Safety of research bronchoscopy, biopsy and bronchoalveolar lavage in asthma

Risk factors associated with severe adverse events in patients with relapsing polychondritis undergoing flexible bronchoscopy

BACKGROUND

Patients with relapsing polychondritis (RP) sometimes experience upper airway collapse or lower airway stenosis, and bronchoscopy may provide a valuable typical image to confirm the diagnosis. This study aimed to identify potential risk factors associated with severe adverse effects during bronchoscopy.

METHODS

We performed a retrospective cohort study of 82 consecutive patients with RP hospitalized at Peking Union Medical College Hospital between January 1, 2012 and December 31, 2022. Clinical features and disease patterns were compared among patients with RP undergoing bronchoscopy with or without severe adverse effects. Binary logistic regression analysis was performed to identify the associated risk factors.

RESULTS

For patients with RP undergoing bronchoscopy with severe adverse effects, the forced vital capacity (FVC), forced vital capacity percent predicted values (FVC%), and peak expiratory flow were significantly lower (P = 0.001, P = 0.001, and P = 0.021, respectively) than those in the non-severe adverse effect subgroup. Binary logistic regression analysis revealed that low FVC% (odds ratio, 0.930; 95% confidence interval, 0.880-0.982; P = 0.009) was an independent risk factor for severe adverse events in patients undergoing bronchoscopy.

CONCLUSIONS

Low FVC or FVC% suggests a high risk of severe adverse effects in patients with RP undergoing bronchoscopy. Patients with such risk factors should be carefully evaluated before bronchoscopy and adequately prepared for emergency tracheal intubation or tracheostomy.

Redefining the Role of Bronchoscopy in the Workup of Severe Uncontrolled Asthma in the Era of Biologics: A Prospective Study

BACKGROUND

Severe uncontrolled asthma (SUA) is frequently treated with biologic therapy if a T2 phenotype is found. Bronchoscopy is not routinely recommended in these patients unless a specific indication to rule out comorbidities is present.

RESEARCH QUESTION

Is routine bronchoscopy safe and useful in phenotyping and endotyping patients with SUA before the indication of a biologic therapy?

STUDY DESIGN AND METHODS

Prospective study of consecutive patients with SUA who were referred to a specialized asthma clinic to assess the indication of a biologic therapy. Patients were clinically phenotyped as T2-allergic, T2-eosinophilic, and non-T2. All patients underwent bronchoscopy, and systematic data collection of endoscopic findings, microbiology of bronchial aspirate, and presence of eosinophils in bronchial biopsy were recorded and compared between asthma phenotypes. Cluster analysis was performed accordingly.

RESULTS

One hundred patients were recruited and classified as T2-allergic (28%), T2-eosinophilic (64%), and non-T2 (8%). On bronchoscopy, signs of gastroesophageal reflux disease were detected in 21%, vocal cord dysfunction in 5%, and tracheal abnormalities in 3%. Bronchial aspirate culture isolated bacteria in 27% of patients and fungi in 14%. Three clusters were identified: nonspecific, upper airway, and infection, the latter being less frequently associated with submucosal eosinophilia. Eosinophils were detected in 91% of bronchial biopsies. Despite a correlation to blood eosinophils, five patients with T2-phenotypes showed no eosinophils in bronchial biopsy, and three patients with non-T2 showed eosinophils in bronchial biopsy. Only one patient had moderate bleeding.

INTERPRETATION

Routine bronchoscopy in SUA eligible for biologic therapy is a safe procedure that can help to better phenotype and personalize asthma management.

Validation of a Pathological Score for the Assessment of Bronchial Biopsies in Severe Uncontrolled Asthma: Beyond Blood Eosinophils

BACKGROUND

Blood eosinophil count (BEC) is currently used as a surrogate marker of T2 inflammation in severe asthma but its relationship with tissue T2-related changes is elusive. Bronchial biopsy could add reliable information but lacks standardization.

OBJECTIVES

To validate a systematic assessment of the bronchial biopsy for the evaluation of severe uncontrolled asthma (SUA) by standardizing a pathological score.

METHODS

A systematic assessment of submucosal inflammation, tissue eosinophilic count/field (TEC), goblet cells hyperplasia, epithelial changes, basement membrane thickening, prominent airway smooth muscle and submucosal mucous glands was initially agreed and validated in representative bronchial biopsies of 12 patients with SUA by 8 independent pathologists. In a second phase, 62 patients with SUA who were divided according to BEC≥300cells/mm³ or less underwent bronchoscopy with bronchial biopsies and the correlations between the pathological findings and the clinical characteristics were investigated.

RESULTS

The score yielded good agreement among pathologists regarding submucosal eosinophilia, TEC, goblet cells hyperplasia and mucosal glands (ICC=0.85, 0.81, 0.85 and 0.87 respectively). There was a statistically significant correlation between BEC and TEC (r=0.393, p=0.005) that disappeared after correction by oral corticosteroids (OCS) use (r=0.170, p=0.307). However, there was statistically significant correlation between FeNO and TEC (r=0.481, p=0.006) that was maintained after correction to OCS use (r=0.419, p=0.021). 82.4% of low-BEC had submucosal eosinophilia, 50% of them moderate to severe.

CONCLUSION

A standardized assessment of endobronchial biopsy is feasible and could be useful for a better phenotyping of SUA especially in those receiving OCS.

Research Bronchoscopies in Critically Ill Research Participants: An Official American Thoracic Society Workshop Report

Bronchoscopy for research purposes is a valuable tool to understand lung-specific biology in human participants. Despite published reports and active research protocols using this procedure in critically ill patients, no recent document encapsulates the important safety considerations and downstream applications of this procedure in this setting. The objectives were to identify safe practices for patient selection and protection of hospital staff, provide recommendations for sample procurement to standardize studies, and give guidance on sample preparation for novel research technologies. Seventeen international experts in the management of critically ill patients, bronchoscopy in clinical and research settings, and experience in patient-oriented clinical or translational research convened for a workshop. Review of relevant literature, expert presentations, and discussion generated the findings presented herein. The committee concludes that research bronchoscopy with bronchoalveolar lavage in critically ill patients on mechanical ventilation is valuable and safe in appropriately selected patients. This report includes recommendations on standardization of this procedure and prioritizes the reporting of sample management to produce more reproducible results between laboratories. This document serves as a resource to the community of researchers who endeavor to include bronchoscopy as part of their research protocols and highlights key considerations for the inclusion and safety of research participants.

Assessment and clinical management of internal contamination

Internal contamination by radionuclides may occur through inhalation, ingestion and absorption through the skin or subcutaneous tissue. The clinical management of internalized radionuclides requires the integration of clinical signs and symptoms with dose estimates in biological tissues obtained from the face, nose, sputum, urine, faeces and/or skin. The assessment of ingested radionuclides includes bioassays of urine and faeces, and if available, whole body counting for radionuclides that emit penetrating x-rays or gamma-rays. An estimate of intake dose may be made at the time of initial patient evaluation by measuring radioactivity, converting counts/minute to depositions/minute with a specific gamma-ray constant, and comparing the amount to its annual limit on intake, clinical decision guide or derived reference level. Since nobody dies from internal contamination per se, medically unstable patients should be stabilized before addressing internal contamination. Whenever possible, internal contaminants should be physically removed as soon as possible after exposure. For inhaled internal contaminants, radionuclide-specific therapy may include the administration of an ion exchange resin (i.e. Prussian blue, PB) or chelating agent (i.e. diethylenetriamine pentaacetate, DTPA, that binds toradioactiveplutonium, americium, and curium), or the physical removal of insoluble particles with a high activity radionuclide (¹⁹²Ir,⁹⁰Sr,²¹⁰Po) by bronchioalveolar lavage. Decorporation with PB, DTPA and other agents is used to enhance excretion. The treatment of wounds contaminated with an actinide includes gentle irrigation, surgical excision of contaminated tissue and DTPA. The averted dose (i.e. the total effective dose averted by therapy) may be calculated for each exposure route.

