A systematic review and meta-analysis of macrolides in the management of adult patients with asthma.

BACKGROUND: The efficacy of macrolides in the management of asthma has been studied but remains controversial. We conducted a systematic review and meta-analysis of macrolides in the management of adult patients with asthma. METHODS: Randomized controlled trials of macrolides used in adult patients with asthma were searched for in MEDLINE, EMBASE, PsycINFO, Cochrane Library, CINAHL, and Igaku Chuo Zasshi databases to evaluate the efficacy and safety of macrolides. RESULTS: Seventeen reports with macrolide treatment durations ranging from 6 to 48 weeks were included. Macrolides did not reduce exacerbations requiring hospitalization, severe exacerbations, or rescue use of short-acting beta-2 agonist inhalers; improve lung function; decrease peripheral blood or sputum neutrophil counts; or decrease fractional exhaled nitric oxide compared to placebo. Macrolides statistically improved asthma control and quality of life but by less than the minimal clinically important difference. Peripheral blood eosinophil counts as well as serum and sputum eosinophilic cationic protein concentrations were significantly decreased with macrolides compared to placebo. The improvement of asthma symptoms and airway hyperresponsiveness varied by study. The safety profile of macrolides was comparable to that of placebo. CONCLUSIONS: Although macrolides have some useful clinical aspects, there is not sufficient evidence to recommend their use in the management of adult patients with asthma.

Methacholine-induced cough as an indicator of bronchodilator-responsive cough.

BACKGROUND: Cough variant asthma (CVA) is the most common cause of chronic cough and responds well to bronchodilator therapy. Previous studies on methacholine -induced cough have shown that heightened cough response due to bronchoconstriction is a feature of CVA. The aim of this study was to assess Mch-induced cough as an indicator of bronchodilator-responsive cough (BRC). METHODS: This was a single-center retrospective study of prolonged/chronic cough cases who underwent evaluation via spirometry, FeNO and bronchial challenge testing using Mch and capsaicin (C5). Resultant bronchoconstriction after Mch challenge was assessed by flow-volume curves measuring the expiratory flow of the partial flow-volume curve 40% above residual volume (PEF40) and FEV1. BRC was defined as a decrease in cough with bronchodilator therapy by 30% or more on a visual analog scoring scale. RESULTS: Of the 100 patients evaluated, 63 were diagnosed with BRC. Mch-induced cough at a decrease in PEF40 of 35% (PC35-PEF40) was predictive of BRC on AUROC analysis with an AUC of 0.82 (95% CI 0.73-0.90) and cut-off of 24. The AUC for C5, FeNO and PC20-FEV1 were 0.65, 0.47, and 0.58, respectively. CONCLUSION: Compared to C5, FeNO and PC20-FEV1, Mch-induced cough better supports a diagnosis of BRC.

Dynamic-Ventilatory Digital Radiography in Air Flow Limitation: A Change in Lung Area Reflects Air Trapping.

OBJECTIVE: The aim of this study was to determine the utility of dynamic-ventilatory digital radiography (DR) for pulmonary function assessment in patients with airflow limitation. METHODS: One hundred and eighteen patients with airflow limitation (72 patients with lung cancer before surgery, 35 patients with chronic obstructive pulmonary disease [COPD], 6 patients with asthma, and 5 patients with asthma-COPD overlap syndrome) were assessed with dynamic-ventilatory DR. The patients were instructed to inhale and exhale slowly and maximally. Sequential chest X-ray images were captured in 15 frames per second using a dynamic flat-panel imaging system. The relationship between the lung area and the rate of change in the lung area due to respiratory motion with respect to pulmonary function was analyzed. RESULTS: The rate of change in the lung area from maximum inspiration to maximum expiration (Rs ratio) was associated with the RV/TLC ratio (r = 0.48, p < 0.01) and the percentage of the predicted FEV1 (r = -0.33, p < 0.01) in patients with airflow limitations. The Rs ratio also decreased in an FEV1-dependent manner. CONCLUSION: The rate of change in the lung area due to respiratory motion evaluated with dynamic DR reflects air trapping. Dynamic DR is a potential tool for the comprehensive assessment of pulmonary function in patients with COPD.

