Airway Diseases

Ko FW, Wang JKL, Hui DSC, Chan JWM, Cheung PS, Yeung YC, Sin KM, Ip MS.
J Asthma Allergy. 2023 Jan 25;16:173-182.

Abstract

Background

Patients with severe asthma have higher total- and asthma-related health burden than those whose disease is not severe. Recent medical advances in biologic therapies allow better control of asthma characterized by type 2 inflammation.

Objective

To study the prevalence of eosinophilic phenotype and IgE levels in Chinese with severe asthma, and the relationship of these type 2 characteristics with asthma control, exacerbations and lung function.

Methods

This was a multicenter cross-sectional observational study in Hong Kong, in Chinese adults with asthma on Step 4 or 5 of GINA treatment. Their blood eosinophil counts and total IgE levels were measured, and the relationship of these phenotypic parameters to the number of exacerbations in the past 12 months, and to symptom control in the past 4 weeks, were investigated.

Results

A total of 232 subjects were recruited from 6 centers. The mean age was 53.9±12.9 years, with 86 (37.1%) male, and the duration of diagnosed asthma was 26.2±15.7 years. A T-helper 2 (Th2) phenotype indicated by elevated eosinophils and/or IgE was present in 169 (72.8%) of patients. Of 232 patients, 43% had an eosinophilic phenotype (blood eosinophil count ≥300 cell/mm³), while 59% had high total IgE levels of >100 IU/mL (overlap with eosinophilic phenotype in 30%) and 44% had IgE levels of >150 IU/mL (overlap with eosinophilic phenotype in 22%). Subjects with eosinophilic phenotype and IgE >150 IU/mL had a higher rate (1.8 times) of uncontrolled asthma compared with those without such a combination.

Conclusions

In Chinese adults with severe asthma defined by the use of conventional maintenance medication regimens, the prevalence of Th2 inflammation is comparable to that reported from other ethnic populations. Those with both eosinophil count ≥300 cell/mm³ and high IgE levels >150 IU/mL had a higher rate of uncontrolled asthma compared with those without a combination of these features.

Chan HS, Ko FWS, Chan JWM, Choo KL, So LKY, Lam DCL, Sin KM, Wong WY, Cheng YL, Wong MML.
Int J Chron Obstruct Pulmon Dis. 2023 Apr 6;18:507-519.

Abstract

Background

Chronic obstructive pulmonary disease (COPD) is a common cause for hospital admission. This study aims to review the hospital burden of COPD in Hong Kong (HK) and the trend from year 2006 to 2014.

Methods

A multi-center, retrospective study of the characteristics of COPD patients discharged from the public hospitals of HK from year 2006 to 2014. Anonymized data retrieval and analysis were performed. The demographic data of the subjects, use of health-care resources, ventilatory support, medications used and mortality of the subjects were analyzed.

Results

Total patient headcount (HC) and admission number reduced from 10,425 and 23,362 in year 2006 to 9613 and 19,771, respectively, in 2014. There was a progressive reduction of female COPD HC from 2193 (21%) in year 2006 to 1517 (16%) in 2014. The utilization of non-invasive ventilation (NIV) increased rapidly and peaked in 2010 (29%) and decreased thereafter. There was a rapid increase in the prescription of long-acting bronchodilators (from 15% to 64%). COPD and pneumonia were the top causes of death, but death due to pneumonia was rapidly increasing while death due to COPD was progressively decreasing over the period.

Conclusions

COPD HC and admission number (particularly in female patients) decreased progressively from year 2006 to 2014. There was also a decreasing trend of severity of disease as reflected by lower NIV use (after year 2010) and lower mortality rate due to COPD. Reduced smoking prevalence and tuberculosis (TB) notification rate in the community in the past might have reduced the incidence and severity of COPD and the hospital burden of disease. We observed an increasing trend of mortality due to pneumonia in COPD patients. Appropriate and timely vaccination programs are recommended for COPD patients as in the general elderly population.