The performance of detecting Mycobacterium tuberculosis complex in lung biopsy tissue by metagenomic next-generation sequencing

Background

Tuberculosis (TB) is a chronic infectious disease caused by the Mycobacterium tuberculosis complex (MTBC), which is the leading cause of death from infectious diseases. The rapid and accurate microbiological detection of the MTBC is crucial for the diagnosis and treatment of TB. Metagenomic next-generation sequencing (mNGS) has been shown to be a promising and satisfying application of detection in infectious diseases. However, relevant research about the difference in MTBC detection by mNGS between bronchoalveolar lavage fluid (BALF) and lung biopsy tissue specimens remains scarce.

Methods

We used mNGS to detect pathogens in BALF and lung biopsy tissue obtained by CT-guide percutaneous lung puncture (CPLP) or radial endobronchial ultrasound transbronchial lung biopsy (R-EBUS-TBLB) from 443 hospitalized patients in mainland China suspected of pulmonary infections between May 1, 2019 and October 31, 2021. Aim to evaluate the diagnostic performance of mNGS for detecting MTBC and explore differences in the microbial composition in the 2 specimen types.

Results

Among the 443 patients, 46 patients finally were diagnosed with TB, of which 36 patients were detected as MTBC positive by mNGS (8.93%). Striking differences were noticed in the higher detection efficiency of lung biopsy tissue compared with BALF (P = 0.004). There were no significant differences between the 2 specimen types in the relative abundance among the 27 pathogens detected by mNGS from the 36 patients.

Conclusions

This study demonstrates that mNGS could offer an effective detection method of MTBC in BALF or lung tissue biopsy samples in patients suspected of TB infections. When it comes to the situations that BALF samples have limited value to catch pathogens for special lesion sites or the patients have contraindications to bronchoalveolar lavage (BAL) procedures, lung biopsy tissue is an optional specimen for MTBC detection by mNGS. However, whether lung tissue-mNGS is superior to BALF-mNGS in patients with MTBC infection requires further prospective multicenter randomized controlled studies with more cases.

Budget Impact of Microbial Cell-Free DNA Testing Using the Karius® Test as an Alternative to Invasive Procedures in Immunocompromised Patients with Suspected Invasive Fungal Infections

BACKGROUND

Invasive fungal infection is a major source of morbidity and mortality. The usage of microbial cell-free DNA for the detection and identification of invasive fungal infection has been considered as a potential alternative to invasive procedures allowing for rapid results.

OBJECTIVE

This analysis aimed to assess the budget implications of using the Karius^® Test in patients suspected of invasive fungal infection in an average state in the USA from a healthcare payer perspective.

METHODS

The analysis used a decision tree to capture key stages of the patient pathway, from suspected invasive fungal infection to either receiving treatment for invasive fungal infection or being confirmed as having no invasive fungal infection. The analysis used published costs and resource use from a targeted review of the literature. Because of the paucity of published evidence on the reduction of diagnostic tests displaced by the Karius Test, the analysis used a 50% reduction in the use of bronchoscopy and/or bronchoalveolar lavage. The impact of this reduction was tested in a scenario analysis.

RESULTS

The results of the analysis show that the introduction of the Karius Test is associated with a cost saving of US$2277 per patient; when multiplied by the estimated number of cases per year, the cost saving is US$17,039,666. The scenario analysis showed that the Karius Test only had an incremental cost of US$87 per patient when there was no reduction in bronchoscopy and bronchoalveolar lavage.

CONCLUSIONS

The Karius Test may offer a valuable and timely option for the diagnosis of invasive fungal infection through its non-invasive approach and subsequent cost savings.

Heterogeneity of lower airway inflammation in patients with NSAID-exacerbated respiratory disease

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) asthma is characterized by chronic rhinosinusitis and intolerance of aspirin and other COX1 inhibitors. Clinical data point to a heterogeneity within the N-ERD phenotype.

OBJECTIVE

Our aim was to investigate immune mediator profiles in the lower airways of patients with N-ERD.

METHODS

Levels of cytokines (determined by using Luminex assay) and eicosanoids (determined by using mass spectrometry) were measured in bronchoalveolar lavage fluid (BALF) from patients with N-ERD (n = 22), patients with NSAID-tolerant asthma (n = 21), and control subjects (n = 11). mRNA expression in BALF cells was quantified by using TaqMan low-density arrays.

RESULTS

Lower airway eosinophilia was more frequent in N-ERD (54.5%) than in NSAID-tolerant asthma (9.5% [P = .009]). The type-2 (T2) immune signature of BALF cells was more pronounced in the eosinophilic subphenotype of N-ERD. Similarly, BALF concentrations of periostin and CCL26 were significantly increased in eosinophilic N-ERD and correlated with T2 signature in BALF cells. Multiparameter analysis of BALF mediators of all patients with asthma revealed the presence of 2 immune endotypes: T2-like (with an elevated level of periostin in BALF) and non-T2/proinflammatory (with higher levels of matrix metalloproteinases and inflammatory cytokines). Patients with N-ERD were classified mostly as having the T2 endotype (68%). Changes in eicosanoid profile (eg, increased leukotriene E₄ level) were limited to patients with N-ERD with airway eosinophilia. Blood eosinophilia appeared to be a useful predictor of airway T2 signature (area under the curve [AUC] = 0.83); however, surrogate biomarkers had moderate performance in distinguishing eosinophilic N-ERD (for blood eosinophils, AUC = 0.72; for periostin, AUC = 0.75).

CONCLUSIONS

Lower airway immune profiles show considerable heterogeneity of N-ERD, with skewing toward T2 response and eosinophilic inflammation. Increased production of leukotriene E₄ was restricted to a subgroup of patients with eosinophilia in the lower airway.

Diagnostic Performance and Safety of Bronchoalveolar Lavage in Thrombocytopenic Haematological Patients for Invasive Fungal Infections Diagnosis: A Monocentric, Retrospective Experience

Background

Although bronchoalveolar lavage (BAL) measurements of galactomannan antigen (GM) seems to be more sensitive than serum testing to detect invasive fungal infection (IFI), a consensus on the most appropriate diagnostic threshold of the BAL GM test is still unclear. Moreover, there is uncertainty as to whether BAL is a safe procedure in patients with hematological malignancies (HM) and thrombocytopenia.

Objectives

Based on this background, 102 adult patients with HM and associated thrombocytopenia were retrospectively analyzed with the dual aim of 1) determining whether BAL is a safe and feasible procedure; and, 2) identifying the most appropriate threshold for GM positivity in the diagnosis of IFI.

Patients/Methods

each BAL was considered as one case/patient. One hundred twelve BALs were carried out in 102 HM patients: at the time of the BAL, the median platelet count (PLTs) in all patients was 47×10⁹/L (1–476), and 31 patients (27%) had PLTs< 20×10⁹/L.

Results

complications from the BAL were infrequent (3.5%) and mild. No bleeding was reported. The BAL GM cut off of >0.8 was associated with the best diagnostic accuracy (sensitivity 72.97% and specificity 80%). Antifungal treatment of patients with BAL GM >0.8 resulted in a clinical-radiological improvement in 35/41 patients (85%).

Conclusions

BAL was a safe procedure also in thrombocytopenic patients, permitting an IFI diagnosis not otherwise identifiable using EORTC/MSG criteria. Our data suggest that a BAL GM value of>0.8 represents the most useful cut-off in terms of sensibility and specificity. Further prospective studies on a more significant number of patients are needed to confirm these results.

