Anna Reed

Relation of interlobar collaterals to radiological heterogeneity in severe emphysema.

Background: A study was undertaken to assess the prevalence of interlobar collateral ventilation in patients with severe emphysema to identify factors that may help to predict patients with significant collateral ventilation. Methods: Between April 2002 and August 2003, ex vivo assessment of the lungs 17 consecutive patients with smoking related severe emphysema was performed. To assess collateral flow, all lobes of explanted specimens were selectively intubated using a wedged cuffed microlaryngeal intubation tube and then manually ventilated using a bagging circuit. Interlobar collateral ventilation was defined as the ability to easily inflate a non-intubated lobe at physiological pressures. Pre-transplant demographic characteristics, physiological data, radiological results, and explant histology were assessed for retrospective relationships with the degree of interlobar collateral ventilation in the explanted lung. Results: A total of 23 lungs were evaluated, 15 of which (66%) had significant collateral interlobar airflow. There were no significant differences in any demographic, physiological, or pathological variables between patients with collateral ventilation and those with no collateral ventilation. However, there was a significant relationship between the presence of interlobar collateral ventilation and radiological scores (p<0.05). Conclusions: Interlobar collateral ventilation occurs to a much greater extent in patients with radiologically homogeneous emphysema than in those with heterogeneous emphysema. Heterogeneity of emphysema may predict patients with a significantly reduced risk of interlobar collateral ventilation.

Phagocytosis-dependent activation of a TLR9–BTK–calcineurin–NFAT pathway co-ordinates innate immunity to Aspergillus fumigatus

Transplant recipients on calcineurin inhibitors are at high risk of invasive fungal infection. Understanding how calcineurin inhibitors impair fungal immunity is a key priority for defining risk of infection. Here, we show that the calcineurin inhibitor tacrolimus impairs clearance of the major mould pathogen Aspergillus fumigatus from the airway, by inhibiting macrophage inflammatory responses. This leads to defective early neutrophil recruitment and fungal clearance. We confirm these findings in zebrafish, showing an evolutionarily conserved role for calcineurin signalling in neutrophil recruitment during inflammation. We find that calcineurin–NFAT activation is phagocytosis dependent and collaborates with NF‐κB for TNF‐α production. For yeast zymosan particles, activation of macrophage calcineurin–NFAT occurs via the phagocytic Dectin‐1–spleen tyrosine kinase pathway, but for A. fumigatus, activation occurs via a phagosomal TLR9‐dependent and Brutons tyrosine kinase‐dependent signalling pathway that is independent of MyD88. We confirm the collaboration between NFAT and NF‐κB for TNF‐α production in primary alveolar macrophages. These observations identify inhibition of a newly discovered macrophage TLR9–BTK–calcineurin–NFAT signalling pathway as a key immune defect that leads to organ transplant‐related invasive aspergillosis.

The Serum Opsonin L-ficolin Is Detected in Lungs of Human Transplant Recipients Following Fungal Infections and Modulates Inflammation and Killing of Aspergillus fumigatus

BACKGROUND Invasive aspergillosis (IA) is a life-threatening systemic fungal infection in immunocompromised individuals that is caused by Aspergillus fumigatus. The human serum opsonin, L-ficolin, has been observed to recognize A. fumigatus and could participate in fungal defense. METHODS Using lung epithelial cells, primary human monocyte-derived macrophages (MDMs), and neutrophils from healthy donors, we assessed phagocytosis and killing of L-ficolin-opsonized live A. fumigatus conidia by flow cytometry and microscopy. Additionally, cytokines were measured by cytometric bead array, and L-ficolin was measured in bronchoalveolar lavage (BAL) fluid from lung transplant recipients by enzyme-linked immunosorbent assay. RESULTS L-ficolin opsonization increased conidial uptake and enhanced killing of A. fumigatus by MDMs and neutrophils. Opsonization was also shown to manifest an increase in interleukin 8 release from A549 lung epithelial cells but decreased interleukin 1β, interleukin 6, interleukin 8, interleukin 10, and tumor necrosis factor α release from MDMs and neutrophils 24 hours after infection. The concentration of L-ficolin in BAL fluid from patients with fungal infection was significantly higher than that for control subjects (P = .00087), and receiving operating characteristic curve analysis highlighted the diagnostic potential of L-ficolin for lung infection (area under the curve, 0.842; P < .0001). CONCLUSIONS L-ficolin modulates the immune response to A. fumigatus. Additionally, for the first time, L-ficolin has been demonstrated to be present in human lungs.

