Infectious complications of lung transplantation. Impact of cystic fibrosis

Antimicrobial Resistance in Organ Transplant Recipients

The overall burden of the main clinically relevant bacterial multidrug-resistant organisms (MDROs) (eg, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum β-lactamase producing or extended-spectrum cephalosporin-resistant Enterobacterales, carbapenem-resistant or carbapenemase-producing Enterobacterales, MDR Pseudomonas aeruginosa, and carbapenem-resistant Acinetobacter baumannii) in solid organ transplant (SOT) populations is summarized showing prevalence/incidence, risk factors, and impact on graft/patient outcome according to the type of SOT. The role of such bacteria in donor-derived infections is also reviewed. As for the management, the main prevention strategies and treatment options are discussed. Finally, nonantibiotic-based strategies are considered as future directions for the management of MDRO in SOT setting.

Nontuberculous Mycobacterial Infections in Cystic Fibrosis

Nontuberculous mycobacteria (NTM) are important pathogens, with a longitudinal prevalence of up to 20% within the cystic fibrosis (CF) population. Diagnosis of NTM pulmonary disease in people with CF (pwCF) is challenging, as a majority have NTM infection that is transient or indolent, without evidence of clinical consequence. In addition, the radiographic and clinical manifestations of chronic coinfections with typical CF pathogens can overlap those of NTM, making diagnosis difficult. Comprehensive care of pwCF must be optimized to assess the true clinical impact of NTM and to improve response to treatment. Treatment requires prolonged, multidrug therapy that varies depending on NTM species, resistance pattern, and extent of disease. With a widespread use of highly effective modulator therapy (HEMT), clinical signs and symptoms of NTM disease may be less apparent, and sensitivity of sputum cultures further reduced. The development of a disease-specific approach to the diagnosis and treatment of NTM infection in pwCF is a research priority, as a lifelong strategy is needed for this high-risk population.

Outcomes of nontuberculous mycobacteria isolation among lung transplant recipients: A matched case-control with retrospective cohort study

DISCLAIMER

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PURPOSE

Lung transplant recipients are at increased risk for acquiring nontuberculous mycobacteria (NTM), but the clinical significance of NTM isolation, particularly among patients not meeting guideline-endorsed diagnostic criteria for NTM pulmonary disease, is unclear.

METHODS

A case-control study of lung transplant recipients with culture-positive NTM infections treated at a large transplant center during a 7-year period (2013-2019) was performed.

RESULTS

Twenty-nine cases were matched 1:2 to non-NTM controls. The median time to NTM isolation was 10.7 months post transplant. Only 34.5% of all cases, and half of treated cases, met diagnostic criteria for NTM pulmonary infection. All-cause mortality at 12 months was numerically higher among NTM cases versus controls (20.7% vs 8.6%, P = 0.169); however, no deaths were attributed to NTM. No increase in the 12-month rate of acute rejection was observed (27.6% vs 36.2%, P = 0.477). Recent augmented immunosuppression was associated with increased odds of NTM isolation, while azithromycin prophylaxis was associated with reduced odds of isolation and was not associated with macrolide resistance. Both adverse events and actual or potential drug-drug interactions occurred in more than 90% of treated cases; these events included ocular toxicity, hearing loss, and supratherapeutic calcineurin inhibitor concentrations. Eight of the 14 treated cases (57.1%) required early antibiotic discontinuation due to adverse events or drug-drug interactions.

CONCLUSION

Among lung transplant recipients, most patients with NTM isolation did not meet guideline criteria for infection and had outcomes similar to non‒NTM-infected patients, which may reflect transient lung colonization by NTM rather than true disease. As adverse events are common with NTM therapy, limiting unnecessary antibiotic treatment represents an area for future antimicrobial stewardship efforts.

Cystic fibrosis foundation consensus statements for the care of cystic fibrosis lung transplant recipients

Cystic fibrosis (CF) is the indication for transplantation in approximately 15% of recipients worldwide, and Cystic Fibrosis Lung Transplant Recipients (CFLTRs) have excellent long-term outcomes. Yet, CFLTRs have unique comorbidities that require specialized care. The objective of this document is to provide recommendations to CF and lung transplant clinicians for the management of perioperative and underlying comorbidities of CFLTRs and the impact of transplantation on these comorbidities. The Cystic Fibrosis Foundation (CFF) organized a multidisciplinary committee to develop CF Lung Transplant Clinical Care Recommendations. Three workgroups were formed to develop focused questions. Following a literature search, consensus recommendations were developed by the committee members based on literature review, committee experience and iterative revisions, and in response to public comment. The committee formulated 32 recommendation statements in the topics related to infectious disease, endocrine, gastroenterology, pharmacology, mental health and family planning. Broadly, the committee recommends close coordination of care between the lung transplant team, the cystic fibrosis care center, and specialists in other disciplines with experience in the care of CF and lung transplant recipients. These consensus statements will help lung transplant providers care for CFLTRs in order to improve post-transplant outcomes in this population.

