Disease surveillance using bronchoalveolar lavage

Commensal bacteria of the lung microbiota synergistically inhibit inflammation in a three-dimensional epithelial cell model

Patients with chronic lung disease suffer from persistent inflammation and are typically colonized by pro-inflammatory pathogenic bacteria. Besides these pathogens, a wide variety of commensal species is present in the lower airways but their role in inflammation is unclear. Here, we show that the lung microbiota contains several species able to inhibit activation of the pro-inflammatory NF-κB pathway and production of interleukin 8 (IL-8), triggered by lipopolysaccharide (LPS) or H₂O₂, in a physiologically relevant three-dimensional (3D) lung epithelial cell model. We demonstrate that the minimal dose needed for anti-inflammatory activity differs between species (with the lowest dose needed for Rothia mucilaginosa), and depends on the type of pro-inflammatory stimulus and read out. Furthermore, we evaluated synergistic activity between pairs of anti-inflammatory bacteria on the inhibition of the NF-κB pathway and IL-8 secretion. Synergistic anti-inflammatory activity was observed for 4/10 tested consortia. These findings indicate that various microbiota members can influence lung inflammation either alone or as a consortium. This information can contribute to a better understanding of the lung microbiota in chronic lung disease development and process, and could open up new avenues for treatment.

Exploring the Cystic Fibrosis Lung Microbiome: Making the Most of a Sticky Situation

Chronic lower respiratory tract infections are a leading contributor to morbidity and mortality in persons with cystic fibrosis (pwCF). Traditional respiratory tract surveillance culturing has focused on a limited range of classic pathogens; however, comprehensive culture and culture-independent molecular approaches have demonstrated complex communities highly unique to each individual. Microbial community structure evolves through the lifetime of pwCF and is associated with baseline disease state and rates of disease progression including occurrence of pulmonary exacerbations. While molecular analysis of the airway microbiome has provided insight into these dynamics, challenges remain including discerning not only "who is there" but "what they are doing" in relation to disease progression. Moreover, the microbiome can be leveraged as a multi-modal biomarker for both disease activity and prognostication. In this article, we review our evolving understanding of the role these communities play in pwCF and identify challenges in translating microbiome data to clinical practice.

Pediatric Airway Endoscopy: Recommendations of the Society for Pediatric Pneumology

For many decades, pediatric bronchoscopy has been an integral part of the diagnosis and treatment of acute and chronic pulmonary diseases in children. Rapid technical advances have continuously influenced the performance of the procedure. Over the years, the application of pediatric bronchoscopy has considerably expanded to a broad range of indications. In this comprehensive and up-to-date guideline, the Special Interest Group of the Society for Pediatric Pneumology reviewed the most recent literature on pediatric bronchoscopy and reached a consensus on a safe technical performance of the procedure.

High levels of inherent variability in microbiological assessment of bronchoalveolar lavage samples from children with persistent bacterial bronchitis and healthy controls

Bronchoalveolar lavage (BAL) is widely regarded as providing "gold standard" samples for infective lower respiratory tract disease. Current approaches have been adopted empirically without robust assessment and hence carry many assumptions that have not been tested. Many of these uncertainties were highlighted in the ATS pediatric bronchoscopy guidelines. This study was designed to explore some of these issues. BAL was undertaken via an endotracheal tube in 13 subjects aged less than 6 years with persistent bacterial bronchitis and five healthy controls. Aliquots of the same pooled BAL sample were sent to two accredited laboratories. one producing semiquantitative results and the other quantitative results. For five patients potentially pathogenic bacteria were grown by one laboratory but not the other, while in three more there were discrepancies in the organisms reported. Despite being symptomatic and off antibiotics, only 3 of 13 patients were reported to have a pathogen at a density of more than 1 × 10⁴ colony forming unit. There was at best a poor correlation between semiquantitative and quantitative data. Potential pathogens were cultured in two of five control samples. The results suggest that the results from conventional microbiological assessment of BAL samples can be highly variable and that the proposal that a discrete cut-off is of value in patients with chronic endobronchial infection is probably invalid.

What did we learn from multiple omics studies in asthma?