Guidelines for diagnostic flexible bronchoscopy in adults: Joint Indian Chest Society/National College of chest physicians (I)/Indian association for bronchology recommendations

Flexible bronchoscopy (FB) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. However, bronchoscopy practices vary widely across India and worldwide. The three major respiratory organizations of the country supported a national-level expert group that formulated a comprehensive guideline document for FB based on a detailed appraisal of available evidence. These guidelines are an attempt to provide the bronchoscopist with the most scientifically sound as well as practical approach of bronchoscopy. It involved framing appropriate questions, review and critical appraisal of the relevant literature and reaching a recommendation by the expert groups. The guidelines cover major areas in basic bronchoscopy including (but not limited to), indications for procedure, patient preparation, various sampling procedures, bronchoscopy in the ICU setting, equipment care, and training issues. The target audience is respiratory physicians working in India and well as other parts of the world. It is hoped that this document would serve as a complete reference guide for all pulmonary physicians performing or desiring to learn the technique of flexible bronchoscopy.

Safety and Tolerability of Comprehensive Research Bronchoscopy in Chronic Obstructive Pulmonary Disease. Results from the SPIROMICS Bronchoscopy Substudy

RATIONALE

There is an unmet need to investigate the lower airways in chronic obstructive pulmonary disease (COPD) to define pathogenesis and to identify potential markers to accelerate therapeutic development. Although bronchoscopy is well established to sample airways in various conditions, a comprehensive COPD research protocol has yet to be published.

OBJECTIVES

To evaluate the safety and tolerability of a comprehensive research bronchoscopy procedure suitable for multicenter trials and to identify factors associated with adverse events.

METHODS

We report the detailed methodology used to conduct the bronchoscopy used in SPIROMICS (the Subpopulations and Intermediate Outcome Measures in COPD Study). The protocol entailed collection of tongue scrapings and oral rinses as well as bronchoscopy with airway inspection, bronchoalveolar lavage (BAL), protected brushings, and endobronchial biopsies. Visual airway characteristics were graded on a scale of 0 (normal appearance) to 3 (severe abnormality) in four domains: erythema, edema, secretions, and friability. Adverse events were defined as events requiring intervention. Logistic regression modeling assessed associations between adverse event occurrence and key variables.

RESULTS

We enrolled 215 participants. They were 61 ± 9 years old, 71% were white, 53% were male, and post-bronchodilator forced expiratory volume in 1 second was 89 ± 19% predicted. Self-reported asthma was present in 22% of bronchoscopy participants. Oral samples were obtained in greater than or equal to 99% of participants. Airway characteristics were recorded in 99% and were most often characterized as free of edema (61.9%). Less than 50% reported secretions, friability, or erythema. BAL yielded 111 ± 57 ml (50%) of the 223 ± 65 ml of infusate, brushes were completed in 98%, and endobronchial biopsies were performed in 82% of procedures. Adverse events requiring intervention occurred in 14 (6.7%) of 208 bronchoscopies. In logistic regression models, female sex (risk ratio [RR], 1.10; 95% confidence interval [CI], 1.02-1.19), self-reported asthma (RR, 1.17; 95% CI, 1.02-1.34), bronchodilator reversibility (RR, 1.17; 95% CI, 1.04-1.32), COPD (RR, 1.10; 95% CI, 1.02-1.20), forced expiratory volume in 1 second (RR, 0.97; 95% CI, 0.95-0.99), and secretions (RR, 1.85; 1.08-3.16) or friability (RR, 1.64; 95% CI, 1.04-2.57) observed during bronchoscopy were associated with adverse events.

CONCLUSIONS

A research bronchoscopy procedure that includes oral sampling, BAL, endobronchial biopsy, and brushing can be safely performed. Airway characteristics during bronchoscopy, demographics, asthma or COPD, and lung function may convey increased risk for procedure-related events necessitating intervention.

Hospital Volume and Mortality following Diagnostic Bronchoscopy in Lung Cancer Patients: Data from a National Inpatient Database in Japan

BACKGROUND

Recent advances in bronchoscopy utilizing endobronchial ultrasound (EBUS) as well as lung cancer therapy may have driven physicians to perform diagnostic bronchoscopy (DB) for high-risk patients.

OBJECTIVES

The aim of this study was to clarify the relationship between hospital volume (HV) and outcomes of DB.

METHODS

We collected data on inpatients with lung cancer who underwent DB from July 2010 to March 31, 2014. The annual HV of DB was classified as "very low" (≤50 cases/year), "low" (51-100 cases/year), "high" (101-300 cases/year), or "very high" (> 300 cases/year). The primary outcome was all-cause 7-day mortality after DB. Multivariable logistic regression fitted with a generalized estimation equation was performed to evaluate the association between HV and all-cause 7-day mortality after DB, adjusted for patient background factors.

RESULTS

We identified a total of 77,755 eligible patients in 954 hospitals. All-cause 7-day mortality was 0.5%. Compared with the low-volume group, 7-day mortality was significantly lower in the high-volume group (odds ratio [OR] = 0.69, 95% confidence interval [CI]: 0.52-0.92, p = 0.010), and a similar trend was shown in the very-high-volume group (OR = 0.67; 95% CI: 0.43-1.05, p = 0.080). Radial EBUS with the guide sheath method and EBUS-guided transbronchial needle aspiration showed a significantly lower 7-day mortality.

CONCLUSIONS

All-cause 7-day mortality was inversely associated with HV. The risk of DB in patients with lung cancer should be recognized, and the exploitation of EBUS may help reduce mortality after DB.

Bronchoscopic mucosal cryobiopsies as a method for studying airway disease

BACKGROUND

Investigating disease mechanisms and treatment responses in obstructive airway diseases with invasive sampling are hampered by the small size and mechanical artefacts that conventional forceps biopsies suffer from. Endoscopic cryobiopsies are larger and more intact and are being increasingly used. However, the technique has not yet been explored for obtaining mucosa biopsies.

OBJECTIVE

To investigate differences in size and quality of endobronchial mucosal biopsies obtained with cryotechnique and forceps. Further, to check for eligibility of cryobiopsies to be evaluated with immunohistochemistry and in situ hybridization and to investigate tolerability and safety of the technique.

METHODS

Endobronchial mucosal biopsies were obtained with cryotechnique and forceps from patients with haemoptysis undergoing bronchoscopy and evaluated by quantitative morphometry, automated immunohistochemistry and in situ hybridization.

RESULTS

A total of 40 biopsies were obtained from 10 patients. Cross-sectional areas were threefold larger in cryobiopsies (median: 3.08 mm² (IQR: 1.79) vs 1.03 mm² (IQR: 1.10), P < 0.001). Stretches of intact epithelium were 8-fold longer (median: 4.61 mm (IQR: 4.50) vs 0.55 mm (IQR: 1.23), P = 0.001). Content of glands (median: 0.095 mm² (IQR: 0.30) vs 0.00 mm² (IQR: 0.01), P = 0.002) and airway smooth muscle (median: 0.25 mm² (IQR: 0.30) vs 0.060 mm² (IQR: 0.11), P = 0.02) was higher in the cryobiopsies compared with forceps biopsies. Further, the cryobiopsies had well-preserved protein antigens and mRNA. Mild to moderate bleeding was the only complication observed.

CONCLUSION AND CLINICAL RELEVANCE

By yielding significantly larger and more intact biopsies, the cryotechnique represents a valuable new research tool to explore the bronchi in airway disease. Ultimately with the potential to create better understanding of underlying disease mechanisms and improvement of treatments.

