Applicable predictive factors extracted from peak flow trajectory for the prediction of asthma exacerbation.

BACKGROUND: Real-time asthma exacerbation prediction and acute asthma attack detection are essential for patients with severe asthma. Peak expiratory flow (PEF) exhibits a potential for use in long-term asthma self-monitoring. However, the method for processing PEF calculations remains to be clarified. OBJECTIVE: To develop clinically applicable novel exacerbation predictors calculated using PEF records. METHODS: Previously proposed exacerbation predictors, including the slope of PEF, percentage predicted PEF, percentage best PEF, the highest PEF over the lowest PEF within specific periods, and PEF coefficient of variation, in addition to a novel indicator delta PEF moving average (ΔMA), defined as the difference between 14-day and 3-day average PEF values, along with moving average (MA) adjusted for PEF reference (%ΔMA), were verified using the Hokkaido-based Investigative Cohort Analysis for Refractory Asthma data of 127 patients with severe asthma from whom 73,503 PEF observations were obtained. Receiver operating characteristic curves for all predictors were drawn, and the corresponding areas under the curve (AUCs) were computed. Regression analysis for MA and percentage MA were conducted. RESULTS: The most outstanding performance was shown by ΔMA and %ΔMA, with AUC values of 0.659 and 0.665 in the univariate model, respectively. When multivariate models were incorporated with random intercepts for individual participants, the AUC for ΔMA and %ΔMA increased to 0.907 and 0.919, respectively. CONCLUSION: The MA and percentage MA are valuable indicators that should be considered when deriving predictors from the PEF trajectory for monitoring exacerbations in patients with severe asthma. TRIAL REGISTRATION: The Hokkaido-based Investigative Cohort Analysis for Refractory Asthma was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN ID: 000003254). https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000003917.

Relationships of computed tomography-based small vessel indices of the lungs with ventilation heterogeneity and high transfer coefficients in non-smokers with asthma.

Background: The mechanism of high transfer coefficients of the lungs for carbon monoxide (Kco) in non-smokers with asthma is explained by the redistribution of blood flow to the area with preserved ventilation, to match the ventilation perfusion. Objectives: To examine whether ventilation heterogeneity, assessed by pulmonary function tests, is associated with computed tomography (CT)-based vascular indices and Kco in patients with asthma. Methods: Participants were enrolled from the Hokkaido-based Investigative Cohort Analysis for Refractory Asthma (Hi-CARAT) study that included a prospective asthmatic cohort. Pulmonary function tests including Kco, using single breath methods; total lung capacity (TLC), using multiple breath methods; and CT, were performed on the same day. The ratio of the lung volume assessed using single breath methods (alveolar volume; VA) to that using multiple breath methods (TLC) was calculated as an index of ventilation heterogeneity. The volume of the pulmonary small vessels <5 mm2 in the whole lung (BV5 volume), and number of BV5 at a theoretical surface area of the lungs from the plural surface (BV5 number) were evaluated using chest CT images. Results: The low VA/TLC group (the lowest quartile) had significantly lower BV5 number, BV5 volume, higher BV5 volume/BV5 number, and higher Kco compared to the high VA/TLC group (the highest quartile) in 117 non-smokers, but not in 67 smokers. Multivariable analysis showed that low VA/TLC was associated with low BV5 number, after adjusting for age, sex, weight, lung volume on CT, and CT emphysema index in non-smokers (not in smokers). Conclusion: Ventilation heterogeneity may be associated with low BV5 number and high Kco in non-smokers (not in smokers). Future studies need to determine the dynamic regional system in ventilation, perfusion, and diffusion in asthma.

Association of serum CC16 levels with eosinophilic inflammation and respiratory dysfunction in severe asthma.

BACKGROUND: There are knowledge gaps in the potential role of Club cell 16-kDa secretory protein (CC16) in severe asthma phenotypes and type 2 inflammation, as well as the longitudinal effect of CC16 on pulmonary function tests and exacerbation risk in epidemiological studies. OBJECTIVE AND METHODS: To assess whether serum CC16 is associated with eosinophilic inflammation in patients with severe asthma. We also examined the effect of this protein on the annual decline in forced expiratory volume in the first second (FEV1) and the risk of exacerbation using a longitudinal approach. We recruited 127 patients with severe asthma from 30 hospitals/pulmonary clinics in Hokkaido, Japan. The least square means and standard error were calculated for T-helper 2 (Th2) biomarkers and pulmonary function test across CC16 tertiles at baseline. We did the same for asthma exacerbation and annual decline in FEV1 with 3 and 5 years' follow-up, respectively. RESULTS: We found that serum CC16 was inversely associated with sputum eosinophils and blood periostin in a dose-response manner. Baseline CC16 and FEV1/forced vital capacity ratio were positively associated in adjusted models (p for trend = 0.008). Patients with the lowest tertile of serum CC16 levels at baseline had a -14.3 mL decline in FEV1 than those with the highest tertile over 5 years of follow-up (p for trend = 0.031, fully adjusted model). We did not find any association of CC16 with exacerbation risk. CONCLUSION: Patients with severe asthma with lower circulatory CC16 had enhanced eosinophilic inflammation with rapid FEV1 decline over time.