More than a decade has passed since the finalization of the Human Genome Project. Omics technologies made a huge leap from trendy and very expensive to routinely executed and relatively cheap assays. Simultaneously, we understood that omics is not a panacea for every problem in the area of human health and personalized medicine. Whilst in some areas of research omics showed immediate results, in other fields, including asthma, it only allowed us to identify the incredibly complicated molecular processes. Along with their possibilities, omics technologies also bring many issues connected to sample collection, analyses and interpretation. It is often impossible to separate the intrinsic imperfection of omics from asthma heterogeneity. Still, many insights and directions from applied omics were acquired-presumable phenotypic clusters of patients, plausible biomarkers and potential pathways involved. Omics technologies develop rapidly, bringing improvements also to asthma research. These improvements, together with our growing understanding of asthma subphenotypes and underlying cellular processes, will likely play a role in asthma management strategies.

Detecting respiratory infection in children with cystic fibrosis: Cough swab, sputum induction or bronchoalveolar lavage

Young children with cystic fibrosis (CF) are generally very well, cough free and non-productive, and are often incapable of spontaneously expectorating sputum even if actively coughing during an exacerbation. Obtaining a meaningful airway sample for microbiological analysis is therefore problematic, yet essential if lower airway infection is to be detected and adequately treated. Recently there has been increasing interest in the use of sputum-induction in young children with CF, as a simple, cost effective, well tolerated and frequently repeatable approach to sampling the lower airway, and the relative merits of this approach to bacterial sampling are discussed. Culture-independent microbiology has increased our understanding of the respiratory microbiota and has challenged the current paradigm of "single pathogen causes disease". Understanding how to diagnose infection using these new, highly sensitive technologies will be important. How we should best intervene to optimise, manipulate and prevent disruption of the respiratory microbiota is likely to greatly influence how we manage infection in the future.

The cumulative effect of inflammation and infection on structural lung disease in early cystic fibrosis

Introduction

Pulmonary inflammation and infection are important clinical and prognostic markers of lung disease in cystic fibrosis (CF). However, whether in young children they are transient findings or have cumulative, long-term impacts on respiratory health is largely unknown. We aimed to determine whether their repeated detection has a deleterious effect on structural lung disease.

Methods

All patients aged <6 years with annual computed tomography (CT) and bronchoalveolar lavage (BAL) were included. Structural lung disease on CT (%Disease) was determined using the PRAGMA-CF (Perth–Rotterdam Annotated Grid Morphometric Analysis for CF) method. The number of times free neutrophil elastase (NE) and infection were detected in BAL were counted, to determine cumulative BAL history. Linear mixed model analysis, accounting for repeat visits and adjusted for age, was used to determine associations.

Results

265 children (683 scans) were included for analysis, with BAL history comprising 1161 visits. %Disease was significantly associated with the number of prior NE (0.31, 95% CI 0.09–0.54; p=0.007) but not infection (0.23, 95% CI −0.01–0.47; p=0.060) detections. Reference equations were determined.

Conclusions

Pulmonary inflammation in surveillance BAL has a cumulative effect on structural lung disease extent, more so than infection. This provides a strong rationale for therapies aimed at reducing inflammation in young children.

The concordance between upper and lower respiratory microbiota in children with Mycoplasma pneumoniae pneumonia

In recent years, the morbidity of Mycoplasma pneumoniae pneumonia (MPP) has dramatically increased in China. An increasing number of studies indicate that an imbalance in the respiratory microbiota is associated with respiratory infection. We selected 28 hospitalized patients infected with M. pneumoniae and 32 healthy children. Nasopharyngeal (NP) and oropharyngeal (OP) swabs were collected from healthy children, whereas NP, OP and bronchoalveolar lavage (BAL) specimens were collected from patients. Microbiota analysis was performed on all microbial samples using 16 S ribosomal RNA (16 S rRNA) sequencing. The NP microbial samples in healthy children were divided into two groups, which were dominated by either Staphylococcus or mixed microbial components. The respiratory microbiota in pneumonia patients harbored a lower microbial diversity compared to healthy children, and both the NP and OP microbiota of patients differed significantly from that of healthy children. Hospitalized MPP children with a higher abundance of Mycoplasma in the BAL fluid (BALF) microbiota tended to suffer longer hospitalization lengths and higher peak fevers and serum C-reactive protein levels. Concordance analysis explained the succession of imbalanced NP microbiota to the OP and lung in diseased children. However, the association of the abundance of Mycoplasma in BALF microbiota with that in NP or OP microbiota varied among individuals, which suggested the sensitivity of BALF in MPP diagnostics, mirroring MPP severity.

