Outcomes of lung transplantation for cystic fibrosis in a large UK cohort

Update on Lung Transplantation for Cystic Fibrosis

Lung transplantation provides a treatment option for many individuals with advanced lung disease due to cystic fibrosis (CF). Since the first transplants for CF in the 1980s, survival has improved and the opportunity for transplant has expanded to include individuals who previously were not considered candidates for transplant. Criteria to be a transplant candidate vary significantly among transplant programs, highlighting that the engagement in more than one transplant program may be necessary. Individuals with highly resistant CF pathogens, malnutrition, osteoporosis, CF liver disease, and other comorbidities may be suitable candidates for lung transplant, or if needed, multi-organ transplant. The transplant process involves several phases, from discussion of prognosis and referral to a transplant center, to transplant evaluation, to listing, transplant surgery, and care after transplant. While the availability of highly effective CF transmembrane conductance regulator (CFTR) modulators for many individuals with CF has improved lung function and slowed progression to respiratory failure, early discussion regarding transplant as a treatment option and referral to a transplant program are critical to maximizing opportunity and optimizing patient and family experience. The decision to be evaluated for transplant and to list for transplant are distinct, and early referral may provide a treatment option that can be urgently executed if needed. Survival after transplant for CF is improving, to a median survival of approximately 10 years, and most transplant survivors enjoy significant improvement in quality of life.

Feasibility and acceptability of a physical activity behavioural modification tele-coaching intervention in lung transplant recipients

BACKGROUND

Despite improvements in pulmonary function following lung transplantation (LTx), physical activity levels remain significantly lower than the general population. To date, there is little research investigating interventions to improve daily physical activity in LTx recipients. This study assessed the feasibility and acceptability of a novel, 12-weeks physical activity tele-coaching (TC) intervention in LTx recipients.

METHODS

Lung transplant recipients within 2 months of hospital discharge were recruited and randomised (1:1) to TC or usual care (UC). TC consists of a pedometer and smartphone app, allowing transmission of activity data to a platform that provides feedback, activity goals, education, and contact with the researcher as required. Recruitment and retention, occurrence of adverse events, intervention acceptability and usage were used to assess feasibility.

RESULTS

Key criteria for progressing to a larger study were met. Of the 15 patients eligible, 14 were recruited and randomised to TC or UC and 12 completed (67% male; mean ± SD age; 58 ± 7 years; COPD n = 4, ILD n = 6, CF n = 1, PH n = 1): TC (n = 7) and UC (n = 5). TC was well accepted by patients, with 86% indicating that they enjoyed taking part. Usage of the pedometer was excellent, with all patients wearing it for over 90% of days and rating the pedometer and telephone contact as the most vital aspects. There were no adverse events related to the intervention. After 12 weeks, only TC displayed improvements in accelerometry steps/day (by 3475 ± 3422; p = .036) and movement intensity (by 153 ± 166 VMU; p = .019), whereas both TC and UC groups exhibited clinically important changes in physical SF-36 scores (by 11 ± 14 and 7 ± 9 points, respectively).

CONCLUSION

TC appears to be a feasible, safe, and well-accepted intervention in LTx.

Survival difference between high-risk and low-risk CFTR genotypes after lung transplant

BACKGROUND

While cystic fibrosis transmembrane conductance regulator (CFTR) genotypes are associated with clinical outcomes in cystic fibrosis patients, it is unknown if genotype impacts lung transplant outcomes. We sought to compare lung transplant survival and time to bronchiolitis obliterans syndrome (BOS) between high-risk, low-risk, and not yet classified CFTR genotypes.

METHODS

We used merged data from the Organ Procurement and Transplantation Network (2005-2017) and United States Cystic Fibrosis Foundation Patient Registry (2005-2016). Cox Proportional Hazards models compared graft failure after lung transplant and time to BOS among high-risk, low-risk, and not yet classified risk CFTR genotype classes.

RESULTS

Among 1,830 cystic fibrosis lung transplant recipients, median survival for those with low-risk, high-risk, and not yet classified genotype was 9.83, 6.25, and 5.75 years, respectively. Adjusted Cox models showed recipients with a low-risk genotype had 39% lower risk of death or re-transplant compared to those with high-risk genotype (adjusted HR 0.61, 95% CI = 0.40, 0.91). A subset of 1,585 lung transplant recipients were included in the BOS subgroup analysis. Adjusted analyses showed no significant difference of developing BOS among high-risk, low-risk, or not yet classified genotypes.

CONCLUSIONS

Lung transplant recipients with low-risk CFTR genotype have better survival after transplant compared to recipients with high-risk or not yet classified genotypes. Given these differences, future studies evaluating the mechanism by which CFTR genotype affects post-transplant survival could identify potential targets for intervention.

Anesthetic considerations in lung transplantation: past, present and future

Lung transplantation is a very complex surgical procedure with many implications for the anesthetic care of these patients. Comprehensive preoperative evaluation is an important component of the transplant evaluation as it informs many of the decisions made perioperatively to manage these complex patients effectively and appropriately. These decisions may involve pre-emptive actions like pre-habilitation and nutrition optimization of these patients before they arrive for their transplant procedure. Appropriate airway and ventilation management of these patients needs to be performed in a manner that provides an optimal operating conditions and protection from ventilatory injury of these fragile post-transplant lungs. Pain management can be challenging and should be managed in a multi-modal fashion with or without the use of an epidural catheter while recognizing the risk of neuraxial technique in patients who will possibly be systemically anticoagulated. Complex monitoring is required for these patients involving both invasive and non-invasive including the use of transesophageal echocardiography (TEE) and continuous cardiac output monitoring. Management of the patient's hemodynamics can be challenging and involves managing the systemic and pulmonary vascular systems. Some patients may require extra-corporeal lung support as a planned part of the procedure or as a rescue technique and centers need to be proficient in instituting and managing this sophisticated method of hemodynamic support.