Repeated bronchoconstriction attenuates the cough response to bronchoconstriction in naïve guinea pigs.

BACKGROUND: Cough variant asthma (CVA) is recognized as a precursor of bronchial asthma (BA). However, the cough response to bronchoconstriction differs between these similar diseases. Repeated bronchoconstriction and the resulting imbalance of endogenous lipid mediators may impact the cough response. METHODS: We investigated the influence of repeated bronchoconstriction on the cough response to bronchoconstriction using naïve guinea pigs. Bronchoconstriction was induced for 3 consecutive days and changes in the cough response and lipid mediators, such as PGE2, PGI2, and cysteinyl-LTs (Cys-LTs), in BAL fluid (BALF) were assessed. We investigated the effect of endogenous PGI2 on the cough response by employing a PGI2 receptor antagonist. In order to investigate the cough response over a longer period, we re-evaluated the cough response 2 weeks after repeated bronchoconstriction. RESULTS: The number of coughs induced by bronchoconstriction were significantly decreased by repeated bronchoconstriction. The levels of PGE2, PGI2, and Cys-LTs, and the ratio of PGI2/PGE2 were significantly increased, following repeated bronchoconstriction. This decrease in the cough response was suppressed by pretreatment with a PGI2 receptor antagonist. Two weeks after repeated bronchoconstriction, the cough response returned to the same level as before repeated bronchoconstriction along with a concomitant return of lipid mediators, such as PGE2, PGI2, and Cys-LTs and the ratio of PGI2/PGE2. CONCLUSIONS: Our results suggest that repeated bronchoconstriction and the resulting imbalance of endogenous lipid mediators contribute to the difference in cough responses to bronchoconstriction in CVA and BA.

Effect of triple therapy in patients with asthma-COPD overlap
.

OBJECTIVE: Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) is of increasing interest because ACO patients have significantly worse outcomes, leading to greater social and economic burdens compared with asthma or COPD alone. Some guidelines for ACO recommend triple therapy with inhaled corticosteroids, long-acting ß2 agonists, and long-acting muscarinic antagonists. However, this approach is based on extrapolating data from patients with asthma or COPD alone. Therapeutic studies for ACO have not previously been conducted. MATERIALS AND METHODS: A 12-week, randomized, open-label cross-over pilot study was conducted in 17 ACO patients to evaluate the effect of umeclidinium (UMEC) 62.5 µg once-daily added to fluticasone furoate/vilanterol (FF/VI) 200/25 µg once-daily. A 4-week run-in, a first and a second 4-week treatment period were included. Respiratory function, respiratory impedance, fractional exhaled nitric oxide, COPD assessment test, and asthma control test scores were evaluated 0, 4, and 8 weeks after randomization. RESULTS: Mean values of post-bronchodilator forced expiratory volume in 1 second as a percentage of the predicted value (%FEV1), after UMEC was added to FF/VI, were significantly higher than after the run-in (p < 0.01). Mean values of resonant frequency during inspiration (Fres), after UMEC was added to FF/VI, were significantly lower than after the run-in (p < 0.01). CONCLUSION: Adding UMEC to FF/VI provides greater improvement in lung function, indicating that triple therapy is a suitable regular treatment for ACO.

Role of prostaglandin E2 in bronchoconstriction-triggered cough response in guinea pigs.

A feature of cough variant asthma is a heightened cough response to bronchoconstriction. The mediators of this response are unknown. This study was designed to elucidate the role of lipid mediators in bronchoconstriction-triggered cough response in an experimental animal model. We examined the influence of bronchoconstriction on cell components and mediators including prostaglandin E2 (PGE2) in bronchoalveolar lavage fluid (BALF). We studied the cough response to bronchoconstriction (CRB) by measuring the correlation between the increase in enhanced pause (Penh), an index of bronchoconstriction, and cough counts induced by methacholine (Mch) inhalation in conscious guinea pigs. We then examined the effects of intraperitoneal pretreatment with 16, 16-dimethyl-prostaglandin E2 (dm-PGE2) on CRB and cough counts. The total number of cells and cell components in the BALF were not influenced by bronchoconstriction. While levels of PGE2, prostaglandin I2, and cysteinyl leukotrienes were significantly increased, levels of prostaglandin D2, thromboxane B2, and substance P in the BALF were not. Dm-PGE2 significantly decreased the Mch-induced increase in Penh. Following bronchoconstriction by additional Mch inhalation, dm-PGE2 produced an increase in CRB and cough counts in a dose-dependent manner. Additionally, the heightened CRB following dm-PGE2 treatment was suppressed by pretreatment with PGE2 receptor (E-prostanoid EP) -1 and EP-3 antagonists in a dose-dependent manner, but not by EP-2 and EP-4 antagonists. The EP-1 antagonist also decreased cough counts. These results suggest that PGE2 acts as an exacerbating factor for bronchoconstriction-triggered cough. EP1 and EP3 may provide new therapeutic targets for cough variant asthma.