The CF-Sputum Induction Trial (CF-SpIT) to assess lower airway bacterial sampling in young children with cystic fibrosis: a prospective internally controlled interventional trial

Background

Pathogen surveillance is challenging but crucial in children with cystic fibrosis—who are often non-productive of sputum even if actively coughing—because infection and lung disease begin early in life. The role of sputum induction as a diagnostic tool for infection has not previously been systematically addressed in young children with cystic fibrosis. We aimed to assess the pathogen yield from sputum induction compared with that from cough swab and single-lobe, two-lobe, and six-lobe bronchoalveolar lavage.

Methods

This prospective internally controlled interventional trial was done at the Children's Hospital for Wales (Cardiff, UK) in children with cystic fibrosis aged between 6 months and 18 years. Samples from cough swab, sputum induction, and single-lobe, two-lobe, and six-lobe bronchoalveolar lavage were matched for within-patient comparisons. Primary outcomes were comparative pathogen yield between sputum induction and cough swab for stage 1, and between sputum induction, and single-lobe, two-lobe, and six-lobe bronchoalveolar lavage for stage 2. Data were analysed as per protocol. This study is registered with the UK Clinical Research Network (14615) and with the International Standard Randomised Controlled Trial Network Registry (12473810).

Findings

Between Jan 23, 2012, and July 4, 2017, 124 patients were prospectively recruited to the trial and had 200 sputum induction procedures for stage 1. 167 (84%) procedures were successful and the procedure was well tolerated. Of the 167 paired samples, 63 (38%) sputum-induction samples were pathogen positive compared with 24 (14%) cough swabs (p<0·0001; odds ratio [OR] 7·5; 95% CI 3·19–17·98). More pathogens were isolated from sputum induction than cough swab (79 [92%] of 86 vs 27 [31%] of 86; p<0·0001). For stage 2, 35 patients had a total of 41 paired sputum-induction and bronchoalveolar lavage procedures. Of the 41 paired samples, 28 (68%) were positive for at least one of the concurrent samples. 39 pathogens were isolated. Sputum induction identified 27 (69%) of the 39 pathogens, compared with 22 (56%; p=0·092; OR 3·3, 95% CI 0·91–12·11) on single-lobe, 28 (72%; p=1·0; OR 1·1, 95% CI 0·41–3·15) on two-lobe, and 33 (85%; p=0·21; OR 2·2, 95% CI 0·76–6·33) on six-lobe bronchoalveolar lavage.

Interpretation

Sputum induction is superior to cough swab for pathogen detection, is effective at sampling the lower airway, and is a credible surrogate for bronchoalveolar lavage in symptomatic children. A substantial number of bronchoscopies could be avoided if sputum induction is done first and pathogens are appropriately treated. Both sputum induction and six-lobe bronchoalveolar lavage provide independent, sizeable gains in pathogen detection compared with the current gold-standard two-lobe bronchoalveolar lavage. We propose that sputum induction and six-lobe bronchoalveolar lavage combined are used as standard of care for comprehensive lower airway pathogen detection in children with cystic fibrosis.

Funding

Health and Care Research Wales—Academic Health Science Collaboration and Wellcome Trust Institutional Strategic Support Fund.

