Clinical approaches towards asthma and chronic obstructive pulmonary disease based on the heterogeneity of disease pathogenesis

Asthma and chronic obstructive pulmonary disease (COPD) are each heterogeneous disease classifications that include several clinical and pathophysiological phenotypes. This heterogeneity complicates characterization of each disease and, in some cases, hinders the selection of appropriate treatment. Therefore, in recent years, emphasis has been placed on improving our understanding of the various phenotypes of asthma and of COPD and identifying biomarkers for each phenotype. Likewise, the concept of the endotype has been gaining acceptance; an endotype is a disease subtype that is defined by unique or distinctive functional or pathophysiological mechanisms. Endotypes of asthma or COPD may be primarily characterized by increased susceptibility to type 2 inflammation, increased susceptibility to viral infections, bacterial colonization or impaired lung development. The ‘Dutch hypothesis’ is as follows: gene variants underlying particular endotypes interact with detrimental environmental stimuli (e.g. smoking, viral infection and air pollution) and contribute to the ultimate development of asthma, COPD or both. Novel approaches that involve multidimensional assessment should facilitate identification and management of the components that generate this heterogeneity. Ultimately, patients with chronic inflammatory lung diseases may be treated based on these endotypes as determined by the respective biomarkers that correspond to individual endotypes instead of on disease labels such as asthma, COPD or even asthma–COPD overlap syndrome (ACOS)

ゲノム情報に基づく難治性気道疾患のエンドタイプの解明に向けた基盤研究

科学研究費助成事業 研究成果報告書：基盤研究(B)2015-2017課題番号 : 15H0482

Genetic analysis of smoking behavior

科学研究費助成事業 研究成果報告書：挑戦的萌芽研究 2012-2014課題番号:2465940

Comprehensive analysis of severe asthma pathogenesis

科学研究費助成事業 研究成果報告書：基盤研究(B)2012-2014 課題番号：2439020

Effects of a single long-acting muscarinic antagonist agent and a long-acting muscarinic antagonist/long-acting β2-adrenoceptor agonist combination on lung function and symptoms in untreated COPD patients in Japan

Background: A large body of evidence suggests that long-acting β2-adrenoceptor agonist (LABA)/long-acting muscarinic antagonist (LAMA) combinations induce a strong synergistic bronchodilatory effect in human isolated airways. Moreover, a recent post hoc analysis demonstrated clinical synergism between LABAs and LAMAs, which induces a synergistic improvement not only in lung function but also in dyspnea in COPD patients.Aim: The aim of this study is to examine the baseline factors related to improvement in lung function or clinical symptoms that results from the administration of LAMA or LAMA/LABA and to compare the differences in improvement in lung function or clinical symptoms between LAMA and LAMA/LABA.Methods: Among 829 patients with COPD who were treated with LAMA or LAMA/LABA in our hospital, 112 patients (aged 40–89 years) matched the criteria. Of these 112 patients, 71 received LAMA (LAMA group) and 41 received LAMA/LABA (LAMA/LABA group) as the initial treatment. Various examination results such as lung function test values, symptom change, and frequency of exacerbations were compared between the two groups.Results: Compared with the monotherapy, the combination therapy significantly improved the FEV1, inspiratory capacity (IC), and total COPD assessment test (CAT) scores. Comparing the improvement in each domain of the CAT produced by the combination therapy with that of the monotherapy, larger improvements were found for the domains of going out and sleeping. The frequency of exacerbations during the 24 weeks was significantly lower in the combination therapy group than in the LAMA monotherapy group (P=0.034). Although no relationship was found between improvement in FEV1 and any pretreatment factors in the LAMA/LABA group, the improvement in the CAT score was strongly related to the baseline CAT score, smoking index, and air trapping index (P-value <1×10-4).Conclusion: In this study of clinical practice, we found that LAMA/LABA combination therapy improved the clinical symptoms of COPD and IC and that the effects of the combination therapy were consistent with those observed in previous clinical trials

Lower FEV1 in non-COPD, nonasthmatic subjects: association with smoking, annual decline in FEV1, total IgE levels, and TSLP genotypes

