Long-term azithromycin for bronchiolitis obliterans syndrome after lung transplantation

The Lung Microbiome Predicts Mortality and Response to Azithromycin in Lung Transplant Recipients with Chronic Rejection

Rationale: Chronic lung allograft dysfunction (CLAD) is the leading cause of death after lung transplant, and azithromycin has variable efficacy in CLAD. The lung microbiome is a risk factor for developing CLAD, but the relationship between lung dysbiosis, pulmonary inflammation, and allograft dysfunction remains poorly understood. Whether lung microbiota predict outcomes or modify treatment response after CLAD is unknown. Objectives: To determine whether lung microbiota predict post-CLAD outcomes and clinical response to azithromycin. Methods: Retrospective cohort study using acellular BAL fluid prospectively collected from recipients of lung transplant within 90 days of CLAD onset. Lung microbiota were characterized using 16S rRNA gene sequencing and droplet digital PCR. In two additional cohorts, causal relationships of dysbiosis and inflammation were evaluated by comparing lung microbiota with CLAD-associated cytokines and measuring ex vivo P. aeruginosa growth in sterilized BAL fluid. Measurements and Main Results: Patients with higher bacterial burden had shorter post-CLAD survival, independent of CLAD phenotype, azithromycin treatment, and relevant covariates. Azithromycin treatment improved survival in patients with high bacterial burden but had negligible impact on patients with low or moderate burden. Lung bacterial burden was positively associated with CLAD-associated cytokines, and ex vivo growth of P. aeruginosa was augmented in BAL fluid from transplant recipients with CLAD. Conclusions: In recipients of lung transplants with chronic rejection, increased lung bacterial burden is an independent risk factor for mortality and predicts clinical response to azithromycin. Lung bacterial dysbiosis is associated with alveolar inflammation and may be promoted by underlying lung allograft dysfunction.

[Chronic lung allograft dysfunction in 2022, past and updates]

INTRODUCTION

While short-term results of lung transplantation have improved considerably, long-term survival remains below that achieved for other solid organ transplants.

CURRENT KNOWLEDGE

The main cause of late mortality is chronic lung allograft dysfunction (CLAD), which affects nearly half of the recipients 5 years after transplantation. Immunological and non-immune risk factors have been identified. These factors activate the innate and adaptive immune system, leading to lesional and altered wound-healing processes, which result in fibrosis affecting the small airways or interstitial tissue. Several phenotypes of CLAD have been identified based on respiratory function and imaging pattern. Aside from retransplantation, which is possible for only small number of patients, no treatment can reverse the CLAD process.

PERSPECTIVES

Current therapeutic research is focused on anti-fibrotic treatments and photopheresis. Basic research has identified numerous biomarkers that could prove to be relevant as therapeutic targets.

CONCLUSION

While the pathophysiological mechanisms of CLAD are better understood than before, a major therapeutic challenge remains.

Conventional and Novel Approaches to Immunosuppression in Lung Transplantation

Most therapeutic advances in immunosuppression have occurred over the past few decades. Although modern strategies have been effective in reducing acute cellular rejection, excess immunosuppression comes at the price of toxicity, opportunistic infection, and malignancy. As our understanding of the immune system and allograft rejection becomes more nuanced, there is an opportunity to evolve immunosuppression protocols to optimize longer term outcomes while mitigating the deleterious effects of traditional protocols.

Effect of azithromycin on bronchiolitis obliterans syndrome in posttransplant recipients: A systematic review and meta-analysis

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) is a devastating complication that occurs after transplantation. Although azithromycin is currently used for the treatment of BOS, the evidence is sparse and controversial. The aim of this meta-analysis is to evaluate the effects of azithromycin on forced expiratory volume in 1 second (FEV1) and patient's survival.

METHODS

PubMed, Embase, Cochrane library, Web of Science databases, and the ClinicalTrials.gov registry were systematically searched from inception until December 2020 for relevant original research articles. Random-effects models were used to calculate pooled-effect estimates.