Bacterial Re-Colonization Occurs Early after Lung Transplantation in Cystic Fibrosis Patients

Most cystic fibrosis (CF) patients referred for lung transplantation are chronically infected with Gram-negative opportunistic pathogens. It is well known that chronic infections in CF patients have a significant impact on lung-function decline and survival before transplantation. The rate and timing of re-colonization after transplantation have been described, but the impact on survival after stratification of bacteria is not well elucidated. We did a single-center retrospective analysis of 99 consecutive CF patients who underwent lung transplantation since the beginning of the Copenhagen Lung Transplant program in 1992 until October 2014. Two patients were excluded due to re-transplantation. From the time of CF diagnosis, patients had monthly sputum cultures. After transplantation, CF-patients had bronchoscopy with bronchoalveolar lavage at 2, 4, 6 and 12 weeks and 6, 12, 18 and 24 months after transplantation, as well as sputum samples if relevant. Selected culture results prior to and after transplantation were stored. We focused on colonization with the most frequent bacteria: Pseudomonas aeruginosa (PA), Stenotrophomonas maltophilia (SM), Achromobacter xylosoxidans (AX) and Burkholderia cepacia complex (BCC). Pulsed-field gel electrophoresis (PFGE) was used to identify clonality of bacterial isolates obtained before and after lung transplantation. Time to re-colonization was defined as the time from transplantation to the first positive culture with the same species. Seventy-three out of 97 (75%) had sufficient culture data for analyses with a median of 7 (1–91) cultures available before and after transplantation. Median colonization-free survival time was 23 days until the first positive culture after transplantation. After 2 years, 59 patients (81%) were re-colonized, 33 (48.5%) with PA, 7 (10.3%) with SM, 12 (17.6%) with AX, and 7 (10.3%) with BCC. No difference in survival was observed between the patients colonized within the first 2 years and those not colonized. Re-colonization of bacteria in the lower airways occurred at a median of 23 days after transplantation in our cohort. In our patient cohort, survival was not influenced by re-colonization or bacterial species.

Novel therapeutic approaches for the management of cystic fibrosis

Cystic fibrosis (CF) is a genetic condition characterised by the build-up of thick, sticky mucus that can damage many of the body's organs. It is a life-long disease that results in a shortened life expectancy, often due to the progression of advanced lung disease. Treatment has previously targeted the downstream symptoms such as diminished mucus clearance and recurrent infection. More recently, significant advances have been made in treating the cause of the disease by targeting the faulty gene responsible. Hope for the development of potential therapies lies with ongoing research into new pharmacological agents and gene therapy. This review gives an overview of CF, and summarises the current evidence regarding the disease management and upcoming strategies aimed at treating or potentially curing this condition.

Timing it right: the challenge of recipient selection for lung transplantation

Selection criteria for the referral and potential listing of patients for lung transplantation (LTx) have changed considerably over the last three decades but one key maxim prevails, the ultimate focus is to increase longevity and quality of life by careful utilization of a rare and precious resource, the donor organs. In this article, we review how the changes have developed and the outcomes of those changes, highlighting the impact of the lung allocation score (LAS) system. Major diseases, including interstitial lung disease (ILD), chronic obstructive pulmonary disease and pulmonary hypertension are considered in detail as well as the concept of retransplantation where appropriate. Results from bridging to LTx using extracorporeal membrane oxygenation (ECMO) are discussed and other potential contraindications evaluated such as advanced age, frailty and resistant infections. Given the multiplicity of risk factors it is a credit to those working in the field that such excellent and improving results are obtained with an ongoing dedication to achieving best practice.

Intravenous antibiotic use and exacerbation events in an adult cystic fibrosis centre: A prospective observational study

INTRODUCTION

In CF, people with higher FEV₁ are less aggressively treated with intravenous (IV) antibiotics, with resultant negative impact on their health outcomes. This could be entirely clinician-driven, but patient choice may also influence IV use. In this prospective observational study, we explored IV recommendations by clinicians and IV acceptance by adults with CF to understand how clinical presentations consistent with exacerbations resulted in IV use.

METHODS

Clinical presentations consistent with exacerbations, IV recommendation by clinicians and IV acceptance by patients were prospectively identified for every adult with CF in Sheffield throughout 2016, excluding those who had lung transplantation (n = 7) or on ivacaftor (n = 13). Relevant demographic data, e.g. %FEV₁, were extracted from medical records. Multi-level mixed-effects logistic regression models were used to compare IV recommendations vs non-recommendations for all clinical encounters, and IV acceptance vs non-acceptance for all IV recommendations.

RESULTS

Among 186 adults (median age 27 years, median FEV₁ 78.5%), there were 434 exacerbation events and 318 IV use episodes following 1010 clinical encounters. Only 254 (58.5%) of exacerbations were IV treated. A diagnosis of exacerbation, higher number of symptoms and lower %FEV₁ were independent predictors for IV recommendation by clinicians. Higher number of symptoms and lower %FEV₁ were also independent predictors for IV acceptance by adults with CF.