Few studies have investigated the significance of decreased FEV1 in non-COPD, nonasthmatic healthy subjects. We hypothesized that a lower FEV1 in these subjects is a potential marker of an increased susceptibility to obstructive lung disease such as asthma and COPD. This was a cross-sectional analysis of 1505 Japanese adults. We divided the population of healthy adults with no respiratory diseases whose FEV1/FVC ratio was ≥70% (n = 1369) into 2 groups according to their prebronchodilator FEV1 (% predicted) measurements: <80% (n = 217) and ≥80% (n = 1152). We compared clinical data – including gender, age, smoking habits, total IgE levels, and annual decline of FEV1 – between these 2 groups. In addition, as our group recently found that TSLP variants are associated with asthma and reduced lung function, we assessed whether TSLP single nucleotide polymorphisms (SNPs) were associated with baseline lung function in non-COPD, nonasthmatic healthy subjects (n = 1368). Although about half of the subjects with lower FEV1 had never smoked, smoking was the main risk factor for the decreased FEV1 in non-COPD, nonasthmatic subjects. However, the subjects with lower FEV1 had a significantly higher annual decline in FEV1 independent of smoking status. Airflow obstruction was associated with increased levels of total serum IgE (P = 0.029) and with 2 functional TSLP SNPs (corrected P = 0.027–0.058 for FEV1% predicted, corrected P = 0.015–0.033 for FEV1/FVC). This study highlights the importance of early recognition of a decreased FEV1 in healthy subjects without evident pulmonary diseases because it predicts a rapid decline in FEV1 irrespective of smoking status. Our series of studies identified TSLP variants as a potential susceptibility locus to asthma and to lower lung function in non-COPD, nonasthmatic healthy subjects, which may support the contention that genetic determinants of lung function influence susceptibility to asthma

IL-17F Induces CCL20 in Bronchial Epithelial Cells

IL-17F plays a crucial role in airway inflammatory diseases including asthma, but its function has not been fully elucidated. CCL20 is also involved in allergic airway inflammation, while its regulatory mechanisms remain to be defined. To further identify a novel role of IL-17F, the expression of CCL20 by IL-17F in bronchial epithelial cells and the signaling mechanisms involved were investigated. Bronchial epithelial cells were stimulated with IL-17F, and the levels of CCL20 gene and protein measured, with the effects of the addition of various kinase inhibitors and siRNAs also investigated. IL-17F significantly induced the expression of CCL20 gene and protein. Pretreatment with inhibitors for MEK1/2, Raf1 and MSK1, and overexpression of a Raf1 dominant-negative mutant significantly diminished IL-17F-induced CCL20 production. Moreover, transfection of the siRNAs targeting MSK1, p90RSK, and CREB blocked CCL20 expression. These findings suggest that IL-17F is able to induce CCL20 via Raf1-MEK1/2-ERK1/2-MSK1/p90RSK-CREB signaling pathway in bronchial epithelial cells. The IL-17F/CCL20 axis may be a novel pharmacological target for asthma

A case of severe eosinophilic asthma and refractory rheumatoid arthritis well controlled by combination of IL-5Rα antibody and TNFα inhibitor

Letter to the Edito

Rechallenge with First-Line Platinum Chemotherapy for Sensitive-Relapsed Small-Cell Lung Cancer

Background: Sensitive-relapsed small-cell lung cancer (SCLC) is thought to be sensitive to chemotherapy; therefore, second-line chemotherapy is recommended. Although platinum rechallenge is performed in the second-line chemotherapy for sensitive-relapsed SCLC, it remains unclear whether such a strategy is effective. Methods: We retrospectively analyzed the outcome of rechallenge chemotherapy for sensitive-relapsed SCLC. The endpoints of this study were progression-free survival from the time of relapse (PFS-Re) and overall survival from the time of relapse (OS-Re). We also compared the toxicity profile of rechallenge chemotherapy to that of first-line chemotherapy. Results: Of the 133 SCLC patients who received first-line treatment, 20 patients satisfied the definition of sensitive relapse and received rechallenge chemotherapy. Combined carboplatin and etoposide was the most commonly used rechallenge regimen, and 17 (85%) received it at a reduced dose due to hematological toxicity during the first-line treatment. Median PFS-Re and OS-Re were 4.5 months (95% CI: 3.5–5.4) and 10.5 months (95% CI: 7.9–13.0), respectively. There was no association between dose adjustment and survival. The frequency of hematologic toxicity tended to be lower with rechallenge than first-line treatment. The incidence of grade 3 febrile neutropenia decreased from 40% in first-line treatment to 15% in rechallenge. Conclusion: Platinum rechallenge could be a useful second-line option for sensitive-relapsed SCLC, having favorable efficacy and safety. Dose adjustment at rechallenge based on the toxicity profile during the first-line chemotherapy could reduce toxicity without weakening efficacy