H‐ficolin binds Aspergillus fumigatus leading to activation of the lectin complement pathway and modulation of lung epithelial immune responses

Aspergillus fumigatus is an opportunistic fungal pathogen that typically infects the lungs of immunocompromised patients leading to a high mortality. H‐Ficolin, an innate immune opsonin, is produced by type II alveolar epithelial cells and could participate in lung defences against infections. Here, we used the human type II alveolar epithelial cell line, A549, to determine the involvement of H‐ficolin in fungal defence. Additionally, we investigated the presence of H‐ficolin in bronchoalveolar lavage fluid from transplant patients during pneumonia. H‐Ficolin exhibited demonstrable binding to A. fumigatus conidia via l‐fucose, d‐mannose and N‐acetylglucosamine residues in a calcium‐ and pH‐dependent manner. Moreover, recognition led to lectin complement pathway activation and enhanced fungal association with A549 cells. Following recognition, H‐ficolin opsonization manifested an increase in interleukin‐8 production from A549 cells, which involved activation of the intracellular signalling pathways mitogen‐activated protein kinase MAPK kinase 1/2, p38 MAPK and c‐Jun N‐terminal kinase. Finally, H‐ficolin concentrations were significantly higher in bronchoalveolar lavage fluid of patients with lung infections compared with control subjects (n = 16; P = 0·00726). Receiver operating characteristics curve analysis further highlighted the potential of H‐ficolin as a diagnostic marker for lung infection (area under the curve = 0·77; P < 0·0001). Hence, H‐ficolin participates in A. fumigatus defence through the activation of the lectin complement pathway, enhanced fungus–host interactions and modulated immune responses.

Mechanical ventilation after lung transplantation

INTRODUCTION To explore the hypothesis that early ventilation strategies influence clinical outcomes in lung transplantation, we have examined our routine ventilation practices in terms of tidal volumes (Vt) and inflation pressures. METHODS A total of 124 bilateral lung transplants between 2010 and 2013 were retrospectively assigned to low (<6 mL/kg), medium (6-8 mL/kg), and high (>8 mL/kg) Vt groups based on ventilation characteristics during the first 6 hours after surgery. Those same 124 patients were also stratified to low-pressure (<25 cm H2O) and high-pressure (≥25 cm H2O) groups. RESULTS Eighty percent of patients were ventilated using pressure control mode. Low, medium, and high Vt were applied to 10%, 43%, and 47% of patients, respectively. After correcting for patients requiring extracorporeal support, there was no difference in short-term to midterm outcomes among the different Vt groups. Low inflation pressures were applied to 61% of patients, who had a shorter length of intensive care unit stay (5 vs 12 days; P = .012), higher forced expiratory volume in 1 second at 3 months (77.8% vs 60.3%; P < .001), and increased 6-month survival rate (95% vs 77%; P = .008). CONCLUSION Low Vt ventilation has not been fully adopted in our practice. Ventilation with higher inflation pressures, but not Vt, was significantly associated with poorer outcomes after lung transplantation.

Modified Technique Using Novalung as Bridge to Transplant in Pulmonary Hypertension

Patients with idiopathic pulmonary artery hypertension in refractory right ventricular failure may decompensate acutely and die while on the lung transplantation waiting list. We describe such a patient bridged to lung transplantation with a modified surgical technique for left pulmonary artery-to-left atrium bypass using Novalung, a low-resistance diffusion membrane device.

