Dexamethasone and losartan combination treatment protected cigarette smoke-induced COPD in rats

Chronic Obstructive Pulmonary Disease (COPD) is a dangerous prevalent smoking-related disease characterized by abnormal inflammation and oxidative stress and expected to be the third cause of death in the world next decade. Corticosteroids have low effects in decreasing numbers of inflammatory mediators specifically in long-term use. Our study designed to investigate the possible protective effects of combined dexamethasone (Dex) (2mg/kg) and losartan (Los) (30mg/kg angiotensin receptor blocker, it possesses antioxidant and anti-inflammatory properties in lung injury in mice) against cigarette -smoke (CS) induced COPD in rats compared with dexamethasone and losartan. Male Sprague Dawley rats (N = 40) divided into five groups (n = 8): control group, CS group, Dex group, Los group, and Dex +Los group. COPD induced in rats by CS exposure twice daily for 10 weeks. After the specified treatment period, bronchoalveolar lavage fluid (BALF) and lung tissue were collected for measurement of SOD, NO, MDA, ICAM-, MMP-9, CRP, NF-κB and histopathology scoring. Our results indicated that Los+Dex significantly prevent CS-induced COPD emphysema, congested alveoli, and elevation of lung injury parameters in BALF. They also showed a significant decrease in MDA, ICAM-1, MMP-9, CRP, and NF-κB and a significant increase in SOD and NO. In conclusion, adding Los to Dex potentiating their activity in inhibition the progression of COPD based on its activity on oxidative stress, inflammation, and NF-κB protein expression.

Airway Microbiology in Tracheostomized Children

BACKGROUND

Potentially pathogenic microorganisms are frequently isolated from tracheostomized children, although evidence for empirical therapy of respiratory exacerbation is limited. We aimed to describe upper airway microbiology as found on endotracheal aspirate (ETA) in tracheostomized children and to correlate it with lower airway microbiology through bronchoalveolar lavage fluid.

METHODS

We retrospectively reviewed records and airway microbiology of all tracheostomized children under the follow-up care of Queensland Children's Hospital. Subanalysis was based on ventilatory and multidrug-resistant organism status. Sensitivity and specificity of ETA for predicting Pseudomonas aeruginosa and Staphylococcus aureus lower airway isolation were calculated using concomitant bronchoalveolar lavage fluid culture as the accepted standard.

RESULTS

From 43 children (18 female, median [interquartile range (IQR)] age 68 (41-115) months, 14 ventilated), 15 different potentially pathogenic microorganisms were isolated (mean ± SD: 3.30 ± 2.23), with S. aureus (n = 33, 77%) and P. aeruginosa (n = 29, 67%) predominating. Significantly more types of potentially pathogenic microorganisms were isolated from ventilated children (median 4.00 [IQR 3.25-5.75]) than from nonventilated children (median 2.00 [IQR 1.00-4.00] (P = .007), with 93% of ventilated children isolating S. aureus and 86% P. aeruginosa. Multidrug-resistant organisms were present in 12 (28%) children, of whom 8 were ventilated. Methicillin-resistant S. aureus (MRSA) was isolated in 9 (21%) children, of whom 6 were ventilated. For P. aeruginosa and S. aureus isolation, ETA had high sensitivity (95% and 100%, respectively) but low specificity (64.7% and 33.3%, respectively) when compared with bronchoalveolar lavage fluid.

CONCLUSIONS

In children with tracheostomy, the predominant respiratory bacterial pathogens were S. aureus and P. aeruginosa, with MRSA being isolated less frequently than previously described. Multidrug-resistant organisms are isolated more frequently from ventilated children. ETA microbiology is a good screening modality, with negative ETA potentially ruling out lower airway S. aureus and P. aeruginosa. Adequately powered prospective studies with quantitative cultures could enhance understanding and guide therapy.

Rapid Diagnosis of IPA Relied on Calcofluor White Fluorescence Staining: Two Cases Report

Invasive pulmonary aspergillosis (IPA) is a serious infectious disease with high mortality. However, the rapid diagnosis of IPA remains difficult since the microbiological evidence is difficult to obtain or time-consuming. Thus, we attempted to rapidly diagnose two pediatric cases with respiratory failure due to IPA via bronchoalveolar lavage fluid with Calcofluor White fluorescence staining, which has rarely been used before.

Bronchoalveolar lavage fluid IMMY Sona Aspergillus lateral-flow assay for the diagnosis of invasive pulmonary aspergillosis: a prospective, real life evaluation

Prompt and reliable diagnosis of invasive pulmonary aspergillosis (IPA) is essential for early initiation of antifungal therapy. We evaluated bronchoalveolar lavage (BAL) fluid IMMY Sona Aspergillus lateral-flow assay (IMMY LFA) in 92 individuals with suspected pulmonary infection. Sensitivity and specificity (vs. host factor but no IPA) of BAL IMMY LFA for diagnosis of IPA in individuals with any European Organisation for Research and Treatment of Cancer-defied "host factor" were 67% and 85%, respectively. Performance appeared better in individuals with renal transplantation (100%, 100%), compared to those with hematological malignancy and/or allogenic stem cell transplantation (70%, 78%). We found BAL IMMY LFA to be a convenient and useful addition to our diagnostic armory for IPA.