Infections Within the First Month After Pediatric Lung Transplantation: Epidemiology and Impact on Outcomes

BACKGROUND

Despite successes in lung transplantation, with infection as the leading cause of death in the first year following lung transplantation, there remains a lag in survival compared with other solid organ transplants. Infections that occur early after transplantation may impact short- and long-term outcomes in pediatric lung transplant recipients (LTRs).

METHODS

We performed a retrospective review of pediatric LTRs at a large quaternary-care hospital from January 2009 to March 2016 to evaluate both epidemiologic features of infection in the first 30 days post-transplantation and mortality outcomes. The 30 days were divided into early (0-7 days) and late (8-30 days) periods.

RESULTS

Among the 98 LTRs, there were 51 episodes of infections. Cystic fibrosis (CF) was associated with early bacterial infections (P = .004) while non-CF was associated with late viral (P = .02) infections. Infection after transplantation was associated with worse survival by Kaplan-Meier analysis (P value log rank test = .007). Viral infection in the late period was significantly associated with 3-year mortality after multivariable analysis (P = .02).

CONCLUSIONS

Infections in pediatric LTRs were frequent in the first 30 days after transplant, despite perioperative antimicrobial coverage. The association of 3-year mortality with late viral infections suggests a possible important role in post-transplant lung physiology and graft function. Understanding the epidemiology of early post-lung transplant infections can help guide post-operative management and interventions to reduce their incidence and the early- and long-term impact in this population.

Surgical site infections: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of post-operative surgical site infections (SSIs) in solid organ transplantation. SSIs are a significant cause of morbidity and mortality in SOT recipients. Depending on the organ transplanted, SSIs occur in 3%-53% of patients, with the highest rates observed in small bowel/multivisceral, liver, and pancreas transplant recipients. These infections are classified by increasing invasiveness as superficial incisional, deep incisional, or organ/space SSIs. The spectrum of organisms implicated in SSIs in SOT recipients is more diverse than the general population due to other important factors such as the underlying end-stage organ failure, immunosuppression, prolonged hospitalizations, organ transportation/preservation, and previous exposures to antibiotics in donors and recipients that could predispose to infections with multidrug-resistant organisms. In this guideline, we describe the epidemiology, clinical presentation, differential diagnosis, potential pathogens, and management. We also provide recommendations for the selection, dosing, and duration of peri-operative antibiotic prophylaxis to minimize post-operative SSIs.

Aspergillus colonization and antifungal immunity in cystic fibrosis patients

Cystic fibrosis (CF), caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, is the most common inherited life-limiting disease in North European people affecting 90,000 people worldwide. Progressive lung damage caused by recurrent infection and chronic airway inflammation is the major determinant of survival with a median age at death of 29 years. Approximately 60% of CF patients are infected with Aspergillus fumigatus, a ubiquitous environmental fungus, and its presence has been associated with accelerated lung function decline. Half of the patients infected with Aspergillus are <18 years of age. Yet time of acquisition of this fungus and determinants of CF-related Aspergillus disease severity and progression are not known. CFTR expression has been demonstrated in cells of the innate and adaptive immune system and has shown to be critical for normal function. Research delineating the role of CFTR-deficient phagocytes in Aspergillus persistence and infection in the CF lung, has only recently received attention. In this concise review we aim to present the current understanding with respect to when people with CF acquire infection with A. fumigatus and antifungal immune responses by CF immune cells.

Nontuberculous Mycobacterial Infections in Cystic Fibrosis

Nontuberculous mycobacteria (NTM) are important emerging cystic fibrosis (CF) pathogens, with estimates of prevalence ranging from 6% to 13%. Diagnosis of NTM disease in patients with CF is challenging, as the infection may remain indolent in some, without evidence of clinical consequence, whereas other patients suffer significant morbidity and mortality. Treatment requires prolonged periods of multiple drugs and varies depending on NTM species, resistance pattern, and extent of disease. The development of a disease-specific approach to the diagnosis and treatment of NTM infection in CF patients is a research priority, as a lifelong strategy is needed for this high-risk population.

Microbiological findings in bronchoalveolar lavage fluid from lung transplant patients in Sweden

Background

Lung transplant patients experience a high risk of airway infections and microbial colonization of the lung due to constant exposure to the environment through inhaled microorganisms, denervation, reduced ciliary transport, and decreased cough.

Methods

In this nationwide prospective study on Swedish lung transplant patients, we evaluated the microbiological panorama of bacteria, fungi, and virus found in bronchoalveolar lavage fluid (BALF) obtained the first year after lung transplantation (LTx). Differences in microbiological findings depending of concomitant signs of infection and background factors were assessed.

