New bronchoscopic microsample probe to measure the biochemical constituents in epithelial lining fluid of patients with acute respiratory distress syndrome

Potential for Lung Recruitment Maneuvers Estimated by the Cytokines in Bronchoalveolar Lavage Fluid in Acute Respiratory Distress Syndrome

Objective: Lung recruitment maneuvers (RMs) is an important treatment for acute respiratory distress syndrome (ARDS) patients; however, assessing lung recruitability is imperative to avoid biotrauma and hemodynamic instability. This study aims to investigate whether the cytokine levels in the bronchoalveolar lavage fluid (BALF) of ARDS patients can serve as an indicator of their lung recruitability. Methods: This study included ARDS patients who received mechanical ventilation for over 24 h. Patients were categorized into lung recruitment maneuver effective (RM-E) group and lung recruitment maneuver noneffective (RM-N) group. Interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-10 (IL-10) in BALF, lung ultrasound (LUS) scores, and the oxygenation index (P/F) were measured. The differences in cytokine levels between the two groups were compared, and correlations between changes in cytokine levels (ΔIL-6, ΔIL-8, and ΔIL-10), ΔLUS, and ΔP/F were analyzed. Results: Sixty-two patients were included in this study (38 in the RM-E group and 24 in the RM-N group). After the RM, compared with the RM-N group, an increase was observed in ΔIL-6 (p=0.013), ΔIL-8 (p=0.045), ΔIL-10 (p=0.039), and ΔLUS (p=0.045) in the RM-E group. A positive linear correlation was found between ΔIL-6 and ΔLUS (r = 0.504, p < 0.001). The area under the lung recruitment potential curve (AUC) predicted by ΔIL-6 was 0.794, the sensitivity was 94.7%, and the specificity was 70.8%. A positive linear correlation was found between ΔIL-6 and ΔLUS (r = 0.504, p < 0.001). The lung recruitment potential curve's AUC predicted by ΔIL-6 was 0.794, with a sensitivity of 94.7% and specificity of 70.8%. Conclusion: Lower levels of cytokines in BALF were observed in the RM-E group. It is possible that the cytokines in BALF, especially IL-6, could be used to determine the need for RM on the basis of lung recruitability.

Case study observational research: inflammatory cytokines in the bronchial epithelial lining fluid of COVID-19 patients with acute hypoxemic respiratory failure

BACKGROUND

In this study, the concentrations of inflammatory cytokines were measured in the bronchial epithelial lining fluid (ELF) and plasma in patients with acute hypoxemic respiratory failure (AHRF) secondary to severe coronavirus disease 2019 (COVID-19).

METHODS

We comprehensively analyzed the concentrations of 25 cytokines in the ELF and plasma of 27 COVID-19 AHRF patients. ELF was collected using the bronchial microsampling method through an endotracheal tube just after patients were intubated for mechanical ventilation.

RESULTS

Compared with those in healthy volunteers, the concentrations of interleukin (IL)-6 (median 27.6 pmol/L), IL-8 (1045.1 pmol/L), IL-17A (0.8 pmol/L), IL-25 (1.5 pmol/L), and IL-31 (42.3 pmol/L) were significantly greater in the ELF of COVID-19 patients than in that of volunteers. The concentrations of MCP-1 and MIP-1β were significantly greater in the plasma of COVID-19 patients than in that of volunteers. The ELF/plasma ratio of IL-8 was the highest among the 25 cytokines, with a median of 737, and the ELF/plasma ratio of IL-6 (median: 218), IL-1β (202), IL-31 (169), MCP-1 (81), MIP-1β (55), and TNF-α (47) were lower.

CONCLUSIONS

The ELF concentrations of IL-6, IL-8, IL-17A, IL-25, and IL-31 were significantly increased in COVID-19 patients. Although high levels of MIP-1 and MIP-1β were also detected in the blood samples collected simultaneously with the ELF samples, the results indicated that lung inflammation was highly compartmentalized. Our study demonstrated that a comprehensive analysis of cytokines in the ELF is a feasible approach for understanding lung inflammation and systemic interactions in patients with severe pneumonia.

The development, validation, and in vivo testing of a high-precision bronchial epithelial lining fluid sampling device

Introduction

Analysis of respiratory biomarkers or pharmaceutical drug concentrations in bronchial epithelial lining fluid (bELF) using a high-precision sampling method is crucial for effective clinical respiratory diagnostics and research. Here, we utilized a cellulose matrix as an absorptive probe for bELF sampling, subsequently testing the design of a device and sampling technique in vivo.

Methods

The absorptive matrix [Whatman® qualitative filter paper (Grade CF-12)] was first tested through tissue-contact experiments on porcine airway tissue. The absorption and elution capacity of the matrix, as well as the laboratory processing and analysis method, was validated with a range of Interleukin-8 (CXCL8) and C-Reactive protein (CRP) stock solutions. Subsequently, the device's design was optimized for universal in-house production and both, safe and efficient sampling. The airway sampling method was then tested in a group of 10 patients with Chronic Obstructive Pulmonary Disease (COPD). For each patient, a bELF sample was obtained using the newly developed bELF probe, as well as a reference 20 mL saline bronchial wash sample. Supernatants were assessed, using an immunoassay, for levels of the pro-inflammatory markers CXCL8, Myeloperoxidase (MPO), and CRP. The bELF samples were compared to bronchial wash.

Results

The Whatman® qualitative filter paper (Grade CF-12) bELF probes adhered to porcine airway tissue, softening slightly upon wetting. The material maintained architectural integrity following the removal of the probes, leaving no residual fibers on the porcine airway mucosa. The bELF probe design was optimized for bronchoscopic delivery and in-house production. On average, a fully saturated bELF probe carried 32 μL of protein-rich fluid. The mean return of CXCL8 and CRP from samples collected from a serial dilution series (1, 5, 10, 20 ng/mL) was 69% (range 48%-87%). The bELF probe detected, on average, 7 (MPO), 14 (CRP), and 59 (CXCL8) times higher equivalent inflammatory protein concentrations in the collected bELF probe samples compared to the bronchial wash.

Conclusion

The bELF probe is an effective absorptive technology for high-precision bELF sampling without dilution. With a simple in-house production procedure and bronchoscopic sampling technique, this method can be introduced in any bronchoscopic center for a consistent sampling of bELF.

