Kate Gould

Pseudomonas aeruginosa colonization of the allograft after lung transplantation and the risk of bronchiolitis obliterans syndrome.

Long-term survival after lung transplantation remains limited by the development of bronchiolitis obliterans syndrome (BOS). Allograft colonization with Pseudomonas aeruginosa is common particularly in recipients with BOS, but a possible etiological relationship remains unexplored. In 155 consecutive lung transplants, the development of allograft colonization with Pseudomonas was strongly associated with the development of BOS within 2 years of transplant (23.4% vs. 7.7% in those colonized and not colonized, respectively, P=0.006). Freedom from BOS was significantly shorter in those patients without any pretransplant bacterial reservoir developing de novo allograft pseudomonal colonization as compared with those remaining free of colonization (Kaplan-Meier log-rank P=0.014). The isolation of Pseudomonas preceded the diagnosis of BOS in 14 of 18 (78%) and by a median of 204 days (95% confidence interval 115–492) in patients developing both these complications. We conclude that de novo colonization of the lung allograft by Pseudomonas is strongly associated with the subsequent development of BOS.

Working formulation for the standardization of definitions of infections in patients using ventricular assist devices

In 2009, the International Society for Heart and Lung Transplantation (ISHLT) recognized the importance of infectionrelated morbidity and mortality in patients using ventricular assist devices (VADs) and the growing need for a consensusbased expert opinion to provide standard definitions of infections in these patients. The aim of these standard definitions is to improve clinical-investigator communication, allowing meaningful comparison in practice and outcomes between different centers and different VAD devices. In 2010, a core group of experts, including infectious diseases specialists, cardiologists, pathologists, radiologists, and cardiothoracic surgeons, formed an ISHLT Infectious Diseases Working Group to develop agreed criteria for definitions of infections in VAD patients. These definitions have been created by adapting and expanding on existing standardized definitions, which are based on the pathophysiology of equivalent infectious processes in prosthetic devices, such as cardiac prosthetic valve infections, intravascular catheter-related infections, and prosthetic joint infections. These definitions have been divided into 3 sections: VAD-specific infections, VAD-related infections, and non-VAD infections. Owing to the constant shortage of donor organs, new allocation systems, and improved medical therapies for congestive cardiac failure, the overwhelming trend in cardiac transplantation has been toward listing principally the most critically ill patients, that is, those requiring inpatient inotropic therapy for mechanical circulatory support (MCS). The ventricular assist device (VAD) has an expanding role in the management of these patients, both as a bridge to transplantation and as a destination therapy (ie, alternative to transplantation). According to United Network of Organ Sharing (UNOS) registry data, 9,000 transplant candidates have undergone MCS since 1999, comprising 33% of all listed patients and 75% of all listed inpatients. 1

Burkholderia cepacia complex genomovars and pulmonary transplantation outcomes in patients with cystic fibrosis

Burkholderia cepacia is a group of organisms that comprises seven genotypically distinct species (B cepacia genomovars I-VII), which are collectively known as the B cepacia complex. Preoperative infection with B cepacia is associated with a poor prognosis in lung transplant recipients with cystic fibrosis. Many centres do not, therefore, offer transplants to these individuals. Our aim was to ascertain whether or not post-transplant mortality is affected by pretransplant genomovar status. We studied archived isolates with PCR-based methods, and recorded excessive mortality in patients infected with B cepacia genomovar III, but not in those infected with other genomovars.

A 2010 working formulation for the standardization of definitions of infections in cardiothoracic transplant recipients

Shahid Husain, MD, MS, Martha L. Mooney, MD, MS, FACP, Lara Danziger-Isakov, MD, MPH, Frauke Mattner, MD, PhD, Nina Singh, MD, Robin Avery, MD, FIDSA, Michael Ison, MD, MS, Atul Humar, MD, MSc, Robert F. Padera, MD, PhD, Leo P. Lawler, MD, FRCR, Andy Fisher, PhD, FRCP, Richard J. Drew, MD, Kate F. Gould, MBBS, MRCP, FRCP, Amparo Sole, MD, PhD, Sean Studer, MD, MSc, Patricia Munoz, MD, Lianne G. Singer, MD, FRCPC, and Margaret Hannan, MD, FRCP, FRCPath, for the ISHLT Infectious Diseases Council Working Group on Definitions From the Division of Infectious Diseases, Transplant Infectious Diseases, University Health Network, University of Toronto, Toronto, Ontario, Canada; Eastern Virginia Medical School, Sentara Norfolk Transplant Center, Norfolk, Virginia; Center for Pediatric Infectious Diseases, Department of Infectious Disease, Medicine Institute, The Cleveland Clinic, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio; Infection Control and Hospital Epidemiology, Institute for Medical Microbiology, Hannover Medical School, Hannover, Germany; Division of Infectious Diseases, Veteran Affairs Hospital, University of Pittsburgh, Pittsburgh, Pennsylvania; Divisions of Infectious Diseases and Organ Transplantation, Northwestern University, Feinberg School of Medicine, Chicago, Illinois; Department of Medicine, Division of Infectious Diseases, University of Alberta, Edmonton, Alberta, Canada; Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts; Respiratory Transplant Medicine, Newcastle University, Institute of Transplantation, Freeman Hospital, Newcastle Upon Tyne, UK; Mater Misericordiae University Hospital, Dublin, Ireland; Health Protection Agency Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle, UK; Hospital Universitario La Fe, Valencia, Spain; Division of Pulmonary & Critical Care, Newark Beth Israel Medical Center, Newark, New Jersey; and Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Maranon, Universidad Complutense, Madrid, Spain.