Ka Pang Chan | Fanny Wai San Ko | Kwun Cheung Ling | Pik Shan Cheung | Lee Veronica Chan | Yu Hong Chan | Yi Tat Lo | Chun Kong Ng | Macy Mei‐sze Lui | Kwok Sang Wilson Yee | Cee Zhung Steven Tseng | Pak Yiu Tse | Mo Lin Maureen Wong | Kah Lin Choo | Wai Kei Lam | Chun Man Wong | Sheng Sheng Ho | Chung Tat Lun | Christopher Kei Wai Lai
On behalf of the Hong Kong Thoracic Society Special Interest Group on Airway Diseases.

Immun Inflamm Dis. 2021 Mar 3. doi: 10.1002/iid3.419. Epub ahead of print. PMID: 33657275.

Abstract

Background

The real‐world relationships between the demographic and clinical characteristics of asthma patients, their prehospitalization management and the frequency of hospitalization due to asthma exacerbation is poorly established.

Objective

To determine the risk factors of recurrent asthma exacerbations requiring hospitalizations and evaluate the standard of baseline asthma care. Methods: A territory‐wide, multicentre retrospective study in Hong Kong was performed. Medical records of patients aged ≥18 years admitted to 11 acute general hospitals from January 1 to December 31, 2016 for asthma exacerbations were reviewed.

Results

There were 2280 patients with 3154 admissions (36.7% male, median age 66.0 [interquartile range: 48.0–81.0] years, 519 had ≥2 admissions). Among them, 1830 (80.3%) had at least one asthma‐associated comorbidity, 1060 (46.5%) and 885 (38.9%) of patients had Accident and Emergency Department (AED) attendance and hospitalization in the preceding year, respectively. Patients with advancing age (incidence rate ratio [IRR]: 1.003 for every year increment), a history of AED visits or hospitalization (IRR: 1.018 and 1.070 for every additional episode, respectively) for asthma exacerbation in the preceding year, the presence of neuropsychiatric (IRR: 1.142) and gastrointestinal (IRR: 1.154) comorbidities were risk factors for an increasing number of admissions for asthma exacerbation. For patients with ≥2 admissions, 17.1% were not prescribed inhaled corticosteroid and only 44.6% had spirometry checked before the index admission. Asthma phenotyping was often incomplete, as assessment of atopy (total serum immunoglobulin E level and senitization to aeroallergens) was only performed in 30 (5.8%) patients with ≥2 admissions.

Conclusions and Clinical Relevance

Improving asthma care, especially in elderly patients with a prior history of urgent healthcare utilization and comorbidities, may help reduce healthcare burden. Suboptimal management before the index admission was common in patients hospitalized for asthma exacerbations. Early identification of patients at risk and enhancement of baseline asthma management may help to prevent recurrent asthma exacerbation and subsequent hospitalization.

(complete article in pdf)

Chan HS, Ko FWS, Chan JWM, So LKY, Lam DCL, Chan VL, Tam CY, Yu WC.
Int J Chron Obstruct Pulmon Dis. 2018 Jun 13;13:1913-1925.

Abstract

Background

COPD is a common cause for hospital admission. Conventional studies of the epidemiology of COPD involved large patient number and immense resources and were difficult to be repeated. The present study aimed at assessing the utilization of a computerized data management system in the collection and analysis of the epidemiological and clinical data of a large COPD cohort in Hong Kong (HK).

Patients and Methods

It was a computerized, multicenter, retrospective review of the characteristics of patients discharged from medical departments of the 16 participating hospitals with the primary discharge diagnosis of COPD in 1 year (2012). Comparison was made between the different subgroups in the use of medications, ventilatory support, and other health care resources. The mortality of the subjects in different subgroups was traced up to December 31, 2014. The top 10 causes of death were analyzed.

