Epithelial Lining Fluid Of Patients Research Articles

Effects of helium-oxygen mechanical ventilation on inflammatory response of diseased lung segments and diaphragm function in patients with pneumonia

To investigate the clinical effect of helium-oxygen mechanical ventilation on inflammation of the diseased lung segment and diaphragm function in patients with acute respiratory distress syndrome (ARDS) caused by pneumonia who suffered difficulty weaning from mechanical ventilation. A prospective controlled study was conducted. A total of 40 patients with ARDS caused by pneumonia and requiring tracheal intubation with difficulty weaning from mechanical ventilation, admitted to the department of critical care medicine in Pingtan Branch of Fujian Medical University Union Hospital from October 2020 to December 2021 were enrolled. Patients were divided into nitrogen oxygen ventilation group and helium-oxygen ventilation group according to random number table, with 20 cases in each group. The nitrogen oxygen ventilation group was given 60% nitrogen and 40% oxygen ventilation treatment, and the helium-oxygen ventilation group was given 60% helium and 40% oxygen ventilation treatment. Peak airway pressure (Ppeak), plateau airway pressure (Pplat), tidal volume (VT), minute ventilation volume (MV) and pulse oxygen saturation (SpO2) were collected at 0, 1, 2, 3 hours after ventilation treatment. At the same time, the concentrations of inflammatory factors interleukin-6 (IL-6) and C-reactive protein (CRP) in epithelial lining fluid in patients with diseased lung segments were measured before and after ventilation treatment for 3 hours, and the diaphragmatic excursion and the diaphragmatic thickening fraction were measured before and after ventilation treatment for 3 hours. There were no significant differences in gender, age, oxygenation index, serum CRP, serum procalcitonin (PCT), body temperature, serum creatinine (SCr), alanine aminotransferase (ALT), fasting blood glucose (FPG), hemoglobin (Hb), and basic heart and lung diseases between the two groups. Under the condition that VT and SpO2 are relatively unchanged, the airway pressure in helium-oxygen ventilation group decreased significantly after 1 hour of ventilation [Ppeak (cmH2O, 1 cmH2O≈0.098 kPa): 22.80±4.47 vs. 28.00±5.07, Pplat (cmH2O): 19.15±3.90 vs. 23.20±3.81, both P < 0.05], and the airway pressure in the nitrogen oxygen ventilation group increased significantly after 1 hour [Ppeak (cmH2O): 22.35±2.13 vs. 19.75±1.94, Pplat (cmH2O): 18.50±1.70 vs. 16.50±1.88, both P < 0.05]. There were no significant differences in CRP and IL-6 levels in epithelial lining fluid in the diseased lung segment before and after ventilation in the nitrogen oxygen ventilation group, while the levels of these indexes in the helium-oxygen ventilation group after ventilation were significantly lower than those before ventilation, and significantly lower than those in the nitrogen oxygen ventilation group [CRP (mg/L): 10.15 (6.39, 15.84) vs. 16.10 (11.63, 18.66), IL-6 (μg/L): 1.15 (0.78, 1.86) vs. 2.67 (1.67, 4.85), both P < 0.05]. There were no statistically significant differences in the diaphragmatic excursion and the diaphragmatic thickening fraction before and after ventilation in the nitrogen oxygen ventilation group, while the above indexes in the helium-oxygen ventilation group were significantly higher than those before ventilation, and were significantly higher than those in the nitrogen oxygen ventilation group [diaphragmatic excursion (cm): 1.93 (1.69, 2.20) vs. 1.34 (1.22, 1.83), diaphragmatic thickening fraction: (48.22±8.61)% vs. (33.29±11.04)%, both P < 0.05]. Helium-oxygen ventilation can reduce the airway pressure of patients with mechanical ventilation, alleviate the inflammatory response of lung segment, improve the function of respiratory muscle, and is expected to be an important treatment for severe lung rehabilitation.

Pharmacokinetic/Pharmacodynamic Parameters of Linezolid in the Epithelial Lining Fluid of Patients With Sepsis.