CONCLUSIONS

Lower IV use among adults with higher %FEV₁ was influenced by both clinicians' and patients' decisions. Using IV antibiotics as an exacerbation surrogate could under-estimate exacerbation rates and conceal differential treatment decisions according to varying clinical characteristics.

Cystic Fibrosis: From Qualification to Lung Transplantation, a Single Center Experience

Background

Cystic fibrosis (CF) is congenital multisystem disorder, that leads to gradual deterioration of pulmonary function. Advancements in therapy of CF-related lung disease have delayed its progression. However, lung transplantation remains the only therapeutic option for majority of such patients. Aim of the study was to assess qualification process and outcome of lung transplantation as a treatment of CF patients qualified in a single center between 2011 and 2018.

Material/Methods

This retrospective study assessed 41 patients who were qualified to be treated by means of lung transplantation due to CF in Lung Transplant Program of Silesian Center for Heart Diseases between 2011 and 2018. Analysis of patients during qualification process and after lung transplantation was performed. Lung recipients were observed during 1-year follow-up by means of pulmonary function tests.

Results

1-year survival was noted among 80% of the patients; 3-year survival and 5-year survival were noted among 70% of the recipients. Mean forced expiratory volume in 1 second (FEV1) increased after lung transplantation: 21.19% at qualification; and 76.67% at 12 months after lung transplantation. Mean forced vital capacity (FVC) results also improved: 34.18% at qualification and 78.34% at 12 months after lung transplantation. The 6-minute walk test (6MWT) before and after treatment noted an increase of 175.55 m.

Conclusions

Lung transplantation improves respiratory capacity of CF patients and prolongs their life.

Pseudomonas aeruginosa bacteremia among liver transplant recipients

Pseudomonas aeruginosa bacteremia remains as a life-threatening complication after liver transplantation (LT) and is intractable because of the high rate of drug resistance to commonly used antibiotics. To better understand the characteristics of this postoperative complication, PubMed and Embase searches as well as reference mining was done for relevant literature from the start of the databases through August 2018. Among LT recipients, the incidence of P. aeruginosa bacteremia ranged from 0.5% to 14.4% and mortality rates were up to 40%. Approximately 35% of all episodes of bloodstream infections (BSIs) were P. aeruginosa bacteremia, of which 47% were multidrug resistant and 63% were extensively drug resistant. Several factors are known to affect the mortality of LT recipients with P. aeruginosa bacteremia, including hypotension, mechanical ventilation, and increasing severity of illness. In LT recipients with P. aeruginosa bacteremia, alteration in DNA gyrase A genes and overexpression of proteins involved in efflux systems, namely the expression of KPC-2-type carbapenemase, NDM-1, and VIM-2-type MBL, contribute to the high resistance of P. aeruginosa to a wide variety of antibiotics. Because of complicated mechanisms of drug resistance, P. aeruginosa causes high morbidity and mortality in bacteremic LT patients. Consequently, early detection and treatment with adequate early targeted coverage for P. aeruginosa BSI are of paramount importance in the early posttransplantation period to obtain a better prognosis for LT patients.

Outcomes of lung transplantation in adults with bronchiectasis

Background

Lung transplantation is a well-established treatment for end-stage non-cystic fibrosis bronchiectasis (BR), though information regarding outcomes of transplantation remains limited. Our results of lung transplantation for Br are reported here.

Methods

A retrospective review of case notes and transplantation databases was conducted for patients that had underwent lung transplantation for bronchiectasis at the Freeman Hospital between 1990 and 2013.

Results

Fourty two BR patients underwent lung transplantation, the majority (39) having bilateral sequential lung transplantation. Mean age at transplantation was 47.1 years. Pre-transplantation osteoporosis was a significant non-pulmonary morbidity (48%). Polymicrobial infection was common, with Pseudomonas aeruginosa infection frequently but not universally observed (67%). Forced expiratory volume in 1 second (% predicted) improved from a pre-transplantation mean of 0.71 L (22% predicted) to 2.56 L (79 % predicted) at 1-year post-transplantation. Our survival results were 74% at 1 year, 64% at 3 years, 61% at 5 years and 48% at 10 years. Sepsis was a common cause of early post-transplantation deaths.

Conclusions

Lung transplantation for end-stage BR is a useful therapeutic option, with good survival and lung function outcomes. Survival values were similar to other bilateral lung transplants at our centre. Pre-transplantation Pseudomonas infection is common.

Lung Transplantation in Cystic Fibrosis and the Impact of Extracorporeal Circulation

INTRODUCTION

Lung disease is the major cause of death among cystic fibrosis (CF) patients, affecting 80% of the population. The impact of extracorporeal circulation (ECC) during transplantation has not been fully clarified. This study aimed to evaluate the outcomes of lung transplantation for CF in a single center, and to assess the impact of ECC on survival.

METHODS

We performed a retrospective observational study of all trasplanted CF patients in a single center between 1992 and 2011. During this period, 64 lung transplantations for CF were performed.

RESULTS

Five- and 10-year survival of trasplanted patients was 56.7% and 41.3%, respectively. Pre-transplantation supplemental oxygen requirements and non-invasive mechanical ventilation (NIMV) do not seem to affect survival (P=.44 and P=.63, respectively). Five- and 10-year survival among patients who did not undergo ECC during transplantation was 75.69% and 49.06%, respectively, while in those did undergo ECC during the procedure, 5- and 10-year survival was 34.14% and 29.87%, respectively (P=.001). PaCO₂ is an independent risk factor for the need for ECC.