Role of prostaglandin I2 in the bronchoconstriction-triggered cough response in guinea pigs.

Purpose/Aim of the study: Methacholine chloride (MCh) inhalation causes bronchoconstriction and cough. Following MCh-induced bronchoconstriction, metabolic products of prostaglandin I2 (PGI2) increase in bronchoalveolar lavage fluid (BALF), suggesting that PGI2 plays a role in the cough response. Accordingly, we used an experimental guinea pig model to evaluate the role of PGI2 in the bronchoconstriction-triggered cough response. MATERIALS AND METHODS: Experiment 1: The concentration of PGF1α, a stable metabolite of PGI2, in BALF was assessed in animals exposed to nebulized MCh and animals exposed to nebulized saline. Experiment 2: Bronchoconstriction and cough were assessed in 3 groups of animals after MCh inhalation (a saline group, low-dose PGI2 group, and high-dose PGI2 group). Enhanced pause (Penh) was used as a measure of bronchoconstriction. Experiment 3: Bronchoconstriction and cough were assessed in 3 groups of animals (groups administered saline, a low dose of a specific antagonist of the PGI2 receptor (IP antagonist), and a high dose of a specific IP antagonist). RESULTS: The PGF1α concentration in BALF was significantly higher in the bronchoconstriction group than in the control group. In animals administered high-dose PGI2, the MCh-induced increase in Penh was significantly suppressed, and the number of coughs induced by bronchoconstriction was significantly decreased. In animals treated with a high dose of an IP antagonist, the MCh-induced increase in Penh was not affected, and the number of coughs increased. CONCLUSIONS: Our results suggest that PGI2 ameliorates a bronchoconstriction-triggered cough. The measurement and administration of PGI2 may assist in the diagnosis and treatment, respectively, of the cough response triggered by bronchoconstriction.

The measurement of cough response to bronchoconstriction induced by methacholine inhalation in healthy subjects: An examination using the Astograph method.

BACKGROUND: We demonstrated that heightened cough response to bronchoconstriction is a fundamental feature of cough variant asthma (CVA). To evaluate this physiological feature of CVA in daily clinical practice, it is necessary to clarify the cough response to bronchoconstriction in healthy subjects. We evaluated cough response to methacholine (MCh)-induced bronchoconstriction in healthy subjects. A forced oscillometry technique was used to measure airway resistance changes with Mch. METHODS: Healthy never-smokers (21 men, 20 women; mean 22.3 ± 3.7 years) participated. None had a >3-week cough history, clinically significant respiratory or cardiovascular disorders, or disorders that might put subjects at risk or influence the study results or the subjects' ability to participate. Twofold increasing concentrations of Mch chloride diluted in phosphate-buffered saline (0.039 to 160 mg/mL) were inhaled from nebulizers at 1-minute intervals during subjects' tidal breathing after the baseline respiratory resistance (Rrs) was recorded. Mch inhalation continued until Rrs reached twice the baseline value and forced expiratory volume in 1 second (FEV1) decreased to <90% of baseline value. Spirometry was measured before Mch inhalation and immediately after Rrs had increased twofold. Coughs were counted during and for 30 minutes after Mch inhalation. The cough reflex sensitivity to capsaicin was also examined. RESULTS: The number of coughs was 11.1 ± 14.3 (median, 7.0; range, 0 to 71; reference range, 0 to 39.7). There was no significant difference in the cough response between the sexes. The reproducibility of the cough response to bronchoconstriction was sufficient. No correlation existed between the bronchoconstriction-induced cough response and capsaicin cough-reflex sensitivity. CONCLUSIONS: Using the Astograph method, cough response to bronchoconstriction could be measured easily, safely and highly reproducibly in healthy subjects.

