight, as a measure of intrauterine growth, is commonly used in epidemiological studies and is reported to be associated with adult lung function. However, findings regarding this association in previous studies have been inconsistent. Furthermore, no studies have reported associations stratified by age or smoking status, or adjusted for eosinophil count or other parameters related to type 2 airway inflammation. METHODS: This cross-sectional study included 2632 men and 7237 women aged ≥20 years living in Miyagi Prefecture, Japan. Lung function was assessed based on spirometry. Birth weight data were obtained through a questionnaire survey. Analysis of covariance was used to evaluate the associations between birth weight and lung function, adjusting for potential confounders. Stratified analyses by age and smoking status were also conducted, together with a sub-analysis for low birth-weight participants. RESULTS: Birth weight was positively associated with forced expiratory volume in 1 s (FEV1) for both sexes and with vital capacity in women, after adjusting for height, age, smoking status, and parameters related to type 2 airway inflammation. The stratified analysis for smoking status revealed associations in never-smokers and ex-smokers. When stratified by age, the associations were confirmed in middle-aged participants. The effect of smoking status on the FEV1 of low birth-weight participants was not significant. CONCLUSIONS: Our analysis of a large, Japanese adult population showed that birth weight was independently and positively associated with adult lung function, even after adjustment for age, height, smoking status, and parameters related to type 2 airway inflammation.

[A SURVEY ON MEDICAL CARE FOR ALLERGIC DISEASES IN MIYAGI].

OBJECTIVE: In Miyagi, the number of allergy specialists per population is higher at Sendai city compared to the other areas (non-Sendai areas). Therefore, the healthcare delivery for allergic diseases are unevenly distributed. In the current study, we investigated differences of medical care for allergic diseases between Sendai city and non-Sendai areas. METHODS: We conducted a web-based questionnaire survey to all of hospitals and clinics in the prefecture. The questionnaire responses were analyzed and compared between the Sendai city and non-Sendai areas. RESULTS: Responses to the questionnaire were obtained from 175 hospitals and clinics, including 72 internal physicians, 34 pediatricians, 17 dermatologists, 15 otorhinolaryngologists, 12 ophthalmologists and 25 others. More clinicians in non-Sendai areas felt the difficulty in treating asthma and chronic urticaria than those in Sendai city. Fewer institutions prescribed biologics for severe allergic diseases in non-Sendai areas than in Sendai city, which might be due to the lack of knowledge on the biologic agents. On the other hand, referring patients with anaphylaxis to specialized hospitals tended to be more difficult in Sendai city compared to in non-Sendai areas. Additionally, the regional medical liaison system is needed to refer patients with severe allergic diseases to advanced medical institutions. CONCLUSION: There are unique problems about allergy care in Miyagi.

Antibody responses to second doses of COVID-19 vaccination in lung cancer patients undergoing treatment.

BACKGROUND: Several reports have revealed that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection tends to have more severe outcomes in cancer patients. Although vaccination reduces the risk of severe disease, data on antibody titers achieved by vaccination is scarce in cancer patients. METHODS: We collected 79 blood samples (69 lung cancer patients and 10 control individuals) and conducted an anti-SARS-CoV-2 antibody assay to compare the antibody titer achieved with current treatment. Sixty-eight patients (86%) received the BNT162 mRNA vaccine and 11 (14%) received the mRNA-1273 vaccine. They were categorized according to the current treatment: control individuals without cancer (cohort A), lung cancer patients who were treated with cytotoxic chemotherapy (cohort B), immunotherapy (cohort C), combination of cytotoxic chemotherapy and immunotherapy (cohort D), tyrosine kinase inhibitors (cohort E), and radiation therapy (cohort F). RESULTS: Among 69 lung cancer patients (cohort B-F), 57 (83%) had adenocarcinoma, and 66 (96%) had advanced-stage cancer. In the anti-SARS-CoV-2 antibody assay, the antibody titer was significantly lower in lung cancer patients than in control individuals (p = 0.01). The median antibody titers were 161 AU/ml in control individuals and 59.9 AU/ml in lung cancer patients. CONCLUSIONS: Antibody titers after the second vaccination were lower in cancer patients than those in healthy individuals. Our findings provide essential information for understanding the benefits and necessity of additional vaccination to prevent SARS-CoV-2 infection in lung cancer patients.