Results

A total of 470 bronchoscopies from 126 patients were evaluated. Sixty‐two percent (n = 293) of BALF samples had positive microbiological finding(s). Forty‐six percent (n = 217) had bacterial growth, 29% (n = 137) fungal growth, and 9% (n = 43) were positive in viral PCR. In 38% of BALF samples (n = 181), a single microbe was found, whereas a combination of bacteria, fungi or virus was found in 24% (n = 112) of bronchoscopies. The most common microbiological findings were Candida albicans, Pseudomonas aeruginosa and coagulase negative Staphylococcus (in 42 (33%), 36 (29%), and 25 (20%) patients, respectively). Microbiological findings were similar in BALF from patients with and without signs of lung infection and the frequency of multidrug resistant (MDR) bacteria was low. No significant association was found between background factors and time to first lung infection.

Conclusion

This study gives important epidemiologic insights and reinforces that microbiological findings have to be evaluated in the light of clinical symptoms and endobronchial appearance in the assessment of lung infections in lung transplant patients.

Clinical risk factors for invasive aspergillosis in lung transplant recipients: Results of an international cohort study

BACKGROUND

Invasive aspergillosis (IA) is a frequent complication in lung transplant recipients (LTRs). Clinical risk factors for IA have not been fully characterized, especially in the era of extensive anti-fungal prophylaxis. The primary objective of this study was to evaluate the clinical risk factors associated with IA in LTRs. The secondary objective was to assess the mortality in LTRs who had at least 1 episode of IA compared with LTRs who never had experienced IA.

METHODS

We conducted an international, multicenter, retrospective cohort study of 900 consecutive adults who received lung transplants between 2005 and 2008 with 4years of follow-up. Risk factors associated with IA were identified using univariate and multiple regression Cox proportional hazards models.

RESULTS

Anti-fungal prophylaxis was administered to 61.7% (555 of 900) of patients, and 79 patients developed 115 episodes of IA. The rate to development of the first episode was 29.6 per 1,000 person-years. Aspergillus fumigatus was the most common species isolated (63% [72 of 115 episodes]). Through multivariate analysis, significant risk factors identified for IA development were single lung transplant (hazard ratio, 1.84; 95% confidence interval, 1.09-3.10; p = 0.02,) and colonization with Aspergillus at 1 year post-transplantation (hazard ratio, 2.11; 95% confidence interval, 1.28-3.49; p = 0.003,). Cystic fibrosis, pre-transplant colonization with Aspergillus spp, and use of anti-fungal prophylaxis were not significantly associated with the development of IA. Time-dependent analysis showed IA was associated with higher mortality rates.

CONCLUSION

Incidence of IA remains high in LTRs. Single-lung transplant and airway colonization with Aspergillus spp. within 1 year post-transplant were significantly associated with IA.

Single-center experience in urgent lung transplantation program in a country with a shortage of donors: Does the end justify the means?

In rapidly deteriorating patients awaiting lung transplantation (LT), supportive strategies are only temporary and urgent lung transplant (ULT) remains the last option. The few publications on this topic report conflicting results. According to the Italian national program, patients on mechanical ventilation and/or extracorporeal membrane oxygenation (ECMO) may be included in urgent list. We reviewed our experience from January 2012 to December 2014 with ULT and elective lung transplantation (ELT), focusing on outcomes. In the study period, 16 patients received ULT, while 51 received ELT. Among ULT, 1 patient (5.8%) died in waiting list (WL) while 16 patients underwent LT with a median WL time of 6 days. ELT WL mortality was 13.5%, and median WL time 368 days. In-hospital mortality was lower in ELT group (5.8% vs 37.5%, P < .01), while the other postoperative outcomes were not significantly different. For ULT patients, the highest impact risk factors for in-hospital mortality were pretransplant plasma transfusion, recipient Pseudomonas aeruginosa colonization, and high level of reactive C-protein and lactic acid. A ULT program with an accurate recipient selection allows earlier transplantation, reducing WL mortality, with acceptable outcomes, although with a higher in-hospital mortality. Larger studies are needed to validate our results.

Analysis of pulmonary non-tuberculous mycobacterial infections after lung transplantation

PURPOSE

Non-tuberculous mycobacteria (NTM) are important pathogens in lung transplant recipients. This study describes the spectrum of NTM respiratory tract infections and examines the association of NTM infections with lung transplant complications.

METHODS

Data from 208 recipients transplanted from November 1990 to November 2005 were analyzed. Follow-up data were available to November 2010. Lung infection was defined by bronchoalveolar lavage, sputum, or blood cultures in the appropriate clinical setting. All identified NTM respiratory tract infections were tabulated. The cohort of patients with NTM lung infections (NTM+) were compared to the cohort without infection (NTM-). Univariate and multivariate analysis was performed to determine characteristics associated with NTM infection. Survival analyses for overall survival and development of bronchiolitis obliterans syndrome (BOS) were also performed.

