Control of pleural effusion with prednisolone in a patient with yellow nail syndrome: A case report.

Yellow nail syndrome (YNS) can induce bilateral exudative pleural effusion; however, to the best of our knowledge, no standard treatment for YNS has been established. The present study describes a patient with YNS for whom the pleural effusion was controlled by prednisolone. A 73-year-old man was referred to the University of Tsukuba Hospital (Ibaraki, Japan) complaining of shortness of breath, which was diagnosed as being due to bilateral pleural effusion. Based on the presence of yellowing and growth retardation of the toenails, lymphedema, bilateral exudative pleural fluid of unknown etiology, and lymphatic congestion on lymphoscintigraphy, the patient was diagnosed with YNS. The pleural fluid was predominantly lymphocytic and responded to systemic steroid administration [prednisolone 30 mg/day (0.5 mg/kg) for 2 weeks, with subsequent weekly tapering]. The general condition of the patient and their dyspnea also improved with treatment. These findings indicated that systemic steroid administration should be considered as one of the treatment options for patients with YNS who are reluctant to undergo chest drainage or pleurodesis due to the potential for a decrease in their ability to perform daily activities and respiratory function.

The primary ciliary dyskinesia-related genetic risk score is associated with susceptibility to adult-onset asthma.

BACKGROUND: Disturbance of mucociliary clearance is an important factor in the pathogenesis of asthma. We hypothesized that common variants in genes responsible for ciliary function may contribute to the development of asthma with certain phenotypes. METHODS: Three independent adult Japanese populations (including a total of 1,158 patients with asthma and 2,203 non-asthmatic healthy participants) were studied. First, based on the ClinVar database (https://www.ncbi.nlm.nih.gov/clinvar/), we selected 12 common single-nucleotide polymorphisms (SNPs) with molecular consequences (missense, nonsense, and 3'-untranslated region mutation) in 5 primary ciliary dyskinesia (PCD)-related genes and calculated a PCD-genetic risk score (GRS) as a cumulative effect of these PCD-related genes. Second, we performed a two-step cluster analysis using 3 variables, including PCD-GRS, forced expiratory volume in 1 second (%predicted FEV1), and age of asthma onset. RESULTS: Compared to adult asthma clusters with an average PCD-GRS, clusters with high and low PCD-GRS had similar overall characteristics: adult-onset, female predominance, preserved lung function, and fewer features of type 2 immunity as determined by IgE reactivity and blood eosinophil counts. The allele frequency of rs1530496, a SNP representing an expression quantitative trait locus (eQTL) of DNAH5 in the lung, showed the largest statistically significant difference between the PCD-GRS-High and PCD-GRS-Low asthma clusters (p = 1.4 x 10-15). CONCLUSION: Genes associated with PCD, particularly the common SNPs associated with abnormal expression of DNAH5, may have a certain influence on the development of adult-onset asthma, perhaps through impaired mucociliary clearance.

Genetic footprints of assortative mating in the Japanese population.

Assortative mating (AM) is a pattern characterized by phenotypic similarities between mating partners. Detecting the evidence of AM has been challenging due to the lack of large-scale datasets that include phenotypic data on both partners, especially in populations of non-European ancestries. Gametic phase disequilibrium between trait-associated alleles is a signature of parental AM on a polygenic trait, which can be detected even without partner data. Here, using polygenic scores for 81 traits in the Japanese population using BioBank Japan Project genome-wide association studies data (n = 172,270), we found evidence of AM on the liability to type 2 diabetes and coronary artery disease, as well as on dietary habits. In cross-population comparison using United Kingdom Biobank data (n = 337,139) we found shared but heterogeneous impacts of AM between populations.

Early chronic obstructive pulmonary disease: Associations of two spirometry criteria with clinical features.