The efficacy profiles of concurrent chemoradiotherapy with intensity-modulated radiotherapy followed by durvalumab in patients with unresectable stage III non-small cell lung cancer: A multicenter retrospective cohort study.

Purpose: Intensity-modulated radiotherapy (IMRT) is currently used more commonly than 3-dimensional conformal radiation for definitive thoracic radiation. We examined the efficacy profiles of concurrent chemoradiotherapy (CCRT) with IMRT after durvalumab became clinically available. Methods: We reviewed the clinical records of patients with stage III non-small cell lung cancer (NSCLC) treated with CCRT and IMRT at seven centers in Japan and investigated relapse and survival from May 2018 to December 2019. The primary endpoint of this report was progression-free survival (PFS). Results: Among 107 patients enrolled in the study, 87 were sequentially administered durvalumab. From CCRT commencement, patients were followed up for a median period of 29.7 months. The median PFS at the end of the CCRT was 20.7 months. Among the 87 patients, 58 experienced disease relapses, of whom 36 (62.1 %) had distant metastases. Multivariate Cox regression analysis revealed that a favorable response to CCRT, a radiation dose ≥ 62 Gy, and stage IIIA NSCLC were associated with prolonged PFS (all P = 0.04). Multivariate logistic regression by landmark analysis revealed that mortality risk factors were durvalumab treatment duration ≤ 11.7 months, a lower maximum grade of immune-related adverse events, FEV1 < 2805 mL, and radiation dose < 62 Gy (P = 0.01, 0.01, 0.03, and 0.04, respectively). Conclusions: In patients with NSCLC receiving CCRT using IMRT, long PFS was associated with a better response to CCRT, stage IIIA NSCLC, and an increased radiation dose. The duration of durvalumab consolidation also played an essential role in the survival of patients receiving CCRT with IMRT. (250 words).

A Novel Development of Sarcoidosis Following COVID-19 Vaccination and a Literature Review.

BNT162b2 (Pfizer/BioNTech) is a coronavirus disease 2019 (COVID-19) vaccine containing nucleoside-modified messenger RNA encoding the severe acute respiratory syndrome coronavirus 2 spike glycoprotein. Recently, ocular complications of mRNA vaccines have been reported increasingly frequently. However, immunological adverse events due to mRNA vaccines in real-world settings are not fully known. We herein report the novel development of sarcoidosis manifested as uveitis, bilateral hilar lymphadenopathy, angiotensin-converting enzyme elevation, and epithelioid and giant cell granuloma formation in the lung soon after the first BNT162b2 injection and review the current literature, including three reported cases of sarcoid-like reaction following COVID-19 vaccination.

COVID-19 in a Hairy Cell Leukemia Patient: A Rare Case Report.

The detailed clinical course of coronavirus disease 2019 (COVID-19) in patients with hairy cell leukemia (HCL) is rarely reported. We report the first case of HCL diagnosed with prolonged pancytopenia after COVID-19 infection in Japan. We describe the case of a 56-year-old man who was diagnosed with COVID-19. Computed tomography revealed ground-glass opacities in the bilateral lung lobes as well as splenomegaly. Remdesivir and dexamethasone were administered for the treatment of COVID-19. Since the pancytopenia persisted, bone marrow examination was performed, and he was diagnosed with HCL. Although pancytopenia can occur with COVID-19 alone, clinicians should be alerted regarding the presence of hematologic malignancies in patients in whom pancytopenia persists after COVID-19 treatment or in those with splenomegaly. Further, the condition of all previously reported patients with COVID-19 associated with HCL was severe enough to require mechanical ventilation. This is the first case in which the disease was not severe. The interleukin-6 (IL-6) level was lower in this case than in previous cases, suggesting that racial differences in IL-6 production may have contributed to COVID-19 severity.