The evolution of lung transplantation for cystic fibrosis: A 2017 update

Lung transplantation (LTx) is an established therapy for patients with end-stage cystic fibrosis (CF). Indeed, CF is the commonest indication for those aged<50years of age needing LTx. CF LTx is associated with a 45% 10year survival - according to the worlds largest registry. It is important all otherwise suitable CF patients with severe lung disease have a timely referral for discussion and consideration of the possibility of LTx. LTx discussions must carefully consider colonisation or infection with Burkholderia cenocepacia, Mycobacterium abscessus and Scediosporium - as good LTx outcomes cannot be guaranteed. A bridge to LTx with extra-corporeal lung support is a realistic option, but remains a relative contraindication to LTx. Improvements in LTx matching technology and post-operative management are steadily improving overall long-term outcomes, although chronic allograft rejection remains problematic. Expert multidisciplinary life-long post-LTx care remains the key to success.

ISHLT Consensus ReportsPrimary Lung Graft DysfunctionReport of the ISHLT Working Group on Primary Lung Graft Dysfunction, part I: Definition and grading—A 2016 Consensus Group statement of the International Society for Heart and Lung Transplantation

From the Allergy, Immunology and Respiratory Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri; Institute for Advanced Organ Disease and Transplantation, Tampa General Hospital/University of South Florida, Tampa, Florida; Department of Surgery, Michigan State University, Ada, Michigan; Lung Transplant Program, University of Chicago, Chicago, Illinois; Lung Transplant Program, Harefield Hospital, Harefield, United Kingdom; Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida, Gainesville, Florida; Division of Pulmonary Medicine, Medical University of South Carolina, Charleston, South Carolina; Section of Lung Transplantation, Department of Cardiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; Section of Pulmonary and Critical Care, Department of Medicine, and Lung Transplant Program, University of Chicago, Chicago, Illinois; Department of Pulmonary, Allergy and Critical Care Medicine, Respiratory Institute, Cleveland Clinic, Cleveland, Ohio; National Pulmonary Hypertension Service (Newcastle), The Newcastle upon Tyne Hospitals NHS Foundation Trust, and Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom; Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; and the Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.

The role of cardiopulmonary bypass in lung transplantation

The risk–benefit for utilizing cardio‐pulmonary bypass (CPB) in lung transplantation (LTx) remains debatable. This study compares outcomes after LTx utilizing different CPB strategies – elective CPB vs. off‐pump vs. off‐pump with unplanned conversion to CPB.

Caspofungin Increases Fungal Chitin and Eosinophil and γδ T Cell–Dependent Pathology in Invasive Aspergillosis

The polysaccharide-rich fungal cell wall provides pathogen-specific targets for antifungal therapy and distinct molecular patterns that stimulate protective or detrimental host immunity. The echinocandin antifungal caspofungin inhibits synthesis of cell wall β-1,3-glucan and is used for prophylactic therapy in immune-suppressed individuals. However, breakthrough infections with fungal pathogen Aspergillus fumigatus are associated with caspofungin prophylaxis. In this study, we report in vitro and in vivo increases in fungal surface chitin in A. fumigatus induced by caspofungin that was associated with airway eosinophil recruitment in neutropenic mice with invasive pulmonary aspergillosis (IA). More importantly, caspofungin treatment of mice with IA resulted in a pattern of increased fungal burden and severity of disease that was reversed in eosinophil-deficient mice. Additionally, the eosinophil granule proteins major basic protein and eosinophil peroxidase were more frequently detected in the bronchoalveolar lavage fluid of lung transplant patients diagnosed with IA that received caspofungin therapy when compared with azole-treated patients. Eosinophil recruitment and inhibition of fungal clearance in caspofungin-treated mice with IA required RAG1 expression and γδ T cells. These results identify an eosinophil-mediated mechanism for paradoxical caspofungin activity and support the future investigation of the potential of eosinophil or fungal chitin-targeted inhibition in the treatment of IA.