Bronchoconstriction-triggered cough in atopic cough: A retrospective study.

BACKGROUND: Atopic cough (AC) and cough variant asthma (CVA) were identified as major causes of chronic non-productive cough in a Japanese study. A characteristic feature of CVA is the presence of a heightened cough response to bronchoconstriction. On the other hand, the cough response to bronchoconstriction in AC remains unclear. METHODS: Methacholine (Mch)-induced cough in AC was measured and compared with that in CVA. Diagnoses of AC and CVA were made based on patient history, physical examination, response to bronchodilator therapy, cough reflex sensitivity to capsaicin, spirometry, and airway responsiveness to methacholine. RESULTS: Thirteen AC patients and 12 CVA patients in whom the criteria were met were recruited to the study. After inhalation of Mch at PC35-PEF40 that means milder bronchoconstriction than PC20-FEV1, cough was triggered a few times in AC. [cough number: 1/ 32 min (0-40)]. Conversely, significantly greater number of coughs was provoked in CVA, compared with AC [cough number: 35.5/ 32 min (25-125), p < 0.05]. CONCLUSIONS: The cough response to bronchoconstriction is reduced in AC compared to CVA. This feature may be useful in the diagnosis of chronic cough.

Paradoxical reaction to antituberculosis therapy after 6 months of treatment for pulmonary tuberculosis: A case report.

Paradoxical reactions (PRs) to antituberculosis (anti-TB) drugs during treatment are well known phenomena, but a PR presenting as a new pulmonary lesion after completion of treatment is extremely rare, and little is known about the management of such cases. A 44-year-old man was diagnosed with pulmonary TB. His sputum cultures became negative 45 days after the initiation of standard anti-TB treatment. Upon the patient's completion of 6 months of anti-TB therapy, computed tomography revealed a new irregularly shaped mass in the lower left pulmonary lobe. A transbronchial lung biopsy (TBLB) revealed caseous necrosis and granulomatosis surrounded by epithelioid and multinucleated giant cells. Cultures of both the TBLB specimen and bronchoalveolar lavage fluid remained negative for TB. The CT shadow disappeared 6 months later without further administration of anti-TB drugs. Careful observation without therapy may be sufficient for a patient treated for TB who develops a PR upon completion of treatment, if the patient has achieved a bacteriological remission.

A comparison of the efficacy of once-daily fluticasone furoate/vilanterole with twice-daily fluticasone propionate/salmeterol in asthma-COPD overlap syndrome.

BACKGROUND: Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is important because patients with ACOS have significantly worse outcomes compared with those with asthma or chronic obstructive pulmonary disease (COPD) alone. Inhaled corticosteroids (ICS), together with a long-acting ß2 agonist (LABA), are recommended, but no therapeutic studies for ACOS have been conducted. Recently, fluticasone furoate/vilanterole (FF/VI) has been approved as the first once-daily ICS/LABA combination therapy for asthma and COPD. METHODS: A 12-week, randomized, open-label cross-over study was conducted in 16 patients with ACOS to compare the effectiveness of once-daily FF/VI 200/25 µg vs. twice-daily fluticasone propionate/salmeterol (FP/SAL) 500/50 µg. The study period included a 4-week run-in, the first 4-week treatment, and the second 4-week treatment. Respiratory functions, including forced expiratory volume in 1 s (FEV1) and respiratory impedance using the forced oscillation technique (FOT), were measured, as was fractional exhaled nitric oxide (FeNO). A COPD assessment test (CAT) scores and asthma control test (ACT) scores were recorded 0, 4, and 8 weeks after randomization. RESULTS: The mean values for the FEV1 were 1.33 (±0.29) L in the run-in period, 1.38 (±0.39) L after the FP/SAL treatment period, and 1.47 (±0.38) L after the FF/VI treatment period. The FEV1 value after the FF/VI treatment was significantly greater than the value after the run-in period (p < 0.01). FOT parameters, FeNO levels, CAT scores, ACT scores, and other blood tests were not significantly different during the run-in period, the FP/SAL treatment period, and the FF/VI treatment period. CONCLUSIONS: FF/VI, the first once-daily ICS/LABA, can provide substantial improvement in lung functions, indicating that FF/VI should be considered for the regular treatment of ACOS.