Acute organ injury and long-term sequelae of severe pneumococcal infections

Streptococcus pneumoniae (Spn) is a major public health problem, as it is a main cause of otitis media, community-acquired pneumonia, bacteremia, sepsis, and meningitis. Acute episodes of pneumococcal disease have been demonstrated to cause organ damage with lingering negative consequences. Cytotoxic products released by the bacterium, biomechanical and physiological stress resulting from infection, and the corresponding inflammatory response together contribute to organ damage accrued during infection. The collective result of this damage can be acutely life-threatening, but among survivors, it also contributes to the long-lasting sequelae of pneumococcal disease. These include the development of new morbidities or exacerbation of pre-existing conditions such as COPD, heart disease, and neurological impairments. Currently, pneumonia is ranked as the 9^th leading cause of death, but this estimate only considers short-term mortality and likely underestimates the true long-term impact of disease. Herein, we review the data that indicates damage incurred during acute pneumococcal infection can result in long-term sequelae which reduces quality of life and life expectancy among pneumococcal disease survivors.

Effects of Thoracic Epidural Anesthesia on Systemic and Local Inflammatory Responses in Patients Undergoing Lung Cancer Surgery: A Randomized Controlled Trial

OBJECTIVE

Inflammatory responses play major roles in the development of acute lung injury following lung cancer surgery. The authors tested the hypothesis that thoracic epidural anesthesia (TEA) during surgery could attenuate both systemic and local inflammatory cytokine productions in patients undergoing lung cancer surgery.

DESIGN

A prospective randomized controlled trial.

SETTING

At Keio University Hospital, Tokyo, Japan.

PARTICIPANTS

Patients scheduled for lung cancer surgery.

INTERVENTIONS

Sixty patients were randomly allocated into two groups (n = 30 each group): the epidural group (group E), in which anesthesia was maintained with propofol, fentanyl, rocuronium, and epidural anesthesia with 0.25% levobupivacaine; or the remifentanil group (group R), in which a remifentanil infusion was used as a potent analgesia instead of epidural anesthesia.

MEASUREMENTS AND MAIN RESULTS

The lung epithelial lining fluid (ELF) and blood sampling were collected prior to one-lung ventilation (OLV) initiation (T1) and at 30 minutes after the end of OLV (T2). The concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 in the ELF at T2 were increased significantly compared with those at T1 in both groups. The ELF concentration of IL-6 in group E was significantly lower than that in group R at T2 (median [interquartile range]: 39.7 [13.8-80.2] versus 76.1 [44.9-138.2], p = 0.008). Plasma IL-6 concentrations at T2, which increased in comparison to that at T1, were not significantly different between the two groups. The plasma concentrations of TNF-α did not change in both groups.

CONCLUSIONS

This randomized clinical trial suggested that TEA could attenuate local inflammatory responses in the lungs during lung cancer surgery.

Biomarkers in pediatric acute respiratory distress syndrome

Pediatric acute respiratory distress syndrome (PARDS) is a heterogenous process resulting in a severe acute lung injury. A single indicator does not exist for PARDS diagnosis. Rather, current diagnosis requires a combination of clinical and physiologic variables. Similarly, there is little ability to predict the path of disease, identify those at high risk of poor outcomes or target therapies specific to the underlying pathophysiology. Biomarkers, a measured indicator of a pathologic state or response to intervention, have been studied in PARDS due to their potential in diagnosis, prognostication and measurement of therapeutic response. Additionally, PARDS biomarkers show great promise in furthering our understanding of specific subgroups or endotypes in this highly variable disease, and thereby predict which patients may benefit and which may be harmed by PARDS specific therapies. In this chapter, we review the what, when, why and how of biomarkers in PARDS and discuss future directions in this quickly changing landscape.

Searching for biomarkers of chronic obstructive pulmonary disease using proteomics: The current state

Detection of proteins which may be potential biomarkers of disorders represents a big step forward in understanding the molecular mechanisms that underlie pathological processes. In this context proteomics plays the important role of opening a path for the identification of molecular signatures that can potentially assist in early diagnosis of several clinical disturbances. Aim of this report is to provide an overview of the wide variety of proteomic strategies that have been applied to the investigation of chronic obstructive pulmonary disease (COPD), a severe disorder that causes an irreversible damage to the lungs and for which there is no cure yet. The results in this area published over the past decade show that proteomics indeed has the ability of monitoring alterations in expression profiles of proteins from fluids/tissues of patients affected by COPD and healthy controls. However, these data also suggest that proteomics, while being an attractive tool for the identification of novel pathological mediators of COPD, remains a technique mainly generated and developed in research laboratories. Great efforts dedicated to the validation of these biological signatures will result in the proof of their clinical utility.

Effect of combining a recruitment maneuver with protective ventilation on inflammatory responses in video-assisted thoracoscopic lobectomy: a randomized controlled trial

BACKGROUND

We hypothesized that the addition of a recruitment maneuver to protective ventilation (PVRM) would result in lower pulmonary and systemic inflammatory responses than traditional ventilation or protective ventilation (PV) alone in patients undergoing lung surgery.

METHODS

Sixty patients who underwent scheduled thoracoscopic lobectomy were randomly assigned to three groups: traditional ventilation, PV, or PVRM. Ventilations were performed using a tidal volume of 10 mL/kg for the traditional ventilation group and either 8 mL/kg (two-lung) or 6 mL/kg (one-lung, OLV) with a positive end-expiratory pressure of 5 cm H₂O for the PV and PVRM groups. The RM was performed 10 min after the start of OLV. Fiberoptic bronchoalveolar lavage (BAL) was performed twice in dependent and non-dependent lungs: before the start and immediately after the end of OLV. Blood samples were collected at the same time points. The levels of cytokines, including TNF-α, IL-1β, IL-6, IL-8, and IL-10, were measured.

RESULTS

After OLV, the level of TNF-α in the BAL fluid of dependent lungs was significantly higher in the PV than in the PVRM group (P = 0.049), whereas IL-1β, IL-6, IL-8, and IL-10 levels were not significantly different among the groups. In non-dependent lung BAL fluid, no cytokines were significantly different among the groups. After OLV, IL-10 serum levels were significantly higher in the traditional ventilation than in the PVRM group (P = 0.027).

CONCLUSIONS

Lower inflammatory responses in the ventilated lung and serum were observed with PVRM than with traditional ventilation or PV alone. Larger multi-center clinical trials are warranted to confirm the effects of different ventilatory strategies on postoperative outcomes.

Recent insights into human bronchial proteomics - how are we progressing and what is next?

The human respiratory system is highly prone to diseases and complications. Many lung diseases, including lung cancer (LC), tuberculosis (TB), and chronic obstructive pulmonary disease (COPD) have been among the most common causes of death worldwide. Cystic fibrosis (CF), the most common genetic disease in Caucasians, has adverse impacts on the lungs. Bronchial proteomics plays a significant role in understanding the underlying mechanisms and pathogenicity of lung diseases and provides insights for biomarker and therapeutic target discoveries. Areas covered: We overview the recent achievements and discoveries in human bronchial proteomics by outlining how some of the different proteomic techniques/strategies are developed and applied in LC, TB, COPD, and CF. Also, the future roles of bronchial proteomics in predictive proteomics and precision medicine are discussed. Expert commentary: Much progress has been made in bronchial proteomics. Owing to the advances in proteomics, we now have better ability to isolate proteins from desired cellular compartments, greater protein separation methods, more powerful protein detection technologies, and more sophisticated bioinformatic techniques. These all contributed to our further understanding of lung diseases and for biomarker and therapeutic target discoveries.