Respiratory Bacterial Culture Sampling in Expectorating and Non-expectorating Patients With Cystic Fibrosis

Purpose: Different respiratory sampling methods exist to identify lower airway pathogens in patients with cystic fibrosis (CF), of which bronchoalveolar lavage (BAL), and expectorated sputum are considered the "gold standard." Because BAL cannot be repeated limitless, the diagnosis of lower respiratory tract infections in non-expectorating patients is challenging. Other sampling techniques are nasal swab, cough swab, and induced sputum. The purpose of this study (NCT02363764) was to compare concordance between the microbiological yield of nasal swab, cough swab, and expectorated sputum in expectorating patients; nasal swab, cough swab, and induced sputum in non-expectorating patients; nasal swab, cough swab, induced sputum, and BAL in patients requiring bronchoscopy ("BAL-group"); and to determine the clinical value of cough swab in non-expectorating patients with CF. Methods: Microbiological yield detected by these different sampling techniques was compared between and within 105 expectorating patients, 30 non-expectorating patients and BAL-group (n = 39) in a single CF clinic. Specificity, sensitivity, positive (PPV), and negative (NPV) predictive values were calculated. Results: Overall low sensitivity (6.3-58.0%) and wide-ranging predictive values (0.0-100.0%) indicated that nasal swab was not appropriate to detect lower airway pathogens [Pseudomonas aeruginosa (Pa), Staphylococcus aureus (Sa), and Haemophilus influenzae (Hi)] in all three patient groups. Microbiological yield, specificity, sensitivity, PPV, and NPV of cough swab and induced sputum were largely similar in non-expectorating patients and in BAL-group (except sensitivity (0.0%) of induced sputum for Hi in BAL-group). Calculations for Pa and Hi could not be performed for non-expectorating patients because of low prevalence (n = 2 and n = 3, respectively). In expectorating patients, concordance was found between cough swab and expectorated sputum, except for Hi (sensitivity of 40.0%). Conclusion: Our findings suggest that cough swab might be helpful in detecting the presence of some typical CF pathogens in the lower airways of clinically stable patients with CF. However, in symptomatic patients, who are unable to expectorate and who have a negative cough swab and induced sample, BAL should be performed as it currently remains the "gold standard."

Initial acquisition and succession of the cystic fibrosis lung microbiome is associated with disease progression in infants and preschool children

The cystic fibrosis (CF) lung microbiome has been studied in children and adults; however, little is known about its relationship to early disease progression. To better understand the relationship between the lung microbiome and early respiratory disease, we characterized the lower airways microbiome using bronchoalveolar lavage (BAL) samples obtained from clinically stable CF infants and preschoolers who underwent bronchoscopy and chest computed tomography (CT). Cross-sectional samples suggested a progression of the lower airways microbiome with age, beginning with relatively sterile airways in infancy. By age two, bacterial sequences typically associated with the oral cavity dominated lower airways samples in many CF subjects. The presence of an oral-like lower airways microbiome correlated with a significant increase in bacterial density and inflammation. These early changes occurred in many patients, despite the use of antibiotic prophylaxis in our cohort during the first two years of life. The majority of CF subjects older than four harbored a pathogen dominated airway microbiome, which was associated with a further increase in inflammation and the onset of structural lung disease, despite a negligible increase in bacterial density compared to younger patients with an oral-like airway microbiome. Our findings suggest that changes within the CF lower airways microbiome occur during the first years of life and that distinct microbial signatures are associated with the progression of early CF lung disease.

Concordance between upper and lower airway microbiota in infants with cystic fibrosis

Nasopharyngeal and oropharyngeal samples are commonly used to direct therapy for lower respiratory tract infections in non-expectorating infants with cystic fibrosis (CF).We aimed to investigate the concordance between the bacterial community compositions of 25 sets of nasopharyngeal, oropharyngeal and bronchoalveolar lavage (BAL) samples from 17 infants with CF aged ∼5 months (n=13) and ∼12 months (n=12) using conventional culturing and 16S-rRNA sequencing.Clustering analyses demonstrated that BAL microbiota profiles were in general characterised by a mixture of oral and nasopharyngeal bacteria, including commensals like Streptococcus, Neisseria, Veillonella and Rothia spp. and potential pathogens like Staphylococcus aureus, Haemophilus influenzae and Moraxella spp. Within each individual, however, the degree of concordance differed between microbiota of both upper respiratory tract niches and the corresponding BAL.The inconsistent intra-individual concordance between microbiota of the upper and lower respiratory niches suggests that the lungs of infants with CF may have their own microbiome that seems seeded by, but is not identical to, the upper respiratory tract microbiome.