BACKGROUND: Two spirometry criteria have been proposed for early chronic obstructive pulmonary disease (COPD) in young smokers: 1) forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < the lower limit of normal (LLN), and 2) FEV1 decline ≥60 ml/year. These criteria have yet to be validated. This study explored clinical factors associated with these two spirometry criteria. METHODS: This retrospective study analysed medical check-up data from 13,010 consecutive subjects aged <50 years who underwent current and 3 previous spirometry tests in Japan. Current ≥10 pack-year smokers were the main focus of analysis; those meeting one or more spirometry criteria were diagnosed with early COPD. Early COPD was categorized into three subtypes: FEV1/FVC < LLN and FEV1 decline <60 ml/year (type 1), FEV1/FVC ≥ LLN and FEV1 decline ≥60 ml/year (type 2), and FEV1/FVC < LLN and FEV1 decline ≥60 ml/year (type 3). RESULTS: Of the 1579 current ≥ 10 pack-year smokers, 488 (30.9%) met the early COPD criteria. Multivariate multinomial logistic models adjusted for age, sex, height, body mass index (BMI) and smoking history indicated that past BMI increase and low exercise were associated with higher type 2 early COPD incidence (odds ratio (OR) [95% confidence interval (CI)] = 4.30 [3.10, 6.04], and 0.80 [0.69, 0.93], respectively) but not with higher type 1 incidence. A history of asthma was associated with higher type 3 incidence (OR [95% CI] = 1.98 [1.18, 3.07]). CONCLUSIONS: The 3 types of spirometry-based early COPD have different clinical factors. Their trajectories should be explored in longitudinal studies.

Common exacerbation-prone phenotypes across asthma and chronic obstructive pulmonary disease (COPD).

BACKGROUND AND OBJECTIVES: Chronic inflammatory airway diseases, including asthma and chronic obstructive pulmonary disease (COPD), are complex syndromes with diverse clinical symptoms due to multiple pathophysiological conditions. In this study, using common and shared risk factors for the exacerbation of asthma and COPD, we sought to clarify the exacerbation-prone phenotypes beyond disease labels, and to specifically investigate the role of the IL4RA gene polymorphism, which is related to type 2 inflammation, in these exacerbation-prone phenotypes. METHODS: The study population comprised patients with asthma (n = 117), asthma-COPD overlap (ACO; n = 37) or COPD (n = 48) and a history of exacerbation within the previous year. Cluster analyses were performed using factors associated with both asthma and COPD exacerbation. The association of the IL4RA gene polymorphism rs8832 with each exacerbation-prone phenotype was evaluated by multinomial logistic analyses using non-asthma non-COPD healthy adults as controls (n = 1,529). In addition, the genetic influence of rs8832 was also examined in asthma patients with allergic rhinitis and no history of exacerbation (n = 130). RESULTS: Two-step cluster analyses identified five clusters that did not necessarily correspond to the diagnostic disease labels. Cluster 1 was characterized by high eosinophil counts, cluster 2 was characterized by smokers with impaired lung function, cluster 3 was characterized by the presence of gastroesophageal reflux, cluster 4 was characterized by non-allergic females, and cluster 5 was characterized by allergic rhinitis and elevated total immunoglobulin E levels. A significant association with rs8832 was observed for cluster 5 (odds ratio, 3.88 (1.34-11.26), p = 0.013) and also for the type 2 exacerbation-prone phenotypes (clusters 1 and 5: odds ratio, 2.73 (1.45-5.15), p = 1.9 × 10-3). DISCUSSION: Our results indicated that the clinical heterogeneity of disease exacerbation may reflect the presence of common exacerbation-prone endotypes across asthma and COPD, and may support the use of the treatable traits approach for the prevention of exacerbations in patients with chronic inflammatory airway diseases.

Expression quantitative trait loci for ETV4 and MEOX1 are associated with adult asthma in Japanese populations.

ETS variant transcription factor 4 (ETV4) is a recently identified transcription factor that regulates gene expression-based biomarkers of asthma and IL6 production in an airway epithelial cell line. Given that ETV4 has not yet been implicated in asthma genetics, we performed genetic association studies of adult asthma in the ETV4 region using two independent Japanese cohorts (a total of 1532 controls and 783 cases). SNPs located between ETV4 and mesenchyme homeobox 1 (MEOX1) were significantly associated with adult asthma, including rs4792901 and rs2880540 (P = 5.63E-5 and 2.77E-5, respectively). The CC haplotype of these two SNPs was also significantly associated with adult asthma (P = 8.43E-7). Even when both SNPs were included in a logistic regression model, the association of either rs4792901 or rs2880540 remained significant (P = 0.013 or 0.007, respectively), suggesting that the two SNPs may have independent effects on the development of asthma. Both SNPs were expression quantitative trait loci, and the asthma risk alleles at both SNPs were correlated with increased levels of ETV4 mRNA expression. In addition, the asthma risk allele at rs4792901 was associated with increased serum IL6 levels (P = 0.041) in 651 healthy adults. Our findings imply that ETV4 is involved in the pathogenesis of asthma, possibly through the heightened production of IL6.