Decreased expression of airway epithelial Axl is associated with eosinophilic inflammation in severe asthma.

BACKGROUND: Airway epithelium-derived cytokines are critical to provoke and perpetuate type 2 inflammation in asthma. Yet it is poorly understood how this epithelial cell-driven inflammatory response is negatively regulated. We previously reported that Axl receptor tyrosine kinase was expressed by basal cells in the airway epithelium and had a role in defining their stem cell identity. However, whether and how Axl regulates airway type 2 inflammation remains unknown. METHODS: We performed immunofluorescence staining to compare Axl expression in airway epithelium between non-asthmatic subjects, mild-moderate asthma and severe asthma. We confirmed this result by interrogating public databases of global gene expression in endobronchial biopsies. We then quantified eosinophil numbers infiltrating into the trachea of wild-type or Axl-knockout mice that were intranasally treated with house dust mite extracts (HDM). Cell-based assays using siRNA targeting Axl were further performed to identify molecules involved in Axl-mediated regulation of inflammation. RESULTS: Histological assessments and transcriptome analyses revealed decreases in protein and mRNA of Axl in airway basal cells of severe asthmatics. This reduction of Axl expression was correlated with infiltration of eosinophils and mast cells in severe asthmatics. Eosinophil infiltration was more evident in the trachea of Axl-knockout mice in response to repetitive HDM administration. siRNA-mediated knockdown of Axl increased mRNA and protein expression of granulocyte macrophage-colony stimulating factor (GM-CSF) in human bronchial epithelial cells. CONCLUSIONS: Axl kinase expressed by basal cells may suppress excessive eosinophilic inflammation via inhibition of GM-CSF in the airway. Axl reduction has clinical implications for the pathogenesis of severe asthma.

Urine autotaxin levels reflect the disease activity of sarcoidosis.

Since the clinical outcome of patients with sarcoidosis is still unpredictable, a good prognostic biomarker is necessary. Autotaxin (ATX) and phosphatidylserine-specific phospholipase A1 (PS-PLA1) function as main enzymes to produce lysophospholipids (LPLs), and these enzymes are attracting attention as useful biomarkers for several chronic inflammatory diseases. Here, we investigated the relationships between LPLs-producing enzymes and the disease activity of sarcoidosis. In total, 157 patients with sarcoidosis (active state, 51%) were consecutively enrolled. Using plasma or urine specimens, we measured the values of LPLs-producing enzymes. Urine ATX (U-ATX) levels were significantly lower in the active state compared to those in the inactive state, while the plasma ATX (P-ATX) and PS-PLA1 levels showed no significant difference between these two states. Concerning the comparison with existing clinical biomarkers for sarcoidosis, U-ATX showed a weak negative correlation to ACE, P-ATX a weak positive correlation to both ACE and sIL-2R, and PS-PLA1 a weak positive one to sIL-2R. Notably, only the U-ATX levels inversely fluctuated depending on the status of disease activity whether OCS had been used or not. These findings suggest that U-ATX is likely to be a novel and useful molecule for assessing the disease activity of sarcoidosis.

Triple versus LAMA/LABA combination therapy for Japanese patients with COPD: A systematic review and meta-analysis.