Induced sputum to detect lung pathogens in young children with cystic fibrosis

INTRODUCTION

Induced sputum sampling holds promise as a method for obtaining samples representative of the lower airways in young children. Collection of induced sputum samples in young children differs from older children and adults' as pharyngeal suctioning is often required. Our aim was to determine the sensitivity and specificity of induced sputum with and without airway clearance techniques to detect lower airway pathogens in children less than age 7 with cystic fibrosis.

METHODS

Microbiological culture results were compared between 61 paired induced sputum and bronchoalveolar lavage fluid samples from young children with cystic fibrosis. The first cohort received no airway clearance and the second cohort received airway clearance. Induced sputum was sampled within 7 days of bronchoscopy.

RESULTS

Median age (range) of participants was 3.3 years (0.9-6.7). Sensitivity and specificity (95%CI) of induced sputum was 36.8% (16.3, 61.6), and 69% (52.9, 82.4), respectively (N = 61). In subgroup analysis, induced sputum with (N = 31) and without airway clearance (N = 30) demonstrated sensitivity of 50% (15.7, 84.3) and 27.3% (6.0, 61.0), respectively, and specificity of 60.9% (38.5, 80.3), and 78.9% (54.4, 93.9), respectively.

CONCLUSION

Induced sputum is not highly sensitive or specific as routine surveillance for detection of lower airway pathogens in young children with cystic fibrosis. Pediatr Pulmonol. 2017;52:182-189. © 2016 Wiley Periodicals, Inc.

Assessment of serology and spirometry and the combination of both to complement microbiological isolation for earlier detection of Pseudomonas aeruginosa infection in children with cystic fibrosis

Background

The aim of this study was to assess whether serology and spirometry and the combination of both can complement culture-based detection for earlier recognition of Pseudomonas aeruginosa infection in children with cystic fibrosis.

Methods

A 4 year longitudinal prospective study that included 67 Slovenian children with cystic fibrosis with a mean age of 10.5 years was conducted. Serology, spirometry and a scoring system combining serology and spirometry were assessed and compared. Infection was confirmed with isolation of Pseudomonas aeruginosa from respiratory samples.

Results

There was a significantly positive correlation between serology and the combination of serology and spirometry and Pseudomonas aeruginosa isolation (P < 0.01 for both) and a significantly negative correlation between spirometry and Pseudomonas aeruginosa isolation (P < 0.05). An increase in serology for 1 ELISA unit increased the possibility of Pseudomonas aeruginosa isolation 1.6 times. A fall in FEV1% predicted for 10% increased the possibility of Pseudomonas aeruginosa isolation 9.8 times. Binary logistic regression analysis was used to determine the odds ratios and 95% confidence intervals for all three approaches. Serology had the highest specificity (0.80) and the combination of serology and spirometry the highest sensitivity (0.90). Both had a high negative predictive value (0.93 and 0.79 respectively).

Conclusion

Using serology and the combination of serology and lung function measurement can be beneficial for earlier detection of infection with Pseudomonas aeruginosa in children with cystic fibrosis when done simultaneously with standard culture-based detection from respiratory samples.

Clinical, cytological and microbiological evaluation of bronchoalveolar lavage in children: A referral hospital-based study

INTRODUCTION

Diffuse lung diseases (DLD) in children involve a group of heterogeneous, rare disorders. In spite of the low diagnostic yield in pediatric DLD, bronchoalveolar lavage (BAL) can be used to diagnose specific disorders. There are few studies about microbial and cellular profiles of BAL samples in these patients. This study was conducted to evaluate the clinical, cytological and microbiological evaluation of BAL in children with DLD.

METHODS

The clinical, cytological and microbiological profiles of BAL samples of all patients with DLD who underwent the fiberoptic bronchoscopy (FOB) at Children's Medical Center, an Iranian referral pediatrics Hospital during a year were evaluated.