Identification of distinct phenotypes related to benralizumab responsiveness in patients with severe eosinophilic asthma.

PURPOSE: To characterize the clinical phenotypes of severe eosinophilic asthma based on early responsiveness to benralizumab in terms of forced expiratory volume in 1 second (FEV1) improvement. PATIENTS AND METHODS: Sixty-four participants diagnosed with severe eosinophilic asthma and who had completed 4 months of benralizumab treatment were included in this analysis. Pre-treatment clinical factors were compared between responders and non-responders according to improvements in ACT or FEV1. Correlations between the sums of increased Type 2-related inflammatory parameters and changes of ACT or FEV1 were also evaluated before and after the 4-month treatment. A two-step cluster analysis was performed to identify distinct phenotypes related to benralizumab responsiveness in terms of FEV1. RESULTS: At the 4-month timepoint, all parameters, except for FeNO, were significantly improved after benralizumab treatment. FEV1 responders were associated with higher levels of Type 2-related inflammatory parameters. An improvement in FEV1 but not in ACT was clearly associated with increases in the sums of increased type 2-related inflammation parameters (p = 0.0001). The cluster analysis identified 5 distinct phenotypes of severe eosinophilic asthma according to the variable FEV1 responsiveness to benralizumab. The greatest response was found in the distinct phenotype of severe eosinophilic asthma, which was characterized by modest increase in total IgE and FeNO relative to blood eosinophils with least exposure to smoking. CONCLUSION: This study, to the best of our knowledge, is the first cluster analysis to report distinct phenotypes related to clinical benralizumab response in a real-world population with severe eosinophilic asthma. These results may help to predict responsiveness to benralizumab in patients with severe eosinophilic asthma.

ORMDL3/GSDMB genotype as a risk factor for early-onset adult asthma is linked to total serum IgE levels but not to allergic sensitization.

BACKGROUND: An orosomucoid-like 3 (ORMDL3)/gasdermin B (GSDMB) gene locus on chromosome 17q is consistently associated with childhood-onset asthma, which is highly atopic. As some evidence suggests the relationship between asthma and allergic sensitization reflects asthma patient susceptibility to augmented IgE responses driven by common environmental allergens rather than an increased asthma risk after allergen exposure, we aimed to determine any relationships between this locus region and childhood-onset adult asthma with regard to serum total IgE levels or allergic sensitization. METHODS: We conducted a case-control association study using three independent Japanese populations (3869 total adults) and analyzed the ORs for association of rs7216389, an expression quantitative trait locus for ORMDL3/GSDMB, with adult asthma according to onset age. Additionally, associations between the rs7216389 genotype and total serum IgE levels or allergic sensitization was examined. RESULTS: Rs7216389 was associated with both childhood-onset adult asthma (OR for asthmatic patients afflicted at the age of 10 years or younger = 1.61, p = 0.00021) and asthmatic patients with higher levels of total serum IgE (OR for asthmatic patients with IgE ≥1000IU/mL = 1.55, p = 0.0033). In both healthy controls and in the combined healthy and asthmatic individuals, rs7216389 was correlated with increased total serum IgE levels (p < 0.0005), but not allergic sensitization (p > 0.1). CONCLUSIONS: ORMDL3/GSDMB is an important susceptibility gene for childhood-onset adult asthma in Japanese populations and this association is linked to elevated total serum IgE levels but not to allergic sensitization.

Genetic impact of CDHR3 on the adult onset of asthma and COPD.