RESULTS

Searches identified 15 eligible studies involving 694 participants. For FEV1 (L), there was a significant increase after short-term (≤12 weeks; P = .00) and mid-term (12-24 weeks; P = .01) administration of azithromycin. For FEV1 (%) compared to baseline, there was a significant increase after short-term (≤12 weeks) administration of azithromycin (P = .02), while there were no statistically significant differences in the medium and long term. When pooled FEV1% was predicted, it exhibited a similar trend to FEV1 (%) compared to baseline. In addition, we discovered that azithromycin reduced the risk of death (hazard ratio = 0.26; 95% confidence interval = 0.17 to 0.40; P = .00) in patients with BOS post-lung transplantation.

CONCLUSIONS

Azithromycin therapy is both effective and safe for lung function improvement in patients with posttransplant BOS after the short- and medium-term administration. Additionally, it has been demonstrated a significant survival benefit among patients with BOS post-lung transplant. Higher quality randomized controlled trials and more extensive prospective cohort studies are needed to confirm the effect of azithromycin on patients with posttransplant BOS.

Bronchiolitis obliterans syndrome after lung or haematopoietic stem cell transplantation: current management and future directions

Bronchiolitis obliterans syndrome (BOS) may develop after either lung or haematopoietic stem cell transplantation (HSCT), with similarities in histopathological features and clinical manifestations. However, there are differences in the contributory factors and clinical trajectories between the two conditions. BOS after HSCT occurs due to systemic graft-versus-host-disease (GVHD), whereas BOS after lung transplantation is limited to the lung allograft. BOS diagnosis after HSCT is more challenging, as the lung function decline may occur due to extrapulmonary GVHD, causing sclerosis or inflammation in the fascia or muscles of the respiratory girdle. Treatment is generally empirical with no established effective therapies. This review provides rare insights and commonalities of both conditions, that are not well elaborated elsewhere in contemporary literature, and highlights the importance of cross disciplinary learning from experts in other transplant modalities. Treatment algorithms for each condition are presented, based on the published literature and consensus clinical opinion. Immunosuppression should be optimised, and other conditions or contributory factors treated where possible. When initial treatment fails, the ultimate therapeutic option is lung transplantation (or re-transplantation in the case of BOS after lung transplantation) in carefully selected candidates. Novel therapies under investigation include aerosolised liposomal cyclosporine, Janus kinase inhibitors, antifibrotic therapies, and (in patients with BOS after lung transplantation) B-cell–directed therapies. Effective novel treatments that have a tangible impact on survival and thereby avoid the need for lung transplantation or re-transplantation are urgently required.

Management of chronic rejection after lung transplantation

Outcomes after lung transplantation are limited by chronic lung allograft dysfunction (CLAD). The incidence of CLAD is high, and its clinical course tends to be progressive over time, culminating in graft failure and death. Indeed, CLAD is the leading cause of death beyond the first year after lung transplantation. Therapy for CLAD has been limited by a lack of high-quality studies to guide management. In this review, we will discuss the diagnosis of CLAD in light of the recent changes to definitions and will discuss the current clinical evidence available for treatment. Recently, the diagnosis of CLAD has been subdivided into bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS). The current evidence for treatment of CLAD mainly revolves around treatment of BOS with more limited data existing for RAS. The best supported treatment to date for CLAD is the macrolide antibiotic azithromycin which has been associated with a small improvement in lung function in a minority of patients. Other therapies that have more limited data include switching immunosuppression from cyclosporine to tacrolimus, fundoplication for gastroesophageal reflux, montelukast, extracorporeal photopheresis (ECP), aerosolized cyclosporine, cytolytic anti-lymphocyte therapies, total lymphoid irradiation (TLI) and the antifibrotic agent pirfenidone. Most of these treatments are supported by case series and observational studies. Finally, we will discuss the role of retransplantation for CLAD.