LAY ABSTRACT

We evaluated a new test for diagnosing invasive pulmonary aspergillosis from bronchoscopy samples. We tested 92 people and found that it was 67% sensitive and 85% specific (compared to diagnosis according to a set of internationally recognised criteria). We found this test convenient and useful.

Protein Glycopatterns in Bronchoalveolar Lavage Fluid as Novel Potential Biomarkers for Diagnosis of Lung Cancer

Lung cancer is one of the most prevalent and life-threatening neoplasias worldwide due to the deficiency of ideal diagnostic biomarkers. Although aberrant glycosylation has been observed in human serum and tissue, little is known about the alterations in bronchoalveolar lavage fluid (BALF) that are extremely associated with lung cancer. In this study, our aim was to systematically investigate and assess the alterations of protein glycopatterns in BALF and possibility as biomarkers for diagnosis of lung cancer. Here, lectin microarrays and blotting analysis were utilized to detect the differential expression of BALF glycoproteins from patients with 80 adenocarcinomas (ADC), 77 squamous carcinomas (SCC), 51 small cell lung cancer (SCLC), and 73 benign pulmonary diseases (BPD). These 281 specimens were then randomly divided into a training cohort and validation cohort for constructing and verifying the diagnostic models based on the glycopattern abundances. Moreover, an independent test was performed with 120 newly collected BALF samples enrolled in the double-blind cohort to further assess the clinical application potential of the diagnostic models. According to the results, there were 15 (e.g., PHA-E, EEL, and BPL) and 14 lectins (e.g., PTL-II, LCA, and SJA) that individually showed significant variations in different types and stages of lung cancer compared to BPD. Notably, the diagnostic models achieved better discriminate power in the validation cohort and exhibited high accuracies of 0.917, 0.864, 0.712, 0.671, and 0.781 in the double-blind cohort for the diagnosis of lung cancer, early stage lung cancer, ADC, SCC, and SCLC, respectively. Taken together, the present study revealed that the abnormally altered protein glycopatterns in BALF are expected to be novel potential biomarkers for the identification and early diagnosis of lung cancer, which will contribute to explain the mechanism of the development of lung cancer from the perspective of glycobiology.

Differential cytology profiles in bronchoalveolar lavage (BAL) in COVID-19 patients: A descriptive observation and comparison with other corona viruses, Influenza virus, Haemophilus influenzae, and Pneumocystis jirovecii

Brochoalvelolar lavages (BALs) from patients suffering from hospitalized infections with SARS-CoV-2, other corona viruses (human coronavirus (HCoV)-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1), Influenza virus type A and B, Haemophilus influenzae and Pneumocystis jirovecii were compared cytopathologically.The aim of the study was to evaluate if the cellular profile detectable in BAL may be specific for the respective pathogens and could lead to diagnosis of COVID-19 even in the absence of PCR results.Differential cytology and flow cytometry datasets of 62 patients were observed and compared.We observed a significant association between individual cell pattern changes and the causing pathogen, but no general cell distribution pattern.The cytology pattern of the BAL fluid in COVID-19 is not specific enough to use it as a sole diagnostic criterion, although it may support clinical decision making.

Bronchial casts associated with Mycoplasma pneumoniae pneumonia in children

Objective

This study was performed to analyze 22 cases of Mycoplasma pneumoniae pneumonia (MPP) associated with bronchial casts (BCs) in children.

Methods

We retrospectively reviewed all cases of MPP in children treated at our institution from November 2015 to December 2016. Demographic information, laboratory parameters, radiologic and fiberoptic bronchoscopy findings, treatment outcomes, and follow-up results were analyzed.

Results

Among 161 patients with MPP, 22 had BCs and 139 had no BCs. All BCs occurred in a segmental or subsegmental bronchus and were removed by fiberoptic bronchoscopy. Patients with BCs had a longer duration of fever after admission and higher incidence of refractory MPP. Substantially more children with than without BCs had a high M. pneumoniae load in the bronchoalveolar lavage fluid. All patients with BCs but only 55.4% without BCs were given methylprednisolone in addition to the standard antibiotic treatment. A significantly higher proportion of children with than without BCs received oxygen therapy. After discharge, complete radiological resolution took significantly longer in children with than without BCs.

Conclusions

In children with MPP, prompt removal of BCs may be necessary to prevent BC propagation. MPP with BCs is more severe than that without BCs, and treatment and recovery are more difficult.

Involvement of Innate Lymphoid Cells and Dendritic Cells in a Mouse Model of Chemical-induced Asthma

PURPOSE

Exposure to low concentrations of toluene diisocyanate (TDI) leads to immune-mediated chemical-induced asthma. The role of the adaptive immune system has already been thoroughly investigated; nevertheless, the involvement of innate immune cells in the pathophysiology of chemical-induced asthma is still unresolved. The aim of the study is to investigate the role of innate lymphoid cells (ILCs) and dendritic cells (DCs) in a mouse model for chemical-induced asthma.