Absorption of Nasal and Bronchial Fluids: Precision Sampling of the Human Respiratory Mucosa and Laboratory Processing of Samples

The methods of nasal absorption (NA) and bronchial absorption (BA) use synthetic absorptive matrices (SAM) to absorb the mucosal lining fluid (MLF) of the human respiratory tract. NA is a non-invasive technique which absorbs fluid from the inferior turbinate, and causes minimal discomfort. NA has yielded reproducible results with the ability to frequently repeat sampling of the upper airway.

By comparison, alternative methods of sampling the respiratory mucosa, such as nasopharyngeal aspiration (NPA) and conventional swabbing, are more invasive and may result in greater data variability. Other methods have limitations, for instance, biopsies and bronchial procedures are invasive, sputum contains many dead and dying cells and requires liquefaction, exhaled breath condensate (EBC) contains water and saliva, and lavage samples are dilute and variable.

BA can be performed through the working channel of a bronchoscope in clinic. Sampling is well tolerated and can be conducted at multiple sites in the airway. BA results in MLF samples being less dilute than bronchoalveolar lavage (BAL) samples.

This article demonstrates the techniques of NA and BA, as well as the laboratory processing of the resulting samples, which can be tailored to the desired downstream biomarker being measured. These absorption techniques are useful alternatives to the conventional sampling techniques used in clinical respiratory research.

Napsin A levels in epithelial lining fluid as a diagnostic biomarker of primary lung adenocarcinoma

BACKGROUND

It is crucial to develop novel diagnostic approaches for determining if peripheral lung nodules are malignant, as such nodules are frequently detected due to the increased use of chest computed tomography scans. To this end, we evaluated levels of napsin A in epithelial lining fluid (ELF), since napsin A has been reported to be an immunohistochemical biomarker for histological diagnosis of primary lung adenocarcinoma.

METHODS

In consecutive patients with indeterminate peripheral lung nodules, ELF samples were obtained using a bronchoscopic microsampling (BMS) technique. The levels of napsin A and carcinoembryonic antigen (CEA) in ELF at the nodule site were compared with those at the contralateral site. A final diagnosis of primary lung adenocarcinoma was established by surgical resection.

RESULTS

We performed BMS in 43 consecutive patients. Among patients with primary lung adenocarcinoma, the napsin A levels in ELF at the nodule site were markedly higher than those at the contralateral site, while there were no significant differences in CEA levels. Furthermore, in 18 patients who were undiagnosed by bronchoscopy and finally diagnosed by surgery, the napsin A levels in ELF at the nodule site were identically significantly higher than those at the contralateral site. In patients with non-adenocarcinoma, there were no differences in napsin A levels in ELF. The area under the receiver operator characteristic curve for identifying primary lung adenocarcinoma was 0.840 for napsin A and 0.542 for CEA.

CONCLUSION

Evaluation of napsin A levels in ELF may be useful for distinguishing primary lung adenocarcinoma.

Polymerization of hexamethylene diisocyanate in solution and a 260.23 m/z [M+H]+ ion in exposed human cells

Hexamethylene diisocyanate (HDI) is an important industrial chemical that can cause asthma, however pathogenic mechanisms remain unclear. Upon entry into the respiratory tract, HDI's N=C=O groups may undergo nucleophilic addition (conjugate) to host molecules (e.g. proteins), or instead react with water (hydrolyze), releasing CO₂ and leaving a primary amine in place of the original N=C=O. We hypothesized that (primary amine groups present on) hydrolyzed or partially hydrolyzed HDI may compete with proteins and water as a reaction target for HDI in solution, resulting in polymers that could be identified and characterized using LC-MS and LC-MS/MS. Analysis of the reaction products formed when HDI was mixed with a pH buffered, isotonic, protein containing solution identified multiple [M+H]⁺ ions with m/z's and collision-induced dissociation (CID) fragmentation patterns consistent with those expected for dimers (259.25/285.23 m/z), and trimers (401.36/427.35 m/z) of partially hydrolyzed HDI (e.g. ureas/oligoureas). Human peripheral blood mononuclear cells (PBMCs) and monocyte-like U937, but not airway epithelial NCI-H292 cell lines cultured with these HDI ureas contained a novel 260.23 m/z [M+H]⁺ ion. LC-MS/MS analysis of the 260.23 m/z [M+H]⁺ ion suggest the formula C₁₃H₂₉N₃O₂ and a structure containing partially hydrolyzed HDI, however definitive characterization will require further orthogonal analyses.

Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels

This protocol describes noninvasive sampling of undisturbed upper airway mucosal lining fluid. It also details the extraction procedure used prior to the analysis of immune mediators in fluid eluates for the study of the airway topical immune signature, without the need for stimulation procedures (often used by other techniques). The mucosal lining fluid is sampled on a strip of filter paper placed at the anterior part of the inferior turbinate and left for 2 min of absorption. Analytes are eluted from the filter papers, and the extracted protein-based eluates are analyzed by an electrochemiluminescence-based immunoassay, allowing for the high-sensitivity quantification of low- and high-level analytes in the same sample. We measured the in vivo levels of 20 preselected immune mediators related to specific immune signaling pathways in the upper airway mucosa, but the technique is not limited to that specific panel or sampling site. The technique was first implemented in 7-year-old children from the Copenhagen Prospective Studies on Asthma in Childhood2000 (COPSAC2000) cohort with allergic rhinitis. It was thereafter used in the longitudinal COPSAC2010 birth cohort, sampled at 1 month, 2 years, and 6 years of age and at instances of acute respiratory symptoms. We successfully obtained and analyzed samples from 620 (89%) of 700 1-month-old children; a few samples were below the assay detection limit (reported as the median (Inter-Quartile Range (IQR)). The number of samples below the detection limit (i.e. from 0 to the set point for the lower limit of detection) for each mediator was 29 (7.25 - 119.5). This technique enables the quantification of the in vivo airway mucosal immune profile from birth, can be applied longitudinally, and can be applied to studies on the effect of genetics and early-life environmental exposures, pathophysiology, endotyping, and monitoring of respiratory diseases, and development and evaluation of novel therapeutics.

A Comprehensive Evaluation of Nasal and Bronchial Cytokines and Chemokines Following Experimental Rhinovirus Infection in Allergic Asthma: Increased Interferons (IFN-γ and IFN-λ) and Type 2 Inflammation (IL-5 and IL-13)

Background

Rhinovirus infection is a major cause of asthma exacerbations.

Objectives

We studied nasal and bronchial mucosal inflammatory responses during experimental rhinovirus-induced asthma exacerbations.