Blood eosinophil count variability in chronic obstructive pulmonary disease and severe asthma.

BACKGROUND: Blood eosinophils are essential biomarkers that vary substantially over time in patients with COPD and asthma. However, no study has identified the changes and effects in the changes of the blood eosinophil counts over time in both diseases. This study aimed to demonstrate blood eosinophil variability in patients with COPD and severe asthma based on these backgrounds. METHODS: A total of 172 patients with COPD from the Hokkaido COPD cohort study and 96 patients with severe asthma from the Hokkaido Severe Asthma Cohort Study, whose blood eosinophil counts were measured annually over a 3-year period, were analyzed. The factors contributing to consistently high or low blood eosinophil counts were examined in each cohort. The stability of the eosinophil classification (<150, 150-299, ≥300 cells/µL) was compared based on the number of asthma-like features in patients with COPD and the smoking status in patients with severe asthma. RESULTS: Among all the patients, the most stable range of baseline blood eosinophil counts differed between the two diseases, with <150 cells/µL in COPD and ≥300 cells/µL in severe asthma. In COPD, the number of asthma-like features (bronchodilator reversibility, blood eosinophilia, and atopy) affects the blood eosinophil count variation patterns. In severe asthma, smoking status did not affect the blood eosinophil count variation patterns. CONCLUSIONS: We identified variations in the blood eosinophil counts and their contributing factors in patients with COPD and severe asthma.

Differential role of mucus plugs in asthma: Effects of smoking and association with airway inflammation.

BACKGROUND: The physiological importance of mucus plugs in computed tomography (CT) imaging is being increasingly recognized. However, whether airway inflammation and smoking affect the association between mucus plugs and clinical-physiological outcomes in asthma remains to be elucidated. The objective of this study is to examine how airway inflammation and/or smoking affect the correlation of CT-based mucus plug scores with exacerbation frequency and airflow limitation indices in asthma. METHODS: A total of 168 patients with asthma who underwent chest CT and sputum evaluation were enrolled and classified in eosinophilic asthma (EA; n = 103) and non-eosinophilic asthma (NEA; n = 65) groups based on sputum eosinophil percentage (cut-off: 3%). The mucus plug score was defined as the number of lung segments with mucus plugs seen on CT. RESULTS: More mucus plugs were detected on CT scans in the EA group than in the NEA group, regardless of smoking status. Mucus plug score and exacerbation frequency during one year after enrollment were significantly associated in the EA group but not in the NEA group after adjusting for demographics, blood eosinophil count, and fractional exhaled nitric oxide. Mucus plug score was associated with percentage of predicted forced expiratory volume in 1 s in non-smoking individuals in the EA and NEA group and in smoking individuals in the EA group but not in the NEA group after adjusting for demographics. CONCLUSIONS: The association of mucus plug score with exacerbation frequency and reduced lung function may vary due to airway inflammatory profile and smoking status in asthma.

Combination therapy with remdesivir and immunomodulators improves respiratory status in COVID-19: A retrospective study.

Immunomodulators (tocilizumab/baricitinib) improve outcomes of coronavirus disease 2019 (COVID-19) patients, but the synergistic effect of remdesivir is unknown. The effect of combination therapy with remdesivir, immunomodulators, and standard treatment in COVID-19 patients was investigated. This retrospective, single-center study included COVID-19 patients who were treated with tocilizumab or baricitinib. The severity of respiratory status in the two groups on Days 14 and 28 and the duration to respiratory recovery in both groups were compared, and the effect of remdesivir use on respiratory status was examined in a multivariate analysis. Ninety-eight patients received tocilizumab or baricitinib; among them, 72 used remdesivir (remdesivir group) and 26 did not (control group). The remdesivir group achieved faster respiratory recovery than the control group (median 11 vs. 21 days, p = 0.033), faster weaning from supplemental oxygen (hazard ratio [HR]: 2.54, 95% confidence interval [CI]: 1.14-5.66, p = 0.021). Age, body mass index, diabetes mellitus, and time from onset to oxygen administration were independent prognostic factors. The remdesivir group achieved better severity level at Days 14 and 28 (p = 0.033 and 0.003, respectively) and greater improvement from baseline severity (p = 0.047 and 0.018, respectively). Remdesivir combination therapy did not prolong survival (HR: 0.31, 95% CI: 0.04-2.16, p = 0.23). Among severely ill COVID-19 patients who received immunomodulator, remdesivir contributed to a shorter respiratory recovery time and better respiratory status at Days 14 and 28. Concomitant remdesivir with immunomodulators and standard treatment may provide additional benefit in improving respiratory status of COVID-19 patients.