Variability in azithromycin practices among lung transplant providers in the International Society for Heart and Lung Transplantation Community

Chronic lung allograft dysfunction (CLAD) is the most important long-term complication after lung transplant (LTx), and clinical experience suggests significant variability in its management. We sought to capture azithromycin practices among LTx providers internationally. A survey was distributed via the International Society for Heart and Lung Transplantation and completed by 103 respondents (15 countries). Azithromycin indications, timing, and dosing varied significantly, and 37 (36%) reported inconsistency even within their center. Thirty (29%) reported initiating azithromycin prophylactically (during initial transplant hospitalization). Of 73 others, only 10 (14%) reported waiting until CLAD diagnosis (with persistent ≥20% pulmonary function decline). Most initiated azithromycin after a CLAD risk-factor and/or event, including 59 (81%) for a persistent ≥10% decrement in FEV₁, 32 (44%) for lymphocytic bronchiolitis, and 27 (37%) for bronchoalveolar lavage neutrophilia. Azithromycin prescribing patterns appear to vary significantly, and further study is needed to elucidate the optimal timing and indications for its initiation after LTx.

Long-term course of bronchial inflammation and pulmonary function testing in children with postinfectious bronchiolitis obliterans

RATIONALE

Postinfectious bronchiolitis obliterans (PIBO) is a rare, chronic respiratory condition, which follows an acute insult due to a severe infection of the lower airways.

OBJECTIVES

The objective of this study was to investigate the long-term course of bronchial inflammation and pulmonary function testing in children with PIBO.

METHODS

Medical charts of 21 children with PIBO were analyzed retrospectively at the Children's University Hospital Frankfurt/Main Germany. Pulmonary function tests (PFTs) with an interval of at least 1 month were studied between 2002 and 2019. A total of 382 PFTs were analyzed retrospectively and per year, the two best PFTs, in total 217, were evaluated. Additionally, 56 sputum analysis were assessed and the sputum neutrophils were evaluated.

RESULTS

The evaluation of the 217 PFTs showed a decrease in FEV1 with a loss of 1.07% and a loss in z score of -0.075 per year. FEV1/FVC decreased by 1.44 per year. FVC remained stable, showing a nonsignificant increase by 0.006 in z score per year. However, FEV1 and FVC in L increased significantly with FEV1 0.032 L per cm and FVC 0.048 L/cm in height. Sputum neutrophils showed a significant increase of 2.12% per year.

CONCLUSION

Our results demonstrated that in patients with PIBO pulmonary function decreased significantly showing persistent obstruction over an average follow-up period of 8 years. However, persistent lung growth was revealed. In addition, pulmonary inflammation persisted clearly showing an increasing amount of neutrophils in induced sputum. Patients did not present with a general susceptibility to respiratory infections.

Chronic Lung Allograft Dysfunction: Evolving Concepts and Therapies

The primary factor that limits long-term survival after lung transplantation is chronic lung allograft dysfunction (CLAD). CLAD also impairs quality of life and increases the costs of medical care. Our understanding of CLAD continues to evolve. Consensus definitions of CLAD and the major CLAD phenotypes were recently updated and clarified, but it remains to be seen whether the current definitions will lead to advances in management or impact care. Understanding the potential differences in pathogenesis for each CLAD phenotype may lead to novel therapeutic strategies, including precision medicine. Recognition of CLAD risk factors may lead to earlier interventions to mitigate risk, or to avoid risk factors all together, to prevent the development of CLAD. Unfortunately, currently available therapies for CLAD are usually not effective. However, novel therapeutics aimed at both prevention and treatment are currently under investigation. We provide an overview of the updates to CLAD-related terminology, clinical phenotypes and their diagnosis, natural history, pathogenesis, and potential strategies to treat and prevent CLAD.