METHODS

On days 1 and 8, BALB/c mice were dermally treated (20 μL/ear) with 0.5% TDI or the vehicle acetone olive oil (AOO; 2:3). On days 15, 17, 19, 22 and 24, the mice received an oropharyngeal challenge with 0.01% TDI or AOO (1:4). One day after the last challenge, airway hyperreactivity (AHR) to methacholine was assessed, followed by an evaluation of pulmonary inflammation and immune-related parameters, including the cytokine pattern in bronchoalveolar lavage fluid, lymphocyte subpopulations of the lymph nodes and their ex vivo cytokine production profile, blood immunoglobulins and DC and ILC subpopulations in the lungs.

RESULTS

Both DC and ILC2 were recruited to the lungs after multiple airway exposures to TDI, regardless of the prior dermal sensitization. However, prior dermal sensitization with TDI alone results in AHR and predominant eosinophilic airway inflammation, accompanied by a typical type 2 helper T (Th2) cytokine profile.

CONCLUSIONS

TDI-induced asthma is mediated by a predominant type 2 immune response, with the involvement of adaptive Th2 cells. However, from our study we suggest that the innate ILC2 cells are important additional players in the development of TDI-induced asthma.

The clinical significance of simultaneous detection of pathogens from bronchoalveolar lavage fluid and blood samples by metagenomic next-generation sequencing in patients with severe pneumonia

Introduction. Bloodstream infection is a common complication in patients with severe pneumonia and is regarded as an independent risk factor for prediction of poor outcome. Metagenomic next-generation sequencing (mNGS) has been widely applied for pathogen determination of various clinical specimens from patients with infectious diseases. However, the clinical significance of and necessity for simultaneous pathogen detection of both blood samples and bronchoalveolar lavage fluid (BALF) by mNGS in patients with severe pneumonia remains unclear.Hypothesis/Gap Statement. Simultaneous detection of pathogens from both BALF and blood samples in patients with severe pneumonia helps to determine the complication of the bloodstream infection.Aims. This study aimed to elucidate the clinical significance and necessity of pathogen detection simultaneously in both blood samples and BALF samples with the application of mNGS in patients with severe pneumonia.Methods. In this study, 20 patients with severe pneumonia were enrolled and the potential pathogens in both BALF and blood samples were detected simultaneously by conventional microbial examination and mNGS tests. Moreover, multiple consecutive microbial detections were undertaken to investigate the dynamic variation of pathogens during the course of disease progression in two of the 20 patients.Results. In 85 % (17/20) of the patients with severe pneumonia, various pathogens were determined positively in the BALF by mNGS, including 10 cases with bacterial infection, five cases with viral infection and two cases with fungal infection. By contrast, pathogens in 50 % (10/20) of cases could be detected positively in the BALF by conventional microbial tests. Among 17 severe pneumonia patients with mNGS-positive BALF, pathogens were also identified in 10 cases with mNGS-positive blood samples. By contrast, only one patient complicated with a bloodstream infection could be found by conventional bacterial culture. Moreover, the pathogens from BALF were highly consistent with that from blood samples detected by mNGS in the early stage of the disease. With disease progression and after recurrent antibiotic treatment, significant dynamic changes of the microbial species from the BALF and blood samples could be clearly found by mNGS.Conclusions. This study emphasizes the utility of mNGS in the rapid simultaneous detection of pathogens from both BALF and blood samples in patients with severe pneumonia, and could allow determination of bloodstream infection and guide clinicians regarding antimicrobial treatments.

Oxidative and Proteolytic Inactivation of Alpha-1 Antitrypsin in Bronchopulmonary Dysplasia Pathogenesis: A Top-Down Proteomic Bronchoalveolar Lavage Fluid Analysis

The study investigates the role of the oxidative and proteolytic inactivation of alpha-1 antitrypsin (AAT) in the pathogenesis of bronchopulmonary dysplasia (BPD) in premature infants. Bronchoalveolar lavage fluid (BALF) samples were collected on the 3rd day of life from mechanically ventilated neonates with gestational age ≤ 30 weeks and analyzed without previous treatment (top-down proteomics) by reverse-phase high-performance liquid chromatography-electrospray ionization mass spectrometry. AAT fragments were identified by high-resolution LTQ Orbitrap XL experiments and the relative abundances determined by considering the extracted ion current (XIC) peak area. Forty preterm neonates were studied: 20 (50%) did not develop BPD (no-BPD group), 17 (42.5%) developed mild or moderate new-BPD (mild + moderate BPD group), and 3 (7.5%) developed severe new-BPD (severe BPD group). Eighteen fragments of AAT and a fragment of AAT oxidized at a methionine residue were identified: significantly higher values of AAT fragments 25-57, 375-418, 397-418, 144-171, and 397-418 with oxidized methionine were found in the severe BPD group. The significantly higher levels of several AAT fragments and of the fragment 397-418, oxidized in BALF of preterm infants developing BPD, underlie the central role of an imbalance between proteases and protease inhibitors in exacerbating lung injury and inducing most severe forms of BPD. The study has some limitations, and between them, the small sample size implies the need for further confirmation by larger studies.