Methods

We used nasosorption on days 0, 2–5 and 7 and bronchosorption at baseline and day 4 to sample mucosal lining fluid to investigate airway mucosal responses to rhinovirus infection in patients with allergic asthma (n = 28) and healthy non-atopic controls (n = 11), by using a synthetic absorptive matrix and measuring levels of 34 cytokines and chemokines using a sensitive multiplex assay.

Results

Following rhinovirus infection asthmatics developed more upper and lower respiratory symptoms and lower peak expiratory flows compared to controls (all P < 0.05). Asthmatics also developed higher nasal lining fluid levels of an anti-viral pathway (including IFN-γ, IFN-λ/IL-29, CXCL11/ITAC, CXCL10/IP10 and IL-15) and a type 2 inflammatory pathway (IL-4, IL-5, IL-13, CCL17/TARC, CCL11/eotaxin, CCL26/eotaxin-3) (area under curve day 0–7, all P < 0.05). Nasal IL-5 and IL-13 were higher in asthmatics at day 0 (P < 0.01) and levels increased by days 3 and 4 (P < 0.01). A hierarchical correlation matrix of 24 nasal lining fluid cytokine and chemokine levels over 7 days demonstrated expression of distinct interferon-related and type 2 pathways in asthmatics. In asthmatics IFN-γ, CXCL10/IP10, CXCL11/ITAC, IL-15 and IL-5 increased in bronchial lining fluid following viral infection (all P < 0.05).

Conclusions

Precision sampling of mucosal lining fluid identifies robust interferon and type 2 responses in the upper and lower airways of asthmatics during an asthma exacerbation. Nasosorption and bronchosorption have potential to define asthma endotypes in stable disease and at exacerbation.

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Following rhinovirus infection asthmatics have increased interferons and type 2 inflammation in airway mucosal lining fluid.

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Nasosorption cytokines and chemokines showed distinct pathways of interferon and type 2 inflammation in asthma.

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Precision mucosal sampling has potential for stratifying molecular endotypes of asthma.

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Validation of nasosorption and bronchosorption will be required for selection of asthmatics for therapy with biologics.

Experimental human rhinovirus (HRV) infection causes more severe upper and lower respiratory tract symptoms in allergic asthmatics than in healthy controls. There is greater induction of cytokines and chemokines in nasal and bronchial mucosal lining fluid (MLF) of asthmatics: with distinct pathways of type 2 and anti-viral/regulatory inflammation.

Subject to further validation, analysis of MLF may prove useful in stratification of patients with asthma, and the definition of molecular endotypes.

Interpretation

Nasosorption and bronchosorption are precision sampling methods with potential for widespread application in respiratory and other mucosal diseases (e.g. gastrointestinal diseases).

Biomarkers identified in nasosorption and bronchosorption samples will need to be validated compared to established airway sampling methods, in a range of asthma phenotypes, and with current and novel therapies.

Bronchopulmonary pharmacokinetics of (R)-salbutamol and (S)-salbutamol enantiomers in pulmonary epithelial lining fluid and lung tissue of horses

AIMS

Salbutamol is usually administered as a racemic mixture but little is known about the enantioselectivity of salbutamol pharmacokinetics in the lung. This study was designed to investigate enantiomer concentrations in lung tissue after inhaled dosing.

METHODS

Horses (n = 12) received racemic salbutamol 1000 μg via inhalation. Enantioselective ultra performance liquid chromatography-tandem mass spectrometry was used to determine salbutamol concentrations in pulmonary epithelial lining fluid (PELF) sampled 2, 5, 10 and 15 min after administration, in central lung (endoscopic bronchial biopsy) and peripheral lung (percutaneous pulmonary biopsy) tissues (at 20 and 25 min respectively), and in plasma samples.

RESULTS

Mean ± 95% confidence interval (CI) yield of PELF was 57 ± 10 mg. Initial mean ± 95%CI (R)- and (S)-salbutamol PELF concentrations were 389 ± 189 ng g^-1 and 378 ± 177 ng g^-1 respectively, and both reduced approximately 50% by 15 min. Mean ± 95%CI central lung levels of drug were higher than peripheral lung tissue for both (R)-salbutamol (875 ± 945 vs. 49.5 ± 12 ng g^-1 ) and (S)-salbutamol (877 ± 955 vs. 50.9 ± 12 ng g^-1 ) respectively. There was no evidence of enantioselectivity in PELF or central lung but minor (~2%) enantioselectivity was observed in the peripheral lung. Enantioselectivity was clearly evident in plasma with (S):(R) ratio of 1.25 and 1.14 for both area under the concentration-time curve (0-25 min) and C_max respectively.

CONCLUSIONS

PELF sampling in horses offers sufficient yield allowing direct detection of drug and, combined with tissue sampling, is a valuable model to investigate bronchopulmonary pharmacokinetics. Salbutamol did not demonstrate enantioselectivity in PELF or central lung tissue uptake following acute dosing, however, enantioselective plasma concentrations were demonstrated, with minor enantioselectivity in the peripheral lung.

A comparative study of bronchoscopic microsample probe versus bronchoalveolar lavage in patients with burns-related inhalational injury, acute lung injury and chronic stable lung disease

BACKGROUND AND OBJECTIVES

The bronchoscopic microsample (BMS) probe allows direct epithelial lining fluid (ELF) level measurement without saline lavage. We investigated whether cytokine levels in ELF from a BMS differed from those obtained by bronchoalveolar lavage (BAL) in stable and acute lung disease.

METHODS

In a single-centre, prospective observational cohort study of 45 patients, a sequential BMS probe procedure and BAL were performed on patients with stable chronic obstructive lung disease, interstitial lung disease, acute lung injury (ALI), burns-related inhalational injury or controls. ELF samples were assayed for IL-1β, IL-6, IL-8, TNF-α and G-CSF.

RESULTS

Both bronchoscopic microsampling and BAL showed significantly higher cytokine levels in the ELF from patients with ALI and burns-related inhalational injury than from those with chronic stable lung disease. The BMS method detected cytokine levels approximately 20- to 80-fold higher than the corresponding BAL (uncorrected for dilution). The ratio of BMS and BAL cytokine levels was as follows: the ratio for IL-1β [mean 55, 95% confidence interval (CI) 34-88] was higher than that for IL-6 (mean 16, 95% CI 10-23, p = 0.015) and IL-8 (mean 13, 95% CI -5 to 36, p = 0.03). The ratio for G-CSF (mean 43, 95% CI 24-75) was higher than that for IL-6 (mean 16, 95% CI 10-23, p = 0.008).

CONCLUSIONS

The BMS probe safely collects ELF with higher equivalent inflammatory cytokine concentrations than via BAL from patients with both acute and chronic lung disease and can be an alternative to saline BAL. Variations in cytokine concentrations between BMS and BAL and sampling-site differences warrant further study.