Effects of obesity on CC16 and their potential role in overweight/obese asthma.

INTRODUCTION: Club cell secretory protein-16 (CC16) is a major anti-inflammatory protein expressed in the airway; however, the potential role of CC16 on overweight/obese asthma has not been assessed. In this study, we examined whether obesity reduces airway/circulatory CC16 levels using experimental and epidemiological studies. Then, we explored the mediatory role of CC16 in the relationship of overweight/obesity with clinical asthma measures. METHODS: Circulating CC16 levels were assessed by ELISA in three independent human populations, including two groups of healthy and general populations and asthma patients. The percentage of cells expressing club markers in obese vs. non-obese mice and human airways was determined by immunohistochemistry. A causal mediation analysis was conducted to determine whether circulatory CC16 acted as a mediator between overweight/obesity and clinical asthma measures. RESULTS: BMI was significantly and monotonously associated with reduced circulating CC16 levels in all populations. The percentage of CC16-expressing cells was reduced in the small airways of both mice and humans with obesity. Finally, mediation analysis revealed significant contributions of circulatory CC16 in the association between BMI and clinical asthma measures; 21.8% of its total effect in BMI's association with airway hyperresponsiveness of healthy subjects (p = 0.09), 26.4% with asthma severity (p = 0.030), and 23% with the required dose of inhaled corticosteroid (p = 0.042). In logistic regression analysis, 1-SD decrease in serum CC16 levels of asthma patients was associated with 87% increased odds for high dose ICS requirement (p < 0.001). CONCLUSIONS: We demonstrate that airway/circulating CC16, which is inversely associated with BMI, may mediate development and severity in overweight/obese asthma.

Comparative Efficacy of Tocilizumab and Baricitinib Administration in COVID-19 Treatment: A Retrospective Cohort Study.

Background and Objectives: Tocilizumab and baricitinib have been observed to improve the outcomes of patients with coronavirus disease 2019 (COVID-19). However, a comparative evaluation of these drugs has not been performed. Materials and Methods: A retrospective, single-center study was conducted using the data of COVID-19 patients admitted to Hokkaido University hospital between April 2020 and September 2021, who were treated with tocilizumab or baricitinib. The clinical characteristics of the patients who received tocilizumab were compared to those of patients who received baricitinib. Univariate and multivariate logistic regression analyses of the outcomes of all-cause mortality and improvement in respiratory status were performed. The development of secondary infection events was analyzed using the Kaplan-Meier method and the log-rank test. Results: Of the 459 patients hospitalized with COVID-19 during the study, 64 received tocilizumab treatment and 34 baricitinib treatment, and those 98 patients were included in the study. Most patients were treated with concomitant steroids and exhibited the same severity level at the initiation of drug treatment. When compared to each other, neither tocilizumab nor baricitinib use were associated with all-cause mortality or improvement in respiratory status within 28 days from drug administration. Conclusions: Age, chronic renal disease and early administration of TCZ or BRT from the onset of COVID-19 were independent prognostic factors for all-cause mortality, whereas anti-viral drug use and the severity of COVID-19 at baseline were associated with an improvement in respiratory status. Secondary infection-free survival rates of patients treated with tocilizumab and those treated with baricitinib did not significantly differ. The results suggest that both tocilizumab and baricitinib could be clinically equivalent agents of choice in treatment of COVID-19.

Further evidence for association of YKL-40 with severe asthma airway remodeling.