BACKGROUND: Adult-onset asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous diseases caused by complex gene-environment interactions. A functional single nucleotide polymorphism of cadherin-related family member 3 (CDHR3), known as a receptor of rhinovirus-C, is associated with childhood-onset asthma especially in atopic individuals. OBJECTIVE: Here, we identified risk factors for adult-onset asthma and COPD, focusing on the impact of the CDHR3 variant in atopic individuals. METHODS: We conducted a longitudinal, retrospective, observational cohort study of 1523 healthy adults with baseline examinations at Tsukuba Medical Center Hospital in 2008 and retrospectively identified new-onset, physician-diagnosed asthma or COPD from 2009 to 2018. We assessed risk factors by the Cox regression analysis. The impact of CDHR3 variant rs6967330 was also examined in individuals with pre-existing atopy. RESULTS: Over 10 study years, 103 people developed airway diseases (79 asthma and 24 COPD; 52 females, average onset-age 55 years old, range 38-80). Higher body mass index (BMI) and lower forced expiratory volume in one second/forced vital capacity (FEV1 /FVC) ratio were significant risk factors (BMI: HR 1.072 [95% CI 1.005-1.14], P = .034; FEV1 /FVC ratio: HR 1.091 [1.044-1.14], P = .00011). Restriction to atopic individuals saw the A allele at rs6967330 and lower FEV1 /FVC ratio to associate with adult-onset disease (A allele: HR 2.89 [1.57-5.20], P = .00062; FEV1 /FVC ratio: HR 1.10 [1.04-1.17], P = .0010). CONCLUSION AND CLINICAL RELEVANCE: Genetic susceptibility to rhinovirus-C infection in atopic individuals is a risk factor for chronic airway diseases even in later life.

High-Yield Production of the Major Birch Pollen Allergen Bet v 1 With Allergen Immunogenicity in Nicotiana benthamiana.

Type I allergy is an immunological disorder triggered by allergens and causes significant health problems. The major allergen of birch pollen is Bet v 1, which belongs to the pathogen-related protein 10 (PR-10) family. Here, we established a rapid and robust method for the production of Bet v 1 in Nicotiana benthamiana leaves, with binding activity to allergic patients' IgE. The Bet v 1 allergen was expressed in N. benthamiana using a strong agroinfiltration-based transient protein expression system, which consists of a deconstructed geminiviral vector system with a double terminator. Five days post-infiltration, the allergen concentration in N. benthamiana leaves was 1.2 mg/g of fresh mass, being this the maximum yield of Bet v 1 in plants reported up to now. A part of plant-derived Bet v 1 was glycosylated. Bet v 1 purified from N. benthamiana or Brevibacillus brevis was used to carry out enzyme-linked immunoassays; both recombinant allergens were found to have comparable binding properties to the IgE of allergic patients. These results suggest that our plant expression system allows rapid and robust production of the allergen, which keeps the immunogenicity.

Effects of Lung Function-Related Genes and TSLP on COPD Phenotypes.

A weighted genetic risk score (GRS) based on 16 SNPs implicated in reduced lung function in both Japanese and non-Japanese populations was previously associated with the onset of COPD and asthma. We here examine the genetic impact of this lung function GRS on specific COPD phenotypes. A cohort of Japanese COPD patients (N = 270) underwent lung function testing followed by genotyping with allele-specific arrays for 16 SNPs as well as expression quantitative trait loci at TSLP (rs2289276, rs3806933). Lung function GRS scoring and two-step cluster analyses grouped patients into different COPD phenotypes based on gender, age, smoking index, %FEV1 and lung function GRS. The genetic effect of TSLP on COPD phenotypes was also examined for interactions with the lung function GRS. A total of 270 participants were grouped into 5 clusters. The cluster with the highest levels of lung function GRS was characterized by moderate to severe airflow obstruction and the highest blood eosinophil counts. Regarding TSLP, an increased number of T alleles at both SNPs was found in the cluster characterized by moderate to severe airflow obstruction and heavy smoking (rs2289276, p value = 0.035; rs3806933, p value = 0.047) independent of the lung function GRS. A genetic susceptibility to impaired lung function carries an increased risk of developing COPD characterized by increased eosinophil counts and severe airflow obstruction while individuals with increased TSLP responses to external stimuli have an independent risk of developing severe airflow obstruction in the presence of heavy smoking.

The Concavity of the Maximal Expiratory Flow-Volume Curve Reflects the Extent of Emphysema in Obstructive Lung Diseases.