Chronic Lung Allograft Dysfunction: Review of CT and Pathologic Findings

Chronic lung allograft dysfunction (CLAD) is the most common cause of mortality in lung transplant recipients after the 1st year of transplantation. CLAD has traditionally been classified into two distinct obstructive and restrictive forms: bronchiolitis obliterans syndrome and restrictive allograft syndrome. However, CLAD may manifest with a spectrum of imaging and pathologic findings and a combination of obstructive and restrictive physiologic abnormalities. Although the initial CT manifestations of CLAD may be nonspecific, the progression of findings at follow-up should signal the possibility of CLAD and may be present on imaging studies prior to the development of functional abnormalities of the lung allograft. This review encompasses the evolution of CT findings in CLAD, with emphasis on the underlying pathogenesis and pathologic condition, to enhance understanding of imaging findings. The purpose of this article is to familiarize the radiologist with the initial and follow-up CT findings of the obstructive, restrictive, and mixed forms of CLAD, for which early diagnosis and treatment may result in improved survival. Supplemental material is available for this article. © RSNA, 2021.

A case of bronchiolitis obliterans after living-donor renal transplantation

We herein report the case of a 20 year-old-man who developed bronchiolitis obliterans after living-donor renal transplantation. The patient presented with dyspnea on exertion and wheezing two years after renal transplantation, and spirometry showed an obstructive pattern. Surgical lung biopsy revealed subepithelial fibrosis that constricted and obstructed the intrabronchiolar space. Based on these findings, the patient was diagnosed with bronchiolitis obliterans. He was prescribed bronchodilators and azithromycin, and he achieved stable respiratory function for two years. The differential diagnosis of respiratory symptoms after renal transplantation includes opportunistic infection and drug-induced lung injury; however, bronchiolitis obliterans should also be considered.

Azithromycin Partially Mitigates Dysregulated Repair of Lung Allograft Small Airway Epithelium

BACKGROUND

Dysregulated airway epithelial repair following injury is a proposed mechanism driving posttransplant bronchiolitis obliterans (BO), and its clinical correlate bronchiolitis obliterans syndrome (BOS). This study compared gene and cellular characteristics of injury and repair in large (LAEC) and small (SAEC) airway epithelial cells of transplant patients.

METHODS

Subjects were recruited at the time of routine bronchoscopy posttransplantation and included patients with and without BOS. Airway epithelial cells were obtained from bronchial and bronchiolar brushing performed under radiological guidance from these patients. In addition, bronchial brushings were also obtained from healthy control subjects comprising of adolescents admitted for elective surgery for nonrespiratory-related conditions. Primary cultures were established, monolayers wounded, and repair assessed (±) azithromycin (1 µg/mL). In addition, proliferative capacity as well as markers of injury and dysregulated repair were also assessed.

RESULTS

SAEC had a significantly dysregulated repair process postinjury, despite having a higher proliferative capacity than large airway epithelial cells. Addition of azithromycin significantly induced repair in these cells; however, full restitution was not achieved. Expression of several genes associated with epithelial barrier repair (matrix metalloproteinase 7, matrix metalloproteinase 3, the integrins β6 and β8, and β-catenin) were significantly different in epithelial cells obtained from patients with BOS compared to transplant patients without BOS and controls, suggesting an intrinsic defect.

CONCLUSIONS

Chronic airway injury and dysregulated repair programs are evident in airway epithelium obtained from patients with BOS, particularly with SAEC. We also show that azithromycin partially mitigates this pathology.

European dermatology forum: Updated guidelines on the use of extracorporeal photopheresis 2020 - Part 2

Background

Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T‐cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multidisciplinary setting. It has confirmed recognition in well‐known documented conditions such as graft‐vs.‐host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease.

Materials and methods

In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added.

