Cough Hypersensitivity Syndrome: A Few More Steps Forward

송우정,Alyn H Morice 대한천식알레르기학회 2017 Allergy, Asthma & Immunology Research Vol.9 No.5

Cough reflex is a vital protective mechanism against aspiration, but when dysregulated, it can become hypersensitive. In fact, chronic cough is a significant medical problem with a high degree of morbidity. Recently, a unifying paradigm of cough hypersensitivity syndrome has been proposed. It represents a clinical entity in which chronic cough is a major presenting problem, regardless of the underlying condition. Although it remains a theoretical construct, emerging evidence suggests that aberrant neurophysiology is the common etiology of this syndrome. Recent success in randomized clinical trials using a P2X3 receptor antagonist is the first major advance in the therapeutics of cough in the past 30 years; it at last provides a strategy for treating intractable cough as well as an invaluable tool for dissecting the mechanism underpinning cough hypersensitivity. Additionally, several cough measurement tools have been validated for use and will help assess the clinical relevance of cough in various underlying conditions. Along with this paradigm shift, our understanding of cough mechanisms has improved during the past decades, allowing us to continue to take more steps forward in the future.

New Insights Into Refractory Chronic Cough and Unexplained Chronic Cough: A 6-Year Ambispective Cohort Study

Zhang Mengru,Morice Alyn H.,Si Fengli,Zhang Li,Chen Qiang,Wang Shengyuan,Zhu Yiqing,Xu Xianghuai,Yu Li,Qiu Zhongmin 대한천식알레르기학회 2023 Allergy, Asthma & Immunology Research Vol.15 No.6

Purpose: Only limited studies have depicted the unique features and management of refractory chronic cough (RCC) and unexplained chronic cough (UCC). These led to the initiation of this study, which reported the demographic characteristics, manifestations, and long-term outcomes on a large series of consecutive RCC/UCC patients, providing a guideline-led real-world clinical experience. Methods: Retrospective baseline information was obtained from Clinical Research Database (January 2016 to May 2021). At least 6 months after the last clinic visit, included subjects were prospectively followed up. Results: Three hundred and sixty-nine RCC and UCC patients (199 females, 53.9%) were analyzed. The median cough duration was 24.0 (12.0–72.0) months. Laryngeal symptoms were reported in 95.9% of the patients. The common triggers for coughing were talking (74.9%), pungent odors (47.3%), eating (45.5%), and cold air (42.8%). RCC was considered in 38.2%, and the remainder of 228 patients had UCC, with an equal sex distribution (P = 0.66). Among the 141 RCCs, 90.8% (128) had refractory reflux cough, which was more responsive to current treatments (P < 0.01). Although most features and test results between RCC and UCC were similar, UCC was more commonly inappropriately treated (P < 0.01). Nineteen (7.7–41.1) months after the final clinic visit, 31.2% still coughed persistently, while 68.8% reported cough improvement or remission. RCC reported more favorable treatment outcomes (including cough improvement, control, and spontaneous remission) than UCC (P < 0.01). Coughs with long duration before the initial cough clinic visit (P < 0.01), frequent urinary incontinence (P < 0.01), and being sensitive to “talking” (P < 0.01) or “cold air” (P < 0.01) were less likely to be solved. Conclusions: The current treatments only improve cough symptoms in two-thirds of patients. Clinical indicators for treatment failure were those coughing for long duration and being sensitive to “talking” or “cold air.”

Inhaled Corticosteroids and Placebo Treatment Effects in Adult Patients With Cough: A Systematic Review and Meta-analysis

이승은,이지향,김현정,이병재,조상헌,David Price,Alyn H. Morice,송우정 대한천식알레르기학회 2019 Allergy, Asthma & Immunology Research Vol.11 No.6

Purpose: Inhaled corticosteroids (ICSs) are often considered an empirical therapy in the management of patients with cough. However, ICS responsiveness is difficult to interpret in daily clinical practice, as the improvements may include placebo effects or self-remission. We aimed to evaluate ICS and placebo treatment effects in adult patients with cough. Methods: Electronic databases were searched for studies published until June 2018, without language restriction. Randomized controlled trials reporting the effects of ICSs compared with placebo in adult patients with cough were included. Random effects meta-analyses were conducted to estimate the treatment effects. Therapeutic gain was calculated by subtracting the percentage change from baseline in the cough score in the ICS treatment group from that in the placebo treatment group. Results: A total of 9 studies were identified and 8 studies measuring cough severity outcomes were included for meta-analyses. Therapeutic gain from ICSs ranged from −5.0% to +94.6% across the studies included; however, it did not exceed +22%, except for an outlier reporting very high therapeutic gains (+45.6% to +94.6%, depending on outcomes). Overall ICS treatment effects in cough severity outcomes were small-to-moderate (standardized mean difference [SMD], −0.38; 95% confidence interval [CI], −0.54, −0.23), which were comparable between subacute and chronic coughs. However, pooled placebo treatment effects were very large in subacute cough (SMD, −2.58; 95% CI, −3.03, −2.1), and modest but significant in chronic cough (SMD, −0.46; 95% CI, −0.72, −0.21). Conclusions: Overall therapeutic gain from ICSs is small-to-moderate. However, placebo treatment effects of ICS are large in subacute cough, and modest but still significant in chronic cough. These findings indicate the need for careful interpretation of ICS responsiveness in the management of cough patients in the clinic, and also for rigorous patient selection to identify ICS-responders.