The aim of this study was to investigate the pharmacokinetic/pharmacodynamic parameters of linezolid in both the plasma and epithelial lining fluid (ELF) of patients with pneumonia-induced sepsis. Blood specimens and bronchoalveolar lavage samples were collected at defined time points after administration of linezolid. The concentration in the ELF was calculated by urea dilution method. PK parameters were calculated, and probability of target attainment was evaluated by Monte Carlo simulations. Twenty-three patients were enrolled, 8 of whom had septic shock. The maximum concentration of linezolid was higher in the ELF than in the plasma (36.02 ± 13.17 vs 19.51±4.83 mg/L, P < .001) in all of the patients. In patients with septic shock, the maximum concentration in the ELF was significantly higher than that in the non-septic shock group (45.25 ± 11.70 vs 31.10 ± 11.38 mg/L, P = .01), while there was no significant difference in the plasma. The corresponding probability of target attainment values were 90.5% and 65.1% in ELF and plasma, respectively, with a minimum inhibitory concentration of 2 mg/L, which were 99.9% in the ELF in the patients with septic shock. Linezolid possesses an efficient penetration into the ELF of patients with pneumonia-induced sepsis with mechanical ventilation. When minimum inhibitory concentration ≤ 2 mg/L, 600 mg of linezolid every 12 hours could achieve the optimal therapeutic targets in the ELF rather than in the plasma of patients with pneumonia-induced sepsis.

1302. Cefiderocol Population Pharmacokinetics and Probability of Target Attainment in Plasma and Epithelial Lining Fluid in Patients with Pneumonia, Bloodstream Infection/Sepsis, or Complicated Urinary Tract Infections

BackgroundCefiderocol (CFDC) is a novel siderophore cephalosporin with activity against a broad range of Gram-negative bacteria. The aim of this study was to perform population pharmacokinetic (PopPK) analysis and evaluate probability of target attainment (PTA) in plasma and epithelial lining fluid (ELF) based on a modeling and simulation approach.MethodsPopPK analysis in plasma was conducted using 3427 concentration data from 425 patients with pneumonia, bloodstream infection/sepsis (BSI/sepsis), complicated urinary tract infection (cUTI), or acute uncomplicated pyelonephritis in 3 Phase 2 or 3 studies (NCT03032380, NCT02714595, and NCT02321800), and 91 subjects without any infection in Phase 1 studies. In addition, intrapulmonary modeling was conducted using ELF concentration data from 7 pneumonia patients (NCT03862040) and 20 healthy subjects. Monte-Carlo simulations were performed by generating 1000 virtual patients for each infection site (pneumonia, BSI/sepsis, or cUTI) to predict PTA for 75% of time for which free drug concentration in plasma or ELF (only pneumonia patients) exceeds the minimum inhibitory concentration (MIC; 0.25–16 µg/mL) over dosing interval following CFDC 2 g q8h infused over 3 hours with dose adjustment based on renal function, including augmented renal clearance.ResultsThe developed PopPK model described the plasma and ELF CFDC concentrations. Creatinine clearance, body weight, infection site, and albumin concentration were statistically significant covariates on CFDC PK in plasma. There were no clinically significant differences in CFDC plasma exposure based on infection site or with/without ventilation. The penetration ratio of ELF to free plasma in pneumonia patients (0.340) was 1.3-fold higher than that in healthy subjects (0.263). As shown in the table below, plasma PTA was >90% against MICs ≤4 μg/mL, regardless of infection site and renal function. ELF PTA in pneumonia patients was >90% against MICs ≤2 μg/mL and >85% against MICs ≤4 μg/mL, regardless of renal function.Table. Probability of Target Attainment for 75% fT>MIC or 75% fT>MIC,ELF ConclusionThe recommended dosing regimen (2 g, q8h, 3-hr infusion) adjusted by renal function provided adequate exposure to CFDC in patients with infections caused by Gram-negative pathogens, irrespective of infection site and renal function.DisclosuresTakayuki Katsube, PhD, Shionogi & Co., Ltd. (Employee) Nao Kawaguchi, BPharm, Shionogi & Co., Ltd. (Employee) Roger Echols, MD, Shionogi Inc. (Consultant) Toshihiro Wajima, PhD, Shionogi & Co., Ltd. (Employee) David P. Nicolau, PharmD, Cepheid (Other Financial or Material Support, Consultant, speaker bureau member or has received research support.)Merck & Co., Inc. (Consultant, Grant/Research Support, Speaker’s Bureau)Wockhardt (Grant/Research Support)

In Vitro Hollow-Fiber Studies Assessing Antibacterial Activity of Ceftolozane/Tazobactam Against Multidrug-Resistant Pseudomonas Aeruginosa.