BACKGROUND: The chitinase-like protein YKL-40 is associated with airflow limitation on spirometry and airway remodeling in patients with asthma. It remains unclear whether YKL-40 is associated with morphologic changes in the airways and parenchyma or with future progression of airflow limitation in severe asthma. OBJECTIVE: To evaluate the association of circulating YKL-40 levels with morphologic changes in the airways and parenchyma and with longitudinal progression of airflow limitation. METHODS: The patients were participants in the Hokkaido Severe Asthma Cohort Study (n = 127), including smokers. This study consisted of 2 parts. In analysis 1, we analyzed associations between circulating YKL-40 levels and several asthma-related indices, including computed tomography-derived indices of proximal wall area percentage, the complexity of the airways (airway fractal dimension), and the parenchyma (exponent D) cross-sectionally (n = 97). In analysis 2, we evaluated the impact of circulating YKL-40 levels on forced expiratory volume in 1 second (FEV1) decline longitudinally for a 5-year follow-up (n = 103). RESULTS: Circulating YKL-40 levels were significantly associated with proximal wall area percentage and airway fractal dimension (r = 0.25, P = .01; r = -0.22, P = .04, respectively), but not with exponent D. The mean annual change in FEV1 was -33.7 (± 23.3) mL/y, and the circulating YKL-40 level was a significant independent factor associated with annual FEV1 decline (ß = -0.24, P = .02), even after controlling for exponent D (ß = -0.26, P = .01). CONCLUSION: These results provide further evidence for the association of YKL-40 with the pathogenesis of airway remodeling in severe asthma.

Combined assessment of pulmonary arterial enlargement and coronary calcification predicts the prognosis of patients with chronic obstructive pulmonary disease.

INTRODUCTION: In chronic obstructive pulmonary disease (COPD), chest computed tomography (CT) provides clinically important cardiovascular findings, which include diameter of pulmonary artery (PA), its ratio to the diameter of the aorta (PA:A ratio), and coronary artery calcium score (CACS). The clinical importance of these cardiovascular findings has not been fully assessed in Japan, where cardiovascular morbidity and/or mortality is reported to be much less compared with Western counterparts. METHODS: PA diameter and PA:A ratio were measured in 172 and 130 patients with COPD who enrolled in the Hokkaido COPD cohort study and the Kyoto University cohort, respectively. CACS was measured in 131 and 128 patients in each cohort. RESULTS: While the highest quartile group in PA diameter was associated with higher all-cause mortality compared to the lowest quartile group in both cohorts, individual assessments of PA:A ratio and CACS were not associated with the long-term clinical outcomes. When PA diameter and CACS were combined, patients with PA enlargement (diameter >29.5 mm) and/or coronary calcification (score >440.8) were associated with higher all-cause mortality in both cohorts. CONCLUSION: Combined assessment of PA enlargement and CACS was associated with poor prognosis, which provides a clinical advantage in management of patients with COPD even in geographical regions with lower risk of cardiovascular diseases.

Determination of the cutoff values of Th2 markers for the prediction of future exacerbation in severe asthma: An analysis from the Hokkaido Severe Asthma Cohort Study.

BACKGROUND: We recently reported that severe asthma patients with frequent exacerbations showed high blood eosinophil counts (Eo) and fractions of exhaled nitric oxide (FeNO) compared with non-exacerbators. However, we did not determine exact cutoff values related to exacerbation. The aim of this study was to determine the cutoff values of Eo and FeNO that could be related to the exacerbation of severe asthma. We also aimed to confirm the clinical utility of Th2 markers related to exacerbation. METHODS: This study included 105 severe asthma patients who completed a three-year follow-up of a severe asthma cohort study, including smokers. Three Th2 markers were selected, viz., Eo, FeNO, and positive atopic status. Regarding Eo and FeNO, we determined the cutoff values for the definition of "positive" Th2 features using receiver operating characteristic curve analyses, based on the comparisons between frequent exacerbators and other patients. RESULTS: The cutoff values for positive Th2 features were Eo ≥ 250 cells/µL and FeNO ≥31 ppb. Sixteen patients (15.2%) had no Th2 features, 40 (38.1%) had one, 25 (23.8%) had two, and 24 (22.9%) had three. A high number of positive Th2 features was significantly associated with exacerbation frequencies over three years (p < 0.05). Similarly, compared to patients with one or no Th2 features, those with three Th2 features had a significantly higher probability of having more than one exacerbation (p < 0.05). CONCLUSIONS: The cutoff values determined in the current analysis were good predictors of future exacerbations in severe asthma patients.

Serum Alpha-1 Antitrypsin Levels and the Clinical Course of Chronic Obstructive Pulmonary Disease.