Prevalence and clonality of Burkholderia cepacia complex genomovars in UK patients with cystic fibrosis referred for lung transplantation

Background: It has previously been reported that patients infected with Burkholderia cenocepacia (genomovar III) before lung transplantation have a poorer outcome than those with other B cepacia complex infections. Methods: An extensive study was conducted to determine the prevalence and clonality of B cepacia complex genomovars isolated from patients referred for transplant assessment between 1989 to the present and, where appropriate, whether strain type was related to transplant outcome. Results: Isolates from 29 patients were identified as B cepacia complex organisms by molecular analysis. Thirteen patients (45%) were infected with the highly transmissible ET-12 strain of B cenocepacia recA lineage III-A, while all remaining patients were infected with genetically unique B cenocepacia, B multivorans, and B vietnamiensis strains. All previously reported deaths following transplantation were associated with ET-12 infection. Conclusions: The ET-12 strain is the predominant cause of B cenocepacia infections in patients with cystic fibrosis referred to our pulmonary transplant centre and is associated with poor transplant outcomes using standard treatment regimens.

The effect of ex vivo lung perfusion on microbial load in human donor lungs

BACKGROUND Ex vivo lung perfusion (EVLP) has emerged as a technique to potentially recondition unusable donor lungs for transplantation. Beneficial effects of EVLP on physiologic function have been reported, but little is known about the effect of normothermic perfusion on the infectious burden of the donor lung. In this study, we investigated the effect of EVLP on the microbial load of human donor lungs. METHODS Lungs from 18 human donors considered unusable for transplantation underwent EVLP with a perfusate containing high-dose, empirical, broad-spectrum anti-microbial agents. Quantitative cultures of bacteria and fungi were performed on bronchoalveolar lavage fluid from the donor lung before and after 3 to 6 hours of perfusion. The identification of any organisms and changes in number of colony forming units before and after EVLP were assessed and anti-microbial susceptibilities identified. RESULTS Thirteen out of 18 lungs had positive cultures, with bacterial loads significantly decreasing after EVLP. Yeast loads increased when no anti-fungal treatment was given, but were reduced when prophylactic anti-fungal treatment was added to the circuit. Six lungs were ultimately transplanted into patients, all of whom survived to hospital discharge. There was 1 death at 11 months. CONCLUSIONS Our study shows that EVLP with high-dose, empirical anti-microbial agents in the perfusate is associated with an effective reduction in the microbial burden of the donor lung, a benefit that has not previously been demonstrated.

Mediastinitis in heart and lung transplantation: 15 years experience

BACKGROUND Mediastinitis after sternotomy carries a very high mortality, especially in patients receiving immunosuppressive treatment. METHODS A retrospective analysis of the data for patients who had undergone cardiopulmonary transplantation between May 1985 and December 2000 was undertaken. A total of 776 patients had either a median sternotomy or a transverse sternotomy through a clam-shell incision. Transplantations were as follows: 591 heart (3 simultaneous heart and renal, and 1 heart and liver), 126 bilateral sequential lung, 57 heart-lung, 1 en bloc double-lung, and 1 heart and single-lung. RESULTS In all, 21 (2.7%) recipients had mediastinitis. Of these, 14 had heart, 3 heart-lung, and 4 bilateral lung transplantation. There were 18 median and 3 transverse sternotomies. There were 6 deaths (28.6%). Treatment consisted of antibiotics alone in 2 patients and subxiphisternal drainage in another 2 patients. The sternum was reopened in 17 (80.95%) patients, with debridement and primary closure alone in 5 of these 17 patients and additional irrigation in the other 12. Those who had resternotomy, debridement, and substernal irrigation had a better outcome when compared with the outcomes of other modes of treatment (1 death among 12 patients) (p = 0.06). Age, cardiopulmonary bypass time, body mass index, time to diagnosis, and treatment did not differ between those who survived and those who did not. CONCLUSIONS Early aggressive debridement with substernal irrigation is the best mode of treatment for patients with posttransplantation mediastinitis.