Pharmacokinetics of arbekacin in bronchial epithelial lining fluid of healthy volunteers

INTRODUCTION

Arbekacin is a unique aminoglycoside antibiotic with anti-methicillin-resistant Staphylococcus aureus activity. The efficacy of aminoglycosides is related to their serum maximum concentration. Local concentration of antibiotics in pulmonary epithelial lining fluid, rather than its serum concentration, can help determine its clinical efficacy more precisely for treatment of respiratory infectious disease. The objective of this study was to sequentially measure arbekacin concentration in epithelial lining fluid after infusion of a single clinically available dose.

METHOD

After the initial blood sampling, arbekacin was intravenously infused into 6 healthy volunteers over 1 h. Epithelial lining fluid and serum samples were collected by bronchoscopic microsampling 1, 1.5, 2, 2.5, 3, 4, 5, and 6 h after the start of 200 mg arbekacin infusion.

RESULTS

Each probe sampled 10.1 ± 5.2 μl bronchial epithelial lining fluid. The sample dilution factor was 266.7 ± 157.1. Drug concentration was successfully measured in all but 2 of the epithelial lining fluid samples. The maximum concentration of arbekacin in epithelial lining fluid and serum was 10.4 ± 1.9 μg/ml and 26.0 ± 12.2 μg/ml, respectively. The ratio of the maximum drug concentration in the epithelial lining fluid to that in the serum was 0.47 ± 0.19.

CONCLUSIONS

The maximum concentration of epithelial lining fluid reached levels that would effectively treat most clinical strains of methicillin-resistant S. aureus.

Acute and chronic inflammatory responses induced by smoking in individuals susceptible and non-susceptible to development of COPD: from specific disease phenotyping towards novel therapy. Protocol of a cross-sectional study

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease with pulmonary and extra-pulmonary manifestations. Although COPD is a complex disease, diagnosis and staging are still based on simple spirometry measurements. Different COPD phenotypes exist based on clinical, physiological, immunological and radiological observations. Cigarette smoking is the most important risk factor for COPD, but only 15-20% of smokers develop the disease, suggesting a genetic predisposition. Unfortunately, little is known about the pathogenesis of COPD, and even less on the very first steps that are associated with an aberrant response to smoke exposure. This study aims to investigate the underlying local and systemic inflammation of different clinical COPD phenotypes, and acute effects of cigarette smoke exposure in individuals susceptible and non-susceptible for the development of COPD. Furthermore, we will investigate mechanisms associated with corticosteroid insensitivity. Our study will provide valuable information regarding the pathogenetic mechanisms underlying the natural course of COPD.

METHODS AND ANALYSIS

This cross-sectional study will include young and old individuals susceptible or non-susceptible to develop COPD. At a young age (18-40 years) 60 'party smokers' will be included who are called susceptible or non-susceptible based on COPD prevalence in smoking family members. In addition, 30 healthy smokers (age 40-75 years) and 110 COPD patients will be included. Measurements will include questionnaires, pulmonary function, low-dose CT scanning of the lung, body composition, 6 min walking distance and biomarkers in peripheral blood, sputum, urine, exhaled breath condensate, epithelial lining fluid, bronchial brushes and biopsies. Non-biased approaches such as proteomics will be performed in blood and epithelial lining fluid.

ETHICS AND DISSEMINATION

This multicentre study was approved by the medical ethical committees of UMC Groningen and Utrecht, the Netherlands. The study findings will be presented at conferences and will be reported in peer-reviewed journals.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00807469 (study 1) and NCT00850863 (study 2).

Early detection of lung cancer by molecular markers in endobronchial epithelial-lining fluid

INTRODUCTION

Early detection of malignancies in the lung by less-invasive methods aims at achieving efficient intervention and subsequently a reduction of the high mortality rate. We investigated whether biomarker analysis in endobronchial epithelial-lining fluid (ELF) collected by bronchoscopic microsampling (BMS) may be useful for a definitive preoperative diagnosis.

METHODS

ELF was collected from subsegmental bronchi close to the indeterminate pulmonary nodule, which was detected by computed tomography, and from the contralateral lung. Diagnosis was confirmed by transbronchial biopsy or surgery. The study includes 142 ELF samples from 51 non-small-cell lung cancer patients and 20 benign cases. Microarray analysis was done with a patient subset (n = 15) to narrow down genes associated with a malignant phenotype. Thirteen potential biomarkers have been further analyzed by quantitative real-time polymerases chain reaction in an independent patient cohort (n = 56).

RESULTS

All patients underwent BMS without complications. Gene-expression analyses by microarrays and quantitative real-time polymerases chain reaction could be reliably applied to ELF samples, and resulted in potential biomarkers for malignant pulmonary nodules. Four genes (tenascin-C, [C-X-C motif] ligand 14, S100 calcium binding protein A9, and keratin 17) were found to be upregulated in ELF of non-small-cell lung cancer patients with adenocarcinoma or squamous cell carcinoma. Combined analysis of tenascin-C expression and the nodule size improved the prediction of malignancy in this patient cohort.

CONCLUSIONS

Our study suggests that the analysis of specific biomarkers in ELF collected by BMS could be a potentially useful adjunct to other diagnostic techniques aiming at the preoperative diagnosis of malignant pulmonary nodules.

Validity of HMGB1 measurement in epithelial lining fluid in patients with COPD

BACKGROUND

It has been known that high-mobility group box 1 (HMGB1) plays an important role in the pathogenesis of various inflammatory disorders in the lung. We attempted to determine the validity of measurement of HMGB1 levels in epithelial lining fluid (ELF) from patients with chronic obstructive pulmonary disease (COPD).

MATERIALS AND METHODS

We measured HMGB1 levels in ELF separately obtained from central or peripheral airways using a bronchoscopic microsampling technique in 14 non-smokers, 13 smokers without COPD and 30 smokers with COPD. We also evaluated whether those levels were correlated with the indexes of pulmonary function and grade of low-attenuation area (LAA) on high-resolution computed tomographic scans.

RESULTS

HMGB1 levels in ELF from central airways did not significantly differ among the three groups. However, HMGB1 levels in peripheral airways were significantly higher in COPD patients than in non-smokers and smokers without COPD. Both the concentrations of interleukin-8 and human polymorphonuclear elastase in peripheral airways were also significantly higher in COPD patients. Moreover, those levels were significantly correlated with HMGB1 level. In addition, HMGB1 level in peripheral airways was closely correlated with the degree of airflow obstruction and grade of LAA in COPD patients.

CONCLUSIONS

HMGB1 levels in peripheral airways were elevated in smokers without COPD, as compared with non-smokers, and those levels were further augmented in COPD patients. Those levels were associated with the severity of COPD. Therefore, HMGB1 in peripheral airways may be a potentially interesting target for new pharmacological treatments in COPD patients.