Development and Validation of a Loop-Mediated Isothermal Amplification (LAMP) Assay for Rapid Detection of Glaesserella (Haemophilus) parasuis

Glaesserella parasuis is a fastidious pathogen that colonizes the respiratory tract of pigs and can lead to considerable economic losses in pig production. Therefore, a rapid detection assay for the pathogen, preferably applicable in the field, is important. In the current study, we developed a new and improved detection method using loop-mediated isothermal amplification (LAMP). This assay, which targets the infB gene, was tested on a collection of 60 field isolates of G. parasuis comprising 14 different serovars. In addition, 63 isolates from seven different closely related species of the family Pasteurellaceae, including A. indolicus, A. porcinus, and A. minor, and a species frequently found in the respiratory tract of pigs were used for exclusivity experiments. This assay showed an analytical specificity of 100% (both inclusivity and exclusivity) and an analytical sensitivity of 10 fg/µL. In further steps, 36 clinical samples were tested with the LAMP assay. An agreement of 77.1 (95% CI: 59.9, 89.6) and 91.4% (95% CI: 75.9, 98.2) to the culture-based and PCR results was achieved. The mean limit of detection for the spiked bronchoalveolar lavage fluid was 2.58 × 102 CFU/mL. A colorimetric assay with visual detection by the naked eye was tested to provide an alternative method in the field and showed the same sensitivity as the fluorescence-based LAMP assay. Overall, the optimized LAMP assay represents a fast and reliable method and is suitable for detecting G. parasuis in the laboratory environment or in the field.

Identification of Pro-Fibrotic Macrophage Populations by Single-Cell Transcriptomic Analysis in West Highland White Terriers Affected With Canine Idiopathic Pulmonary Fibrosis

Canine idiopathic pulmonary fibrosis (CIPF) affects old dogs from the West Highland white terrier (WHWT) breed and mimics idiopathic pulmonary fibrosis (IPF) in human. The disease results from deposition of fibrotic tissue in the lung parenchyma causing respiratory failure. Recent studies in IPF using single-cell RNA sequencing (scRNA-seq) revealed the presence of profibrotic macrophage populations in the lung, which could be targeted for therapeutic purpose. In dogs, scRNA-seq was recently validated for the detection of cell populations in bronchoalveolar lavage fluid (BALF) from healthy dogs. Here we used the scRNA-seq to characterize disease-related heterogeneity within cell populations of macrophages/monocytes (Ma/Mo) in the BALF from five WHWTs affected with CIPF in comparison with three healthy WHWTs. Gene set enrichment analysis was also used to assess pro-fibrotic capacities of Ma/Mo populations. Five clusters of Ma/Mo were identified. Gene set enrichment analyses revealed the presence of pro-fibrotic monocytes in higher proportion in CIPF WHWTs than in healthy WHWTs. In addition, monocyte-derived macrophages enriched in pro-fibrotic genes in CIPF compared with healthy WHWTs were also identified. These results suggest the implication of Ma/Mo clusters in CIPF processes, although, further research is needed to understand their role in disease pathogenesis. Overexpressed molecules associated with pulmonary fibrosis processes were also identified that could be used as biomarkers and/or therapeutic targets in the future.

Diagnostic Value of Metagenomic Next-Generation Sequencing for the Detection of Pathogens in Bronchoalveolar Lavage Fluid in Ventilator-Associated Pneumonia Patients

Objective: To evaluate the diagnostic performance of metagenomic next-generation sequencing (mNGS) using bronchoalveolar lavage fluid (BALF) in patients with ventilator-associated pneumonia (VAP).

Methods: BALF samples of 72 patients with VAP were collected from August 2018 to May 2020. The diagnostic performance of conventional testing (CT) and mNGS methods were compared based on bacterial and fungal examinations. The diagnostic value of mNGS for viral and mixed infections was also analyzed.

Results: The percentage of mNGS positive samples was significantly higher than that estimated by the CT method [odds ratio (OR), 4.33; 95% confidence interval (CI), 1.78–10.53; p < 0.001]. The sensitivity and specificity of mNGS for bacterial detection were 97.1% (95% CI, 93.2–101.0%) and 42.1% (95 CI, 30.7–53.5%), respectively, whereas the positive predictive value (PPV) and the negative predictive value (NPV) were 60.0% (95% CI, 48.7–71.3%) and 94.1% (95% CI, 88.7–99.6%), respectively. A total of 38 samples were negative for bacterial detection as determined by the CT method, while 22 samples were positive as shown by the mNGS method. Conflicting results were obtained for three samples between the two methods of bacterial detection. However, no significant differences were noted between the mNGS and CT methods (OR, 1.42; 95% CI, 0.68–2.97; p = 0.46) with regard to fungal infections. The sensitivity and specificity of mNGS were 71.9% (95% CI, 61.5–82.3%) and 77.5% (95% CI, 67.9–87.1%), respectively. mNGS exhibited a PPV of 71.9% (95% CI, 61.5–82.3%) and an NPV of 77.5% (95% CI, 67.9–87.1%). A total of 9 out of 40 samples were found positive for fungi according to mNGS, whereas the CT method failed to present positive results in these samples. The mNGS and CT methods produced conflicting results with regard to fungal detection of the two samples. A total of 30 patients were virus-positive using mNGS. Furthermore, 42 patients (58.3%) were identified as pulmonary mixed infection cases.