CONCLUSIONS

The survival rates of CF patients undergoing lung transplantation in our hospital are similar to those described in international registries. Survival is lower among patients receiving ECC during the procedure. PaCO₂ is a risk factor for the need for ECC during lung transplantation.

Clinical characteristics of cystic fibrosis patients prior to lung transplantation: An international comparison between Canada and the United States

BACKGROUND

Cystic fibrosis (CF) patients from Canada have better-reported post-lung transplant survival compared to patients from the United States. We hypothesized the clinical characteristics of CF patients prior to lung transplant differ between the two countries.

METHODS

Population-based cohort study utilizing combined Canadian CF Registry and US CF Foundation Patient Registry data from 1986 to 2013. Demographic and clinical variables were analyzed prior to lung transplant.

RESULTS

Between 1986 and 2013, 607 (10.2%) CF patients underwent lung transplantation in Canada and 3428 (7.5%) in the United States. A lower proportion of recipients had growth of B. cepacia complex prior to transplant in the United States compared to Canada (0.8% vs 4.3%). Lung function was similar between recipients from the two countries. The proportion of patients classified as underweight was significantly higher in the United States compared to Canada (39.8% vs 28.0%; SD 26.1) despite higher rates of feeding tube use (42.5% vs 28.6%; SD 29.0).

CONCLUSIONS

CF lung transplant recipients from the United States have similar lung function, lower rates of B. cepacia complex, and worse nutritional parameters prior to transplant compared to counterparts in Canada. Future studies are necessary to evaluate the impact of these differences on post-transplant survival.

Devices for ex vivo heart and lung perfusion

INTRODUCTION

The number of organs available for heart and lung transplantation is far short of the number that is needed to meet demand. Perfusion and ventilation of donor organs after procurement has led to exciting advances in the field of cardiothoracic transplantation. The clinical implications of this technology allows for techniques to evaluate the quality of an organ, active rehabilitation of organs after procurement and prior to implantation, and increased time between organ procurement and implantation. This ex-vivo perfusion technique has also been referred to in the lay press as the 'heart in a box' or 'lung in a box.'

AREAS COVERED

This review includes information from case reports, case series, and clinical trials on ex vivo heart and lung perfusion. The focus is on the devices, ventilation and perfusion techniques, outcomes, and application of the technology.

EXPERT COMMENTARY

Ex vivo perfusion of donor hearts and lungs prior to transplantation has proven to be a viable alternative to standard cold-preservation strategies. Its use has allowed for ongoing expansion of the donor pool. The biggest barriers to expansion of this technology are access, cost, and lack of evidence which clearly supports superior outcomes.

Management of multidrug resistant Gram-negative bacilli infections in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations

Solid organ transplant (SOT) recipients are especially at risk of developing infections by multidrug resistant (MDR) Gram-negative bacilli (GNB), as they are frequently exposed to antibiotics and the healthcare setting, and are regulary subject to invasive procedures. Nevertheless, no recommendations concerning prevention and treatment are available. A panel of experts revised the available evidence; this document summarizes their recommendations: (1) it is important to characterize the isolate's phenotypic and genotypic resistance profile; (2) overall, donor colonization should not constitute a contraindication to transplantation, although active infected kidney and lung grafts should be avoided; (3) recipient colonization is associated with an increased risk of infection, but is not a contraindication to transplantation; (4) different surgical prophylaxis regimens are not recommended for patients colonized with carbapenem-resistant GNB; (5) timely detection of carriers, contact isolation precautions, hand hygiene compliance and antibiotic control policies are important preventive measures; (6) there is not sufficient data to recommend intestinal decolonization; (7) colonized lung transplant recipients could benefit from prophylactic inhaled antibiotics, specially for Pseudomonas aeruginosa; (8) colonized SOT recipients should receive an empirical treatment which includes active antibiotics, and directed therapy should be adjusted according to susceptibility study results and the severity of the infection.

The changing epidemiology and demography of cystic fibrosis

Once considered a pediatric disease with a poor prognosis, individuals born with cystic fibrosis (CF) today can expect to live well into adulthood. The implementation of multidisciplinary care, novel treatments and newborn screening has resulted in the rapid evolution in the demographics of the CF population. The purpose of this review is to highlight the evolving epidemiology and demographics of the CF population internationally.

High tacrolimus blood concentrations early after lung transplantation and the risk of kidney injury

PURPOSE

Lung transplant recipients often develop acute kidney injury (AKI) evolving into chronic kidney disease (CKD). The immunosuppressant tacrolimus might be associated with the emergence of AKI. We analyzed the development and recovery of kidney injury after lung transplantation and related AKI to whole-blood tacrolimus trough concentrations and other factors causing kidney injury.

METHODS

We retrospectively studied kidney injury in 186 lung-transplantation patients at the UMC Utrecht between 2001 and 2011. Kidney function and whole-blood tacrolimus trough concentrations were determined from day 1 to 14 and at 1, 3, 6, and 12 months postoperative. Systemic inflammatory response syndrome (SIRS), septic shock, and nephrotoxic medications were evaluated as covariates for AKI. We analyzed liver injury and drug-drug interactions.