Effect of a syringe aspiration technique versus a mechanical suction technique and use of N-butylscopolammonium bromide on the quantity and quality of bronchoalveolar lavage fluid samples obtained from horses with the summer pasture endophenotype of equine asthma

OBJECTIVE To evaluate the effect of 2 bronchoalveolar lavage (BAL) sampling techniques and the use of N-butylscopolammonium bromide (NBB) on the quantity and quality of BAL fluid (BALF) samples obtained from horses with the summer pasture endophenotype of equine asthma. ANIMALS 8 horses with the summer pasture endophenotype of equine asthma. PROCEDURES BAL was performed bilaterally (right and left lung sites) with a flexible videoendoscope passed through the left or right nasal passage. During lavage of the first lung site, a BALF sample was collected by means of either gentle syringe aspiration or mechanical suction with a pressure-regulated wall-mounted suction pump. The endoscope was then maneuvered into the contralateral lung site, and lavage was performed with the alternate fluid retrieval technique. For each horse, BAL was performed bilaterally once with and once without premedication with NBB (21-day interval). The BALF samples retrieved were evaluated for volume, total cell count, differential cell count, RBC count, and total protein concentration. RESULTS Use of syringe aspiration significantly increased total BALF volume (mean volume increase, 40 mL [approx 7.5% yield]) and decreased total RBC count (mean decrease, 142 cells/μL), compared with use of mechanical suction. The BALF nucleated cell count and differential cell count did not differ between BAL procedures. Use of NBB had no effect on BALF retrieval. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that retrieval of BALF by syringe aspiration may increase yield and reduce barotrauma in horses at increased risk of bronchoconstriction and bronchiolar collapse. Further studies to determine the usefulness of NBB and other bronchodilators during BAL procedures in horses are warranted.

Asthma biomarkers in the age of biologics

The heterogeneous nature of asthma has been understood for decades, but the precise categorization of asthma has taken on new clinical importance in the era of specific biologic therapy. The simple categories of allergic and non-allergic asthma have given way to more precise phenotypes that hint at underlying biologic mechanisms of variable airflow limitation and airways inflammation. Understanding these mechanisms is of particular importance for the approximately 10% of patients with severe asthma. Biomarkers that aid in phenotyping allow physicians to "personalize" treatment with targeted biologic agents. Unfortunately, testing for these biomarkers is not routine in patients whose asthma is refractory to standard therapy. Scientific advances in the recognition of sensitive and specific biomarkers are steadily outpacing the clinical availability of reliable and non-invasive assessment methods designed for the prompt and specific diagnosis, classification, treatment, and monitoring of severe asthma patients. This article provides a practical overview of current biomarkers and testing methods for prompt, effective management of patients with severe asthma that is refractory to standard therapy.

Utility of bronchoalveolar lavage in diagnosing respiratory tract infections in patients with hematological malignancies: are invasive diagnostics still needed?

BACKGROUND

Patients treated for hematological malignancies have an increased risk of serious infections. Diagnosis and prompt initiation of therapy are essential. Bronchoalveolar lavage (BAL) is a well-established investigation for identifying the cause of pulmonary infiltrates in immunocompromised patients. The aim of the study was to determine the diagnostic yield of BAL in patients treated for hematological malignancies and how often it contributed to a modification of the anti-infectious therapy.

METHODS

We reviewed records from 151 consecutive BAL procedures in 133 adult patients with hematological malignancies, treated at a tertiary hematology unit from 2004 to 2013. Extensive microbiological work-ups on BAL samples had been performed according to a standardized protocol.

RESULTS

A microbiological finding causing the infectious episode could be identified in 59 (39%) cases. In 44 (29%) of the cases, results from BAL had an impact on clinical management either by contributing to a specific diagnosis (25%) or by leading to cessation of ongoing microbiological therapy. The most common diagnoses were invasive pulmonary aspergillosis (IPA) and Pneumocystis jirovecii pneumonia (PJP). Diagnoses of IPA and PJP were based on results from BAL in 65% and 93% of cases, respectively. Several microbiological tests on BAL samples rendered no positive results. Complications were few and mainly mild.

CONCLUSION

BAL is still important for either verifying or excluding some of the most important respiratory tract pathogens in patients with hematological malignancies, particularly IPA and PJP. Standardized procedures for BAL sampling should be continually revised to exclude unnecessary microbiological tests.

Complications and discomfort of bronchoscopy: a systematic review

Objective

To identify bronchoscopy-related complications and discomfort, meaningful complication rates, and predictors.

Method

We conducted a systematic literature search in PubMed on 8 February 2016, using a search strategy including the PICO model, on complications and discomfort related to bronchoscopy and related sampling techniques.

Results

The search yielded 1,707 hits, of which 45 publications were eligible for full review. Rates of mortality and severe complications were low. Other complications, for instance, hypoxaemia, bleeding, pneumothorax, and fever, were usually not related to patient characteristics or aspects of the procedure, and complication rates showed considerable ranges. Measures of patient discomfort differed considerably, and results were difficult to compare between different study populations.

Conclusion

More research on safety aspects of bronchoscopy is needed to conclude on complication rates and patient- and procedure-related predictors of complications and discomfort.

No direct association between asthma and the microbiome based on currently available techniques

Current uses of culture-independent tools in previous studies have shown a significant relationship between microbiota and asthma. Although these studies are relatively new, there is also evidence of the possibility of new therapeutic strategies for the treatment or prevention of asthma. This article retrospectively examines the possible association between microorganisms and asthma. Data on all patients with different types of asthma were collected from hospital charts from the Department of Internal Medicine, Saarland University Medical Center, Germany, within the study period of 2011 to 2012. The tracheal secretions of asthmatics obtained by bronchoalveolar lavage, bronchial aspirates through flexible bronchoscopy, and directly in sputum were examined microbiologically for microorganisms. Thirty-one (10.47%, 95% CI, 6.98-13.96) of a total of 296 patients were found to have asthma microorganisms in their airways. We could not establish a causal relationship between microorganisms and asthma based on the results of our study (P = 0.893). Additionally, acute respiratory infections did not affect the microbiological colonization in asthmatics' airways (P = 0.472). We were unable to find a direct association between asthma and the microbiome based on existing diagnostic techniques.

Technical and physiological determinants of airway smooth muscle mass in endobronchial biopsy samples of asthmatic horses

Morphometric analyses of endobronchial biopsies are commonly performed in asthma research but little is known about the technical and physiological parameters contributing to measurement variability. We investigated factors potentially affecting biopsy size, quality, and airway smooth muscle (ASM) content in heaves, an asthma-like disease of horses. Horses with heaves in clinical exacerbation (n = 6) or remission (n = 6) from the disease and six controls were studied using a crossover design. The effect of disease status, age, bronchodilation, biopsy forceps type, and carina size on total biopsy area (Atot), ASM area (AASM), ASM% (AASM/Atot), and histologic quality were assessed. Concordance among different measuring techniques was also assessed. Compared with other groups, horses with heaves in exacerbation yielded larger biopsies (P < 0.05). Better quality biopsies were obtained from carinae of small size compared with large ones (P = 0.02), and carina size and forceps type significantly affected the ASM content of the biopsy (interaction, P < 0.05). AASM increased with age only in heaves-affected horses (r = 0.9, P < 0.05), and ASM% was negatively correlated with pulmonary resistance at 5 Hz in heaves-affected horses (r = -0.74, P = 0.01), likely because of the increased thickness of the extracellular matrix layer in this group (P = 0.01). In conclusion, disease status, carina thickness, and the forceps used may significantly affect biopsy size, quality, and ASM content. Endobronchial biopsies are not appropriate samples for ASM quantification in heaves, and studies measuring ASM mass should not be compared when measuring techniques differ.

Safety of research bronchoscopy in critically ill patients

OBJECTIVE

Bronchoscopy and bronchoalveolar lavage (BAL) are common procedures in intensive care units; however, no contemporaneous safety and outcomes data have been reported, particularly for critically ill patients.

DESIGN

This is a retrospective analysis of prospectively collected data from teaching hospital adult intensive care units.

INTERVENTIONS

One hundred mechanically ventilated patients with severe sepsis, septic shock, acute lung injury (ALI), and/or acute respiratory distress syndrome underwent bronchoscopy with unilateral BAL. Data collected included demographics, presence of sepsis or ALI, Pao2 to Fio2 ratio, positive end-expiratory pressure, Acute Physiology and Chronic Health Evaluation score, Sequential Organ Failure Assessment score, and peri- or postprocedural complications.