Our hollow-fiber infection model simulated the projected steady-state pharmacokinetics of ceftolozane and tazobactam in lung epithelial lining fluid of patients with pneumonia receiving 3 g of ceftolozane/tazobactam every 8 hours. Results confirmed the previously established in vitro activity of ceftolozane/tazobactam at and above approved breakpoints against multidrug-resistant Pseudomonas aeruginosa, regardless of Pseudomonas-derived cephalosporinase allele.

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

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). 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. 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. 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.

Permeability and Concentration of Levofloxacin in Epithelial Lining Fluid in Patients With Lower Respiratory Tract Infections

The purpose of the study was to assess the bactericidal effects of a single oral dose of levofloxacin (LVFX) by examining the concentration of LVFX in alveolar epithelial lining fluid (ELF) from patients with lower respiratory tract infections (LRTI). Forty patients with LRTI took 500 mg of LVFX and then received a fiberoptic bronchoscopic procedure randomly 1, 4, 8, 12, or 24 hours following dosing. Bronchoalveolar lavage fluid and blood were collected at the time of the bronchopulmonary procedure, and the LVFX concentration was determined. The mean peak concentrations of LVFX in plasma and ELF were achieved at 1.5 hours (4.07 mg/L) and 1 hour (3.44 mg/L), respectively. The AUC(24h) samples were 50.12 mg . h/L and 34.51 mg . h/L, respectively. The permeability of LVFX, which was estimated based on the ratio of LVFX concentration in tissue fluids to that in plasma, was 0.78 on average across all time points. After a single dose of LVFX in patients with LRTI, the drug rapidly distributed into bronchopulmonary tissue, thereby suggesting this dose is capable of achieving the concentration in target organs required for bactericidal efficacy.

Concentrations of clarithromycin and active metabolite in the epithelial lining fluid of patients with Mycobacterium avium complex pulmonary disease

Objectives Clarithromycin (CAM) is widely accepted for the treatment of Mycobacterium avium complex (MAC) pulmonary diseases. This study measured (a) the concentrations of CAM and its active metabolite (14OH-CAM) in bronchial epithelial lining fluid (ELF) obtained by bronchoscopic microsampling (BMS), and (b) the minimal inhibitory concentrations (MIC) of CAM for each MAC isolate. Methods We studied eight patients with MAC pulmonary disease treated with oral CAM, 400 ( n = 4) or 800 ( n = 4) mg/day. BMS was performed 3 h after the last CAM dose, and the concentrations of CAM and 14OH-CAM were measured in ELF collected from the diseased and normal contralateral pulmonary segments, and in serum. Results The mean ± SEM ELF concentrations of CAM (23.85 ± 7.64 μg/ml) and CAM + 14OH-CAM (28.71 ± 8.37 μg/ml) in the 800 mg/day treatment group were significantly higher than in the 400 mg/day group (7.48 ± 2.58 μg/ml and 9.63 ± 2.99 μg/ml, respectively; both p < 0.05), while the serum concentrations were similar in both groups. In both treatment groups, the mean ELF concentrations sampled from diseased and normal segments were higher than the MIC against MAC isolates. The mean ELF concentration of CAM in the 400 mg/day treatment group was <8 μg/ml (the breakpoint concentration of CAM against M. avium recommended by the Clinical Laboratories Standards Institute), while the mean concentration in the 800 mg/day treatment group was >8 μg/ml. Conclusion These observations suggest that CAM, 800 mg/day, is an appropriate dose to treat MAC pulmonary disease, and prevent its spread from diseased to non-diseased lung segments.

Bronchoscopic Microsampling to Analyze the Epithelial Lining Fluid of Patients with Pulmonary Mycobacterium avium Complex Disease

Background: A new bronchoscopic microsampling (BMS) probe has recently been developed, which allows the minimally invasivecollection of epithelial lining fluid (ELF) simultaneously from multiple sites. While the number of immunocompetent patients with pulmonary Mycobacterium avium complex(MAC) disease is growing, the precise pathogenesis of the disease remains to be clarified. Objectives: This study aimed to measure biochemical markers in the ELF of patients with pulmonary MAC disease using BMS. Methods: We studied 8 healthy volunteers (controls) and 8 patients with pulmonary MAC disease. In the patients, ELF was collected from visibly abnormal (involved) and normal (uninvolved) sites using high-resolution computed tomography (HRCT). Results: The concentration of IFN-γ (means ± SEM) was significantly higher in patient ELF sampled from involved (26.62 ± 9.66 pg/ml) than from uninvolved sites (5.33 ± 1.44 pg/ml; p < 0.05) or from normal controls (<1.56 pg/ml; p < 0.05). In most patients, there was no difference in IFN-γ concentrations between the involved and uninvolved sites. The concentration of KL-6 in ELF was significantly higher in the involved (793 ± 108 U/ml) than in the uninvolved sites (192 ± 43 U/ml;p < 0.05) or in normal controls (186 ± 38 U/ml;p < 0.05). Conclusions: The specific inflammatory reaction caused by MAC infection might not be limited to sites that were visibly abnormal on HRCT. Although further improvement has to be considered, BMS may help to increase the understanding of the pathogenesis of various respiratory disorders.