Conclusions: mNGS detection using BALF improved the sensitivity and specificity of bacterial identification in patients who developed VAP. In addition, mNGS exhibited apparent advantages in detecting viruses and identifying mixed infections.

Secretory Phospholipase A2-IIA Protein and mRNA Pools in Extracellular Vesicles of Bronchoalveolar Lavage Fluid from Patients with Early Acute Respiratory Distress Syndrome: A New Perception in the Dissemination of Inflammation?

Secretory phospholipase-IIA A₂ (sPLA₂-IIA) is expressed in a variety of cell types under inflammatory conditions. Its presence in the bronchoalveolar lavage (BAL) fluid of patients with acute respiratory distress syndrome (ARDS) is associated with the severity of the injury. Exosomal type extracellular vesicles, (EVs), are recognized to perform intercellular communication. They may alter the immune status of recipient target cells through cargo shuttling. In this work, we characterized the exosomal type EVs isolated from BAL fluid of patients with early and late ARDS as compared to control/non-ARDS patients, through morphological (confocal and electron microscopy) and biochemical (dynamic light scattering, qRT-PCR, immunoblotting) approaches. We provide evidence for the presence of an sPLA₂-IIA-carrying EV pool that coprecipitates with exosomes in the BAL fluid of patients with ARDS. PLA2G2A mRNA was present in all the samples, although more prominently expressed in early ARDS. However, the protein was found only in EVs from early phase ARDS. Under both forms, sPLA₂-IIA might be involved in inflammatory responses of recipient lung cells during ARDS. The perception of the association of sPLA₂-IIA to the early diagnosis of ARDS or even with a mechanism of development and propagation of lung inflammation can help in the adoption of appropriate and innovative therapeutic strategies.

Performance of Aspergillus Galactomannan Lateral Flow Assay on Bronchoalveolar Lavage Fluid for the Diagnosis of Invasive Pulmonary Aspergillosis

Background: Several newly developed biomarker tests for invasive pulmonary aspergillosis (IPA) have been developed, including the IMMY Aspergillus galactomannan lateral flow assay (Aspergillus GM-LFA) evaluated in this study. Methods: Twenty patients with proven/probable IPA (EORTC/MSGERC criteria) were matched by age and underlying disease with 20 patients without IPA. Bronchoalveolar lavage fluid (BALF) was analyzed in duplicate using the Aspergillus GM-LFA. Results were read visually by two blinded observers, and the optical density index (ODI) was obtained digitally with a cube reader. Results: Using a cutoff of ≥0.5 ODI, the Aspergillus GM-LFA had a sensitivity of 40%, specificity of 80%, positive predictive value (PPV) of 67% and negative predictive value (NPV) of 57%. When the cutoff was increased to ≥1.0 ODI, sensitivity remained at 40%, specificity rose to 95%, PPV was 89%, and NPV was 61%. Excellent agreement was found when duplicate samples were read either visually (κ = 1) or with the cube reader (κ = 0.89). Correlation of results obtained by visual inspection and those obtained using the cube reader was excellent (κ = 0.82). Conclusion: The Aspergillus GM-LFA had poor sensitivity but excellent specificity for proven/probable IPA in BALF. The assay was easy to interpret, and there was high concordance between results obtained visually and with a cube reader.

Proteomic characteristics of bronchoalveolar lavage fluid in critical COVID-19 patients

Up to 10-20% of patients with coronavirus disease 2019 (COVID-19) develop a severe pulmonary disease due to immune dysfunction and cytokine dysregulation. However, the extracellular proteomic characteristics in respiratory tract of these critical COVID-19 patients still remain to be investigated. In the present study, we performed a quantitative proteomic analysis of the bronchoalveolar lavage fluid (BALF) from patients with critical COVID-19 and from non-COVID-19 controls. Our study identified 358 differentially expressed BALF proteins (P < 0.05), among which 41 were significantly changed after using the Benjamini-Hochberg correction (q < 0.05). The up-regulated signaling was found to be mainly involved in inflammatory signaling and response to oxidative stress. A series of increased extracellular factors including Tenascin-C (TNC), Mucin-1 (KL-6 or MUC1), Lipocalin-2 (LCN2), periostin (POSTN), Chitinase 3-like 1 (CHI3L1 or YKL40), and S100A12, and the antigens including lymphocyte antigen 6D/E48 antigen (LY6D), CD9 antigen, CD177 antigen, and prostate stem cell antigen (PSCA) were identified, among which the proinflammatory factors TNC and KL-6 were further validated in serum of another thirty-nine COVID-19 patients and healthy controls, showing high potentials of being biomarkers or therapeutic candidates for COVID-19. This BALF proteome associated with COVID-19 would also be a valuable resource for researches on anti-inflammatory medication and understanding the molecular mechanisms of host response. DATABASE: Proteomic raw data are available in ProteomeXchange (http://proteomecentral.proteomexchange.org) under the accession number PXD022085, and in iProX (www.iprox.org) under the accession number IPX0002429000.