RESULTS

In 18 patients (18.4%) of the 98 cases studied, 22 pathogens were obtained as etiologic agents. The mean total cells count of BAL was 23.9 × 104 ± 12.9 × 104/ml. The mean percentages of cellular components were macrophages (70.2%), neutrophils (16.3%), lymphocytes (11.8%) and eosinophils (1.4%), respectively. The type of lung disease was significantly associated with the mean percentage of lymphocytes (p = 0.005) and the percentage of neutrophils (p = 0.042).

CONCLUSION

FOB and BAL evaluation in combination with clinical and radiographic imaging data may be helpful for identifying of presumptive diagnosis of DLD in children.

Exhaled breath hydrogen cyanide as a marker of early Pseudomonas aeruginosa infection in children with cystic fibrosis

Hydrogen cyanide is readily detected in the headspace above Pseudomonas aeruginosa cultures and in the breath of cystic fibrosis (CF) patients with chronic (P. aeruginosa) infection. We investigated if exhaled breath HCN is an early marker of P. aeruginosa infection. 233 children with CF who were free from P. aeruginosa infection were followed for 2 years. Their median (interquartile range) age was 8.0 (5.0-12.2) years. At each study visit, an exhaled breath sample was collected for hydrogen cyanide analysis. In total, 2055 breath samples were analysed. At the end of the study, the hydrogen cyanide concentrations were compared to the results of routine microbiology surveillance. P. aeruginosa was isolated from 71 children during the study with an incidence (95% CI) of 0.19 (0.15-0.23) cases per patient-year. Using a random-effects logistic model, the estimated odds ratio (95% CI) was 3.1 (2.6-3.6), which showed that for a 1- ppbv increase in exhaled breath hydrogen cyanide, we expected a 212% increase in the odds of P. aeruginosa infection. The sensitivity and specificity were estimated at 33% and 99%, respectively. Exhaled breath hydrogen cyanide is a specific biomarker of new P. aeruginosa infection in children with CF. Its low sensitivity means that at present, hydrogen cyanide cannot be used as a screening test for this infection.

Induced sputum in young healthy children with cystic fibrosis

Young children with CF are often asymptomatic and non-productive, yet CF lung disease occurs early in life. Cough swabs are used routinely to sample bacteria from the CF respiratory tract in non-productive healthy children; bronchoscopy is used to definitively sample the lower airway, but is an invasive procedure. Induced sputum is a non-invasive approach to sampling the lower airway. The article concentrates on how well it is tolerated in children, how successful it is in identifying respiratory pathogens, and how it may be important in routine surveillance if 16S technology is to be used in the clinical forum.

Asthma and COPD proteomics: current approaches and future directions

Although asthma and chronic obstructive pulmonary disease COPD represent the two most common chronic respiratory diseases worldwide, the mechanisms underlying their pathobiology need to be further elucidated. Presently, differentiation of asthma and COPD are largely based on clinical and lung function parameters. However, the complexity of these multifactorial diseases may lead to misclassification and to inappropriate management strategies. Recently, tremendous progress in MS has extended the sensitivity, accuracy, and speed of analysis, enabling the identification of thousands of proteins per experiment. Beyond identification, MS has also greatly implemented quantitation issues allowing to assess qualitative-quantitative differences in protein profiles of different samples, in particular diseased versus normal. Herein, we provide a summary of recent proteomics-based investigations in the field of asthma/COPD, highlighting major issues related to sampling and processing procedures for proteomic analyses of specific airway and parenchymal specimens (induced sputum, exhaled breath condensate, epithelial lining fluid, bronchoalveolar and nasal lavage fluid), as well as blood-derived specimen (plasma and serum). Within such a context, together with current difficulties and limitations mainly due to lack of general standardization in preanalytical sampling procedure, our discussion will focus on the challenges and possible benefits of proteomic studies in phenotypic stratification of asthma and COPD.