EDITORIAL

We start this issue with the first of a set of two ‘Year-in-Review’ papers, highlighting important findings in respiratory medicine from articles published in Respirology in 2007. The first paper by Professor Bardin and Professor Ruffin reviews the clinical science publications in Respirology in 2007. The second ‘Year-in-Review’ paper, which will appear in the next issue, will review the respiratory science publications reported in the Journal in 2007. This issue features the last review in the Presidents' Series by the immediate past-President of the American College of Chest Physicians, Professor Mark Rosen. In his review ‘Pulmonary Complications of HIV Infection’, Professor Rosen discusses the incidence of different pulmonary disorders associated with HIV infection, and their diagnosis and treatment. Professor Rosen is Chief of the Divisions of Pulmonary, Critical Care and Sleep Medicine at North Shore University Hospital and Long Island Jewish Medical Center. His research interests include pulmonary disease and critical care in patients with HIV infection, respiratory failure and medical ethics. He has published extensively on the subject of pulmonary disease in patients with HIV infection and is co-editor of the textbook ‘HIV and the Lung’. I highly recommend this paper to you as it is a comprehensive review of the topic and should be of great interest. We regret to announce the cancellation of the Presidents' Review by Dr Nan Zhong from the APSR owing to unforeseen circumstances. Our next Presidents' Series with reviews by the new Presidents of the major respiratory societies will commence in a later issue this year. Three highlights in this issue are articles studying the role of mitogen-activated protein kinase pathways in airway epithelial cells. The first of these articles ‘Involvement of the p38 MAPK pathway in IL-13-induced mucous cell metaplasia in mouse tracheal epithelial cells’ by Dr Fujisawa et al. (pp. 191–202), demonstrates that the p38 MAPK pathway is involved in IL-13-induced mucous cell metaplasia and MUC5AC mRNA regulation in mouse tracheal epithelial cells and that phosphorylation of p38 MAPK may require STAT6-dependent de novo protein synthesis induced by IL-13. The same study also shows that the ERK1/2 pathway is not directly activated by IL-13. The article ‘Analysis of gene expression in human bronchial epithelial cells upon influenza virus infection and regulation by p38 MAP kinase and JNK’ by Dr Hayashi et al. (pp. 203–214) reports on the role of p38 MAPK in gene expression in human bronchial epithelial cells following influenza virus infection. In ‘Erythromycin attenuates MUC5AC synthesis and secretion in cultured human tracheal cells infected with RV14’ (pp. 215–220), Dr Inoue et al. examine the inhibitory effect of erythromycin on RV14-induced p44/42 MAPK activation and MUC5AC protein production and hypersecretion in human tracheal cells, suggesting a link between the two. Another highlight in this issue is the article by Dr Long et al. entitled ‘Rapid non-genomic effects of glucocorticoids on oxidative stress in a guinea pig model of asthma’ (pp. 227–232). In this study, the authors identify a rapid non-genomic mechanism whereby glucocorticoids reduce oxidative stress in ‘asthmatic’ guinea pigs. These findings may contribute to future developments in the clinical treatment of asthma. The article by Dr Bu et al.‘Effects of independent lung ventilation and lateral position on cytokine markers of inflammation after unilateral lung acid injury in dogs’ (pp. 233–239) compared the effects of different mechanical ventilation settings and lateral body position on inflammatory markers in an animal model of unilateral lung acid injury. Their results suggest that the release of pro-inflammatory cytokines in the injured lung is attenuated by independent lung ventilation and lateral positioning. Early initiation of this type of mechanical ventilation may be of benefit in patients with severe unilateral lung injury. Finally, the Short Communication by Dr Koh et al.‘Vascular endothelial growth factor in epithelial lining fluid of patients with acute respiratory distress syndrome’ (pp. 281–284) demonstrates that elevated levels of vascular endothelial growth factor in lung epithelial lining fluid may predict a better outcome in patients with acute lung injury and acute respiratory distress syndrome. Professor Chong-Kin Liam from the University of Malaya, Malaysia has decided to retire early from his role as Associate Editor of Respirology. Professor Liam joined the Journal in April 2006. His contribution over the past year and a half has been greatly appreciated and we are very grateful for his assistance. Professor Liam will continue to be involved with Respirology as an Editorial Board member. I hope you enjoy this issue of Respirology.