Lipid Laden Macrophages in Respiratory Disease

( Laura R Sadofsky ),( Yvette A Hayman ),( Simon P Hart ),( Alyn H Morice ) 대한소화기기능성질환·운동학회 2017 Journal of Neurogastroenterology and Motility (JNM Vol.23 No.3

Impact of Chronic Cough on Health-Related Quality of Life in the Korean Adult General Population: The Korean National Health and Nutrition Examination Survey 2010–2016

Ha-Kyeong Won,Ji-Hyang Lee,Jin An,손경희,Min-Gyu Kang,Sung-Yoon Kang,Alyn H. Morice,조상헌,송우정 대한천식알레르기학회 2020 Allergy, Asthma & Immunology Research Vol.12 No.6

Purpose: Chronic cough is a prevalent condition in the community and may pose considerable impairment to quality of life (QoL). However, its disease burden remains largely undefined in the general population. The present study investigated the relationship between chronic cough and health-related QoL in a Korean nationwide population database, with an emphasis on clinical conditions which may confound the impact of cough. Methods: This study analyzed cross-sectional datasets of adults (aged ≥ 40 years) in the Korean National Health and Nutrition Examination Survey 2010–2016. Health-related QoL was assessed using the 3-level EuroQoL 5-dimension component (EQ-5D-3L) index score. The presence of chronic cough and other conditions were defined using structured questionnaires. Results: The prevalence of chronic cough was 3.48% ± 0.17% among adults aged ≥ 40 years. The overall EQ-5D-3L index score was significantly lower in subjects with than without chronic cough (0.79 ± 0.01 vs. 0.86 ± 0.00, P < 0.001). In subgroup analyses by age and sex, chronic cough had a notably large impact on QoL in women aged ≥ 65 years (vs. those without chronic cough: 0.55 ± 0.04 vs. 0.70 ± 0.01, P < 0.001), although the mean difference in the scores exceeded the minimally important difference score of 0.05 in all subgroups. In multivariate analyses, chronic cough was significantly associated with QoL, independent of confounders including depression, arthritis, asthma, and chronic obstructive pulmonary disease. In dimension analyses, chronic cough was more associated with anxiety/depression, pain/discomfort, and usual activities than with self-care or mobility in the EQ-5D. Conclusions: The present study demonstrated significant associations between chronic cough and health-related QoL in a nationwide large general adult population aged ≥ 40 years, which were independent of clinical confounders. The impact of chronic cough was greater in women aged ≥ 65 years. These findings indicate a considerable burden of chronic cough in the general population and warrant further investigations to assess the disease burden of chronic cough in a global scale.

Defining Chronic Cough: A Systematic Review of the Epidemiological Literature

송우정,장윤석,Shoaib Faruqi,강민구,김주영,강민규,김수정,조은정,이승은,김민혜,Jana Plevkova,박흥우,조상헌,Alyn H. Morice 대한천식알레르기학회 2016 Allergy, Asthma & Immunology Research Vol.8 No.2

Purpose: Recent evidence suggests a global burden of chronic cough in general populations. However, the definitions vary greatly among epidemiological studies, and none have been validated for clinical relevance. We aimed to examine previous epidemiological definitions in detail and explore the operational characteristics. Methods: A systematic review was conducted for epidemiological surveys that reported the prevalence of chronic cough in general adult populations during the years 1980 to 2013. A literature search was performed on Pubmed and Embase without language restriction. Epidemiological definitions for chronic cough were classified according to their components, such as cutoff duration. Meta-analyses were performed for the male-to-female ratio of chronic cough prevalence to explore operational characteristics of epidemiological definitions. Results: A total of 70 studies were included in the systematic review. The most common epidemiological definition was identified as ‘cough ≥3 months’ duration without specification of phlegm (n=50); however, it conflicted with the cutoff duration in current clinical guidelines (cough ≥8 weeks). Meta-analyses were performed for the male-to-female ratio of chronic cough among 28 studies that reported sex-specific prevalence using the most common definition. The pooled male-to-female odds ratio was 1.26 (95% confidence interval 0.92-1.73) with significant heterogeneity (I2=96%, P<0.001), which was in contrast to clinical observations of female predominance from specialist clinics. Subgroup analyses did not reverse the ratio or reduce the heterogeneity. Conclusions: This study identified major issues in defining chronic cough in future epidemiological studies. The conflict between epidemiological and clinical diagnostic criteria needs to be resolved. The unexpected difference in the gender predominance between the community and clinics warrants further studies. Clinical validation of the existing definition is required.