RESULTS

In total, 52 isolates of NTM lung infection were identified in 30 patients. The isolates included Mycobacterium abscessus (46%), Mycobacterium avium complex (MAC) (36%), Mycobacterium gordonae (9%), Mycobacterium chelonae (7%), and Mycobacterium fortuitum (2%), with multiple NTM isolates seen on 3 different occasions. The overall incidence was 14%, whereas cumulative incidences at 1, 3, and 5 years after lung transplantation were 11%, 15%, and 20%, respectively. Comparisons between the NTM+ and NTM- cohorts revealed that NTM+ patients were more likely to be African-American and have cytomegalovirus mismatch. Although no difference was seen in survival, the NTM+ cohort was more likely to develop BOS (80% vs. 58%, P = 0.02). NTM+ infection, however, was not independently associated with development of BOS by multivariate analysis.

CONCLUSION

With nearly 20 years of follow-up, 14% of lung recipients develop NTM respiratory tract infections, with M. abscessus and MAC more commonly identified. M. gordonae was considered responsible for nearly 10% of NTM infections. Although survival of patients with NTM infections is similar, a striking difference in BOS rates is present in the NTM+ and NTM- groups.

Critical Care Aspects of Lung Transplant Patients

Major strides have been made in lung transplantation during the 1990s and it has become an established treatment option for patients with advanced lung disease. Due to improvements in organ preservation, surgical techniques, postoperative intensive care, and immunosuppression, the risk of perioperative and early mortality (less than 3 months after transplantation) has declined [1]. The transplant recipient now has a greater chance of realizing the benefits of the long and arduous waiting period.

Despite these improvements, suboptimal long-term outcomes continue to be shaped by issues such as opportunistic infections and chronic rejection. Because of the wider use of lung transplantation and the longer life span of recipients, intensivists and ancillary intensive care unit (ICU) staff should be well versed with the care of lung transplant recipients.

In this clinical review, issues related to organ donation will be briefly mentioned. The remaining focus will be on the critical care aspects of lung transplant recipients in the posttransplant period, particularly ICU management of frequently encountered conditions. First, the groups of patients undergoing transplantation and the types of procedures performed will be outlined. Specific issues directly related to the allograft, including early graft dysfunction from ischemia-reperfusion injury, airway anastomotic complications, and infections in the setting of immunosuppression will be emphasized. Finally nonpulmonary aspects of posttransplant care and key pharmacologic points in the ICU will be covered.

Nontuberculous Mycobacterial Infections in Cystic Fibrosis

Nontuberculous mycobacteria (NTM) are important emerging cystic fibrosis (CF) pathogens, with estimates of prevalence ranging from 6% to 13%. Diagnosis of NTM disease in patients with CF is challenging, as the infection may remain indolent in some, without evidence of clinical consequence, whereas other patients suffer significant morbidity and mortality. Treatment requires prolonged periods of multiple drugs and varies depending on NTM species, resistance pattern, and extent of disease. The development of a disease-specific approach to the diagnosis and treatment of NTM infection in CF patients is a research priority, as a lifelong strategy is needed for this high-risk population.

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.

Achromobacter xylosoxidans induced bronchiolitis obliterans in cystic fibrosis

We report a 12-year-old boy with progressive bronchiolitis obliterans caused by Achromobacter xylosoxidans (Ax) colonization after liver transplantation, resulting in a steep decline in lung function.

Combined heterotopic liver-pancreas transplantation as a curative treatment for liver cirrhosis and diabetes mellitus in cystic fibrosis

Cystic fibrosis (CF) is an inherited disease with a defect in epithelial chloride transport that results in a multisystem disease. Although pulmonary disease remains the primary cause of morbidity and mortality, focal biliary cirrhosis and portal hypertension may develop in up to 8% of these patients. Liver transplantation (TX) is an accepted therapy and shows good results. We report on a patient with cystic fibrosis homozygous for the most common CFTR mutation delta F 508 who received a combined heterotopic liver and pancreas transplantation at the age of 18 yr. He suffered from CFRD, which untypically required high doses of insulin. In addition, the patient had pulmonary complications, was chronically colonized with multiresistant Pseudomonas aeruginosa (MBL) and had an allergic bronchopulmonary aspergillosis (ABPA). The patient remained in stable health for 54 months post-TX and was able to live a nearly normal life. With a follow-up of five yr, the function of the liver and pancreas allografts was excellent. However, and sadly, his pulmonary function continued to deteriorate from progression of his CF, and he died of respiratory failure due to a severe pneumonia and septicemia at the age of 23 yr and five months.

Life-threatening infection in transplant recipients

Modern post-transplant care pathways commonly encompass periods of critical care support. Infectious events account for many of these interactions making critical care physicians integral members of multidisciplinary transplant teams. Despite continuing advances in clinical care and infection prophylaxis, the morbidity and mortality attributable to infection post-transplant remains considerable. Emerging entities constantly add to the breadth of potential opportunistic pathogens. Individualized risk assessments, rapid and thorough diagnostic evaluation, and prompt initiation of appropriate antimicrobial therapies are essential. The approach to managing transplant recipients with infection in critical care is discussed and common and emerging opportunistic pathogens are reviewed.