Results and conclusion

These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines were divided into two parts: PART I covers Cutaneous T‐cell lymphoma, chronic graft‐vs.‐host disease and acute graft‐vs.‐host disease, while PART II will cover scleroderma, solid organ transplantation, Crohn’s disease, use of ECP in paediatric patients, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

Therapeutic effect of budesonide, montelukast and azithromycin on post-infectious bronchiolitis obliterans in children

Optimal treatment options for post-infectious bronchiolitis obliterans (PIBO) have not yet been established. The present study retrospectively analyzed the effect of budesonide, montelukast and azithromycin on treating PIBO in children <5 years old.. Based on treatment regimen, the cohort was divided into group A and group B. Group A received a combination of budesonide, montelukast and azithromycin for at least 3 months and group B received unconventional treatment (budesonide for nebulization intermittently, prednisone, montelukast and antibiotics if necessary) compared with standard treatment. Tidal pulmonary function and symptoms assessment were performed at diagnosis and after 3 months of therapy. There were no significant differences in the sex, age, pulmonary function and symptoms assessment between groups A and B at diagnosis. However, following 3 months of treatment, the time to peak tidal expiratory flow as a proportion of expiratory time, and volume to peak expiratory flow as a proportion of exhaled volume in group A were significantly higher compared with those in group B. The respiratory rate in group A was significantly lower compared with group B. The symptoms assessment score in group A was significantly higher compared with that of group B. In conclusion, the present study demonstrates that combination therapy with budesonide, montelukast and azithromycin improves pulmonary function and respiratory symptoms in PIBO children <5 years old. The present study was retrospectively registered on March 22, 2020 with register no. YY202003-008-HB03.

Mathematical modeling of peripheral blood neutrophil kinetics to predict CLAD after lung transplantation

BACKGROUND

The presence of neutrophils in the lung was identified as a factor associated with CLAD but requires invasive samples. The aim of this study was to assess the kinetics of peripheral blood neutrophils after lung transplantation as early predictor of CLAD.

METHODS

We retrospectively included all recipients transplanted in our center between 2009 and 2014. Kinetics of blood neutrophils were evaluated to predict early CLAD by mathematical modeling using unadjusted and adjusted analyses.

RESULTS

103 patients were included, 80 in the stable group and 23 in the CLAD group. Bacterial infections at 1 year were associated with CLAD occurrence. Neutrophils demonstrated a high increase postoperatively and then a progressive decrease until normal range. Recipients with CLAD had higher neutrophil counts (mixed effect coefficient beta over 3 years = +1.36 G/L, 95% Confidence Interval [0.99-1.92], p < .001). A coefficient of celerity (S for speed) was calculated to model the kinetics of return to the norm before CLAD occurrence. After adjustment, lower values of S (slower decrease of neutrophils) were associated with CLAD (Odds Ratio = 0.26, 95% Confidence Interval [0.08-0.66], p = .01).

CONCLUSION

A slower return to the normal range of blood neutrophils was early associated with CLAD occurrence.

Immunosuppressive strategies in lung transplantation

Lung transplantation is a viable option for those with end-stage lung disease which is evidenced by the continued increase in the number of lung transplantations worldwide. However, patients and clinicians are constantly faced with acute and chronic rejection, infectious complications, drug toxicities, and malignancies throughout the lifetime of the lung transplant recipient. Conventional maintenance immunosuppression therapy consisting of a calcineurin inhibitor (CNI), anti-metabolite, and corticosteroids have become the standard regimen but newer agents and modalities continue to be developed. Here we will review induction agents, maintenance immunosuppressives, adjunctive therapies and other strategies to improve long-term outcomes.

Imatinib melylate as second-line treatment of bronchiolitis obliterans after allogenic hematopoietic stem cell transplantation in children

BACKGROUND

The onset of bronchiolitis obliterans (BO) as a pulmonary manifestation of chronic graft vs host disease dramatically changes the prognosis of children undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study aimed to evaluate the overall survival (OS) of children with BO treated with imatinib mesylate (IM).

METHODS

This study included children who underwent allo-HSCTs between January 2000 and December 2016.