RESULTS

Men comprised 51% of the patients; 81% of the patients were black, and 15% were white. The mean age was 52 (SD, ±16) years. The mean Acute Physiology and Chronic Health Evaluation score was 22 (±7.5), whereas the median Sequential Organ Failure Assessment score was 9 (interquartile range, 5-12). Ten patients (10%) had complications during or immediately after the procedure. Hypoxemia during or immediately after the BAL was the most common complication. Ninety percent of the complications were related to transient hypoxemia, whereas bradycardia and hypotension each occurred in 1 patient. Age, female sex, and higher positive end-expiratory pressure were associated with complications.

CONCLUSIONS

Bronchoscopy with BAL in critically ill patients with sepsis and ALI is well tolerated with low risk of complications, primarily related to manageable hypoxemia.

Importance of fiberoptic bronchoscopy in identifying asthma phenotypes to direct personalized therapy

PURPOSE OF REVIEW

This review summarizes the phenotyping of refractory asthma with an emphasis on how direct bronchoscopic observation and analysis of bronchoalveolar lavage (BAL), biopsy, and brushings of the airways helps direct specific personalized therapy. Additional testing used in phenotyping asthmatic patients is reviewed.

RECENT FINDINGS

Several studies and publications over the past decade have emphasized the importance of phenotyping refractory asthmatic patients to offer a better understanding of the pathobiology of disease. Bronchoscopy is a useful tool in phenotyping asthma with objective data obtained from BAL, endobronchial biopsy, and brushings. Phenotyping asthma with bronchoscopy affords personalized and successful therapy.

SUMMARY

By using fiberoptic bronchoscopy, specific asthma phenotypes can be identified: laryngopharyngeal reflux with silent aspiration; subacute bacterial infection; tissue eosinophilia; a combination of two or three of these; and nonspecific. Identifying these phenotypes and personalizing therapy with bronchoscopy leads to improved outcomes.

Changes in exhaled breath condensate pH in healthy and asthmatic pregnant women

OBJECTIVE

Asthma is a common chronic disease complicating pregnancy with a risk for perinatal complications. Control of airway inflammation in the asthmatic pregnancy improves pregnancy outcomes. Our aim was to evaluate pH of exhaled breath condensate (EBC), a non-invasive method for the assessment of asthmatic airway inflammation, in healthy and asthmatic pregnancies.

DESIGN

Cross-sectional study.

SETTING

Hungarian university clinics.

POPULATION

Seventeen healthy pregnant women, 21 asthmatic pregnant women, 23 healthy non-pregnant women and 22 asthmatic non-pregnant women.

METHODS

EBC samples were collected using a portable condenser, EBC pH was measured after argon deaeration.

MAIN OUTCOME MEASURE

EBC pH.

RESULTS

EBC pH (mean ± SD) of healthy non-pregnant and asthmatic non-pregnant women was similar (7.75 ± 0.27 vs. 7.54 ± 0.57; p = 0.118), probably indicating an optimal control of airway inflammation in asthmatic women. On the other hand, EBC pH was higher in healthy pregnant women compared with healthy non-pregnant women (8.02 ± 0.43 vs. 7.75 ± 0.27; p = 0.017). Higher EBC pH accompanying healthy pregnancy was absent in asthmatic pregnant patients whose EBC pH was lower (7.65 ± 0.38) than that of healthy pregnant women (p = 0.006), and it was similar to that in asthmatic and healthy non-pregnant women (p = 0.470 and p = 0.300, respectively). The EBC pH in asthmatic pregnant women correlated positively with birthweight (r = 0.49, p = 0.047) and negatively with forced vital capacity (r = 0.45, p = 0.039). EBC pH was not related to blood pH.

CONCLUSIONS

EBC pH is higher in healthy pregnant women but not in asthmatic pregnant women compared with data from healthy non-pregnant women, indicating that oxidative inflammatory processes induced by asthma may compromise the regulatory mechanisms causing alkaline pH in the airways during pregnancy.

Bone marrow mononuclear cell therapy in experimental allergic asthma: intratracheal versus intravenous administration

We hypothesized that the route of administration would impact the beneficial effects of bone marrow-derived mononuclear cell (BMDMC) therapy on the remodelling process of asthma. C57BL/6 mice were randomly assigned to two main groups. In the OVA group, mice were sensitized and challenged with ovalbumin, while the control group received saline using the same protocol. Twenty-four hours before the first challenge, control and OVA animals were further randomized into three subgroups to receive saline (SAL), BMDMCs intravenously (2×10(6)), or BMDMCs intratracheally (2×10(6)). The following changes were induced by BMDMC therapy in OVA mice regardless of administration route: reduction in resistive and viscoelastic pressures, static elastance, eosinophil infiltration, collagen fibre content in airways and lung parenchyma; and reduction in the levels of interleukin (IL)-4, IL-13, transforming growth factor-β and vascular endothelial growth factor. In conclusion, BMDMC modulated inflammatory and remodelling processes regardless of administration route in this experimental model of allergic asthma.

Relation of circulating T cell profiles to airway inflammation and asthma control in asthmatic pregnancy

Asthmatic inflammation during pregnancy poses a risk for maternal and fetal morbidities. Circulating T cell immune phenotype is known to correlate with airway inflammation (detectable by fractional concentration of nitric oxide present in exhaled breath (FENO)) in non-pregnant allergic asthmatics. The aim of this study was to assess the relationship of peripheral T cell phenotype to FENO and clinical variables of asthma during pregnancy.We examined 22 pregnant women with allergic asthma in the 2nd/3rd trimester. The prevalence of Th1, Th2, regulatory T (Treg) and natural killer (NK) cell subsets was identified with flow cytometry using cell-specific markers. FENO, Asthma Control Test (ACT) total score and lung function were evaluated.Peripheral blood Th1, Th2, Treg, and NK cell prevalence were not significantly correlated to airway inflammation assessed by FENO in asthmatic pregnant women (all cells p > 0.05; study power > 75%). However, an inverse correlation was detected between Th2 cell prevalence and ACT total scores (p = 0.03) in asthmatic pregnancy.Blunted relationship between T cell profile and airway inflammation may be the result of pregnancy induced immune tolerance in asthmatic pregnancy. On the other hand, increased Th2 response impairs disease control that supports direct relationship between symptoms and cellular mechanisms of asthma during pregnancy.

Fiberoptic bronchoscopy, as a valuable diagnostic option in sputum negative pulmonary tuberculosis: A prospective study

CONTEXT

World Health Organization recommends bacteriological confirmation of pulmonary tuberculosis (PTB) by the detection of acid-fast bacilli (AFB) in respiratory specimens. However about 40-60% of patients with PTB suspected clinically or radiologically may fail to produce sputum, or when it is available, AFB may be negative on repeated smear examination. These sputum smear negative patients and those who fail to produce any sputum can be diagnosed by flexible fiberoptic bronchoscopy.

AIMS

Our study was an attempt to analyze the role of fiberoptic bronchoscopy in sputum smear negative PTB patients with respect to their association with clinical and radiological profile.

MATERIALS AND METHODS

In this prospective, open label, observational study, 40 cases of sputum smear negative PTB were subjected to bronchoscopic examination after taking informed consent and samples like bronchial aspirate, bronchoalveolar lavage and post bronchoscopy sputum were collected. The data was analysed and the results were given in percentage.

RESULTS

Out of the total 40 patients, overall diagnosis was confirmed in 24 (60%) patients. Of these 24 patients, 17 patients were confirmed for PTB whereas 7 had other diagnoses.