Vascular endothelial growth factor in epithelial lining fluid of patients with acute respiratory distress syndrome

Vascular endothelial growth factor (VEGF) is known to contribute to the development of pulmonary oedema, and has been suggested to have a protective role against lung injury. To determine the role of VEGF in acute lung injury (ALI) and ARDS, VEGF levels were measured in lung epithelial lining fluid (ELF) collected from patients with ALI/ARDS. Forty patients with ALI/ARDS underwent bronchoscopic microsampling to collect ELF on days 0 (onset of ALI/ARDS), 1, 3, 5, 7 and 10, unless the patient was extubated or had died. Twelve patients, who underwent bronchoscopy for examination of small, peripheral pulmonary nodules, served as controls. The initial (day 0) levels of VEGF in ELF of the ALI/ARDS patients who survived and those who did not were 5.5 ng/mL (IQR: 2.3-19.7) and 1.7 ng/mL (IQR: 0.0-6.4), respectively. On days 0, 5, 7 and 10, the VEGF levels in ELF were significantly greater in survivors than in non-survivors (P < 0.05). VEGF levels on days 1 and 3 did not differ between survivors and non-survivors. There was no significant difference in ELF VEGF levels between control subjects and patients with ALI/ARDS at any time point. Lung injury score was inversely correlated with VEGF concentration in ELF (P < 0.001). In patients with ALI/ARDS, elevated VEGF levels in ELF may predict a better outcome. Increased production of VEGF in the injured lung may contribute to resolution of inflammation in the lung.

EDITORIAL

EDITORIAL

Endothelin‐1 level in epithelial lining fluid of patients with acute respiratory distress syndrome

Endothelin-1 (ET-1), a potent vasoconstrictor peptide produced by endothelial cells, has been implicated in the dysfunction of various organs. To determine the role of ET-1 in acute lung injury (ALI) and ARDS, ET-1 levels were measured in epithelial lining fluid (ELF) and plasma obtained from patients with ALI/ARDS. A cross-sectional study of patients with ALI/ARDS in the intensive care unit of two university hospitals was performed. Patients with ALI/ARDS underwent bronchoscopic microsampling to collect ELF on the day of onset of the disease. Patients who underwent bronchoscopy to examine a small peripheral pulmonary nodule served as controls. In the 23 patients with ALI/ARDS, the ET-1 level in ELF was significantly greater than that in plasma (P < 0.001). In contrast, ET-1 was not detectable in the ELF from six of the seven control subjects. The albumin concentration of ELF, used as a marker of endothelial and epithelial permeability, correlated with the ET-1 level in ELF (P < 0.001). The oxygenation index (PaO(2)/FiO(2)) was also correlated with ET-1 concentration in ELF (P < 0.001). In patients with ALI/ARDS, ET-1 is produced mainly in the lung and is associated not only with pulmonary vasoconstriction but also the development of permeability oedema, leading to the impairment of oxygenation.

Significance of human β-defensins in the epithelial lining fluid of patients with chronic lower respiratory tract infections

Human beta-defensins (hBDs) are the most abundant antimicrobial peptides in epithelial cells, and function in the host immune system. Respiratory epithelial cells express hBDs to inhibit bacterial proliferation during respiratory tract infections. The aim of this study was to investigate the release of hBDs into the respiratory tract and their benefit as a host defence system in chronic Pseudomonas aeruginosa infections. The levels of four hBD peptides (hBD-1-hBD-4) were measured in the bronchial epithelial lining fluid (ELF) of nine patients with chronic lower respiratory tract infection caused by P. aeruginosa. Eight patients with idiopathic pulmonary fibrosis and eight volunteers free of pulmonary disease were recruited as controls. ELF was obtained by bronchoscopic microsampling and hBD levels were measured by radioimmunoassays. The antimicrobial effects of hBDs were studied individually and in combination using an in-vitro colony count assay for P. aeruginosa. Concentrations of hBD-1 and hBD-3 tended to be higher in patients with chronic lower respiratory tract infection than in the controls. hBD-2 and hBD-4 were detected in ELF from five and four of nine patients, respectively, but the hBD levels in controls were all below the limits of detection. All patients with infection caused by mucoid P. aeruginosa had detectable hBD-2 and hBD-4 levels in ELF. In-vitro colony count assays showed a potential synergism between hBD-2 and hBD-4 in inhibiting bacterial proliferation. The findings indicate that hBDs, especially hBD-2 and hBD-4, are pathophysiologically important in infections caused by mucoid strains of P. aeruginosa.