Beraprost, a stable analog of prostacyclin, enhances cough reflex sensitivity to capsaicin in bronchitic patients.

AIMS: Inflammatory mediators are involved in the pathophysiology of neutrophilic bronchial disorders presenting with chronic productive cough. Accumulating evidence indicates that prostanoids are key elements in the pathophysiology of these disorders. However, little is known about the role of prostacyclin in neutrophilic bronchial inflammation. METHODS: The effect of beraprost, a chemically and biologically stable analog of prostacyclin, on cough response to inhaled capsaicin was examined in 14 patients with chronic bronchitis, a neutrophilic bronchial disorder, in a randomized, placebo-controlled crossover study. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of the airway cough reflex sensitivity. RESULTS: After a 2-week treatment with beraprost (80 µg twice a day orally), the cough threshold was significantly (P < .05) decreased as compared with placebo [12.2 (geometric standard error of the mean [GSEM] 1.5) µM vs. 24.4 (GSEM 1.3)]. CONCLUSIONS: These findings indicate that prostacyclin is involved in the pathophysiology of cough reflex sensitivity in patients with chronic bronchitis, a frequently encountered neutrophilic bronchial disorder presenting with chronic productive cough.

Benefit-Risk Profile of P2X3 Receptor Antagonists for Treatment of Chronic Cough: Dose-Response Model-Based Network Meta-Analysis.

BACKGROUND: Refractory or unexplained chronic cough disrupts quality of life and burdens health care systems around the world. The P2X3 receptor antagonist gefapixant is approved in many countries for its antitussive effects, but taste disturbances are a common adverse effect. Four newer, more selective P2X3 receptor antagonists have been developed to address this problem. RESEARCH QUESTION: How does the benefit-risk profile vary across the five available P2X3 receptor antagonists? STUDY DESIGN AND METHODS: A systematic review and network meta-analysis was conducted to evaluate the efficacy of P2X3 receptor antagonists, including gefapixant, sivopixant, eliapixant, camlipixant, and filapixant. Primary outcomes were a reduction rate in 24-h cough frequency and incidence of taste disturbance. Dose-response curves and median effective dose (ED50) were calculated. Effect size at ED50 was ranked according to the surface under the cumulative ranking curve. The confidence was evaluated by Confidence In Network Meta-Analysis. RESULTS: Sixteen randomized controlled trials involving 4,904 participants were analyzed. The gefapixant regimen demonstrated an ED50 of 90.7 mg/d for cough frequency reduction. Gefapixant showed the highest antitussive effectiveness at ED50 (reduction rate in 24-h cough frequency: median, 28.1%; 95% credible interval [CrI], 21.0%-35.6%; ranked 1 of 5; moderate certainty) but the highest prevalence of taste disturbance (absolute risk difference per 100 patients: median, 38; 95% CrI, 27-51; ranked 5 of 5; high certainty) and the highest prevalence of discontinuation. Camlipixant had a well-balanced profile (reduction rate in 24-h cough frequency: median, 14.7%; 95% CrI, 5.4%-26.0%; ranked 3 of 5; low certainty; and taste disturbance; absolute risk difference per 100 patients; median, 2; 95% CrI, 1-6; ranked 2 of 5; low certainty). Placebo had a mean of 33.1% reduction in 24-h cough frequency. INTERPRETATION: When used at safe doses, gefapixant had a favorable risk-benefit profile compared with the other four agents. Camlipixant showed initial promise, which may be further investigated by phase III trials currently underway. CLINICAL TRIAL REGISTRATION: UMIN000050622; URL.

Prognostic value of coexisting conditions and complications in pleuroparenchymal fibroelastosis: a single-center retrospective study.