A concave-shaped maximal expiratory flow-volume (MEFV) curve is a spirometric feature in chronic obstructive pulmonary disease (COPD). The MEFV curve is characterized by an increase in the Obstructive Index, which is defined as a ratio of forced vital capacity to the volume-difference between two points of half of the peak expiratory flow on the MEFV curve. We hypothesized that the Obstructive Index would reflect the severity of emphysema in patients with COPD and asthma-COPD overlap (ACO). Thus, the aim of this retrospective study was to evaluate whether the Obstructive Index on spirometry is associated with the extent of emphysema on computed tomography (CT) in patients with COPD, ACO, and asthma (N = 65, 15, and 53, respectively). The percentage of low-attenuation volume (LAV%) and wall area (WA%) were measured on CT. The Obstructive Index was higher in patients with COPD and ACO than in those with asthma. Spearman correlation showed that a greater Obstructive Index was associated with a higher LAV%, but not WA%. Multivariate analysis showed that Obstructive Index was associated with LAV% (standardized ß = 0.43, P < 0.0001) independent of other spirometric indices. The Obstructive Index is a useful spirometric index that reflects the extent of emphysema.

A cis-eQTL allele regulating reduced expression of CHI3L1 is associated with late-onset adult asthma in Japanese cohorts.

BACKGROUND: The chitinase-like protein YKL-40 plays a major role in inhibiting the inflammasome. Deregulation of inflammasome activation is emerging as a key modulator of pathologic airway inflammation in patients with asthma. We determined whether cis-expression quantitative trait loci (eQTLs) of the gene that encodes YKL-40, chitinase 3-like 1 (CHI3L1), are involved in the onset of asthma or in specific asthma phenotypes. METHODS: This case-control study, which was conducted at the University of Tsukuba, Japan, included a total of 2709 adults from the Tsukuba genome-wide association study (GWAS) cohort (734 healthy volunteers and 237 asthma patients), the Tsukuba replication cohort (375 healthy adult volunteers and 381 adult asthma patients), and the Hokkaido replication cohort (554 healthy adult volunteers and 428 adult asthma patients). Among 34 cis-eQTLs in CHI3L1 in the lung, rs946261 was associated with adult asthma in these Japanese cohorts. The genetic impact of rs946261 on asthma was also examined according to the age at onset and adult asthma clusters. RESULTS: In the Tsukuba GWAS cohort, the C allele at rs946261 was significantly associated with reduced expression of CHI3L1 mRNA in the lung and with development of asthma (odds ratio (OR) 1.27; P = 0.036). The association was also observed following analysis of the three Japanese cohorts (OR 1.16; P = 0.013). A stronger association was found with late-onset asthma that developed at 41 years of age or later (OR 1.24; 95% confidence interval (CI) 1.07-1.45; P = 0.0058) and with a specific asthma phenotype characterized by late onset, less atopy, and mild airflow obstruction (OR 1.29; 95% CI 1.03-1.61; P = 0.027). CONCLUSIONS: The genotype consisting of the cis-eQTL allele that reduces expression of CHI3L1 was specifically associated with late-onset adult asthma. Given the important role of YKL-40 in many pathophysiological processes, including cell growth, migration, chemotaxis, reorganization, and tissue remodeling, it may be involved in an important pathogenic role in the establishment of inflammation and remodeling in asthmatic airways. Our findings may indicate the presence of a specific endotype related to exaggerated activation of YKL-40 in the pathogenesis of late-onset adult asthma.

Association analyses of eQTLs of the TYRO3 gene and allergic diseases in Japanese populations.