Case Studies Discussing the Pathology, Immunogenicity, and Proposed Mechanism of Toxicity of an Inhaled Anti-TGFβ Humanized Fab Antibody in Non-Human Primates and Mice

Treatment of nonhuman primates and mice with a humanized antigen-binding fragment (Fab) antibody (UCBFab) inhibiting transforming growth factor β via daily inhalation for up to 13 weeks resulted in low systemic exposure but high local exposure in the lung. Target engagement was demonstrated by reduced levels of signal transducers, phosphoSMAD and plasminogen activator inhibitor-1 in the bronchoalveolar lavage fluid (BALF). Treatment was associated with a high frequency and titer of antidrug antibodies, indicating high local immunogenicity, and local pathology within the lung and draining lymph nodes. Microscopic changes were characterized by perivascular (PV) and peribronchiolar (PB) mononuclear inflammatory cell (MIC) infiltrates that were principally lymphocytic in nature and mixed inflammatory cell infiltrates and/or inflammation within the alveoli. Immunohistochemical investigation revealed a predominantly CD68-positive macrophage and CD3- and CD8>CD4-positive T-cell response in the alveoli, whereas within the airways, there was a variable mixture of CD3-positive T cells, CD20-positive B cells, and CD68-positive macrophages. Increased cellularity of the draining lymph nodes was also noted, indicating the presence of an immune response to the inhaled test article. Morphologic changes did not progress over time, and all changes partially recovered. Increased leukocytes (principally macrophages) in BALF cytology correlated with the changes seen by histopathology.

Development of a Sensitive High-Resolution Mass Spectrometry Approach for Urea Nitrogen Quantitation in Small Volumes of Bronchoalveolar Lavage Fluid (BALF)

A sensitive, selective, and quantitative method incorporating high-resolution mass spectrometry was developed for the determination of blood urea nitrogen (BUN) in bronchoalveolar lavage fluid. The method requires no sample cleanup or derivatization prior to analysis. High-performance liquid chromatography (HPLC) on a Hypersil Gold PFP column (100 × 3 mm, 3 μm particle size) connected to a C18 guard column was employed for a 10 min chromatographic separation. The detection of urea was achieved using a Thermo Scientific Q-Exactive Plus instrument incorporating selected ion monitoring (SIM) modes for the protonated adduct of urea. The urea analytical measuring range for the method is 0.047-17.134 mg/dL, resulting in a BUN analytical measurement range of 0.022-8.007 mg/dL, which allows for quantitation over 3 orders of magnitude (R² = 0.999). In addition, the method is suitable for small sample volumes (15 μL) with a high level of accuracy, precision, and specificity.

Pathogenic Analysis of the Bronchoalveolar Lavage Fluid Samples With Pediatric Refractory Mycoplasma pneumoniae Pneumonia

Background: We conducted a pathogenic analysis in the bronchoalveolar lavage fluid (BALF) samples from refractory Mycoplasma pneumoniae pneumonia (RMPP) children.

Methods: A total of 150 BALF samples from 60 RMPP patients were analyzed to investigate pathogenic changes. The characteristics of M. pneumoniae were analyzed through culture, real-time PCR, genotyping, antimicrobial susceptibility testing and proteomics. The other pathogens were determined using culture, sequencing and nucleic acid detection.

Results: In 60 RMPP cases, the bacterial co-infection rate was 5%, while that of virus was 33.3%. The poor prognosis rate was 61.7%. The DNA positive rate among the 150 samples was 98.7%, while the culture positive rate was 56.7% for M. pneumoniae. Significant differences were noticed in the positivity of M. pneumoniae culture obtained from samples with a disease course of at least 3 weeks compared with those within 3 weeks. The genotype 1 M. pneumoniae strains showed a macrolide resistant (MLr) rate of 100%, and that for genotype 2 was 90.1%. Proteomics showed that there were 57 proteins up-regulated in the MLs M. pneumoniae, half of which were membrane-associated protein with adhesion or toxicity.

Conclusions: Pediatric RMPP usually presented with viral co-infection, but it caused limited effects on the progression and prognosis of RMPP. Persistent presence of viable M. pneumoniae is not necessary in the later stage of RMPP. The expression of virulence factor in the MLr M. pneumoniae was higher than that of the MLs M. pneumoniae, which was more common in the RMPP children.

Novel methods for the analysis of toxicants in bronchoalveolar lavage fluid samples from e-cigarette, or vaping, product use-associated lung injury cases: Selected petroleum distillates

RATIONALE

Over 2700 e-cigarette, or vaping, product use-associated lung injury (EVALI) cases were reported to the Centers for Disease Control and Prevention (CDC) during August 2019-February 2020. Bronchoalveolar lavage (BAL) fluid samples from 51 EVALI and 99 non-EVALI cases were analyzed for toxicants including petroleum distillates. We describe a novel method to measure petroleum distillates in BAL fluid using gas chromatography-mass spectrometry (GC/MS).