CONCLUSION

The study concludes that fiberoptic bronchoscopy is a useful tool in diagnosing sputum smear negative PTB patients with respect to their association with clinical and radiological profile, and also identifies individuals at a higher risk for progression of disease, at an early stage despite not meeting routine bacteriological criteria for confirmation of PTB.

Cell recovery in bronchoalveolar lavage fluid in smokers is dependent on cumulative smoking history

Background

Smoking is a risk factor for various lung diseases in which BAL may be used as a part of a clinical investigation. Interpretation of BAL fluid cellularity is however difficult due to high variability, in particular among smokers. In this study we aimed to evaluate the effect of smoking on BAL cellular components in asymptomatic smokers. The effects of smoking cessation, age and gender were also investigated in groups of smokers and exsmokers.

Methods

We performed a retrospective review of BAL findings, to our knowledge the largest single center investigation, in our department from 1999 to 2009. One hundred thirty two current smokers (48 males and 84 females) and 44 ex-smokers (16 males and 28 females) were included. A group of 295 (132 males and 163 females) never-smokers served as reference.

Result

The median [5–95 pctl] total number of cells and cell concentration in current smokers were 63.4 [28.6–132.1]×10⁶ and 382.1 [189.7–864.3]×10⁶/L respectively and correlated positively to the cumulative smoking history. Macrophages were the predominant cell type (96.7% [90.4–99.0]) followed by lymphocytes (2% [0.8–7.7]) and neutrophils (0.6% [0–2.9]). The concentration of all inflammatory cells was increased in smokers compared to never smokers and ex-smokers. BAL fluid recovery was negatively correlated with age (p<0.001). Smoking men had a lower BAL fluid recovery than smoking women.

Conclusion

Smoking has a profound effect on BAL fluid cellularity, which is dependent on smoking history. Our results performed on a large group of current smokers and ex-smokers in a well standardized way, can contribute to better interpretation of BAL fluid cellularity in clinical context.

Relationships of methacholine and adenosine 5'-monophosphate (AMP) responsiveness to the postbronchodilator FEV₁/FVC ratio in children with asthma

BACKGROUND

Airway remodeling has been assumed to cause bronchial hyperresponsiveness (BHR). A low postbronchodilator FEV₁/FVC ratio has been suggested to be a functional surrogate marker of airway remodeling in asthma. BHR is commonly assessed by bronchial challenges using direct or indirect stimuli.

OBJECTIVE

The aim of this study was to compare BHR to methacholine and adenosine 5'-monophosphate (AMP) with regard to their relationship with a marker of airway remodeling in children with asthma.

METHODS

Methacholine and AMP challenge tests were performed in 129 children with asthma, aged 12 years, and a provocative concentration causing a 20% fall in FEV₁ (PC₂₀) was calculated for each challenge. All subjects also underwent pre- and postbronchodilator spirometry. A postbronchodilator FEV₁/FVC ratio below the lower limits of normal was used as a marker of airway remodeling.

RESULTS

A low postbronchodilator FEV₁/FVC ratio was found in 17 subjects (13.2%). These subjects had a significantly lower methacholine PC₂₀ (geometric mean: 0.63 mg/mL, range of 1 SD: 0.17-2.29) than those (n = 112) with a normal postbronchodilator FEV₁/FVC ratio (2.42 mg/mL, 0.57-10.32, p = .000), whereas AMP PC₂₀ was similar between the two groups (22.1 mg/mL, 3.9-125.9 vs. 27.7 mg/mL, 4.2-183.5, p = .231). In the whole group of subjects, methacholine PC₂₀, but not AMP PC₂₀, correlated significantly with the postbronchodilator FEV₁/FVC ratio (r = 0.340, p = .000, and r = 0.056, p = .526, respectively).

CONCLUSIONS

Our results provide evidence, though indirect, that BHR to methacholine is related to airway remodeling in children with asthma and suggest that BHR to methacholine may be a better marker of airway remodeling than BHR to AMP.

Elevated levels of NO are localized to distal airways in asthma

The contribution of nitric oxide (NO) to the pathophysiology of asthma remains incompletely defined despite its established pro- and anti-inflammatory effects. Induction of the inducible nitric oxide synthase (iNOS), arginase, and superoxide pathways is correlated with increased airway hyperresponsiveness in asthmatic subjects. To determine the contributions of these pathways in proximal and distal airways, we compared bronchial wash (BW) to traditional bronchoalveolar lavage (BAL) for measurements of reactive nitrogen/oxygen species, arginase activation, and cytokine/chemokine levels in asthmatic and normal subjects. Levels of NO were preferentially elevated in the BAL, demonstrating higher level NOS activation in the distal airway compartment of asthmatic subjects. In contrast, DHE(+) cells, which have the potential to generate reactive oxygen species, were increased in both proximal and distal airway compartments of asthmatics compared to controls. Different patterns of cytokines and chemokines were observed, with a predominance of epithelial cell-associated mediators in the BW compared to macrophage/monocyte-derived mediators in the BAL of asthmatic subjects. Our study demonstrates differential production of reactive species and soluble mediators within the distal airways compared to the proximal airways in asthma. These results indicate that cellular mechanisms are activated in the distal airways of asthmatics and must be considered in the development of therapeutic strategies for this chronic inflammatory disorder.

Safety of investigative bronchoscopy in the Severe Asthma Research Program

BACKGROUND

Investigative bronchoscopy was performed in a subset of participants in the Severe Asthma Research Program to gain insights into the pathobiology of severe disease. We evaluated the safety aspects of this procedure in this cohort with specific focus on patients with severe asthma.

OBJECTIVE

To evaluate prospectively changes in lung function and the frequency of adverse events related to investigative bronchoscopy.

METHODS

Bronchoscopy was performed by using a common manual of procedures. A subset of very severe asthma was defined by severe airflow obstruction, chronic oral corticosteroid use, and recent asthma exacerbations. Subjects were monitored for changes in lung function and contacted by telephone for 3 days after the procedure.

RESULTS

A total of 436 subjects underwent bronchoscopy (97 normal, 196 not severe, 102 severe, and 41 very severe asthma). Nine subjects were evaluated in hospital settings after bronchoscopy; 7 of these were respiratory-related events. Recent emergency department visits, chronic oral corticosteroid use, and a history of pneumonia were more frequent in subjects who had asthma exacerbations after bronchoscopy. The fall in FEV₁ after bronchoscopy was similar in the severe and milder asthma groups. Prebronchodilator FEV₁ was the strongest predictor of change in FEV₁ after bronchoscopy with larger decreases observed in subjects with better lung function.

CONCLUSION

Bronchoscopy in subjects with severe asthma was well tolerated. Asthma exacerbations were rare, and reduction in pulmonary function after the procedure was similar to that in subjects with less severe asthma. With proper precautions, investigative bronchoscopy can be performed safely in severe asthma.

Endobronchial and transbronchial biopsies in children

The aim of this review is to describe the indications, techniques and side effects of bronchial biopsies in children. At present, two different types of bronchial biopsies are currently used: endobronchial biopsies (EBBs) and transbronchial biopsies (TBBs). These procedures are becoming more diffuse thanks to the extensive use of pediatric fiber optic bronchoscopes (FOBs). EBBs can be used to obtain specimens from the bronchial wall and from endobronchial masses, while TBBs permit collection of samples from peripheral lung parenchyma. The use of FOBs with a working channel of more than 2 mm in diameter allows the utilization of adequate forceps to obtain good specimens, even in children less than 2 years of age. This amplifies the research field of persistent lung diseases, such as cystic fibrosis and bronchial asthma. The main contraindication to perform bronchial biopsies is bleeding disorders. For research purposes, it is mandatory to obtain the approval of the Institutional Ethical Committee, the signed consent of the parents and the age-appropriate assent of the child.

