RESEARCH QUESTION: What is the association between chitinase activity, airway fungi and clinical outcomes in bronchiectasis and bronchiectasis-COPD overlap?
STUDY DESIGN AND METHODS: A prospective cohort of 463 individuals were recruited across five hospital sites in three countries (Singapore, Malaysia, and Scotland) including individuals who were not diseased (n = 35) and who had severe asthma (n = 54), COPD (n = 90), bronchiectasis (n = 241) and BCO (n = 43). Systemic chitinase levels were assessed for bronchiectasis and BCO and related to clinical outcomes, airway Aspergillus status, and underlying pulmonary mycobiome profiles.
RESULTS: Systemic chitinase activity is elevated significantly in bronchiectasis and BCO and exceed the activity in other airway diseases. CHIT1 activity strongly predicts bronchiectasis exacerbations and is associated with the presence of at least one Aspergillus species in the airway and frequent exacerbations (≥3 exacerbations/y). Subgroup analysis reveals an association between CHIT1 activity and the "frequent exacerbator" phenotype in South-East Asian patients whose airway mycobiome profiles indicate the presence of novel fungal taxa that include Macroventuria, Curvularia and Sarocladium. These taxa, enriched in frequently exacerbating South-East Asian patients with high CHIT1 may have potential roles in bronchiectasis exacerbations.
INTERPRETATION: Systemic CHIT1 activity may represent a useful clinical tool for the identification of fungal-driven "frequent exacerbators" with bronchiectasis in South-East Asian populations.
RESEARCH QUESTION: We aim to determine if clusters of Chinese patients with COPD exist and their association with clinical outcomes and inflammation.
STUDY DESIGN AND METHODS: Chinese patients with stable COPD were prospectively recruited into two cohorts (derivation and validation) from six hospitals across three Southeast Asian countries (Singapore, Malaysia, and Hong Kong; n = 1,480). Each patient was followed more than 2 years. Clinical data (including co-morbidities) were employed in unsupervised hierarchical clustering (followed by validation) to determine the existence of patient clusters and their prognostic outcome. Accompanying systemic cytokine assessments were performed in a subset (n = 336) of patients with COPD to determine if inflammatory patterns and associated networks characterized the derived clusters.
RESULTS: Five patient clusters were identified including: (1) ex-TB, (2) diabetic, (3) low comorbidity: low-risk, (4) low comorbidity: high-risk, and (5) cardiovascular. The cardiovascular and ex-TB clusters demonstrate highest mortality (independent of Global Initiative for Chronic Obstructive Lung Disease assessment) and illustrate diverse cytokine patterns with complex inflammatory networks.
INTERPRETATION: We describe clusters of Chinese patients with COPD, two of which represent high-risk clusters. The cardiovascular and ex-TB patient clusters exhibit high mortality, significant inflammation, and complex cytokine networks. Clinical and inflammatory risk stratification of Chinese patients with COPD should be considered for targeted intervention to improve disease outcomes.
RESEARCH QUESTION: The differential impact of frequently used CSs and their regimens on long-term (> 5 years) cardiorespiratory progression in children with DMD is unknown.
STUDY DESIGN AND METHODS: This was a retrospective longitudinal study including children with DMD followed at Dubowitz Neuromuscular Centre, Great Ormond Street Hospital London, England, from May 2000 to June 2017. Patients enrolled in any interventional clinical trials were excluded. We collected patients' anthropometrics and respiratory (FVC, FVC % predicted and absolute FVC, and noninvasive ventilation requirement [NIV]) and cardiac (left ventricular shortening function [LVFS%]) function. CSs-naïve patients had never received CSs. Patients who were treated with CSs took either deflazacort or prednisolone, daily or intermittently (10 days on/10 days off) for > 1 month. Average longitudinal models were fitted for yearly respiratory (FVC % predicted) and cardiac (LVFS%) progression. A time-to-event analysis to FVC % predicted < 50%, NIV start, and cardiomyopathy (LVFS% < 28%) was performed in CS-treated (daily and intermittent) vs CS-naïve patients.