Results

In total, 9,776 subjects (82.6% men, mean age = 78 years) were identified. Of the 1,918 subjects with lung function coding, 85 (4.4%), 488 (25.5%), 808 (42.1%), and 537 (28.0%) subjects had the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1, 2, 3, and 4 classes, respectively. Patients with higher GOLD classes had higher number of hospital admissions, longer hospital stay, increased usage of noninvasive mechanical ventilation (NIV), combinations of long-acting bronchodilators, and higher mortality. Of the 9,776 subjects, 2,278 (23.3%) received NIV, but invasive mechanical ventilation was uncommon (134 of 9,776 subjects [1.4%]); 4,427 (45.3%) subjects had died by the end of 2014. The top causes of death were COPD, pneumonia, lung cancer, and other malignancies.

Conclusion

Patients admitted to hospitals for COPD in HK had significant comorbidities, mortality, and imposed heavy burden on health care resources. It is possible to collect and analyze data of a large COPD cohort through a computerized system. Suboptimal coding of lung function results was observed, and underutilization of long-acting bronchodilators was common.

Lau WK, Chan-Yeung MM, Yip BH, Cheung AH, Ip MS, Mak JC; COPD Study Group of the Hong Kong Thoracic Society.
PLoS One. 2012;7(2):e31617.

Abstract

Background

Cigarette smoking is a major risk factor in the development of age-related chronic obstructive pulmonary disease (COPD). The serotonin transporter (SERT) gene polymorphism has been reported to be associated with COPD, and the degree of cigarette smoking has been shown to be a significant mediator in this relationship. The interrelation between circulating serotonin (5-hydroxytyptamine, 5-HT), cigarette smoking and COPD is however largely unknown. The current study aimed at investigating the mediation effects of plasma 5-HT on cigarette smoking-induced COPD and the relation between plasma 5-HT levels and age.

Methods

The association between plasma 5-HT, age and COPD was analyzed in a total of 62 COPD patients (ever-smokers) and 117 control subjects (healthy non-smokers and ever-smokers). Plasma 5-HT levels were measured by enzyme-linked immuno assay (EIA).

Results

The elevated plasma 5-HT levels were significantly associated with increased odds for COPD (OR = 1.221, 95% CI = 1.123 to 1.319, p<0.0001). The effect remained significant after being adjusted for age and pack-years smoked (OR = 1.271, 95% CI = 1.134 to 1.408, p = 0.0003). Furthermore, plasma 5-HT was found to mediate the relation between pack-years smoked and COPD. A positive correlation (r = 0.303, p = 0.017) was found between plasma 5-HT levels and age in COPD, but not in the control subjects (r = -0.149, p = 0.108).

Conclusion

Our results suggest that cigarette smoke-induced COPD is partially mediated by the plasma levels of 5-HT, and that these become elevated with increased age in COPD. The elevated plasma 5-HT levels in COPD might contribute to the pathogenesis of this disease.

Chan KH, Yeung SC, Yao TJ, Ip MS, Cheung AH, Chan-Yeung MM, Mak JC; COPD Study Group of the Hong Kong Thoracic Society. 
Int J Tuberc Lung Dis. 2010 Sep;14(9):1193-200. 

Abstract

Background

Adiponectin is an anti-inflammatory adipokine that may play a role in chronic obstructive pulmonary disease (COPD) pathogenesis.

Objective

To investigate the relationship between adiponectin, interleukin (IL) 6, IL-8 and C-reactive protein (CRP) and COPD by evaluating these biomarkers in ever-smokers with or without the disease.

Methods

Plasma levels of adiponectin, IL-6, IL-8 and CRP were measured using commercially available kits in COPD patients (n = 71), healthy ever-smokers (n = 62) and non-smokers (n = 51).