High-mobility group box 1: role in ARDS

Extracellular high-mobility group box 1 (HMGB-1), first isolated approximately 30 years ago from the thymus as a chromosomal protein and recognized as a transcriptional factor, has recently been proposed as one of the late mediators of sepsis and lipopolysaccharide (LPS) endotoxin acute lung injury (ALI) [1,2]. In recent studies, HMGB-1 has been implicated in the development of arthritis, activation of human monocytes, smooth muscle cell chemotaxis, and induction of adhesion molecules in endothelial cells. These observations suggest that HMGB-1 is a key mediator of cell injury, and that its inhibition may be key in improving clinical outcomes. We conducted a translational study to examine the participation of HMGB-1 in the pathogenesis of ALI caused by sepsis. To test the hypothesis that HMGB-1 plays a key role as a late mediator, we first measured its concentrations and those of its related compound, HMGB-2, in the blood and lungs of patients presenting with septic ALI/ARDS, and in a murine model of LPS-induced lung injury. We then studied the localization of the extracellular HMGB-1 protein and examined the anti-inflammatory effects of anti-HMGB-1 antibodies in our LPS-induced lung injury murine model. The direct effects of HMGB-1 and HMGB-2 on the lung were also examined. This study was performed to examine the putative role of HMGB protein in the pathogenesis of ALI. Observations were made (1) in 21 septic patients with ALI and 15 patients with normal lung function, and (2) in a mouse model, 24 hours after intratracheal instillation of lipopolysaccharide. The concentrations of HMGB-1 were increased in plasma and lung epithelial lining fluid of patients with ALI and mice instilled with LPS. LPS-induced ALI was mitigated by anti-HMGB-1 antibody. Although this protein was not detected in the plasma of control humans or mice, the concentrations of HMGB-1 in lung epithelial lining fluid or in bronchoalveolar lavage fluid were unexpectedly high. The nuclear expression of HMGB-1 was apparent in epithelial cells surrounding terminal bronchioles in normal mice, while its nuclear and cytoplasmic expression was observed in alveolar macrophages in LPS-instilled mice. Lung instillation of HMGB-2 did not cause as much inflammation as HMGB-1. Extracellular HMGB-1 may play a key role in the pathogenesis of clinical and experimental ALI. However, its expression in normal airways is noteworthy, and suggests that it also plays a physiologic role in the lung.

Contributions of high mobility group box protein in experimental and clinical acute lung injury.

This study was performed to examine the putative role of high mobility group box (HMGB) protein in the pathogenesis of acute lung injury (ALI). Observations were made (1) in 21 patients who were septic with ALI and 15 patients with normal lung function and (2) in a mouse model 24 hours after intratracheal instillation of lipopolysaccharide (LPS). The concentrations of HMGB1 were increased in plasma and lung epithelial lining fluid of patients with ALI and mice instilled with LPS. LPS-induced ALI was mitigated by anti-HMGB1 antibody. Although this protein was not detected in the plasma of control humans or mice, the concentrations of HMGB1 in lung epithelial lining fluid or in bronchoalveolar lavage fluid were unexpectedly high. The nuclear expression of HMGB1 was apparent in epithelial cells surrounding terminal bronchioles in normal mice, whereas its nuclear and cytoplasmic expression was observed in alveolar macrophages in LPS-instilled mice. Lung instillation of HMGB2 did not cause as much inflammation as HMGB1. Extracellular HMGB1 may play a key role in the pathogenesis of clinical and experimental ALI. However, its expression in normal airways is noteworthy and suggests that it also plays a physiologic role in the lung.