Capsule type of Streptococcus pneumoniae determines growth phenotype

The polysaccharide capsule of Streptococcus pneumoniae defines over ninety serotypes, which differ in their carriage prevalence and invasiveness for poorly understood reasons. Recently, an inverse correlation between carriage prevalence and oligosaccharide structure of a given capsule has been described. Our previous work suggested a link between serotype and growth in vitro. Here we investigate whether capsule production interferes with growth in vitro and whether this predicts carriage prevalence in vivo. Eighty-one capsule switch mutants were constructed representing nine different serotypes, five of low (4, 7F, 14, 15, 18C) and four of high carriage prevalence (6B, 9V, 19F, 23F). Growth (length of lag phase, maximum optical density) of wildtype strains, nontypeable mutants and capsule switch mutants was studied in nutrient-restricted Lacks medium (MLM) and in rich undefined brain heart infusion broth supplemented with 5% foetal calf serum (BHI+FCS). In MLM growth phenotype depended on, and was transferred with, capsule operon type. Colonization efficiency of mouse nasopharynx also depended on, and was transferred with, capsule operon type. Capsule production interfered with growth, which correlated inversely with serotype-specific carriage prevalence. Serotypes with better growth and higher carriage prevalence produced thicker capsules (by electron microscopy, FITC-dextran exclusion assays and HPLC) than serotypes with delayed growth and low carriage prevalence. However, expression of cpsA, the first capsule gene, (by quantitative RT-PCR) correlated inversely with capsule thickness. Energy spent for capsule production (incorporation of H3-glucose) relative to amount of capsule produced was higher for serotypes with low carriage prevalence. Experiments in BHI+FCS showed overall better bacterial growth and more capsule production than growth in MLM and differences between serotypes were no longer apparent. Production of polysaccharide capsule in S. pneumoniae interferes with growth in nutrient-limiting conditions probably by competition for energy against the central metabolism. Serotype-specific nasopharyngeal carriage prevalence in vivo is predicted by the growth phenotype.

Streptococcus pneumoniae bacteria are responsible for serious human infections including meningitis, pneumonia and bacteraemia and are a common cause of otitis media (ear infection) in children. However, they most often reside harmlessly in the infant nasopharynx. An association has long been observed between the type of polysaccharide capsule surrounding the bacteria and harmless colonization versus invasive disease. Here we suggest that capsule types that are costly for the bacteria to make are produced in lower quantities and their production limits the growth of the bacteria in nutrient-restricted conditions. In contrast, bacteria with capsules that require less energy can produce more capsule and grow more successfully. This may be an explanation for why S. pneumoniae with certain capsule types can be effective long-term colonizers of the nasopharynx while others need a richer nutritional environment to flourish and so are most often associated with invasive disease. This information may be of use when considering which capsules types to target in future vaccines.

Bronchoscopic microsampling is a useful complementary diagnostic tool for detecting lung cancer

PURPOSE

Bronchoscopic microsampling (BMS) is a novel and direct method with which to obtain epithelial lining fluid (ELF) from the lungs. Analysis of DNA hypermethylation of tumor suppressor genes (TSGs) is expected to be a sensitive tool for the early detection of lung cancer. It has been reported that the existence of EGFR mutations and EML4-ALK gene rearrangements are related to the sensitivity of corresponding kinase inhibitors. We aimed to evaluate the suitability of ELF as a sample for analyzing molecular changes specific for lung cancer.

PATIENTS AND METHODS

We collected ELF from 61 lung cancer patients by BMS from the airway close to the peripheral lung nodule and purified the nucleic acids. We performed methylation specific PCR in each ELF as well as matched serum and tumor tissue for TSGs for DNA methylation analysis. We also examined EGFR mutations and EML4-ALK rearrangement.

RESULTS

The sensitivity for detecting DNA hypermethylation in ELF vs serum was 74.1% vs 18.5%. We found 60.1% of patients had at least one hypermethylation in ELF, while only 27.9% had it in serum. Of note, DNA hypermethylation was detected even in stage I patients (60.0%) and the detection rate was almost the same level in each stage. We also found the sensitivity for detecting EGFR mutation in ELF vs serum was 58.3% vs 8.3%. We detected an EML4-ALK fusion gene using ELF in one patient.

CONCLUSIONS

BMS is an alternative method to detect cancer specific genetic and epigenetic alterations and will be a useful complementary diagnostic tool for lung cancer.

SUMMARY

Investigation of genetic and epigenetic changes associated with lung cancer has clinical importance for its diagnosis and management. The clinical usefulness of bronchoscopic microsampling (BMS) in lung cancer has not yet been evaluated. This study demonstrates that BMS could be useful for detecting lung cancer specific molecular changes and valuable for early diagnosis and determination of treatment options for lung cancer.

KL-6 concentration in pulmonary epithelial lining fluid is a useful prognostic indicator in patients with acute respiratory distress syndrome

BACKGROUND

KL-6 is a mucin-like glycoprotein expressed on the surface of alveolar type II cells. Elevated concentrations of KL-6 in serum and epithelial lining fluid (ELF) in patients with acute respiratory distress syndrome (ARDS) have been previously reported; however, kinetics and prognostic significance of KL-6 have not been extensively studied. This study was conducted to clarify these points in ARDS patients.

METHODS

Thirty-two patients with ARDS who received mechanical ventilation under intubation were studied for 28 days. ELF and blood were obtained from each patient at multiple time points after the diagnosis of ARDS. ELF was collected using a bronchoscopic microsampling procedure, and ELF and serum KL-6 concentrations were measured.

RESULTS

KL-6 levels in ELF on days 0 to 3 after ARDS diagnosis were significantly higher in nonsurvivors than in survivors, and thereafter, there was no difference in concentrations between the two groups. Serum KL-6 levels did not show statistically significant differences between nonsurvivors and survivors at any time point. When the highest KL-6 levels in ELF and serum sample from each patient were examined, KL-6 levels in both ELF and serum were significantly higher in nonsurvivors than in survivors. The optimal cut-off values were set at 3453 U/mL for ELF and 530 U/mL for serum by receiver operating characteristic (ROC) curve analyses. Patients with KL-6 concentrations in ELF higher than 3453 U/mL or serum concentrations higher than 530 U/mL had significantly lower survival rates up to 90 days after ARDS diagnosis.

CONCLUSIONS

ELF and serum KL-6 concentrations were found to be good indicators of clinical outcome in ARDS patients. Particularly, KL-6 levels in ELF measured during the early period after the diagnosis were useful for predicting prognosis in ARDS patients.