Purpose: Alpha-1 antitrypsin deficiency is associated with the development of chronic obstructive pulmonary disease (COPD), whereas increased levels of serum alpha-1antitrypsin occur in response to inflammation. The effects of alpha-1 antitrypsin levels on the clinical course of COPD had been unclear. We investigated the association of serum alpha-1 antitrypsin levels with the clinical course of COPD patients based on data from a 10-year prospective cohort study. Patients and methods: We analyzed 278 COPD patients who participated in the Hokkaido COPD cohort study and who did not meet the criteria for alpha-1 antitrypsin deficiency. We divided the subjects into 3 groups according to quartiles of serum alpha-1 antitrypsin levels at baseline: lower group (<116 mg/dL, n = 66); middle group (116 to ≤141 mg/dL, n = 145); and higher group (>141 mg/dL, n = 67). The annual change in forced expiratory volume in 1 s (FEV1) and events of COPD exacerbation were monitored during the first 5 years, and mortality was followed-up during the entire 10 years. Results: At baseline, the higher group showed lower body mass index; higher computed tomography emphysema score; lower diffusing capacity; higher levels of acute-phase proteins; and higher blood neutrophil counts. Longitudinal analyses revealed that in the higher group, the annual decline in FEV1 was rapid and the 10-year mortality was higher, but there was no association between serum alpha-1 antitrypsin levels and time to first exacerbation. Conclusion: COPD subjects with higher serum alpha-1 antitrypsin levels were associated with a worse systemic inflammation status and higher 10-year mortality.

Impact of Abdominal Visceral Adiposity on Adult Asthma Symptoms.

BACKGROUND: Previous studies have shown the association of anthropometric measures with poor asthma symptoms, especially among women. However, the potential influence of visceral adiposity on asthma symptoms has not been investigated well. OBJECTIVE: In this study, we have evaluated whether visceral adiposity is related to poor adult asthma symptoms independent of anthropometric measures and sex. If this relationship presented, we investigated whether it is explained by influence on pulmonary functions and/or obesity-related comorbidities. METHODS: We analyzed data from 206 subjects with asthma from Japan. In addition to anthropometric measures (body mass index and waist circumference), abdominal visceral and subcutaneous fat were assessed by computed tomography scan. Quality of life was assessed using the Japanese version of the Asthma Quality of Life Questionnaire. RESULTS: All obesity indices had inverse association with reduced asthma quality of life among females. However, only the visceral fat area showed a statistical inverse association with Asthma Quality of Life Questionnaire in males. Only abdominal visceral fat was associated with higher gastroesophageal reflux disease and depression scores. Although all obesity indices showed inverse association with functional residual capacity, only visceral fat area had a significant inverse association with FEV1 % predicted, independent of other obesity indices. CONCLUSIONS: Regardless of sex, abdominal visceral fat was associated with reduced asthma quality of life independent of other obesity indices, and this may be explained by the impact of abdominal visceral fat on reduced FEV1 % predicted and higher risk for gastroesophageal reflux disease and depression. Therefore, visceral adiposity may have more clinical influence than any other obesity indices on asthma symptoms.

Associations of Current Wheeze and Body Mass Index with Perennial and Seasonal Allergic Rhinitis in Young Adults.

BACKGROUND: The coexistence of asthma and allergic rhinitis (AR) and its distinct association with obesity have been reported. However, few studies have differentiated the two types of AR, i.e., perennial (PAR) and seasonal AR (SAR), with regard to their associations with asthma and obesity. The aim of this study was to evaluate the coexistence of current wheeze and two types of AR and the impact of body mass index (BMI) on these two conditions in Japanese young adults. METHODS: First-year students from Hokkaido University were enrolled into this study from 2011 to 2016. A questionnaire survey including the prevalence of current wheeze, PAR, and SAR every year for 11,917 nonsmoking young adults was conducted. The difference in the impact of current wheeze and BMI on these two types of AR was separately evaluated. RESULTS: Although both PAR and SAR were significantly associated with current wheeze, the impact of these two AR types on current wheeze was different (OR for PAR = 2.46 vs. OR for SAR = 1.29). When we classified all of the subjects into 4 groups with or/and without the two types of AR, the prevalence of current wheeze was significantly higher in subjects with PAR than in those without PAR (p < 0.001). However, the prevalence of current wheeze did not differ between subjects with or without SAR. Multinomial regression analyses showed that the association of wheeze with PAR and/or SAR was stronger compared to that of wheeze with SAR without PAR. The prevalence of PAR was not associated with BMI. Contrarily, a low BMI was significantly associated with a high SAR prevalence (p < 0.05). CONCLUSION: Comparisons between PAR and SAR showed that the conditions are differentially associated with current wheeze and BMI.