RESULTS

AKI was present in 85 (46%) patients. Tacrolimus concentrations were supra-therapeutic in 135 of 186 patients (73%). AKI in the first week after transplantation was related to supra-therapeutic tacrolimus concentrations (OR 1.55; 95% CI 1.06-2.27), ≥3 other nephrotoxic drugs (OR 1.96; 95% CI 1.02-3.77), infection (OR 2.48; 95% CI 1.31-4.70), and cystic fibrosis (OR 2.17; 95% CI 1.16-4.06). Recovery rate of AKI was lower than expected (19%), and the cumulative incidence of severe CKD at 1 year was 15%.

CONCLUSIONS

After lung transplantation, AKI is common and often evolves into severe CKD, which is a known cause of morbidity and mortality. Supra-therapeutic whole-blood tacrolimus trough concentrations are related to the early onset of AKI. Conscientious targeting tacrolimus blood concentrations might be vital in the early phase after lung transplantation. What is known about this subject? • Lung transplant recipients often develop acute kidney injury evolving into chronic kidney disease increasing both morbidity and mortality. • To date, the pathophysiology of kidney injury after lung transplantation has not been fully elucidated. • The immunosuppressant tacrolimus is difficult to dose, especially in the unstable clinical setting, and is nephrotoxic.

WHAT THIS STUDY ADDS

• For the first time, supra-therapeutic whole-blood tacrolimus trough concentrations are related to the emergence of acute kidney injury in the first days after lung transplantation. • Supra-therapeutic whole-blood tacrolimus trough concentrations often occur early after lung transplantation. • AKI after lung transplantation shows low recovery rates.

Microbiome in the pathogenesis of cystic fibrosis and lung transplant-related disease

Significant advances in culture-independent methods have expanded our knowledge about the diversity of the lung microbial environment. Complex microorganisms and microbial communities can now be identified in the distal airways in a variety of respiratory diseases, including cystic fibrosis (CF) and the posttransplantation lung. Although there are significant methodologic concerns about sampling the lung microbiome, several studies have now shown that the microbiome of the lower respiratory tract is distinct from the upper airway. CF is a disease characterized by chronic airway infections that lead to significant morbidity and mortality. Traditional culture-dependent methods have identified a select group of pathogens that cause exacerbations in CF, but studies using bacterial 16S rRNA gene-based microarrays have shown that the CF microbiome is an intricate and dynamic bacterial ecosystem, which influences both host immune health and disease pathogenesis. These microbial communities can shift with external influences, including antibiotic exposure. In addition, there have been a number of studies suggesting a link between the gut microbiome and respiratory health in CF. Compared with CF, there is significantly less knowledge about the microbiome of the transplanted lung. Risk factors for bronchiolitis obliterans syndrome, one of the leading causes of death, include microbial infections. Lung transplant patients have a unique lung microbiome that is different than the pretransplanted microbiome and changes with time. Understanding the host-pathogen interactions in these diseases may suggest targeted therapies and improve long-term survival in these patients.

The Distribution and Resistance of Pathogens Among Solid Organ Transplant Recipients with Pseudomonas aeruginosa Infections

Background

Pseudomonas aeruginosa infection remains a life-threatening complication after solid organ transplantation (SOT). We aimed to investigate the distribution and drug susceptibility of pathogens, and clinical characteristics of SOT recipients with Pseudomonas aeruginosa infections.

Material/Methods

A total of 55 SOT recipients who developed 61 episodes of Pseudomonas aeruginosa infections between January 1, 2003 and July 31, 2015 were retrospectively analyzed. The distribution and the drug susceptibility of Pseudomonas aeruginosa were reviewed.

Results

The most common site from which 61 Pseudomonas aeruginosa rods were isolated were the lungs (57.4%, n=37), followed by the blood (27.9%, n=17). There were 35, 18, and 9 recipients accompanied with a serum creatinine level of >1.5 mg/dL, lymphocyte count of <300/mm³, and a serum albumin level of <30 g/L, respectively. Seven patients each presented with white blood cell count of >15 000/mm³ and platelet count of <50 000/mm³. There were 6 (10.9%) cases of septic shocks and 18 (32.7%) deaths. Antibiotic resistance rate of all Pseudomonas aeruginosa to 4 of 10 antibiotics investigated was more than 50%. Of these 61 Pseudomonas aeruginosa isolates, 47.5% were carbapenem-resistant. The rods were relatively sensitive to piperacillin-tazobactam, levofloxacin, amikacin, and cefoperazone-sulbactam (resistance rate <40%).

Conclusions

The clinical presentation of Pseudomonas aeruginosa infections included high body temperature, decreased platelet count, elevated white blood cell count, a high nosocomial origin and mortality, and onset in the late period after transplantation. According to our findings, piperacillin-tazobactam, levofloxacin, amikacin, and cefoperazone-sulbactam, alone or combination, are recommended to treat SOT recipients with Pseudomonas aeruginosa infections.

Current and Emerging Therapies for the Treatment of Cystic Fibrosis or Mitigation of Its Symptoms

Clinical presentation of the chronic, heritable condition cystic fibrosis (CF) is complex, with a diverse range of symptoms often affecting multiple organs with varying severity. The primary source of morbidity and mortality is due to progressive destruction of the airways attributable to chronic inflammation arising from microbial colonisation. Antimicrobial therapy combined with practises to remove obstructive mucopurulent deposits form the cornerstone of current therapy. However, new treatment options are emerging which offer, for the first time, the opportunity to effect remission from the underlying cause of CF. Here, we discuss these therapies, their mechanisms of action, and their successes and failures in order to illustrate the shift in the nature of how CF will likely be managed into the future.