METHODS

n-Hexane, n-heptane, n-octane, methylcyclopentane, and cyclohexane were measured in BAL fluid specimens by headspace solid-phase microextraction/GC/MS. We created and characterized BAL fluid pools from non-EVALI individuals to determine assay accuracy, precision, linearity, limits of detection (LODs), and analytical specificity. All measurements were conducted in accordance with the rigorous method validation procedures of CDC's Division of Laboratory Sciences.

RESULTS

Matrix validation experiments showed that calibration curves in BAL fluid and saline had similar slopes, with differences less than 5%. Assay precision ranged from 1.98% to 18%. In addition, the LODs for the five analytes ranged from 0.05 to 0.10 μg/L, and their linearity was confirmed with R² values >0.99. The analysis of selected petroleum distillates in BAL fluid analysis was shown to be comparable with their analysis in blood in which the 95th percentiles are below detection.

CONCLUSIONS

We developed and validated a method to quantify petroleum distillates in BAL fluid specimens using GC/MS. The assay provided precise and accurate analyses of EVALI and non-EVALI BAL fluid specimens in support of CDC's EVALI response. This method is applicable to the determination of a broad range of volatile organic compounds in BAL fluid specimens.

Novel methods for the analysis of toxicants in bronchoalveolar lavage fluid samples from e-cigarette, or vaping, product use associated lung injury (EVALI) cases: Terpenes

RATIONALE

Over 2800 e-cigarette, or vaping, product use-associated lung injury (EVALI) cases were reported to the Centers for Disease Control and Prevention (CDC) during August 2019 to February 2020. Bronchoalveolar lavage (BAL) fluid samples from 51 EVALI and 99 non-EVALI cases were analyzed for toxicants including terpenes. We describe a novel method to measure selected terpenes in BAL fluid by gas chromatography/tandem mass spectrometry (GC/MS/MS).

METHODS

α-Pinene, β-pinene, β-myrcene, 3-carene, and limonene were measured in BAL fluid specimens by headspace solid-phase microextraction/gas chromatography/tandem mass spectrometry. We created and characterized BAL fluid pools from non-EVALI individuals to determine assay accuracy, precision, linearity, limits of detection, and analytical specificity. All measurements were conducted in accordance with the CDC's Division of Laboratory Sciences rigorous method validation procedures.

RESULTS

Matrix validation experiments showed that calibration curves in BAL fluid and saline had similar slopes, with differences of less than 7%. The assay precision ranged from 2.52% to 5.30%. In addition, the limits of detection for the five analytes ranged from 1.80 to 16.8 ng/L, and the linearity was confirmed with R² values >0.99.

CONCLUSIONS

We developed and validated a method to quantify selected terpenes in BAL fluid specimens using GC/MS/MS. The assay provided accurate and precise analyses of EVALI and non-EVALI BAL fluid specimens in support of CDC's EVALI response. This method is applicable to the determination of a broad range of terpenes in BAL fluid specimens.

Comprehensive pulmonary toxicity assessment of cetylpyridinium chloride using A549 cells and Sprague-Dawley rats

Cetylpyridinium chloride (CPC), a quaternary ammonium compound and cationic surfactant, is used in personal hygiene products such as toothpaste, mouthwash, and nasal spray. Although public exposure to CPC is frequent, its pulmonary toxicity has yet to be fully characterized. Due to high risks of CPC inhalation, we aimed to comprehensively elucidate the in vitro and in vivo toxicity of CPC. The results demonstrated that CPC is highly cytotoxic against the A549 cells with a half-maximal inhibitory concentration (IC₅₀ ) of 5.79 μg/ml. Following CPC exposure, via intratracheal instillation (ITI), leakage of lactate dehydrogenase, a biomarker of cell injury, was significantly increased in all exposure groups. Further, repeated exposure of rats to CPC for 28 days caused a decrease in body weight of the high-exposure group and the relative weights of the lungs and kidneys of the high recovery group, but no changes were evident in the histological and serum chemical analyses. The bronchoalveolar lavage fluid (BALF) analysis showed a significant increase in proinflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α levels. ITI of CPC induced focal inflammation of the pulmonary parenchyma in rats' lungs. Our study demonstrated that TNF-α was the most commonly secreted proinflammatory cytokine during CPC exposure in both in vitro and in vivo models. Polymorphonuclear leukocytes in the BALF, which are indicators of pulmonary inflammation, significantly increased in a concentration-dependent manner in all in vivo studies including the ITI, acute, and subacute inhalation assays, demonstrating that PMNs are the most sensitive parameters of pulmonary toxicity.