The Role of Infections in BOS

Background: Infectious agents, particularly cytomegalovirus (CMV), have long been considered to be potential triggers for BOS, although the exact magnitude of the role of infections and the mechanisms thereof remain an area of active research. Methods: This chapter will review previous literature and newer results concerning the possible roles of CMV, other herpesviruses, community-acquired respiratory viruses, bacteria (including Pseudomonas, other gram-negative, gram-positive, and atypical organisms), and fungi, including colonization as well as invasive infection. Results: The text reviews and evaluates the body of literature supporting a role for these infectious agents as risk factors for BOS and time to BOS. Changing patterns of infection over time are taken into account, and studies that have shown an association between BOS (or lack thereof) and CMV are reviewed. Strategies for prevention or early treatment of infections are discussed as potential means of preserving allograft function long term. Immunizations, stringent infection-control practices, and antimicrobial treatment including newer therapies will be discussed. Conclusion: In addition to the classic literature that has focused on CMV, an expanding spectrum of infectious organisms has been implicated as possible risk factors for BOS. Increasing knowledge of the impact of long-term antiviral suppression, prophylaxis, and outcomes of early therapy will help guide future recipient management.

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.

Tracheobronchial manifestations of Aspergillus infections

Human lungs are constantly exposed to a large number of Aspergillus spores which are present in ambient air. These spores are usually harmless to immunocompetent subjects but can produce a symptomatic disease in patients with impaired antifungal defense. In a small percentage of patients, the trachea and bronchi may be the main or even the sole site of Aspergillus infection. The clinical entities that may develop in tracheobronchial location include saprophytic, allergic and invasive diseases. Although this review is focused on invasive Aspergillus tracheobronchial infections, some aspects of allergic and saprophytic tracheobronchial diseases are also discussed in order to present the whole spectrum of tracheobronchial aspergillosis. To be consistent with clinical practice, an approach basing on specific conditions predisposing to invasive Aspergillus tracheobronchial infections is used to present the differences in the clinical course and prognosis of these infections. Thus, invasive or potentially invasive Aspergillus airway diseases are discussed separately in three groups of patients: (1) lung transplant recipients, (2) highly immunocompromised patients with hematologic malignancies and/or patients undergoing hematopoietic stem cell transplantation, and (3) the remaining, less severely immunocompromised patients or even immunocompetent subjects.

Non-tuberculous mycobacterium infection after lung transplantation is associated with increased mortality

BACKGROUND

Pulmonary non-tuberculous mycobacterial (NTM) infection is relatively common after lung transplantation, but the effect on mortality remains undetermined. Herein we describe our experience with pulmonary NTM infection after lung transplantation and hypothesized that non-tuberculous mycobacterial infection after lung transplantation would be associated with increased mortality.

METHODS

We retrospectively evaluated 201 primary lung transplant recipients transplanted between January 2000 and August 2006. Serial bronchoscopies with bronchoalveolar lavage and transbronchial biopsy were performed according to a surveillance protocol and when clinically indicated. The diagnosis NTM infection was established by a positive NTM culture in a bronchoalveolar lavage sample or in at least two separate expectorated sputum samples. NTM infections were further classified as "disease" or "colonization," based on whether or not NTM infection patients developed symptoms and characteristic radiographic findings.

RESULTS

Thirty-six (18%) recipients were diagnosed with pulmonary NTM infection at a median of 97 days post-transplantation: 9 were classified as NTM disease and the remaining 27 as NTM colonization cases. Single lung transplant was a significant risk factor for NTM infection (HR 2.25, p = 0.02). NTM colonization was a risk factor for NTM disease (HR 8.39, p = 0.003). NTM infection significantly increased the risk of death after lung transplantation (HR 2.61, p = 0.001) and persisted in multivariate models controlling for single lung transplant and bronchiolitis obliterans syndrome. The increased risk was seen for both NTM colonization and NTM disease. Among the patients who died, non-NTM infection was a more common contributing factor in the cause of death for the NTM infection group (44% vs 12%, p = 0.04).

CONCLUSIONS

Non-tuberculous mycobacterial infection is common after lung transplantation. NTM colonization and treated acute rejection are risk factors for NTM disease. NTM infection is associated with increased risk of mortality independent of bronchiolitis obliterans syndrome.

Radiological abnormalities associated with Aspergillus colonization in a cystic fibrosis population

OBJECTIVE

To determine if sputum colonization with Aspergillus species in patients with cystic fibrosis (PWCF) correlates with radiological abnormalities and/or a reduction in pulmonary function (FEV1).

METHODS

We prospectively evaluated 32 PWCF utilizing high resolution computed tomography (HRCT) of the thorax and pulmonary function testing (PFT). The cohort was assessed as two groups: Aspergillus positive (n=16) and Aspergillus negative (n=16) based on sputum culture for Aspergillus species. A modified Bhalla scoring system was applied to each HRCT scan by two blinded radiologists.