Pretransplant HRCT Characteristics Are Associated with Worse Outcome of Lung Transplantation for Cystic Fibrosis Patients

Objectives

Peri- and postoperative complications diminish the outcome of lung transplantation (LTx) in patients with cystic fibrosis (CF). We hypothesized that the degree of pathological findings on pre-LTx high resolution computed tomography (HRCT) is associated with higher morbidity and mortality in CF.

Methods

All our CF patients undergoing LTx between 2001 and 2011 were included. HRCT examinations were evaluated according to a scoring system for pulmonary disease in CF patients, the Severe Advanced Lung Disease (SALD) score and for pleural involvement.

Results

Fifty-three patients were included. Dominant infectious/inflammatory disease according to the SALD score was observed in 10 patients (19%). Five (50%) of those patients died within one week after LTx, compared to 2 (5%) patients without dominant infectious/inflammatory disease (p<0.001). This difference in survival percentage remained also significant in multivariate analysis. Patients with infectious/inflammatory disease received more packed red blood cells; 26 versus 8 in the first week (p<0.001). Pleural thickening was associated with higher requirement (10 units) for blood transfusion during LTx, compared to patients with normal pleura (4 units).

Conclusions

The analysis of HRCT in CF patients according to the SALD score showed that dominant infectious/inflammatory disease is associated with a higher mortality after LTx. If confirmed in other studies, HRCT might aid estimation of surgical risk in some adult CF patients.

Causes of death in French cystic fibrosis patients: The need for improvement in transplantation referral strategies!

BACKGROUND

Little data exist on causes of death in cystic fibrosis (CF) patients in the era of lung transplantation.

METHODS

Deaths in CF patients in France (2007-2010) were identified using the French CF Registry and causes of deaths were determined based on medical files by a mortality adjudication committee.

RESULTS

Of 256 deaths, half occurred after lung transplantation and were related to early or late complications of transplantation, whereas half occurred in patients who did not receive lung transplantation and were primarily related to respiratory failure or massive hemoptysis. Among patients who did not receive lung transplantation, only 19% died while waiting on a lung transplantation list. Lack of listing for lung transplantation was primarily related to late, or to lack of transplantation referral, rather than to contraindication to transplantation.

CONCLUSIONS

These data suggest that improvement in transplantation referral strategies may result in transplantation-related survival benefits.

Residence in biofilms allows Burkholderia cepacia complex (Bcc) bacteria to evade the antimicrobial activities of neutrophil-like dHL60 cells

Bacteria of the Burkholderia cepacia complex (Bcc) persist in the airways of people with cystic fibrosis (CF) despite the continuous recruitment of neutrophils. Most members of Bcc are multidrug resistant and can form biofilms. As such, we sought to investigate whether biofilm formation plays a role in protecting Bcc bacteria from neutrophils. Using the neutrophil-like, differentiated cell line, dHL60, we have shown for the first time that Bcc biofilms are enhanced in the presence of these cells. Biofilm biomass was greater following culture in the presence of dHL60 cells than in their absence, likely the result of incorporating dHL60 cellular debris into the biofilm. Moreover, we have demonstrated that mature biofilms (cultured for up to 72 h) induced necrosis in the cells. Established biofilms also acted as a barrier to the migration of the cells and masked the bacteria from being recognized by the cells; dHL60 cells expressed less IL-8 mRNA and secreted significantly less IL-8 when cultured in the presence of biofilms, with respect to planktonic bacteria. Our findings provide evidence that biofilm formation can, at least partly, enable the persistence of Bcc bacteria in the CF airway and emphasize a requirement for anti-biofilm therapeutics.

The Bacteremia Caused by Non-Lactose Fermenting Gram-Negative Bacilli in Solid Organ Transplant Recipients

BACKGROUND

Blood stream infections (BSIs) remain as a serious life-threatening condition after solid organ transplant (SOT). In recent years, a progressive growth in the incidence of bacteremia caused by non-lactose fermenting gram-negative bacilli (NLF GNB) has been observed. NLF GNB led to high mortality among SOT recipients with bacteremia and were difficult to treat because of their high drug resistance to commonly used antibiotics.

METHODS

Two electronic databases, PUBMED and EMBASE, were searched for relevant literature published up to January 2015, to better understand the characteristics of bacteremia because of NLF GNB.

RESULTS

The morbidity and mortality rates of bacteremia because of NLF GNB depend on the types of organisms and transplantation. Multi-drug resistant NLF GNB ranged from 9.8% to 12.5% of all NLF GNB causing BSIs among SOT recipients. Certain factors can predispose SOT recipients to NLF GNB bacteremia, which included previous transplantation, hospital-acquired BSIs, and prior intensive care unit admission. Combination therapy may be beneficial in the treatment of NLF GNB bacteremia to enhance antimicrobial activity, provide synergistic interactions, relieve side effects, and minimize superinfections.

CONCLUSIONS

Prevention is pivotal in minimizing the morbidity and mortality associated with NLF GNB bacteremia after SOT. To improve the outcomes of SOT recipients with NLF GNB bacteremia, prevention is pivotal, and combination therapy of antibiotics may be beneficial.

Clinical and demographic factors associated with post-lung transplantation survival in individuals with cystic fibrosis

BACKGROUND

Contemporary studies evaluating post-transplant survival are limited and often include data from single centers or selected sub-groups. The purpose of this study was to evaluate overall transplant survival and to identify risk factors associated with death after transplant.