Microbiomic Analysis on Low Abundant Respiratory Biomass Samples; Improved Recovery of Microbial DNA From Bronchoalveolar Lavage Fluid

In recent years the study of the commensal microbiota is driving a remarkable paradigm shift in our understanding of human physiology. However, intrinsic technical difficulties associated with investigating the Microbiomics of some body niches are hampering the development of new knowledge. This is particularly the case when investigating the functional role played by the human microbiota in modulating the physiology of key organ systems. A major hurdle in investigating specific Microbiome communities is linked to low bacterial density and susceptibility to bias caused by environmental contamination. To prevent such inaccuracies due to background processing noise, harmonized tools for Microbiomic and bioinformatics practices have been recommended globally. The fact that the impact of this undesirable variability is negatively correlated with the DNA concentration in the sample highlights the necessity to improve existing DNA isolation protocols. In this report, we developed and tested a protocol to more efficiently recover bacterial DNA from low volumes of bronchoalveolar lavage fluid obtained from infants and adults. We have compared the efficiency of the described method with that of a commercially available kit for microbiome analysis in body fluids. We show that this new methodological approach performs better in terms of extraction efficiency. As opposed to commercial kits, the DNA extracts obtained with this new protocol were clearly distinguishable from the negative extraction controls in terms of 16S copy number and Microbiome community profiles. Altogether, we described a cost-efficient protocol that can facilitate microbiome research in low-biomass human niches.

Diagnostic Performance of Bronchoalveolar Lavage (1,3)-β-d-Glucan Assay for Pneumocystis jirovecii Pneumonia

We evaluated the performance of the (1,3)-β-d-glucan (BDG) assay on bronchoalveolar lavage fluid (BALF) as a possible aid to the diagnosis of Pneumocystis jirovecii pneumonia. BALF samples from 18 patients with well-characterized proven, probable, and possible Pneumocystis pneumonia and 18 well-matched controls were tested. We found that the best test performance was observed with a cut-off value of 128 pg/mL; receiver operating characteristic/area under the curve (ROC/AUC) was 0.70 (95% CI 0.52–0.87). Sensitivity and specificity were 78% and 56%, respectively; positive predictive value was 64%, and negative predictive value was 71%. The low specificity that we noted limits the utility of BALF BDG as a diagnostic tool for Pneumocystis pneumonia.

Local and Systemic Concentrations of Pattern Recognition Receptors of the Lectin Pathway of Complement in a Cohort of Patients With Interstitial Lung Diseases

Background

The role of the lectin pathway of complement in the pathogenesis of interstitial lung diseases (ILDs) is largely unknown. Pattern recognition receptors (PRR) of the lectin pathway are involved in the clearance of apoptotic cells either via activation of the complement system or as direct opsonins. As recent findings suggest a role of apoptosis in the development of pulmonary fibrosis, the influence of plasma lectins has lately been considered in various ILDs, but data on local concentrations in the lungs are lacking. This study investigated the role of mannose-binding lectin (MBL), ficolin-2 and ficolin-3 in ILD patients with a focus on idiopathic pulmonary fibrosis (IPF) and sarcoidosis.

Methods

A case control study was conducted involving 80 patients with different forms of ILD as well as 40 control patients undergoing routine flexible bronchoscopy with bronchoalveolar lavage (BAL). Plasma and BAL fluid (BALF) levels of MBL, ficolin-2 and ficolin-3 as well as complement split products C4d and C5a (only in BALF) were measured by enzyme-linked immunosorbent assays. Eight single-nucleotide polymorphisms (SNPs) of MBL and ficolin-2 were determined by genotyping and tested for their association with ILDs.

Results

We included 35, 35, 10, and 40 patients with sarcoidosis, idiopathic pulmonary fibrosis (IPF), other ILD, and a control group, respectively. BALF but not plasma levels of the three PRR were significantly elevated in sarcoidosis patients compared to a control group without ILD (MBL: median 66.8 vs. 24.6 ng/ml, p = 0.02, ficolin-2: 140 vs. 58.8 ng/ml, p = 0.01, ficolin-3: 2523 vs. 1180 ng/ml, p = 0.02), whereas the frequency of the investigated SNPs was similar. In line, complement split products were markedly elevated in BALF of sarcoidosis patients (C4d, median 97.4 vs. 0 ng/ml, p = 0.10; C5a, 23.9 vs. 9.1 ng/ml, p = 0.01). There was a weak positive correlation of BALF ficolin-3 with serum neopterin, a marker of sarcoidosis activity. In IPF patients, we observed numerically higher MBL plasma and BALF levels (plasma, median 1511 vs. 879 ng/ml, p = 0.44; BALF, 37.5 vs. 24.6 ng/ml, p = 0.7) as well as lower ficolin-2 plasma levels (plasma 1111 vs. 1647 ng/ml, p = 0.11). Ficolin-2 plasma levels were inversely correlated with the forced vital capacity (r = 0.55, p = 0.1).

Conclusion

This is the first study to simultaneously assess systemic and local lectin pathway protein levels in ILD patients. Our data suggest an involvement of PRR of the lectin pathway in the pathogenesis of sarcoidosis given the significantly higher BALF levels compared to a control group. Additional analyses in a larger patient cohort are required to confirm or refute a potential effect of local and/or systemic ficolin-2 levels in IPF patients.