BACKGROUND: Pleuroparenchymal fibroelastosis (PPFE) is a rare idiopathic interstitial lung disease (ILD) characterized by subpleural parenchymal fibrosis and elastosis mainly in the upper lobes. PPFE occurs in a secondary form that overlaps with underlying medical conditions or complications. This study evaluated the clinical impact of coexisting factors on the survival of patients with PPFE. METHODS: Fifty-five PPFE patients were retrospectively evaluated. The patients' diagnoses were categorized as "idiopathic PPFE" with no known cause or "secondary PPFE" with underlying medical conditions or complications. The clinical characteristics and survival rates of these groups were compared. RESULTS: Twenty-eight patients (50.9%) were diagnosed with idiopathic PPFE and 27 (49.1%) with secondary PPFE, including cases of occupational dust exposure, connective tissue disease (CTD), post-hematopoietic stem cell transplantation (HSCT), and a family history of ILD. The idiopathic and secondary PPFE groups had similar clinical features, laboratory tests, and pulmonary function profiles, including a low body mass index, normal Krebs von den Lungen-6, high surfactant protein-D, and high residual volume/total lung capacity. In the secondary PPFE group, post-HSCT was associated with a worse prognosis, and CTD was associated with better prognosis. A multivariate analysis demonstrated that post-HSCT and a reduced forced vital capacity were significantly associated with a worsened survival in patients with PPFE. CONCLUSIONS: The prognosis of PPFE is highly influenced by underlying medical conditions or complications. Patients with post-HSCT PPFE should be monitored particularly closely, as they are at higher risk of a poor prognosis than others.

Patients with idiopathic pulmonary fibrosis and refractory cough have traction bronchiectasis and distorted airway architecture: a retrospective case review study.

Cough is a common and important sign/symptom in patients with idiopathic pulmonary fibrosis (IPF). However, there have been few reports focusing on cough, and the exact mechanisms for cough in patients with IPF have remained unclear. The objective of this study was to investigate the clinical features of IPF patients with refractory cough and to clarify mechanisms for cough in these patients. We retrospectively reviewed the files of patients with the diagnosis of IPF at Kanazawa University Hospital and compared the clinical features of IPF patients with refractory cough with the clinical features of IPF patients without refractory cough. Among a total of 23 patients with IPF, 10 patients (43.5%) had chronic cough. Of the ten patients, seven patients had concomitant conditions that could lead to cough. Of these seven patients, the cough of four patients was resolved after treatment of their concomitant condition. Finally, among the 23 patients there were 6 (26.1%) with refractory cough associated with IPF. Significant differences were seen between the following clinical features of IPF patients with or without refractory cough, respectively, as follows: lower body mass index (BMI; 18.8±2.5 vs. 22.8±2.5 kg/m2, P<0.01), lower forced vital capacity (FVC; 77.5%±30.4% predicted vs. 99.9%±0.53% predicted, P=0.046), and presence of traction bronchiectasis and distorted airway architecture on high-resolution computed tomography (HRCT; 83.3% vs. 11.8%, P<0.01). The difference between the proportions of patients with or without refractory cough with capsaicin cough sensitivity was not significant. Mechanical stress on the airways due to traction bronchiectasis and distorted airway architecture is a possible mechanism for cough in IPF patients.

Comparing region of interest selection and whole-field analysis for measurement of ciliary beat frequency in high-speed video analysis.

BACKGROUND: Ciliary beat frequency (CBF) is crucial in mucociliary clearance. High-speed video analysis (HSVA) is commonly used to measure CBF but lacks standardization. We compared visual observation and computer-assisted calculation using fast Fourier transformation (FFT) in freshly collected bronchial ciliary epithelial cells and cultured cells. METHODS: Bronchial epithelial cells were obtained from 12 patients who required bronchoscopic examination. Eighty-five videos of ciliary movement of freshly collected and cultured cells were recorded and used to calculate CBF using manual observation, region of interest (ROI) selection, and whole-field analysis. RESULTS: CBF measured by the ROI selection method strongly correlated with that measured using manual observation, especially in freshly collected cells. However, 27.8% of the manual observation method values were doubled in the ROI selection method, probably because a round trip of cilia was calculated as two cycles and needed to be corrected to 1/2 value. Upon increasing the number of ROIs, the results of the ROI selection method came closer to that of WFA. CONCLUSIONS: Computer-assisted calculation using FFT can aid in measuring CBF; however, current methods require visual confirmation. Further automated evaluation techniques are needed to establish more standardized and generalized CBF measurement methods using HSVA.