Challenges in inhaled product development and opportunities for open innovation

Dosimetry, safety and the efficacy of drugs in the lungs are critical factors in the development of inhaled medicines. This article considers the challenges in each of these areas with reference to current industry practices for developing inhaled products, and suggests collaborative scientific approaches to address these challenges. The portfolio of molecules requiring delivery by inhalation has expanded rapidly to include novel drugs for lung disease, combination therapies, biopharmaceuticals and candidates for systemic delivery via the lung. For these drugs to be developed as inhaled medicines, a better understanding of their fate in the lungs and how this might be modified is required. Harmonized approaches based on 'best practice' are advocated for dosimetry and safety studies; this would provide coherent data to help product developers and regulatory agencies differentiate new inhaled drug products. To date, there are limited reports describing full temporal relationships between pharmacokinetic (PK) and pharmacodynamic (PD) measurements. A better understanding of pulmonary PK and PK/PD relationships would help mitigate the risk of not engaging successfully or persistently with the drug target as well as identifying the potential for drug accumulation in the lung or excessive systemic exposure. Recommendations are made for (i) better industry-academia-regulatory co-operation, (ii) sharing of pre-competitive data, and (iii) open innovation through collaborative research in key topics such as lung deposition, drug solubility and dissolution in lung fluid, adaptive responses in safety studies, biomarker development and validation, the role of transporters in pulmonary drug disposition, target localisation within the lung and the determinants of local efficacy following inhaled drug administration.

Bronchoscopic microsampling for bacterial colony counting in relevant lesions in patients with pulmonary Mycobacterium avium complex infection

OBJECTIVE

The incidence of pulmonary Mycobacterium avium complex (MAC) infections with nodular/bronchiectasis lesions is increasing. However, factors determining deterioration are unknown. In the present study, we investigated quantitative MAC cultures obtained through bronchoscopic microsampling (BMS) from patients with pulmonary MAC infection and analyzed the relationship between MAC culture and the short-term natural history. We also assessed chest computed tomography (CT) findings for the deteriorating factors.

DESIGN

For this prospective study, MAC was collected from peripheral lung lesions by BMS through endobronchial ultrasonography. MAC colonies were counted on Middlebrook 7H11 agar. We compared the number of MAC colonies with laboratory data and chest CT findings.

PATIENTS

We studied 26 patients with pulmonary MAC infection.

RESULTS

The patients were divided into 2 groups: 11 patients in the non-deteriorated group and 15 patients in the deteriorated group. The number of MAC colonies was significantly correlated with deterioration of MAC infection (p < 0.001). In the non-deteriorated group, chest CT scans showed nodular/bronchiectasis lesions in 8 patients (73%) and consolidated lesions in 3 patients (27%). In the deteriorated group, chest CT scans showed nodular/bronchiectasis lesions in 1 patient (7%), consolidated lesions in 6 patients (40%), and cavitary lesions in 8 patients (53%).

CONCLUSION

The number of MAC colonies in relevant lesions investigated by BMS was significantly larger in the deteriorated group than in the non-deteriorated group. Cavitary and consolidated lesions observed from chest CT scans are thought to indicate a high risk of progression of pulmonary MAC infection.

Proteomics of epithelial lining fluid obtained by bronchoscopic microprobe sampling

Epithelial lining fluid (ELF) forms a thin fluid layer that covers the mucosa of the alveoli, the small airways, and the large airways. Since it constitutes the first barrier between the lung and the outer world, it is an interesting target for proteomics studies that focus on lung disease. Bronchoscopic microprobe (BMP) sampling of ELF uses small probes with an absorptive tip that are introduced bronchoscopically. In contrast to other methods used so far for the collection of biofluids from the lung (e.g., bronchoalveolar lavage fluid, induced sputum), this technique has the advantage that ELF is not diluted and contains high concentrations of biomolecules. In addition, the investigated location in the tracheobronchial tree is well defined, and there is no contamination with oropharyngeal bacteria or saliva. Despite occasional blood contamination of the probes by scratching the mucosa of the airways, the proteomic analysis of microprobe-sampled ELF opens new possibilities for research in lung diseases. Our work focuses particularly on the induction and progression of cigarette smoke-induced Chronic Obstructive Pulmonary Disease (COPD). In this chapter, we describe the practical aspects of sampling ELF followed by a detailed description of proteomics analysis by LC-MS/MS after protein separation by SDS-PAGE and in-gel digestion. As an example, we apply this proteomic platform to the identification and quantification of proteins in ELF from COPD patients and healthy subjects.

Increased levels of Nε-(carboxymethyl)lysine in epithelial lining fluid from peripheral airways in patients with chronic obstructive pulmonary disease: a pilot study

It has been reported that small airway inflammation is closely associated with the severity of airflow limitation in COPD (chronic obstructive pulmonary disease). We tested a new method of measurement of biochemical constituents in ELF (epithelial lining fluid) obtained separately from the central or peripheral airways using a bronchoscopic microsampling technique. The present study was designed to determine the validity of measuring CML [Nε-(carboxymethyl)lysine] levels in ELF for the assessment of small airway inflammation in COPD. Ten non-smokers, ten current smokers and 16 COPD patients were included in the present study. Concentrations of CML, 8-isoprostane and IL-8 (interleukin-8) were measured in ELF separately from the central or peripheral airways. CML levels in central airways did not differ significantly, but were markedly higher in peripheral than in central airways in the three groups. However, CML levels in peripheral airways of COPD patients were significantly higher than those in non-smokers and current smokers. In COPD patients, the CML level in peripheral airways was significantly correlated with FEV1 (forced expiratory volume in 1 s) (r=−0.82, P=0.002) and FEV1/FVC (forced vital capacity) (r=−0.57, P=0.03). Moreover, CML levels in peripheral airways were significantly correlated with levels of both 8-isoprostane (r=0.76, P=0.003) and IL-8 (r=0.67, P=0.01). In conclusion, these findings suggest that elevated levels of CML in ELF from peripheral airways were observed in COPD patients, and this parameter was correlated with the severity of airflow limitation.

Effect of a neutrophil elastase inhibitor on acute lung injury after cardiopulmonary bypass

Cardiopulmonary bypass (CPB) has been implicated as a cause of acute lung injury (ALI) in cardiac surgical patients. We used a bronchoscopic microsampling (BMS) probe to examine alveolar biochemical constituents and evaluated the effect of sivelestat sodium hydrate, a novel synthesized polymorphonuclear (PMN) neutrophil elastase inhibitor, on ALI induced by CPB. Twelve patients undergoing aortic valve replacement were treated with either sivelestat 0.2 mg/kg/h (sivelestat group, n=6) or 0.9% saline (control group, n=6) from the start of surgery. Samples were collected by the BMS probe at three time points: after tracheal intubation, 1 h after CPB introduction, and 3 h after CPB termination. Pulmonary function was assessed perioperatively. There were no differences in baseline characteristics. The concentration of PMN elastase was significantly suppressed in the sivelestat group, compared with the control group (P=0.001). The sivelestat group also had lower levels of interleukin-6 and interleukin-8. Alveolar-arterial oxygen difference markedly increased, and a worsening of the PaO(2)/FiO(2) ratio indicated severe impairment after CPB. However, sivelestat attenuated the pattern of physiological deterioration of gas exchange. Sivelestat may attenuate neutrophil elastase or proinflammatory cytokines, and improve pulmonary dysfunction in patients undergoing CPB.