METHODS

The Canadian Cystic Fibrosis Registry, a population-based cohort, was used to describe survival after lung transplant. Pre-transplant factors associated with post-transplant survival were estimated using Cox proportional hazards models.

RESULTS

Between 1988 and 2012, 580 patients received a lung transplant. In the entire cohort, post-lung transplant 1-year survival was 87.8%, 5-year survival was 66.7%, and 10-year survival was 50.2%. Median post-transplant survival was 3.3 years (95% confidence interval [CI] = 2.13-6.56) in patients infected with Burkholderia cepacia complex compared with 12.36 years (95% CI = 10.34-17.96) in patients without B cepacia infection (hazard ratio [HR] = 2.63, 95% CI = 2.0-3.44). After adjustment, there was a non-significant trend toward better post-transplant survival with increasing year of transplant (HR = 0.98, 95% CI = 0.96-1.00). Pancreatic sufficiency (HR = 2.13, 95% CI = 1.41-3.20) and age at transplant such that youngest and oldest had the poorest survival (p < 0.001) were significant negative predictors of survival. The risk of death after transplant for patients infected with B cepacia was highest within the first year (HR = 6.29, 95% CI = 3.87-10.21) but remained elevated >1 year after transplant (HR = 1.92, 95% CI = 1.33-2.77) compared with patients without B cepacia infection.

CONCLUSIONS

After lung transplantation, 5-year survival in Canadians with CF is 67%, and 50% of patients live >10 years. Despite these impressive probabilities, age at transplant, pancreatic sufficiency and B cepacia infection remain important determinants of survival after lung transplantation.

Lung transplantation for cystic fibrosis: results, indications, complications, and controversies

Survival in patients with cystic fibrosis (CF) has improved dramatically over the past 30 to 40 years, with mean survival now approximately 40 years. Nonetheless, progressive respiratory insufficiency remains the major cause of mortality in CF patients, and lung transplantation (LT) is eventually required. Timing of listing for LT is critical, because up to 25 to 41% of CF patients have died while awaiting LT. Globally, approximately 16.4% of lung transplants are performed in adults with CF. Survival rates for LT recipients with CF are superior to other indications, yet LT is associated with substantial morbidity and mortality (∼50% at 5-year survival rates). Myriad complications of LT include allograft failure (acute or chronic), opportunistic infections, and complications of chronic immunosuppressive medications (including malignancy). Determining which patients are candidates for LT is difficult, and survival benefit remains uncertain. In this review, we discuss when LT should be considered, criteria for identifying candidates, contraindications to LT, results post-LT, and specific complications that may be associated with LT. Infectious complications that may complicate CF (particularly Burkholderia cepacia spp., opportunistic fungi, and nontuberculous mycobacteria) are discussed.

Multidrug-resistant Gram-negative bacteria in solid organ transplant recipients with bacteremias

Bloodstream infections (BSIs) remain as life-threatening complications and are associated with significant morbidity and mortality among solid organ transplant (SOT) recipients. Multidrug-resistant (MDR) Gram-negative bacteria can cause serious bacteremias in these recipients. Reviews have aimed to investigate MDR Gram-negative bacteremias; however, they were lacking in SOT recipients in the past. To better understand the characteristics of bacteremias due to MDR Gram-negative bacteria, optimize preventive and therapeutic strategies, and improve the outcomes of SOT recipients, this review summarize the epidemiology, clinical and laboratory characteristics, and explores the mechanisms, prevention, and treatment of MDR Gram-negative bacteria.

Inflammation, oxidative stress, and cardiovascular disease risk factors in adults with cystic fibrosis

Cystic fibrosis (CF) represents one of a number of localized lung and non-lung diseases with an intense chronic inflammatory component associated with evidence of systemic oxidative stress. Many of these chronic inflammatory diseases are accompanied by an array of atherosclerotic processes and cardiovascular disease (CVD), another condition strongly related to inflammation and oxidative stress. As a consequence of a dramatic increase in long-lived patients with CF in recent decades, the specter of CVD must be considered in these patients who are now reaching middle age and beyond. Buttressed by recent data documenting that CF patients exhibit evidence of endothelial dysfunction, a recognized precursor of atherosclerosis and CVD, the spectrum of risk factors for CVD in CF is reviewed here. Epidemiological data further characterizing the presence and extent of atherogenic processes in CF patients would seem important to obtain. Such studies should further inform and offer mechanistic insights into how other chronic inflammatory diseases potentiate the processes leading to CVDs.

Intra-operative extracorporeal membrane oxygenation use in pediatric lung transplantation--the Zurich experience

There is a lack of data regarding use of ECMO in children undergoing lung transplantation. We evaluated our experience of ECMO in pediatric lung transplant recipients. All patients (<18 yr) who underwent lung transplants between 1997 and 2011 were included (17 children; nine males; median age 16 yr), and the use of intra-operative ECMO evaluated. Transplant procedures were carried out with intra-operative ECMO in seven children (all bilateral lung transplants). Demographics of ECMO and non-ECMO patients were comparable. One child was already on ECMO pre-operative. Lung graft size reduction was undertaken in five ECMO and four non-ECMO cases, respectively. Five patients were taken off ECMO intra-operatively; the other patients were weaned off ECMO within 48 h post-operatively. Three-months survival was 100%. By 12 months post-transplantation, one patient each died in the ECMO and in the non-ECMO group. At the end of the study, six of seven ECMO cases were still alive (median survival 48.5 months); one patient required a retransplant at 53 months. Our small case series suggests that lung transplant procedures can be safely carried out in selected children on intra-operative ECMO support; however, our pediatric experience regarding this scenario is very limited but probably almost unique.

