Geographic variation in the aetiology, epidemiology and microbiology of bronchiectasis

Bronchiectasis is a disease associated with chronic progressive and irreversible dilatation of the bronchi and is characterised by chronic infection and associated inflammation. The prevalence of bronchiectasis is age-related and there is some geographical variation in incidence, prevalence and clinical features. Most bronchiectasis is reported to be idiopathic however post-infectious aetiologies dominate across Asia especially secondary to tuberculosis. Most focus to date has been on the study of airway bacteria, both as colonisers and causes of exacerbations. Modern molecular technologies including next generation sequencing (NGS) have become invaluable tools to identify microorganisms directly from sputum and which are difficult to culture using traditional agar based methods. These have provided important insight into our understanding of emerging pathogens in the airways of people with bronchiectasis and the geographical differences that occur. The contribution of the lung microbiome, its ethnic variation, and subsequent roles in disease progression and response to therapy across geographic regions warrant further investigation. This review summarises the known geographical differences in the aetiology, epidemiology and microbiology of bronchiectasis. Further, we highlight the opportunities offered by emerging molecular technologies such as -omics to further dissect out important ethnic differences in the prognosis and management of bronchiectasis.NMRC (Natl Medical Research Council, S’pore)MOH (Min. of Health, S’pore)Published versio

Reference values of Forced Expiratory Volumes and pulmonary flows in 3–6 year children: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>The aims of this study were to verify the feasibility of respiratory function tests and to assess their validity in the diagnosis of respiratory disorders in young children.</p> <p>Methods</p> <p>We performed spirometry and collected information on health and parents' lifestyle on a sample of 960 children aged 3–6.</p> <p>Results</p> <p>The cooperation rate was 95.3%. Among the valid tests, 3 or more acceptable curves were present in 93% of cases. The variability was 5% within subjects in 90.8% of cases in all the parameters. We propose regression equations for FVC (Forced Vital Capacity), FEV1, FEV0.5, FEV0.75 (Forced Expiratory Volume in one second, in half a second and in 3/4 of a second), and for Maximum Expiratory Flows at different lung volume levels (MEF75, 50, 25). All parameters are consistent with the main reference values reported in literature. The discriminating ability of respiratory parameters versus symptoms always shows a high specificity (>95%) and a low sensitivity (<20%) with the highest OR (10.55; IC95% 4.42–25.19) for MEF75. The ability of FEV0.75 to predict FEV1 was higher than that of FEV0.50: FEV0.75 predicts FEV1 with a determination coefficient of 0.95.</p> <p>Conclusion</p> <p>Our study confirms the feasibility of spirometry in young children; however some of the current standards are not well suited to this age group. Moreover, in this restricted age group the various reference values have similar behaviour.</p

Função pulmonar persistentemente reduzida em crianças e adolescentes com asma Persistent pulmonary function impairment in children and adolescents with asthma

OBJETIVO: A asma é a doença pulmonar crônica mais comum na infância, caracterizada por inflamação brônquica. Algumas crianças com asma podem apresentar função pulmonar persistentemente reduzida. A prevalência e etiologia dessa anormalidade em crianças com asma em países em desenvolvimento ainda não são conhecidas. O objetivo deste estudo foi estimar a proporção de pacientes com função pulmonar reduzida, sem resposta a tratamento, em um grupo de crianças e adolescentes com asma, e descrever as características fenotípicas da amostra. MÉTODOS: Foram selecionados pacientes ambulatoriais (5-17 anos) diagnosticados com asma persistente através de um questionário padronizado. Esses pacientes foram submetidos a espirometria e teste cutâneo para aeroalérgenos comuns. Definiu-se como função pulmonar persistentemente reduzida apresentar relação VEF1/CVF < 0,80, mesmo após ter recebido tratamento com broncodilatador e corticoide oral por 10 dias. O índice de intensidade de atopia foi utilizado para diferenciar pacientes pouco reatores daqueles multirreatores (ponto de corte: 4 alérgenos). RESULTADOS: Foram incluídos 96 pacientes, com média de idade de 10,6 anos. Desses, 52 (54,1%) eram do sexo masculino, e 89 (92,7%) eram atópicos. Dos 96 pacientes, 8 (8,3%) apresentaram redução da função pulmonar mesmo após o tratamento. Desses pacientes, 8 (100%) eram atópicos, 7 (87,5%) apresentavam asma moderada ou grave, e 7 (87,5%) tinham história de hospitalização por bronquiolite aguda. CONCLUSÕES: Crianças e adolescentes com asma moderada a grave podem apresentar função pulmonar reduzida e sem resposta a tratamento. Essa situação clínica é pouco estudada em países em desenvolvimento, e seus fatores de risco e etiologia serão mais bem entendidos somente com estudos de coorte de nascimento.<br>OBJECTIVE: Asthma is the most common chronic pulmonary disease, characterized by bronchial inflammation. Some children with asthma have persistent pulmonary function impairment. The prevalence and etiology of this abnormality in children with asthma in developing countries remain unknown. The objective of this study was to estimate the proportion of patients with impaired pulmonary function who were unresponsive to treatment in a group of children and adolescents with asthma, and to describe the phenotypic characteristics of the sample. METHODS: Using a standardized questionnaire, we selected outpatients (5-17 years of age) diagnosed with persistent asthma. These patients underwent spirometry and skin prick tests for sensitivity to common aeroallergens. Persistent pulmonary function impairment was defined as an FEV1/FVC ratio < 0.80, even after 10 days of treatment with bronchodilators and oral corticosteroids. We used the atopic index to differentiate between patients with little or no response to the skin prick test and those with a strong response (cut-off point: 4 allergens). RESULTS: We included 96 patients with a mean age of 10.6 years. Of those, 52 (54.1%) were male, and 89 (92.7%) were atopic. Of the 96 patients, 8 (8.3%) had impaired pulmonary function even after the treatment. Among those patients, 8 (100%) were atopic, 7 (87.5%) had moderate or severe asthma, and 7 (87.5%) had a history of hospitalization for acute bronchiolitis. CONCLUSIONS: Children and adolescents with moderate or severe asthma can present with impaired pulmonary function and be unresponsive to treatment. This clinical situation has been little studied in developing countries, and its risk factors and etiology will be better understood only through birth cohort studies