Pharmacodynamic target attainment analysis against Streptococcus pneumoniae using levofloxacin 500 mg, 750 mg and 1000 mg once daily in plasma (P) and epithelial lining fluid (ELF) of hospitalized patients with community acquired pneumonia (CAP)

The pharmacokinetics and pharmacodynamics of levofloxacin in patients with respiratory infections such as community-acquired pneumonia (CAP) are poorly documented. This work aimed at assessing the pharmacodynamic target attainment against Streptococcus pneumoniae using levofloxacin 500 mg, 750 mg and 1000 mg administered once daily in plasma (P) and epithelial lining fluid (ELF) of hospitalized patients with community acquired pneumonia. The pharmacokinetics of levofloxacin in elderly (≥65 years) compared with younger patients (<65 years) hospitalized with CAP were simulated. Susceptibility data with S. pneumoniae from our ongoing national surveillance study ( Canadian Respiratory Organism Susceptibility Study—CROSS) were then used to produce pharmacodynamic indices of AUC 0–24/MIC all. Monte Carlo simulations were then used to analyse target attainment of levofloxacin using doses of 500 mg, 750 mg and 1000 mg once daily to achieve free drug AUC 0–24/MIC all ≥ 30–100 versus S. pneumoniae in patients with CAP. Pharmacokinetics of levofloxacin simulated after 500 mg, 750 mg and 1000 mg once daily dosing resulted in levofloxacin volume of distribution: elderly patients = younger patients, while levofloxacin clearance was: elderly patients < younger patients. Levofloxacin t 1/2 values were longer in elderly patients (9.8 ± 2.5 h) than younger patients with CAP (7.4 ± 2.5 h). Free levofloxacin AUC 0–24 as well as AUC 0–24/MIC all for S. pneumoniae were higher in elderly patients than younger patients. Monte Carlo simulation using levofloxacin 500 mg yielded probabilities of achieving free-drug AUC 0–24/MIC all of 30 in P and ELF (95.7% and 98.1%) in elderly and younger patients (72.7% and 80.6%) respectively. Levofloxacin 750 mg and 1000 mg once daily had probability of achieving free-drug AUC 0–24/MIC all of 30 in P/ELF of 98.1%/98.6% and 99.2%/99.0%, respectively, in elderly patients compared with 89.9%/94.1% and 95.2%/96.5%, respectively, for younger patients. Probability of achieving of AUC 0–24/MIC all of 100 in P or ELF was very low in both patient populations at different doses except in the case of elderly patients receiving levofloxacin in a dose of 1000 mg once daily P/ELF of 78.5%/87.0%. We conclude that levofloxacin pharmacokinetics in elderly patients with CAP are markedly different from those of younger patients. Levofloxacin 750 mg OD provides high probabilities of achieving free-drug AUC 0–24/MIC all of 30 in both plasma and epithelial lining fluid in patients with CAP including younger patients. Levofloxacin 500 mg OD provides high probabilities of achieving free-drug AUC 0–24/MIC all of 30 in elderly patients with CAP, although we favour the 750 mg dosing in these patients as well. Levofloxacin 750 mg OD results in high probability of pharmacodynamic target attainment and improved bacteriological outcome against S. pneumoniae in patients with CAP.

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

A noninvasive bronchoscopic microsampling (BMS) probe was developed to sample biochemical constituents of the epithelial lining fluid in small airways. Observational, controlled study. Intensive care unit of academic medical center. PATIENTS AND PROCEDURE: BMS was applied in a control group of seven patients who had hemoptysis or small solitary peripheral nodules but no hypoxemia or other signs of acute inflammation and in four patients with acute respiratory distress syndrome (ARDS), to test whether BMS can ascertain the presence of acute pulmonary inflammation without complications. Complications, including a significant decrease in arterial oxygen saturation, were observed neither during nor after BMS. In the ARDS group, albumin, lactate dehydrogenase, interleukin-6, basic fibroblast growth factor, and neutrophil elastase concentrations in epithelial lining fluid were significantly higher (p <.0001, p =.012, p <.0001, p <.0001, and p <.0001, respectively) than in the control group. Serial BMS was safely performed in one patient with ARDS, allowing us to observe a correlation between changes in the concentration of inflammation-related biochemical markers and clinical course of the disease. These results suggest that BMS is safe and useful to monitor pulmonary biochemical events in ARDS.

Type III and type I procollagen markers in fibrosing alveolitis.