RESULTS: There were 270 patients, with a mean age at baseline of 6.2 ± 2.3 years. The median follow-up time was 5.6 ± 3.5 years. At baseline, 263 patients were ambulant. Sixty-six patients were treated with CSs daily, 182 patients underwent CSs intermittent > 60% treatment, and 22 were CS-naïve patients. Yearly FVC % predicted declined similarly from 9 years (5.9% and 6.9% per year, respectively; P = .27) in the CSs-daily and CSs-intermittent groups. The CSs-daily group declined from a higher FVC % predicted than the CSs-intermittent group (P < .05), and both reached FVC % predicted < 50% and NIV requirement at a similar age, > 2 years later than the CS-naïve group. LVFS% declined by 0.53% per year in the CSs-treated group irrespective of the CSs regimen, significantly slower (P < .01) than the CSs-naïve group progressing by 1.17% per year. The age at cardiomyopathy was 16.6 years in the CSs-treated group (P < .05) irrespective of regimen and 13.9 years in the CSs-naïve group.
INTERPRETATION: CSs irrespective of the regimen significantly improved respiratory function and delayed NIV requirement and cardiomyopathy.
RESEARCH QUESTION: What is the occurrence and clinical relevance of Aspergillus sensitization and ABPA in BCO when compared with individuals with COPD or bronchiectasis without overlap?
STUDY DESIGN: Prospective, observational, cross-sectional study.
METHODS: We prospectively recruited 280 patients during periods of clinical stability with bronchiectasis (n = 183), COPD (n = 50), and BCO (n = 47) from six hospitals across three countries (Singapore, Malaysia, and Scotland). We assessed sensitization responses (as specific IgE) to a panel of recombinant Aspergillus fumigatus allergens and the occurrence of ABPA in relationship to clinical outcomes.
RESULTS: Individuals with BCO show an increased frequency and clinical severity of ABPA compared with those with COPD and bronchiectasis without overlap. BCO-associated ABPA is associated with more severe disease, higher exacerbation rates, and lower lung function when compared with ABPA occurring in the absence of overlap. BCO with a severe bronchiectasis severity index (BSI; > 9) is associated significantly with the occurrence of ABPA that is unrelated to underlying COPD severity.
CONCLUSIONS: BCO demonstrates a high frequency of ABPA that is associated with a severe BSI (> 9) and poor clinical outcomes. Clinicians should maintain a high index of suspicion for the potential development of ABPA in patients with BCO with high BSI.
RESEARCH QUESTIONS: In critically ill patients, what is the association between pre-existing malnutrition and time to discharge alive (TTDA), and does high protein treatment modify this association?
STUDY DESIGN AND METHODS: This was a multicenter randomized controlled trial involving 16 countries designed to investigate the effects of high vs. usual protein treatment in 1301 critically ill patients. The primary outcome was TTDA. Multivariable regression was used to identify if pre-existing malnutrition was associated with TTDA, and if protein delivery modified their association.
RESULTS: The prevalence of pre-existing malnutrition was 43.8%, and the cumulative incidence of live hospital discharge by day 60 was 41.2% vs. 52.9% in the groups with and without pre-existing malnutrition, respectively. The average protein delivery in the high vs. usual treatment groups was 1.6 vs. 0.9 g/kg/day. Pre-existing malnutrition was independently associated with slower TTDA (Adj HR 0.81, 95% CI 0.67-0.98). However, high protein treatment in patients with and without pre-existing malnutrition was not associated with TTDA (Adj HR 0.84, 95% CI 0.63-1.11; and 0.97, 95% CI 0.77-1.21, respectively). Furthermore, no effect modification was observed (ratio of Adj HR 0.84, 95% CI 0.58-1.20).
INTERPRETATION: Malnutrition was associated with slower TTDA, but high protein treatment did not modify the association. These findings challenge current international critical care nutrition guidelines.