BACKGROUND: TYRO3 is a member of the TAM (TYRO3, AXL, MERTK) receptor tyrosine kinase family and functions to limit type 2 immune responses implicated in allergic sensitization. Recent studies have shown that multiple intronic variants of TYRO3 were associated with asthma, implying that genetic variation could contribute to errant immune activation. We therefore hypothesized that expression quantitative trait loci (eQTLs) of the TYRO3 gene influence the development of allergic diseases (including asthma and allergic rhinitis) in Japanese populations. METHODS: We performed a candidate gene case-control association study of 8 eQTLs of TYRO3 on atopy, asthma, and allergic rhinitis using 1168 unrelated Japanese adults who had GWAS genotyping. We then examined the genetic impact of rs2297377 (TYRO3) on atopy and allergic rhinitis in 2 other independent Japanese populations. RESULTS: A meta-analysis of 3 Japanese populations (a total of 2403 Japanese adults) revealed that rs2297377 was associated with atopy and allergic rhinitis (OR = 1.29 and 1.31; P = 0.00041 and 0.0010, respectively). The risk allele at rs2297377 correlated with decreased expression of TYRO3 mRNA. The gene-gene interaction between HLA-DPB1 and TYRO3 was not significant with regard to sensitization. The estimated proportion of atopy and allergic rhinitis cases attributable to the risk genotype was 14% and 16%, respectively. CONCLUSIONS: Our study identified TYRO3 as an important susceptibility gene to atopy and allergic rhinitis in Japanese.

Genetic association of the functional CDHR3 genotype with early-onset adult asthma in Japanese populations.

BACKGROUND: Recent studies have demonstrated that a coding SNP (rs6967330, Cys529→Tyr) in cadherin-related family member 3 (CDHR3), which was previously associated with wheezing illness and hospitalizations in infancy, could support efficient human rhinovirus C (RV-C) entry and replication. Here, we sought to examine the genetic contribution of this variant to the development of adult asthma. METHODS: We performed a candidate gene case-control association study of 2 independent Japanese populations (a total of 3366 adults). The odds ratios (ORs) for association of the A allele at rs6967330 with adult asthma were calculated according to age at onset of asthma. In addition, the effect of the CDHR3 genotype on the development of specific asthma phenotypes was examined. RESULTS: The A allele was associated with asthma (OR = 1.56; Mantel-Haenszel p = 0.0040) when the analysis was limited to patients with early-onset adult asthma. In addition, when the analysis was limited to atopic individuals, a stronger association of the CDHR3 variant with early-onset asthma was found, and interaction of the CDHR3 genotype with atopy was demonstrated. Finally, a significant association of this variant was specifically found with a phenotype of asthma characterized by atopy, early-onset, and lower lung function. CONCLUSIONS: Our study supports the concept that the CDHR3 variant is an important susceptibility factor for severe adult asthma in individuals who develop the disease in early life. The interaction between the CDHR3 variant and atopy indicates that genetic predisposition to early respiratory viral infection is combined with atopy in promoting asthma.

GENETIC INTERACTIONS BETWEEN ADRB2 AND PTGER4 ON RESPONSES TO SALMETEROL OR MONTELUKAST IN JAPANESE PATIENTS WITH MILD PERSISTENT ASTHMA.

BACKGROUND: Long-acting ß2-agonists (LABA) and leukotriene receptor antagonists (LTRA) are two principal agents that can be added to inhaled corticosteroids (ICS) for patients with asthma that is not adequately controlled by ICS alone. In our previous study, the Gly16Arg genotype of the ß2-adrenergic receptor (ADRB2) gene did not influence the differential bronchodilator effect of salmeterol versus montelukast as an add-on therapy to ICS within 16 weeks of follow-up (the J-Blossom study). METHODS: We examined if genes encoding CYSLTR1, CYSLTR2, PTGER2 or PTGER4 could explain differential responses to salmeterol versus montelukast using the participants of the J-Blossom study. This study included 76 patients with mild-to-moderate asthma. The difference in peak expiratory flow (PEF) (ΔPEF, l/min) after 16 weeks of treatment with salmeterol (ΔPEFsal) versus montelukast (ΔPEFmon) was associated with the genotypes at each of 4 genes. In addition, multivariate analyses were used to identify a gene-gene interaction between ADRB2 gene and each of these 4 genes. RESULTS: Although none of 4 genes were associated with ΔPEFsal-ΔPEFmon in the univariate analyses, multivariate analysis showed that PTGER4 gene, interacting with ADRB2 Gly16Arg, was associated with ΔPEFsal-ΔPEFmon (p=0.0032). CONCLUSION: Our findings suggested that the interactions between two genetic loci at ADRB2 and PTGER4 is important in determining the differential response to salmeterol versus montelukast in patients with chronic adult asthma.