Deposition of types I and III collagen is a typical feature in the development of pulmonary fibrosis. We assessed the propeptides of these procollagens as prognostic markers in 18 patients with fibrosing alveolitis. We analyzed the amino-terminal propeptide of type III procollagen (PIIINP) and the carboxy-terminal propeptide of type I procollagen (PICP) from samples of bronchoalveolar lavage fluid (BALF) and serum, and also estimated their concentrations in epithelial lining fluid (ELF) by the urea method. The level of PIIINP in serum (p < 0.05), BALF (p < 0.05), and ELF (p < 0.05), and the levels of PICP in BALF (p < 0.001) and ELF (p < 0.001) but not in serum, were significantly increased in the patients with fibrosing alveolitis as compared with 17 controls who had been investigated for minor respiratory symptoms. In the BALF and ELF of patients with fibrosing alveolitis, PICP but not PIIINP had significant negative correlations with the specific diffusion coefficient for carbon monoxide (DLCO/ VA). The amino-terminal propeptide of type III procollagen and the carboxy-terminal propeptide of type I procollagen in BALF correlated significantly with one another. During the follow-up period of 6 yr, seven of the 18 patients with fibrosing alveolitis died of the disease, 3 others died of malignancy, and one patient died from an unknown cause. DLCO (p < 0.05) differed significantly between the surviving patients and those who died of fibrosing alveolitis, and detectable PIIINP in BALF predicted death from fibrosing alveolitis (p = 0.05). In conclusion, these results show that PIIINP in BALF, ELF, and serum, and PICP in BALF and ELF, are increased in patients with fibrosing alveolitis. A high level of PICP in BALF, and especially in ELF, suggests a chronic process and increased synthesis of type I collagen in the lungs, whereas PIIINP in BALF and ELF suggests active disease and a poor prognosis.

Tobramycin penetration into epithelial lining fluid of patients with pneumonia.

To study the penetration of tobramycin in lung tissue evaluated as the concentration in epithelial lining fluid and to characterize the time course of the drug in the treatment of patients with pneumonia. The subjects were 16 patients with pneumonia and taking tobramycin who had clinical indications for bronchoscopy. Bronchoscopy with bronchoalveolar lavage of the pneumonic area was performed once on each patient 1/2%, 2, 4, or 8 hours after the previous tobramycin dose. Urea was used as an endogenous marker for quantification of epithelial lining fluid obtained at bronchoalveolar lavage. Tobramycin concentrations in serum were measured for all patients at the aforementioned 4 time points. Tobramycin concentration was determined by means of fluorescent polarization immunoassay modified for bronchoalveolar samples. Levels of tobramycin in the fluid of the epithelial lining were 2.33+/-0.5 at 1/2 hour, 1.67+/-0.6 at 2 hours, 1.62+/-1.19 at 4 hours, and 0.77+/-0.38 microg/mL at 8 hours. The ratio of epithelial lining fluid to serum concentration of tobramycin was 0.30+/-0.03 at 1/2 hour, 0.42+/-0.16 at 2 hours, 0.64+/-0.37 at 4 hours, and 1.53+/-0.76 at 8 hours. The ratio at peak serum time was similar to that reported for tobramycin and netilmicin. High peak serum concentrations of tobramycin are necessary to obtain microbiologically active concentrations at the alveolar level. The fluid of the epithelial lining constitutes a deep compartment for aminoglycosides. The disappearance of tobramycin was slower than at the serum level.

Gelatinases in epithelial lining fluid of patients with adult respiratory distress syndrome.

Gelatinases A and B are matrix metalloproteinases secreted as inactive pro forms and are capable of degrading basement membrane components after activation in the extracellular environment. To determine whether the presence of gelatinases A (noninflammatory cells) and B (inflammatory cells) in epithelial lining fluid (ELF) is associated with the adult respiratory distress syndrome (ARDS), we studied 28 patients divided into four groups based on the presence of ARDS and/or multiple organ failure (MOF). Gelatinase activities were quantified in ELF using zymography. ARDS patients had larger ELF volumes than non-ARDS patients: 9.2 +/- 8.5 ml/100 ml recovered lavage fluid (n = 18) vs. 1.9 +/- 1.7 ml/100 ml (n = 11), respectively (P < 0.001). The presence of activated gelatinase A in ELF was a sensitive (16 out of 18 ARDS patients, 89%) and specific (0 out of 11 non-ARDS patients with or without MOF) marker for ARDS. Activated gelatinase (A + B) activities per microliter ELF were correlated with albumin concentrations in ELF (P < 0.01), and activated gelatinase activities in ELF were correlated with the volume of ELF (P < 0.0005). This could suggest an involvement of these gelatinases in alveolar-capillary permeability increase.