RESULTS

Aspergillus positive patients had more severe and significant bronchiectasis compared to those Aspergillus negative (p<0.05). This was most marked in the right upper and lower lobes (RUL, RLL). Total Bhalla score was clinically significant in both groups and approached statistical significance between groups (p=0.063). No difference in pulmonary function between the groups was detected.

CONCLUSION

PWCF colonized by Aspergillus species have greater radiological abnormalities undetectable by PFTs. Early radiological evaluation of Aspergillus colonized PWCF is therefore warranted.

Clinical significance of microbial infection and adaptation in cystic fibrosis

A select group of microorganisms inhabit the airways of individuals with cystic fibrosis. Once established within the pulmonary environment in these patients, many of these microbes adapt by altering aspects of their structure and physiology. Some of these microbes and adaptations are associated with more rapid deterioration in lung function and overall clinical status, whereas others appear to have little effect. Here we review current evidence supporting or refuting a role for the different microbes and their adaptations in contributing to poor clinical outcomes in cystic fibrosis.

Mortality associated with Acinetobacter baumannii infections experienced by lung transplant recipients

Lung transplantation (LTX) requires continual systemic immunosuppression, which can result in infections that may compromise recipient survival. A recent outbreak of Acinetobacter baumannii at our institution resulted in infections experienced in both LTX recipients and nontransplant patients. A retrospective review was conducted of patients who had A. baumannii recovered from blood, other normally sterile body fluids, and/or respiratory secretions and who had clinical follow-up extending to 1 year postinfection. A. baumannii was considered "multidrug-resistant" when its growth was not inhibited by minimum inhibitory concentrations of multiple antibiotics. Despite the resistance profile, patients were treated with a combination of antibiotics, which included tigecycline, colistimethate, and when susceptible, imipenem. Once infection was diagnosed, immunosuppression was reduced in all LTX recipients. Six LTX recipients became infected with A. baumannii and were contrasted to infections identified in 14 non-LTX, nonimmunosuppressed patients. A. baumannii was persistently recovered in 4 of 6 LTX recipients (66.7%) compared with only 1 of 14 (7.1%) non-LTX patients (χ(2) = 9.9, p = 0.005). LTX recipients received antibiotic therapy for an average of 76 ± 18.4 days compared with 16.0 ± 6.8 days for the non-LTX patients (p = 0.025, Mann-Whitney U test). All 4 of the 6 (66.7%) LTX recipients died as a consequence of their infection compared with 1 of 14 (7.1%) of the non-LTX patients (χ(2) = 9.9, p = 0.005). Despite receiving more antibiotic therapy, LTX recipients who were infected with multidrug-resistant A. baumannii were less likely to clear their infection and experienced greater mortality compared with non-LTX patients.

Epidemiology of invasive aspergillosis and risk factors in non neutropaenic patients

INTRODUCTION

Invasive aspergillosis is a major cause of mortality in allogeneic bone marrow transplant recipients and patients treated for blood malignancies. The diagnostic tools, treatments and preventive strategies, essentially developed for neutropaenic patients, have not been assessed in populations whose immune systems are considered to be competent.

STATE OF THE ART

Beside the standard picture of chronic Aspergillus infection, the incidence of invasive aspergillosis is increasing in non neutropaenic patients, such as those with chronic lung diseases or systemic disease treated with long-term immunosuppressive drugs and solid organ transplant recipients. This study reviews the specific features of invasive aspergillosis in non neutropaenic subjects (NNS) and discusses the value of the diagnostic tools and treatment in this population.

PROSPECTS

A better understanding of the pathophysiology and the epidemiological characteristics of invasive aspergillosis would provide a means of adapting the staging and classification of the disease for NNS.

CONCLUSIONS

Invasive aspergillosis is under diagnosed in NNS who may already be colonised when they receive immunosuppressive treatment; this can lead to an adverse outcome in patients who are considered to be a moderate risk population.

Impact of mold infections in explanted lungs on outcomes of lung transplantation

INTRODUCTION

Little is known about the incidence or significance of mold infections in the explanted lungs of lung transplant recipients.

METHOD

We reviewed the histopathology of the explanted lungs from 304 patients who underwent lung transplantation at our institution from 2005 to 2007 and received alemtuzumab induction therapy and posttransplant voriconazole prophylaxis.

RESULTS

Invasive mold infections were present in the explanted lungs of 5% (14 of 304) of patients, including chronic necrotizing pneumonias (n=7), mycetomas (n=4), and invasive fungal pneumonias (n=3). Only 21% (3 of 14) received immunosuppressive therapy within 1 year before lung transplantation, suggesting that lung damage itself predisposed patients to mold infections. The risk of mold infection was higher in patients with cystic fibrosis (11%, 4 of 35) than other underlying lung diseases (4%, 10 of 269). Pulmonary mold infections were not diagnosed or suspected in 57% (8 of 14) of patients. Despite secondary voriconazole prophylaxis, fungal infections developed in 43% (6 of 14) of patients with mold infections of the explanted lungs compared with 14% (42 of 290) of patients without mold infections (P=0.01). Three patients developed invasive fungal infections while on voriconazole prophylaxis and three developed fungal infections more than 8 months after the discontinuation of voriconazole. The mortality attributable to invasive fungal infections among patients with mold infections of the explanted lungs was 29% (4 of 14).