Ethics of mandatory research biopsy for correlative end points within clinical trials in oncology

Clinical investigators in oncology are increasingly interested in using molecular analysis of cancer tissue to understand the biologic bases of response or resistance to novel interventions and to develop prognostic and predictive biomarkers that will guide clinical decision making. Some scientific questions of this nature can only be addressed, or may best be addressed, through the conduct of a clinical trial in which research biopsies are obtained from all participants. However, trial designs with mandatory research biopsies have raised ethical concerns related to the risk of harm to participants, the adequacy of voluntary informed consent, and the potential for misunderstanding among research participants when access to an experimental intervention is linked to the requirement to undergo a research biopsy. In consideration of the ethical and scientific issues at stake in this debate, the Cancer and Leukemia Group B Ethics Committee proposes guidelines for clinical trials involving mandatory research biopsies. Any cancer clinical trial that requires research biopsies of participants must be well designed to address the scientific question, obtain the biopsy in a way that minimizes risk, and ensure that research participants are fully informed of the risks, rationale, and requirements of the study, as well as of treatment alternatives. Further guidelines and discussions of this issue are specified in this position paper. We feel that if these principles are respected, an informed adult with cancer can both understand and voluntarily consent to participation in a clinical trial involving mandatory research biopsy for scientific end points.

Engineering tissue alternatives to animals: applying tissue engineering to basic research and safety testing

The focus for the rapid progress in the field of tissue engineering has been the clinical potential of the technology to repair, replace, maintain or enhance the function of a particular tissue or organ. However, tissue engineering has much wider applicability in basic research and safety testing, which is often not recognized owing to the clinical focus of tissue engineers. Using examples from a recent National Centre for the Replacement, Refinement and Reduction of Animals in Research/Biotechnology and Biological Sciences Research Council symposium, which brought together tissue engineers and scientists from other research communities, this review highlights the potential of tissue engineering to provide scientifically robust alternatives to animals to address basic research questions and improve drug and chemical development in the pharmaceutical and chemical industries.

Topographical distribution of bronchial eosinophilia: significance for biopsy diagnosis

Field-by-field (0.324 x 0.09 microM) counts of eosinophils were applied to the lamina propria of cartilaginous bronchi from 47 Los Angeles and 22 Miami residents 11 to 30 years of age who died suddenly from violence. A highly variable topographical distribution was found that appeared to be due mainly to variations in confluent eosinophil-positive fields and "hot spots" (>or=3 eosinophils per field). Since biopsy is the gold standard for the diagnosis of bronchial eosinophilia, there is a need to resolve the problem of non-uniformity. New measurements applicable to biopsy diagnosis are presented having potential usefulness for providing insight into the severity and topographical distribution of eosinophilia within bronchi that are the sites of biopsy. The additional finding of a 30.4% incidence of moderate to marked eosinophilia (>1.5 eosinophils/mm reticular basement membrane) suggests a high level of asthma or asthmatic-like disease in the young subjects of this study.

Quality of bronchial biopsies for morphology study and cell sampling: a comparison of asthmatic and healthy subjects

BACKGROUND

Bronchial biopsies are widely used for histopathological, primary cell culture and genetic studies, but very few reports have evaluated their quality.

OBJECTIVES AND METHODS

The present project evaluated the quality (using a scoring system) and the general morphology of a pool of six bronchial biopsy specimens taken from three different sampling sites (the lobar, segmental and subsegmental carinae) in 27 subjects (13 asthmatic subjects and 14 healthy controls). The present study also assessed quantitative measurements of structural changes related to asthma.

RESULTS

In total, 94.4% of the biopsy attempts had enough tissue to be processed. From these, 61.7% were scored with a good to excellent quality, while 76.5% presented smooth muscle bundles and 40.5% had an intact epithelium wall. The data also confirmed the structural changes observed in asthma, such as increased apparent thickening of the basement membrane, reduced amounts of smooth muscle for healthy controls and decreased percentage of intact epithelium for asthmatic subjects.

CONCLUSION

A pool of six bronchial biopsy specimens can provide tissue of excellent quality in both asthmatic and healthy subjects and, consequently, a valuable sample for morphological analysis of mucosal structures.

[Bronchial thermoplasty: report on the first endoscopic treatment for asthma in Latin America]

Bronchial thermoplasty is a new bronchoscopic procedure that delivers radiofrequency energy to the airway and potentially reduces the smooth muscle-mediated bronchoconstriction. We report the case of a 48-year-old man with persistent moderate asthma submitted to bronchial thermoplasty. The treatment increased the forced expiratory volume in one second, increased the number of symptom-free days, reduced the use of relief medications, and improved the Juniper Asthma Quality of Life Scale score. In this patient, bronchial thermoplasty was well tolerated and safe. This was the first bronchial thermoplasty performed in Latin America. At 12 months after the procedure, the results were encouraging in terms of its potential benefits in patients with difficult-to-control asthma.

[Diagnostic flexible bronchoscopy. Recommendations of the Endoscopy Working Group of the French Society of Pulmonary Medicine]

These guidelines on flexible bronchoscopy depict important clues to be known and taken into account while practicing flexible bronchoscopy, in adult, except in emergency situations. This is a practical clarification. Safety conditions, complications, anesthesia, infectious risks, cleaning and disinfection are detailed from a review of the literature. Intensive care practice of bronchoscopy requires more attention due to higher risks patients and is discussed extensively. Standards and performances of the various sampling techniques complete this work. Indications for bronchoscopy, therapeutic and paediatric bronchoscopy are not covered in these guidelines.

Specificity of basement membrane thickening in severe asthma

BACKGROUND

Reticular basement membrane (RBM) thickness is considered a hallmark for airway remodeling in airway diseases such as asthma. It is still unclear whether this measurement could be associated with disease severity or apply to chronic obstructive pulmonary disease (COPD). A wide range of results, at baseline or after therapeutic intervention, have been reported using different measurement methods.

OBJECTIVE

To determine whether increased RBM thickness could be associated specifically with severe asthma and in COPD in large samples.

METHODS

We blindly measured RBM thickness in endobronchial biopsies from 50 patients with severe asthma (mean age, 53 years; FEV(1) 66% predicted, inhaled steroids > or =1500 microg and 20 mg daily dose of oral corticosteroids, lifelong nonsmokers), 50 untreated patients with mild asthma (mean age, 33 years; FEV(1) 93%pred, lifelong nonsmokers), 50 patients with COPD (mean age, 57 years; FEV(1) 53%pred, all current smokers), and 18 control subjects using 2 different validated quantitative and computer-assisted methods (repeated multiple point-to-point vs area by length ratio).

RESULTS

Reticular basement membrane thickness was higher in severe asthma compared with mild asthma and COPD (P = .0053). On the basis of receiver operating characteristic curves, RBM thickness was effective in differentiating severe asthma from other groups (sensitivity and specificity, 98% and 95%, respectively, above a threshold of 5 microm vs control, 70% and 75% at 7 microm vs mild, 83% and 68% at 6 microm vs COPD).

CONCLUSION

Increased RBM thickness was specifically associated with severe asthma, whereas surprisingly, COPD and mild asthma had similar remodeling features.

CLINICAL IMPLICATIONS

Reticular basement membrane thickness can be considered a hallmark of severe asthma.

Efficacy of azithromycin administration in prevention of respiratory tract infection after bronchoscopic biopsy: a randomized, controlled trial

BACKGROUND AND OBJECTIVE

Respiratory tract infection is a serious complication associated with bronchoscopic biopsy. This study attempted to examine its incidence and determine an efficacious therapy for preventing such infections.

METHODS

Nine hundred and thirty patients who underwent bronchoscopic biopsy in Osaka City University Hospital outpatient clinic were enrolled in the study. All patients were randomly assigned to receive a 3-day course of azithromycin (500 mg/day), cefcapene pivoxil hydrochloride (300 mg/day) or no antibiotics. The primary outcome was the incidence of respiratory tract infection after bronchoscopic biopsy among the three groups.