Prevalence and causes of chronic cough in Japan.

BACKGROUND: Chronic cough is one of the most common symptoms of respiratory diseases and can adversely affect patients' quality of life and interfere with social activities, resulting in a significant social burden. A survey is required to elucidate the frequency and treatment effect of chronic cough. However, clinical studies that cover all of Japan have not yet been conducted. METHODS: Patients who presented with a cough that lasted longer than 8 weeks and visited the respiratory clinics or hospitals affiliated with the Japan Cough Society during the 2-year study period were registered. RESULTS: A total of 379 patients were enrolled, and those who did not meet the definition of chronic cough were excluded. A total of 334 patients were analyzed: 201 patients had a single cause, and 113 patients had two or more causes. The main causative diseases were cough variant asthma in 92 patients, sinobronchial syndrome (SBS) in 36 patients, atopic cough in 31 patients, and gastroesophageal reflux (GER)-associated cough in 10 patients. The time required to treat undiagnosed patients and those with SBS was significantly longer and the treatment success rate for GER-associated cough was considerably poor. CONCLUSIONS: We confirmed that the main causes of chronic cough were cough variant asthma, SBS, atopic cough, and their complications. We also showed that complicated GER-associated cough was more likely to become refractory. This is the first nationwide study in Japan of the causes and treatment effects of chronic cough.

Bronchial Thermoplasty Attenuates Cough Reflex Sensitivity in Severe Asthma : A Single-Center Retrospective Study with 2-year Follow-up.

Despite the relatively short follow-up period in our previous study, we had reported that increased cough reflex sensitivity (CRS) may predict the efficacy of bronchial thermoplasty (BT) for treating asthma. Herein, we examined whether CRS predicts the efficacy of BT 2 years after the final BT treatment. We also investigated the influence of BT on CRS. We reviewed 10 patients 2 years after their final BT treatment. CRS, asthma-related symptoms, asthma exacerbations, and cough-related quality of life were assessed at baseline and 2 years after BT. Five patients responded positively to BT (BT responders) and their asthma control improved. No significant difference in CRS at baseline was detected between the BT responders and nonresponders. In contrast, BT responders exhibited significant improvements in CRS 2 years after BT. CRS at baseline could not predict the BT efficacy after 2 years. This is the first report demonstrating BT desensitized CRS in consecutive case series. J. Med. Invest. 70 : 271-275, February, 2023.

Bronchial thermoplasty improves cough hypersensitivity and cough in severe asthmatics.

BACKGROUND: Cough is a troublesome symptom of asthma because it is associated with disease severity and poor asthma control. Bronchial thermoplasty (BT) may be effective in improving cough severity and cough-related quality of life in severe uncontrolled asthma. OBJECTIVE: To evaluate the efficacy of BT for cough in severe uncontrolled asthma. METHODS: Twelve patients with severe uncontrolled asthma were enrolled in this study between 2018 May and March 2021 and arbitrarily divided into cough-predominant [cough severity Visual Analog Scale (VAS) ≥ 40 mm, n = 8] and typical asthma (cough VAS <40 mm, n = 4) groups. Clinical parameters, such as capsaicin cough sensitivity [C-CS: the concentrations to inhaled capsaicin required to induce at least two (C2) and five (C5) coughs], lung function, and type-2-related biomarkers (fractional nitric oxides and absolute eosinophil counts) and cough-related indices [cough severity VAS and the Leicester Cough Questionnaire (LCQ)] were evaluated before and 3 months after performing BT. RESULTS: BT significantly improved both cough-related indices and C-CS in the cough-predominant group. Changes in C-CS were significantly correlated with changes in the LCQ scores (C5: r = 0.65, p = 0.02 for all patients, and r = 0.81, p = 0.01 for the cough-predominant group). CONCLUSIONS: BT may be effective for cough in severe uncontrolled asthma by improving C-CS. However, further larger cohort studies are necessary to confirm the effect of BT for cough in asthma. CLINICAL TRIAL REGISTRATION: This study was registered in the UMIN Clinical Trials Registry (Registry ID UMIN: 000031982).