Systems Biology and Ratio-Based, Real-Time Disease Surveillance

Most infectious disease surveillance methods are not well fit for early detection. To address such limitation, here we evaluated a ratio- and Systems Biology-based method that does not require prior knowledge on the identity of an infective agent. Using a reference group of birds experimentally infected with West Nile virus (WNV) and a problem group of unknown health status (except that they were WNV-negative and displayed inflammation), both groups were followed over 22 days and tested with a system that analyses blood leucocyte ratios. To test the ability of the method to discriminate small data sets, both the reference group (n = 5) and the problem group (n = 4) were small. The questions of interest were as follows: (i) whether individuals presenting inflammation (disease-positive or D+) can be distinguished from non-inflamed (disease-negative or D-) birds, (ii) whether two or more D+ stages can be detected and (iii) whether sample size influences detection. Within the problem group, the ratio-based method distinguished the following: (i) three (one D- and two D+) data classes; (ii) two (early and late) inflammatory stages; (iii) fast versus regular or slow responders; and (iv) individuals that recovered from those that remained inflamed. Because ratios differed in larger magnitudes (up to 48 times larger) than percentages, it is suggested that data patterns are likely to be recognized when disease surveillance methods are designed to measure inflammation and utilize ratios.

Comparison of the US and Australian cystic fibrosis registries: the impact of newborn screening

BACKGROUND AND OBJECTIVES

National data registries for cystic fibrosis (CF) enable comparison of health statistics between countries. We examined the US and Australian CF data registries to compare demographics, clinical practice and outcome measures.

METHODS

We compared the 2003 US and Australian registries. Differences in pulmonary and growth outcomes were assessed by creating models controlling for differences in age, gender, genotype, and diagnosis after newborn screening.

RESULTS

Data on 12 994 US and 1220 Australian patients aged ≤18 years were analyzed. A significant difference was noted in the proportion who had been diagnosed after newborn screening (Australian 65.8% vs United States 7.2%; P < .001). Australian children had significantly greater mean height percentile (41.0 vs 32.6; P < .001) and weight percentile (43.5 vs 36.1; P = .028) than US children. Mean forced expiratory volume in 1 second (FEV(1)) percent predicted adjusted for age, gender, and genotype was similar in the 2 countries (P = .80). Patients diagnosed after newborn screening had higher mean FEV(1) (5.3 [95% confidence interval (CI): 3.6-7.0]) percent predicted and BMI (0.26 [95% CI: 0.09-0.43]). Mean FEV(1) of Australian patients diagnosed after newborn screening was lower by 5.2 (95% CI: 2.8-7.6) percent predicted compared with US children.

CONCLUSIONS

Children diagnosed with CF after newborn screening benefited from better lung function and BMI than those diagnosed clinically. The benefit of newborn screening on lung function was significantly less in Australian children compared with US children. Statistical comparisons between CF registries are feasible and can contribute to benchmarking and improvements in care.

Pulmonary exacerbations in cystic fibrosis with negative bacterial cultures

BACKGROUND

Pulmonary exacerbations are a major cause of morbidity in cystic fibrosis (CF) and likely contribute to lung function decline. Exacerbations are often associated with characteristic airway bacteria [CF related bacteria (CFRB)]. However, some patients do not have CFRB detected by culture during exacerbations.

OBJECTIVES

We sought to determine the proportion of airway cultures negative for CFRB during pulmonary exacerbations, and to characterize patients who were CFRB-negative versus CFRB-positive.

METHODS

We performed a retrospective study of patients with CF admitted for a pulmonary exacerbation. Patients were classified as CFRB-positive or CFRB-negative based on admission airway cultures. Demographics, clinical presentation, lung function, history of chronic Pseudomonas aeruginosa infection and improvement in lung function with treatment were compared between groups.

MAIN RESULTS

There were 672 admissions for exacerbation involving 211 patients over 5 years. Seventeen percent were classified as CFRB-negative. Forty-one percent of bronchoalveolar lavage (BAL), 32% of throat and 10% of sputum samples were CFRB-negative. Among patients capable of expectorating sputum, the CFRB-negative group was younger, less likely to have chronic P. aeruginosa, had higher lung function and body mass index (BMI), and had a lower systemic inflammatory response on admission compared to those with CFRB-positive cultures. The two groups had similar numbers of patients with three or more signs and symptoms of a pulmonary exacerbation (88% vs. 92%). Both groups returned to baseline lung function following treatment.