Results

There were significant increases in plasma adiponectin, IL-6 and CRP in COPD patients (median [IQR] 4.39 microg/ml [2.68-6.98], 4.19 pg/ml [<2.40-6.40], 8.75 mg/l [4.26-40.63], respectively) compared to healthy ever-smokers (1.90 microg/ml [0.86-2.86], <2.40 pg/ml [<2.40-2.77], 3.71 mg/l [1.97-10.37 mg/l], respectively, P < 0.001) and non-smokers (1.76 microg/ml [1.34-2.52], <2.40 pg/ml [<2.40-2.78], 3.12 mg/l [2.11-5.71], respectively, P < 0.001). COPD patients had lower plasma IL-8 levels than healthy ever-smokers. Among ever-smokers with or without COPD, plasma adiponectin, IL-6 and CRP levels were inversely correlated with forced expiratory volume in 1 second (% predicted) after adjustment for age, body mass index, smoking status and pack-years.

Conclusion

Our findings suggest that in COPD patients, adiponectin might be associated with COPD pathogenesis.

Mak JC, Chan-Yeung MM, Ho SP, Chan KS, Choo K, Yee KS, Chau CH, Cheung AH, Ip MS
Respir Med. 2009 Jul;103(7):1083-9.

Abstract

Background

Transforming growth factor-beta(1) (TGF-beta(1)), a multifunctional cytokine, has been implicated to be responsible for the increased deposition of extracellular matrix in the airways, and increased submucosal collagen expression in chronic obstructive pulmonary disease (COPD). We determined plasma TGF-beta(1) levels in patients with COPD and explored its association with common functional polymorphisms of TGF-beta(1) gene at C-509T and T869C in the development of COPD in a case-control study.

Methods

Stable COPD patients who were ever smokers, and age and pack-years smoked matched healthy controls (n = 205 in each group) were recruited for measurement of plasma TGF-beta(1) levels using commercially available ELISA kit, and genotyped at C-509T and T869C functional polymorphisms of TGF-beta(1) gene using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP).

Results

COPD patients had significantly elevated plasma TGF-beta(1) levels in comparison to healthy controls irrespective of the genotypes. Allele frequencies and genotype distributions at both polymorphic sites were not different among COPD patients or controls. TGF-beta(1) levels were inversely correlated (Pearson’s correlation analysis) with FEV(1) (% predicted) (p < 0.001) and FVC (% predicted) (p < 0.001).

Conclusion

The findings of elevated plasma TGF-beta(1) levels in patients with COPD suggest that TGF-beta(1) may play a role in COPD pathogenesis. The C-509T and T869C functional polymorphisms of TGF-beta(1) gene do not represent a genetic predisposition to COPD susceptibility in Hong Kong Chinese patients.

Chan-Yeung M, Ho AS, Cheung AH, Liu RW, Yee WK, Sin KM, Wong MM, Lam CW, Chan KS, Lam WK; Hong Kong Thoracic Society COPD Study Group.
Int J Tuberc Lung Dis. 2007 May;11(5):502-7.

Abstract

Background

The prevalence of chronic obstructive pulmonary disease (COPD) is rising in many parts of the world. This is a study of risk factors for COPD in Chinese patients in Hong Kong.

Design

Case-control study matched by sex and age (+/-5 years).

Methods

A total of 289 consecutive patients with COPD were recruited from out-patient clinics while healthy controls were recruited from two sources: random population and community centres for senior citizens. All patients and controls underwent a questionnaire-based interview and spirometry.

Results

The mean ages of COPD patients and controls were 71.1 +/- 9.4 and 67.5 +/- 9.3 years, respectively. The male to female ratio of COPD patients was 5 to 1. Smoking was found to be the most important determinant for COPD, followed by poor education and low body mass index adjusted for confounders. A dose-dependent relationship was found between the risk of COPD and pack-years smoked. Place of birth, exposure to environmental tobacco smoke and a history of asthma and tuberculosis were not associated with increased risk of COPD.

Conclusion

Despite a progressive reduction in prevalence, smoking remains the most important predictor of COPD in Hong Kong. Greater anti-smoking efforts are warranted.