The 2015 International Society for Heart and Lung Transplantation Guidelines for the management of fungal infections in mechanical circulatory support and cardiothoracic organ transplant recipients: Executive summary.

Shahid Husain, MD, MS, Amparo Sole, MD, PhD, Barbara D. Alexander, MD, MHS, Saima Aslam, MD, MS, Robin Avery, MD, Christian Benden, MD, Eliane M. Billaud, PharmD, PhD, Daniel Chambers, MBBS, MD, Lara Danziger-Isakov, MD, Savitri Fedson, MD, Kate Gould, MD, Aric Gregson, MD, Paolo Grossi, MD, PhD, Denis Hadjiliadis, MD, Peter Hopkins, MD, Me-Linh Luong, MD, Debbie J.E. Marriott, MD, Victor Monforte, MD, Patricia Munoz, MD, PhD, Alessandro C. Pasqualotto, MD, PhD, Antonio Roman, MD, Fernanda P. Silveira, MD, Jeffrey Teuteberg, MD, MS, Stephen Weigt, MD, Aimee K. Zaas, MD, MHS, Andreas Zuckerman, MD, and Orla Morrissey, MD, PhD

Pseudomonas aeruginosa accentuates epithelial to mesenchymal transition in the airway

Epithelial-to-mesenchymal transition (EMT) has been implicated in the dysregulated epithelial wound repair that contributes to obliterative bronchiolitis (OB) after lung transplantation. Acquisition of Pseudomonas aeruginosa in the transplanted airway has been shown to be a risk factor for the development of OB. We investigated the potential of P. aeruginosa to drive EMT in primary bronchial epithelial cells (PBECs) isolated from lung transplant recipients. Changes in the expression of epithelial and mesenchymal markers was assessed in cells challenged with clinical isolates of P. aeruginosa or co-cultured with P. aeruginosa-activated monocytic cells (THP-1) in the presence or absence of transforming growth factor (TGF)-&bgr;1. P. aeruginosa did not drive or accentuate TGF-&bgr;1-driven EMT directly. Co-culturing P. aeruginosa-activated THP-1 cells with PBECs did not drive EMT. However, co-culturing P. aeruginosa-activated THP-1 cells with PBECs significantly accentuated TGF-&bgr;1-driven EMT. P. aeruginosa, via the activation of monocytic cells, can accentuate TGF-&bgr;1-driven EMT. These in vitro observations may help explain the in vivo clinical observation of a link between acquisition of P. aeruginosa and an increased risk of developing OB.

Pulmonary transplantation for cystic fibrosis: Pre-transplant recipient characteristics in patients dying of peri-operative sepsis

BACKGROUND Pulmonary transplantation has emerged as a successful treatment for end-stage cystic fibrosis. Despite the chronic bronchial sepsis and often multi-resistant organisms seen in this group of recipients, death due to post-operative sepsis is relatively scarce. Identifying potential recipient risk factors for poor outcome may further improve the utilization of a scarce donor pool. METHODS We assessed the role of pre-operative clinical measures of sepsis, microbial characteristics and recipient characteristics on post-transplant outcome in 85 cystic fibrosis patients who underwent pulmonary transplantation. Ten percent of patients died in the early post-operative period due to sepsis. The prognostic role of recipient factors including markers of sepsis, such as white cells and C-reactive protein (CRP), and the influence of multi-resistant organisms, in particular organisms from the Burkholderia cepacia complex, on outcomes were investigated. RESULTS We found no prognostic effect of gender, pre-transplant CRP, forced expiratory volume in 1 second (FEV(1)), weight, diabetic status or infection with multi-resistant Pseudomonas organisms. A raised white cell count or temperature or a pre-transplant infection with B cepacia was, however, associated with a significantly poorer prognosis at p = 0.03, 0.03 and 0.001, respectively. CONCLUSIONS Pre-operative B cepacia complex infection, leukocytosis and pyrexia, but not CRP, weight, diabetes or lung function, were found to be associated with poorer post-transplant outcome. The most clinically relevant of these to the subsequent risk of post-operative death from sepsis appear to be B cepacia infection and pyrexia.