Lung transplantation in patients with cystic fibrosis

Cystic fibrosis (CF) an autosomal recessive genetic disorder, affects many organs. The great majority of deaths occur due to respiratory failure after many years of chronic pulmonary infection. Despite recent progress in early detection by studies of genetic mutations and better understanding to treat nutritional and infectious states, lung transplantation is the CF treatment for most advanced cases. According to the International Society for Heart and Lung Transplantation (ISHLT) data, CF is the third most common reason for lung transplantation (16.8%) showing the best survival rate (60% at 5 years). We have described our experience in lung transplantation of CF patients between January 2000 and December 2011, reviewing medical charts of these patients were for gender, age, body mass index (BMI), comorbidities, disease duration, previous sputum gram stain, ischemic time, incidence of severe primary graft dysfunction (PGD Grade 3), intensive care unit (ICU) length of stay, and Kaplan-Meier survival. Among 150 lung transplantation, the 30 CF patients (20%) represented the second most common cause. The average age was 27.4 ± 9.2 years, with a slight predominance of males (n = 16; 53.3%). The average BMI was 18.9 ± 2.6. Most patients (60%) had pancreatic exocrine dysfunction. Also, 83.3% of patients showed a positive sputum culture for Pseudomonas, while Burkholderia cepacia was identified in only 4 patients (13.3%). The average time of the disease was 20.8 ± 9.7 years. All transplantation were bilateral with an average ischemic time of 472 ± 98.3 minutes and ICU length of stay of 9.9 ± 6.3 days. The survival rates at 1 and 5 years were 92% and 77%, respectively, corresponding to the best outcomes among underlying diseases, comparable with other worldwide series and better than the ISHLT reports. CF, the second most common cause for lung transplantation among our cases, showed the best survival rate among all causes. Our survival rate was comparable with other reports.

Respiratory infections in patients with cystic fibrosis undergoing lung transplantation

Cystic fibrosis is an inherited disease characterised by chronic respiratory infections associated with bronchiectasis. Lung transplantation has helped to extend the lives of patients with cystic fibrosis who have advanced lung disease. However, persistent, recurrent, and newly acquired infections can be problematic. Classic cystic fibrosis-associated organisms, such as Staphylococcus aureus and Pseudomonas aeruginosa, are generally manageable post-transplantation, and are associated with favourable outcomes. Burkholderia cenocepacia poses particular challenges, although other Burkholderia species are less problematic. Despite concerns about non-tuberculous mycobacteria, especially Mycobacterium abscessus, post-transplantation survival has not been definitively shown to be less than average in patients with these infections. Fungal species can be prevalent before and after transplantation and are associated with high morbidity, so should be treated aggressively. Appropriate viral screening and antiviral prophylaxis are necessary to prevent infection with and reactivation of Epstein-Barr virus and cytomegalovirus and their associated complications. Awareness of drug pharmacokinetics and interactions in cystic fibrosis is crucial to prevent toxic effects and subtherapeutic or supratherapeutic drug dosing. With the large range of potential infectious organisms in patients with cystic fibrosis, infection control in hospital and outpatient settings is important. Despite its complexity, lung transplantation in the cystic fibrosis population is safe, with good outcomes if the clinician is aware of all the potential pathogens and remains vigilant by means of surveillance and proactive treatment.

Managing complications following lung transplantation

Lung transplantation has become a proven therapeutic option for patients with end-stage lung disease, extending life and providing improved quality of life to those who otherwise would continue to be breathless and oxygen-dependent. Over the past 20 years, considerable experience has been gained in understanding the multitude of medical and surgical issues that impact upon patient survival. Today, clinicians have an armamentarium of tools to manage diverse problems such as primary graft dysfunction, acute and chronic allograft rejection, airway anastomotic issues, infectious complications, renal dysfunction, diabetes and osteoporosis, hematological and gastrointestinal problems, malignancy, and other unique issues that confront immunosuppressed solid organ transplant recipients.

Diabetes before and after lung transplantation in patients with cystic fibrosis and other lung diseases

AIMS

The aims of the study are to investigate the prevalence of diabetes in patients with cystic fibrosis compared with patients without cystic fibrosis, and its impact on the outcome after lung transplantation.

METHODS

Data were reviewed from 77 lung transplantation recipients in our centre between 2001 and 2010; 43 patients had cystic fibrosis and 34 patients had other lung diseases (no cystic fibrosis). To define diabetes, we used the American Diabetes Association definition.

RESULTS

Before lung transplantation, diabetes was diagnosed in 63% of patients with cystic fibrosis and 6% of patients without cystic fibrosis (P<0.001). In both groups, approximately 60% of the patients at risk developed new-onset diabetes after transplantation. The mortality in patients with cystic fibrosis was higher in patients with diabetes diagnosed before lung transplantation compared with those without (44 vs. 6%, P=0.04). Diabetes remained an independent factor in multivariate analyses.

CONCLUSIONS

Diabetes diagnosed before lung transplantation has a negative effect on survival after lung transplantation in patients with cystic fibrosis. Pre-existing diabetes is common in patients with cystic fibrosis, in contrast to patients without cystic fibrosis. Development of new-onset diabetes after transplantation is similar in both groups.