CONCLUSION

Invasive mold infections in the explanted lungs are often not recognized before lung transplantation and are associated with poor outcomes.

Survival after lung transplantation of cystic fibrosis patients infected with Burkholderia cepacia complex

Within the Burkholderia cepacia complex (Bcc), B. cenocepacia portends increased mortality compared with other species. We investigated the impact of Bcc infection on mortality and re-infection following lung transplant (LT). Species designation for isolates from Bcc-infected patients was determined using 16S rDNA and recA gene analyses. Of 75 cystic fibrosis patients undergoing LT from September 1992 to August 2002, 59 had no Bcc and 16 had Bcc (including 7 B. cenocepacia) isolated in the year before LT. Of the latter, 87.5% had Bcc recovered after transplantation, and all retained their pretransplant strains. Survival was 97%, 92%, 76% and 63% for noninfected patients; 89%, 89%, 67% and 56% for patients infected with Bcc species other than B. cenocepacia; and 71%, 29%, 29% and 29% for patients with B. cenocepacia (p = 0.014) at 1 month, 1 year, 3 years and 5 years, respectively. Patients infected with B. cenocepacia before transplant were six times more likely to die within 1 year of transplant than those infected with other Bcc species (p = 0.04) and eight times than noninfected patients (p < 0.00005). Following LT, infection with Bcc species other than B. cenocepacia does not significantly impact 5-year survival whereas infection with B. cenocepacia pretransplant is associated with decreased survival.

[Infection in lung transplantation]

Actualmente, el trasplante de pulmón se considera un tratamiento válido para un buen número de pacientes con insuficiencia respiratoria grave. De todas formas, las complicaciones son muy frecuentes y pueden llevar a fracaso del injerto a medio y largo plazo y menor supervivencia. De acuerdo con el registro de la International Society for Heart and Lung Transplantation, las tasas de supervivencia al primer, segundo y quinto año fueron, en 2006, del 74, 65 y 47%, respectivamente. El principal obstáculo para el éxito a largo plazo del trasplante de pulmón es el rechazo crónico, caracterizado histológicamente como bronquiolitis obliterante, que acontece en cerca de dos terceras partes de los pacientes. Uno de los factores más importantes para el desarrollo de bronquiolitis obliterante, además del número de rechazos agudos, es la infección y la enfermedad por citomegalovirus (CMV). Recientemente, se ha destacado el papel de la infección por diferentes virus respiratorios como factores de riesgo para el desarrollo de rechazo crónico en receptores de un trasplante de pulmón. Las complicaciones infecciosas son una causa frecuente de morbimortalidad en este tipo de pacientes, y la causa de muerte de cerca de la mitad de ellos. La infección bacteriana es la complicación más frecuente de un receptor de un trasplante de pulmón. Del total, el 35-66% son bacterianas y el 50-85% de los pacientes presentan como mínimo un episodio de infección bacteriana. La segunda causa más frecuente de infección, después de la bacteriana, es la infección por CMV. A pesar de utilizar diferentes estrategias de prevención, la incidencia sigue siendo elevada, y se sitúa alrededor del 7% el primer año postrasplante. Es el único tipo de trasplante de órgano sólido en el cual la etiología más frecuente de la infección fúngica es Aspergillus spp., a diferencia del resto, en que típicamente se deben a Candida spp. La incidencia de aspergilosis invasora se cifra en alrededor del 4%.

Effects of Sinus Surgery on lung Transplantation Outcomes in Cystic Fibrosis

Background

In cystic fibrosis (CF) patients who are candidates for lung transplant, pretransplant sinus surgery has been advocated to avoid bacterial seeding of the transplanted lungs. This study reviews the 17-year experience of pretransplant sinus surgery among CF patients at a major transplant center.

Methods

Retrospective chart review was performed in all CF patients who underwent heart-lung or lung transplantation at Stanford Medical Center between 1988 and 2005. Postoperative culture data from bronchoalveolar lavage (BAL) and sinus aspirates were evaluated, in addition to survival data.

Results

Eighty-seven CF transplant recipients underwent pretransplant sinus surgery; 87% (n = 59/68) of patients showed recolonization of the lung grafts with Pseudomonas on BAL cultures. The median postoperative time to recolonization was 19 days. Bacterial floras cultured from sinuses were similar in type and prevalence as the floras cultured from BAL. When compared with published series of comparable cohorts in which pretransplant sinus surgery was not performed, there was no statistically significant difference in the prevalence of Pseudomonas recolonization. Times to recolonization also were similar. Survival rates in our cohort were similar to national survival rates for CF lung transplant recipients.