BACKGROUND: In symptomatic COPD patients with a history of exacerbations, additional treatment with inhaled corticosteroid (ICS) to long-acting muscarinic antagonist (LAMA) and long-acting beta-agonist (LABA) combination therapy is recommended based on the evidence of low incidence of exacerbations but with a caution for pneumonia. However, ethnic differences may affect the response to drugs. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety of this treatment in the Japanese population (PROSPERO: CRD42020191978). METHODS: We searched relevant randomized control trials and analyzed the exacerbations, quality of life, lung function, and adverse events including pneumonia and mortality as the outcomes of interest. RESULTS: We identified a total of three RCTs (N = 632). Treatment with ICS/LAMA/LABA triple therapy significantly decreased the exacerbations (rate ratio, 0.56; 95% CI, 0.38 to 0.85) and improved the trough FEV1 (mean difference, 0.04; 95% CI, 0.01 to 0.07) compared to LAMA/LABA therapy. However, triple therapy showed a significantly higher incidence of pneumonia compared to LAMA/LABA (odds ratio, 3.38; 95% CI, 1.58 to 7.22). Concerning other adverse events including mortality, there were no significant difference between these therapies. CONCLUSIONS: In the current meta-analysis of the Japanese population, we confirmed that triple therapy causes a higher incidence of pneumonia than LAMA/LABA treatment but is a more preferable treatment since it showed a lower incidence of exacerbations and higher trough FEV1 in patients with symptomatic moderate to severe COPD. However, since the sample sizes were not statistically large enough, further trials involving Japanese patients are needed.

Increased LHX9 expression in alveolar epithelial type 2 cells of patients with chronic obstructive pulmonary disease.

BACKGROUND: Alveolar epithelial type 2 (AT2) cells serve as stem cells in alveolar epithelium and are assumed to lose their stem cell function in the lungs of chronic obstructive pulmonary disease (COPD). Although we previously reported that LHX9 mRNA expression was up-regulated in AT2 cells of COPD lung tissues, it is yet to be elucidated how LHX9 is associated with the vulnerability of AT2 cells in COPD. METHODS: AT2 cells were isolated from lung tissues of 10 non-COPD subjects and 11 COPD patients. LHX9 mRNA expression was determined by quantitative RT-PCR. To identify up-stream molecules, an alveolar epithelial cell line A549 was exposed to pro-inflammatory cytokines in vitro. siRNA-mediated Lhx9 knockdown was performed to determine how Lhx9 affected the cellular viability and the cell-division cycle. RESULTS: LHX9 mRNA expression was increased in AT2 cells from COPD lung tissues, compared to those from non-COPD tissues. The airflow obstruction was independently correlated with the increase in LHX9 expression. Among several pro-inflammatory cytokines, interferon-γ was a strong inducer of LHX9 expression in A549 cells. Lhx9 was involved in the increased susceptibility to serum starvation-induced death of A549 cells. CONCLUSIONS: Our data suggest that IFN-γ predominantly increases the LHX9 expression which enhances the susceptibility to cell death. Considering the independent association of the increased LHX9 expression in AT2 cells with airflow obstruction, the IFN-γ-Lhx9 axis might contribute to the vulnerability of AT2 cells in the lungs of COPD patients.

Genetic loci for lung function in Japanese adults with adjustment for exhaled nitric oxide levels as airway inflammation indicator.

Lung function reflects the ability of the respiratory system and is utilized for the assessment of respiratory diseases. Because type 2 airway inflammation influences lung function, genome wide association studies (GWAS) for lung function would be improved by adjustment with an indicator of the inflammation. Here, we performed a GWAS for lung function with adjustment for exhaled nitric oxide (FeNO) levels in two independent Japanese populations. Our GWAS with genotype imputations revealed that the RNF5/AGER locus including AGER rs2070600 SNP, which introduces a G82S substitution of AGER, was the most significantly associated with FEV1/FVC. Three other rare missense variants of AGER were further identified. We also found genetic loci with three candidate genes (NOS2, SPSB2 and RIPOR2) associated with FeNO levels. Analyses with the BioBank-Japan GWAS resource revealed genetic links of FeNO and asthma-related traits, and existence of common genetic background for allergic diseases and their biomarkers. Our study identified the genetic locus most strongly associated with airway obstruction in the Japanese population and three genetic loci associated with FeNO, an indicator of type 2 airway inflammation in adults.