CONCLUSIONS

A significant number of patients with CF and pulmonary exacerbation did not have typical CFRB detected by culture. Patients without CFRB still had characteristic signs and symptoms of pulmonary exacerbation and responded to treatment. Understanding the causes of illness in these patients may improve the diagnosis and treatment of pulmonary exacerbations in CF.

Endogenous Levels of Five Fatty Acid Metabolites in Exhaled Breath Condensate to Monitor Asthma by High-Performance Liquid Chromatography: Electrospray Tandem Mass Spectrometry

Airway inflammation characterizing asthma and other airway diseases may be monitored through biomarker analysis of exhaled breath condensate (EBC). In an attempt to discover novel EBC biomarkers, a high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method was used to analyze EBC from ten control non-asthmatics and one asthmatic individual for five fatty acid metabolites: 9,12,13-trihydroxyoctadecenoic acid (9,12,13-TriHOME), 9,10,13-TriHOME, 12,13-dihydroxyoctadecenoic acid (12,13-DiHOME), 12-hydroxyeicosatetraenoic acid (12-HETE), and 12(13)-epoxyoctadecenoic acid (12(13)-EpOME). The method was shown to be sensitive, with an on-column limit of quatitation (LOQ) in the pg range (corresponding to pM concentrations in EBC), and linear over several orders of magnitude for each analyte in the calibrated range. Analysis of EBC spiked with the five fatty acid metabolites was within 81%-119% with only a few exceptions. Endogenous levels in EBC exhibited intra- and inter-assay precision of 10%-22%, and 12%-36%, respectively. EBC from the healthy subjects contained average analyte levels between 15 and 180 pM with 12-HETE present above the LOQ in only one of the subjects at a concentration of 240 pM. Exposure of the asthmatic subject to allergen led to increased EBC concentrations of 9,12,13-TriHOME, 9,10,13-TriHOME, 12,13-DiHOME, and 12(13)-EpOME when compared to levels in EBC collected prior to allergen exposure (range =40-510 pM). 12,13-DiHOME was significantly increased (Student's t-test, p < 0.05). In conclusion, we have developed a new HPLC-ESI-MS/MS method for the analysis of five fatty acid metabolites in EBC, which are potential biomarkers for asthma monitoring and diagnosis.

Airway foreign body removal by flexible bronchoscopy: experience with 1027 children during 2000-2008

BACKGROUND

Foreign body aspiration (FBA) into the tracheobronchial tree is a common problem in children necessitating prompt recognition and management. This study aimed to report our experience in airway foreign body removal by flexible bronchoscopy in children.

METHODS

A total of 1027 patients with FBA were reviewed retrospectively. They were 626 boys and 401 girls aged from 5 months to 14 years with a median age of 17 months. The clinical manifestations, radiological findings, bronchoscopic findings and complications of the procedure were analyzed.

RESULTS

Among the patients, only 53.4% had a definite history of FBA. The most frequent symptom was paroxysmal cough (84.3%), followed by stridor or wheezing, fever and dyspnea. Chest X-ray showed emphysema in 68.8% of the patients, atelectasis in 13.3% and bronchopneumonia in 56.3%. A bronchoscope was inserted intranasally in most children, but through mouth and endotracheal tube in 17 and 3 children, respectively. Foreign bodies were removed successfully by flexible bronchoscopy with disposable grasping forceps or biopsy forceps in 938 (91.3%) of the patients. The other 89 patients turned to rigid bronchoscopy. During the procedures, 132 (12.9%) of the patients showed transient hypoxia, which was alleviated by oxygen supplement and/or temporary cessation of the procedure. A small amount of bleeding was found in 17 patients and bradycardia in 3. Air leak and laryngeal edema were noted in 2 patients and relieved within 24 hours.

CONCLUSIONS

Flexible bronchoscopy is useful and safe in retrieving airway foreign bodies in children. With skilled personnel and perfect equipments, flexible bronchoscopy could be considered as the first choice for the removal of airway foreign body.