Conclusion

Despite pretransplant sinus surgery, recolonization of lung grafts occurs commonly and rapidly with a spectrum of flora that mimics the sinus flora. Survival rates of CF patients who undergo prophylactic sinus surgery are similar to those from centers where prophylactic sinus surgery is not performed routinely. Pretransplant sinus surgery does not appear to prevent lung graft recolonization and is not associated with overall survival benefit.

Lung transplantation for cystic fibrosis: Current concepts and one center's experience

BACKGROUND

Although new approaches to the treatment of patients with cystic fibrosis (CF) are significantly prolonging their lives, most patients will eventually develop respiratory failure due to progressive bronchiectasis caused by chronic lung infection and inflammation and die from to respiratory failure. We examined our center's (University of Wisconsin Hospital and Clinics) experience with lung transplantation for patients with CF and reviewed the literature to examine current and evolving approaches to transplantation for this indication.

METHODS

We reviewed all published literature pertaining to lung transplantation for CF through 2006, and we reviewed all aspects of transplantation for patients with CF at our institution from 1994 to 2005.

RESULTS

Major complications following lung transplantation include acute rejection, bacterial infection, and bronchiolitis obliterans. Five-year survival at UWHC (Kaplan-Meier) is 67%, and survival was not adversely affected by transplanting patients receiving mechanical ventilation. The major cause of death for transplant recipients was bronchiolitis obliterans syndrome (BOS).

CONCLUSIONS

Lung transplantation for CF is associated with acceptable survival rates and can improve quality of life. Lung transplant should be offered to all patients with advanced CF lung disease if they meet currently accepted inclusion and exclusion criteria.

Advances in Lung Transplantation for Patients Who Have Cystic Fibrosis

Transplantation in patients who have cystic fibrosis (CF) presents important challenges regarding candidate selection and preoperative management, technical obstacles in the perioperative period, the postoperative management of medical comorbidities related to CF, and the psychosocial impact of transplantation. This article outlines some of these challenges and describes recent advances in approaching this endeavor in patients who have CF.

Improved Survival Following Lung Transplantation with Long-Term Use Of Bilevel Positive Pressure Ventilation in Cystic Fibrosis

Bilevel positive airway pressure ventilation (BIPAP) has been used in cystic fibrosis (CF) patients as a bridge to transplantation. Our aim was to evaluate the effect of BIPAP use before transplantation on post-transplantation morbidity and mortality. We performed a retrospective study at a tertiary care center. Twelve CF patients (9 males; mean age = 26 years) were assessed. Group 1 consisted of eight patients that did not use BIPAP before lung transplantation. Group 2 comprised four patients who used BIPAP for 3-15 months while awaiting transplantation. Patients were evaluated before and two to ten years after transplantation. All eight patients who did not use BIPAP died two months to ten years after transplantation. All four BIPAP users are alive with no evidence of bronchiolitis obliterans two to eight years after lung transplantation. We demonstrated a significant improvement in acid-base balance (p < 0.01) and body mass index (p < 0.05) and a tendency toward improvement in the work of breathing and number of hospitalizations. We conclude that improvement in nutritional status and respiratory muscle strength before lung transplantation in BIPAP users may prevent post lung transplantation infection and acute rejection rate, which in turn may reduce chronic rejection (bronchiolitis obliterans) and improve long-term survival after lung transplantation.

Non-tuberculous mycobacteria in end stage cystic fibrosis: implications for lung transplantation

BACKGROUND

WC and NS contributed equally. Non-tuberculous mycobacteria (NTM) frequently colonise patients with end stage cystic fibrosis (CF), but its impact on the course of the disease following lung transplantation is unknown.

METHODS

Lung transplant recipients with CF who underwent lung transplantation at our institution between January 1990 and May 2003 (n=146) and CF patients awaiting lung transplantation in May 2003 (n=31) were studied retrospectively.

RESULTS

The prevalence rate of NTM isolated from respiratory cultures in patients with end stage CF referred for lung transplantation was 19.7%, compared with a prevalence rate of 13.7% for NTM isolates in CF lung transplant recipients. The overall prevalence of invasive NTM disease after lung transplantation was low (3.4%) and was predicted most strongly by pre-transplant NTM isolation (p=0.001, Fisher's exact test, odds ratio (OR) 6.13, 95% CI 3.2 to 11.4). This association was restricted to Mycobacterium abscessus (p = 0.005, Fisher's exact test, OR 7.45, 95% CI 2.9 to 16.9). While NTM disease caused significant morbidity in a small number of patients after transplantation, it was successfully treated and did not influence the post-transplant course of the disease.

CONCLUSION

The isolation of NTM before transplantation in CF patients should not be an exclusion criterion for lung transplantation, but it may alert the clinician to patients at risk of recurrence following transplantation.