Antigenic changes in human albumin caused by reactivity with the occupational allergen diphenylmethane diisocyanate

Diphenylmethane diisocyanate (MDI), the chemical commonly used as a cross-linking agent in commercial polyurethane production, is a well-recognized cause of asthma. Reaction products between MDI and "self" proteins are hypothesized to act as antigens capable of inducing airway inflammation and asthma; however, such MDI antigens remain incompletely understood. We used a variety of analytical methods to characterize the range of MDI-albumin reaction products that form under physiological conditions. Sites of MDI conjugation on antigenic MDI-albumin products, as defined by serum immunoglobulin G (IgG) from MDI-exposed workers, were determined by high-performance liquid chromatography (HPLC) followed by tandem mass spectrometry (MS/MS). The data identified 14 MDI conjugation sites (12 lysines and 2 asparagines) on human albumin and highlight reaction specificity for the second lysine in dilysine (KK) motifs, and this may be a common characteristic of "immune-sensitizing" chemicals. Several of the MDI conjugation sites are not conserved in albumin from other species, and this may suggest species differences in epitope specificity for self protein (albumin)-isocyanate conjugates. The study also describes new applications of contemporary proteomic methodology for characterizing and standardizing MDI-albumin conjugates destined for use in clinical research.

Laminin gamma2 fragments are increased in the circulation of patients with early phase acute lung injury

Objective

Laminin-5, a cell adhesive molecule expressed solely by epithelium, is known to enhance epithelial cell migration and repair of injured epithelium, after its essential component γ2-chain is processed proteolytically. Our previous study revealed circulating levels of amino-terminal fragment of laminin γ2-chain (G2F) reflect epithelial tumor invasiveness in carcinoma patients, but its physiological role in alveolar epithelial injury remains unknown.

Design

Sampling of epithelial lining fluids or pulmonary edema fluids from patients with acute lung injury (ALI) or related diseases was performed. Plasma samples were obtained from them at the time of disease onset or later. G2F concentrations were determined by immunoassay constructed by ourselves.

Results

We found a significantly higher amount of G2F in pulmonary edema and epithelial lining fluids of patients with ALI, as compared with those with the other respiratory diseases. Their plasma levels were also elevated significantly early at the onset of ALI (mean ± SD; 147 ± 82 ng/ml in non-surviving and 90 ± 56 in surviving patients) as compared with those in the patients with cardiogenic pulmonary edema (59 ± 36) or idiopathic pulmonary fibrosis (37 ± 17), indicating alveolar epithelium rapidly secrete laminin-5 in ALI. At 5 days after onset, non-surviving patients maintained higher plasma concentrations (152 ± 84), but in contrast, the levels in surviving patients declined (71 ± 35), suggesting secretion of laminin-5 was suppressed, associated with recovery from ALI.

Conclusion

Circulating G2F may be a biomarker for alveolar laminin-5 secreted early at disease onset in ALI, potentially regulating alveolar re-epithelialization.

Gene expression analysis of endobronchial epithelial lining fluid in the evaluation of indeterminate pulmonary nodules

OBJECTIVE

Making a definitive preoperative diagnosis in patients with indeterminate pulmonary nodules is still a challenge. Gene expression profiling may be a useful adjunctive diagnostic utility in this regard. We investigated the feasibility of bronchoscopic microsampling to collect endobronchial epithelial lining fluid to obtain RNA as a starting point for gene expression profiling.

METHODS

In 15 patients, epithelial lining fluid was collected in triplicate from subsegmental bronchi close to the pulmonary nodules and from contralateral lungs. Diagnosis was confirmed by transbronchial biopsy or surgery (non-small cell lung cancer, n = 11; benign or other lesions, n = 4). Total RNA was isolated from the samples and evaluated concerning quantity and quality. The complementary DNA was generated and analyzed by quantitative real-time polymerase chain reaction for potential lung cancer associated genes like matrix metalloprotinase (MMP9).

RESULTS

Total RNA of adequate amount (>0.8 microg) and sufficient quality was obtained in 13 (86%) of the 15 patients. In patients with lung cancer, normalized MMP9 gene expression levels in endobronchial lining fluid samples collected close to the lesions were in median 12 times higher than levels in the matching contralateral samples. MMP9 expression levels were particularly high in endobronchial lining fluid samples collected from patients with squamous cell carcinoma but not elevated in the case of benign lesions.

CONCLUSIONS

Our results show that quantitative gene expression analysis of endobronchial lining fluid collected by bronchoscopic microsampling is both feasible and reliable and may therefore be a useful additional diagnostic method in patients with indeterminate pulmonary nodules.

Comparison of the pharmacodynamics of biapenem in bronchial epithelial lining fluid in healthy volunteers given half-hour and three-hour intravenous infusions

The time above the MIC (T>MIC) is the pharmacokinetic/pharmacodynamic (PK/PD) parameter that correlates with the therapeutic efficacy of beta-lactam antibiotics. A prolonged infusion can provide plasma drug concentrations that remain above the MIC for a long period. The objective of this study was to compare the PK/PD parameters in bronchial epithelial lining fluid (ELF) of biapenem given as 0.5-h and 3-h infusions by using bronchoscopic microsampling (BMS). Six healthy adult volunteers received 0.5-h and 3-h infusions of 0.3 g of biapenem with a washout interval. BMS was performed repeatedly from 0.5 to 24 h after biapenem administration in order to determine the pharmacokinetics in bronchial ELF. The subjects received intravenous biapenem with the same regimens again and then underwent bronchoalveolar lavage (BAL) at the end of infusion in order to determine the concentration of the drug in alveolar ELF. The percentages (means +/- standard deviations) of T>MIC in bronchial ELF at MICs from 0.25 to 4 microg/ml ranged from zero to 34.6% +/- 5.2% after the 0.5-h infusion and from 5.1% +/- 5.6% to 52.2% +/- 17.0% after the 3-h infusion. The percentage of T>MIC in bronchial ELF after the 3-h infusion tended to be higher than that after the 0.5-h infusion. The concentrations of the drug in alveolar ELF after 0.5-h and 3-h infusions were 3.5 +/- 1.2 microg/ml and 1.3 +/- 0.3 microg/ml, respectively. The present results support the use of prolonged infusions of beta-lactam antibiotics and may provide critical information for successful treatment of lower respiratory tract infections based on PK/PD parameters in bronchial ELF.