RESULTS

In the no-treatment group, nine of the 310 patients (2.9%) had respiratory tract infection after bronchoscopic biopsy. All patients with infection had abnormal bronchoscopic findings. Of the patients with respiratory tract infection, 60% were in the no-treatment group, 26.7% in the cefcapene group and 13.3% in the azithromycin group. Although not statistically significant, the incidence in the azithromycin group (0.7%) was lower than in the no-treatment group (P = 0.06). Among the patients with abnormal bronchoscopic findings, the incidence in the azithromycin group was significantly lower than that in the no-treatment group (3.0% vs. 14.8%; P = 0.02). Moreover, maximum C-reactive protein values also appeared to be lower in the azithromycin group than in the no-treatment group and the cefcapene group.

CONCLUSIONS

A 3-day course of azithromycin administration is well tolerated and effective in preventing infection post bronchoscopy.

Effects of the bronchoalveolar lavage procedure on lung function in horses with clinical exacerbation of recurrent airway obstruction

OBJECTIVE

To evaluate whether bronchoalveolar lavage (BAL) alters respiratory mechanics of horses with recurrent airway obstruction (ie, heaves) over a 48-hour period.

ANIMALS

6 horses affected with heaves.

PROCEDURES

Horses were subjected to a complete BAL procedure, which included sedation with xylazine and butorphanol, intratracheal administration of lidocaine, and instillation and aspiration of two 250-mL boluses of saline (0.9% NaCl) solution through an endoscope (study 1). To evaluate the effects of saline solution, horses were subjected to the same procedure without saline solution instillation and aspiration (study 2). Lastly, the endoscope was similarly introduced into the lower airways, without sedation or saline instillation and aspiration (study 3). Respiratory mechanics were performed at baseline (time 0) and at 3, 6, 12, 24, and 48 hours after each procedure.

RESULTS

In study 1, BAL induced a significant decrease in pulmonary resistance lasting up to 6 hours. This may have resulted from clearance of mucus in large airways. We also observed a significant increase in lung elastance and transpulmonary pressure at 12 hours after BAL in all 3 studies, which may be attributed to a circadian effect.

CONCLUSIONS AND CLINICAL RELEVANCE

Our results indicate that the temporal effects of BAL procedures on lung mechanics should be taken into account when designing research protocols involving horses with heaves. Future studies should address the immediate effects of BAL on lung function.

Functional implications of BAL in the presence of restrictive or obstructive lung disease

Most of the complications associated to bronchoscopy are related to changes of the respiratory function during or after its performance. Prevention of complications should be achieved by understanding the effects of bronchoscopic procedures and their relation to the pulmonary function deterioration. Previous studies regarding the functional impairment caused by bronchoalveolar lavage (BAL) were mostly limited by the presence of interferent factors such as sedative drugs. Furthermore, it is not clear whether or not patients with different ventilatory disturbances present the same functional response to bronchoscopy and BAL. The aim of this study was to determine the additional effects of BAL over the respiratory function deterioration related to bronchoscopy in patients with different respiratory function profiles (normal, restrictive and obstructive). Forty patients submitted to bronchoscopy without premedication were divided into four groups: group I-normal pulmonary function submitted to basic bronchoscopy; group II-bronchoscopy in combination with BAL, subdivided according to pulmonary function: group IIa (normal function), group IIb (restrictive ventilatory disturbances) and group IIc (obstructive ventilatory disturbances). Spirometry was made before and after the bronchoscopic procedure. Baseline hemoglobin saturation was compared to the lowest level during the procedure. Functional worsening caused by the procedure was observed with a decrease in forced vital capacity (FVC), forced expiratory volume in the first second (FEV(1)) and Hemoglobin saturation in all groups. Comparison between groups showed no significant difference regarding the changes in FVC (P=0.8324), FEV(1) (P=0.6952) and hemoglobin saturation (P=0.5044). We conclude that standardized BAL, like the one used in our study, does not result in an increased risk for ventilatory impairment compared to bronchoscopy itself, independently of the presence of previous respiratory disease.

The safety of bronchoscopy in a pulmonary fellowship program

STUDY OBJECTIVE

To determine the complication rate from supervised training bronchoscopy in a single pulmonary fellowship program, and to examine the effects of fellow and faculty experience on this complication rate.

DESIGN

A retrospective review of preexisting quality improvement data from one center for the time period July 1, 1991, until June 30, 2005, was performed. The data were stratified based on the fellow year group and the staff experience level. The types of complications were recorded.

SETTING

The study was performed at an accredited pulmonary and critical care fellowship program at a military medical center in the United States.

PARTICIPANTS

Fifty-one pulmonary and critical care medicine fellows and 20 staff supervising physicians performed the bronchoscopies that were included in this study.

RESULTS

A total of 3,538 training bronchoscopies were performed during the study period with 73 complications for a complication rate of 2.06%. The most common complication was pneumothorax. The overall complication rates for first-year fellows (1stYFs), second-year fellows, and third-year fellows were not significantly different from the total complication rate. Training bronchoscopies supervised by junior staff had a complication rate not significantly different from that of senior staff. The cumulative complication rate for the first trimester for 1stYFs was 3.1%, whereas the cumulative complication rate for the second plus the third trimester for 1stYFs was 1.57% (p < 0.05).

CONCLUSIONS

Training bronchoscopy performed during a pulmonary fellowship is a safe procedure in a supervised setting. Patients undergoing bronchoscopy performed by novice bronchoscopists have an increased complication rate during the first trimester of bronchoscopist training.

[Use of induced sputum in the investigation of occupational asthma]

The diagnosis of occupational asthma relies mainly on the demonstration of changes in airway calibre and airway responsiveness after exposure to occupational agents in the laboratory or at the workplace. However, spirometry or peak expiratory flow measurements may be open to misinterpretation when they are not performed optimally. As in non-occupational asthma, airway inflammation is one of the main characteristics of occupational asthma. Induced sputum, a non invasive method to assess airway inflammation, has been successfully used in the management of asthma. This article reviews the studies that have investigated and characterized the changes in sputum cell counts occurring in subjects with occupational asthma after exposure to occupational agents in the laboratory or at the workplace in order to assess the place of induced sputum in the investigation of occupational asthma. It also reviews the use of induced sputum during the follow-up of workers with occupational asthma after removal from exposure. This article also describes a new condition identified thanks to the use of induced sputum : occupational eosinophilic bronchitis. In conclusion, induced sputum is a useful tool in the investigation of occupational asthma. Its use on a regular basis in the investigation of occupational asthma also allows for the possibility of diagnosis of overlooked conditions such as occupational eosinophilic bronchitis. Its role in the surveillance of workers at risk to develop occupational asthma remains to be determined.

Bronchial thermoplasty in asthma

In this review we discuss the potential of a new procedure, termed Bronchial Thermoplasty to prevent serious consequences resulting from excessive airway narrowing. The most important factor in minimizing an asthmatic attack is limiting the degree of smooth muscle shortening. The premise that airway smooth muscle can be either inactivated or obliterated without any long-term alteration of other lung tissues, and that airway function will remain normal, albeit with reduced bronchoconstriction, has now been demonstrated in dogs, a subset of normal subjects, and mild asthmatics. Bronchial Thermoplasty may thus develop into a useful clinical procedure to effectively impair the ability for airway smooth muscle to reach the levels of pathologic narrowing that characterizes an asthma attack. It may also enable more successful treatment of asthma patients who are unresponsive to more conventional therapies. Whether this will remain stable for the lifetime of the patient still remains to be determined, but at the present time, there are no indications that the smooth muscle contractility will return. This successful preliminary experience showing that Bronchial Thermoplasty could be safely performed in patients with asthma has led to an ongoing clinical trial at a number of sites in Europe and North America designed to examine the effectiveness of this procedure in subjects with moderately severe asthma.