RESULTS

Among 345 patients who underwent HSCTs, 293 were evaluable for BO and 26 (8.9%) developed BO. The cumulative incidence of BO was 4.8% (95% confidence interval [CI], 2.8-7.5) at 1 year and 7.7% (95% CI, 5.1-11.1) at 3 years after transplantation. In the group of HSCTs (n = 67) complicated by chronic GvHD (c-GVHD), the incidence rate of BO was 38.8%. In total, 96.1% of patients with BO had c-GvHD worse than moderate grade, which was present in 70.7% of patients without BO (P = .011). The mortality rates were 46.1% in the BO group and 27.4% in the group without BO. Half of the patients with BO (n = 13) received IM, and the overall response rate was 76.9%. Four years after HSCT, OS was 42.6% (95% CI, 18.2-65.3) in the group without IM and 83.3% (95% CI, 27.3-97.5) in the group with IM.

CONCLUSIONS

BO after HSCT in the pediatric population has a high incidence and mortality rate. In terms of overall response and tolerability, this study showed relevant improvements in the prognosis of children with BO after the introduction of IM. Further prospective studies among children are needed to confirm these results.

Safety and Efficacy of Steroid Pulse Therapy for Acute Loss of FEV1 in Lung Transplant Recipients After Exclusion of Acute Cellular Rejection

BACKGROUND

The standard treatment of acute cellular rejection after lung transplantation (LTx) is a high-dose steroid pulse therapy. In our center, this therapy is also the standard of care for LTx recipients with acute loss of forced expiratory volume in 1 second (FEV₁), after excluding specific causes such as acute rejection on biopsy. The aim of this retrospective study was to evaluate the safety and efficacy of steroid pulse therapy.

METHODS

From 2015 to 2018, 33 consecutive patients (17 male patients, mean age ± SD, 50.5 ± 12.5 years) were included. All patients underwent routine examinations to exclude acute cellular rejection and other specific causes. FEV₁ was routinely measured after 5 days, and 1, 3, and 6 months. Positive response to steroid pulse therapy was defined by increase of FEV₁ > 10%.

RESULTS

The mean decrease ± SD from baseline in FEV₁ at the start of steroid pulse therapy was 380 ± 630 mL (P = .02). FEV₁ changed after 5 days by 170 ± 180 mL (P = .0007), and after 1 month by 140 ± 230 mL (P = .70), 3 months by -60 ± 240 mL (P = .15), and 6 months by -80 ± 290 mL (P = .73). A positive response was observed in 21% of patients after 3 months and 12% after 6 months. High bronchoalveolar lavage (BAL) eosinophil count correlated with a higher FEV₁ after steroid pulse therapy. Serious complications were observed in 4 out of 33 patients (12%) with 1 fatal event (pneumonia).

CONCLUSIONS

Only a minority of patients after LTx with loss of FEV₁ after exclusion of acute cellular rejection benefit from steroid pulse therapy. Patients with BAL eosinophilia are more likely to respond. However, severe complications were observed.

Clinical profile and course of children with postinfectious bronchiolitis obliterans from a tertiary care hospital

Background:

Postinfectious bronchiolitis obliterans (PIBO) is a chronic obstructive lung disease with scanty information in literature on etiology, clinical profile, treatment, and outcome.

Objective:

The objective of the study is to describe the clinical profile and course of children diagnosed with PIBO.

Methods:

A chart review of children below 18 years of age diagnosed as PIBO over the past 9 years was carried out. Details of clinical profile, laboratory investigations, imaging, treatment received, and outcome were recorded.

Results:

Eight children (boys 4) with PIBO were identified. Median (interquartile range [IQR]) age at the first episode of acute severe bronchiolitis such as illness and diagnosis of PIBO was 15 (6, 23.5) and 30 (16.5, 60) months, respectively, indicating a delay in diagnosis. The most common symptoms were recurrent episodes of cough (100%), fast breathing (100%), wheezing (87.5%), and fever (62.5%). Median (IQR) number of hospitalizations and episodes of antibiotic use prior to diagnosis were 2.5 (2, 5.5) and 2 (2, 4), respectively. Three (37.5%) children received mechanical ventilation during previous hospitalizations. Chest computed tomography revealed mosaic attenuation in 8 (100%), ground-glass opacities in 2 (25%), and bronchial wall thickening in 2 (25%). After diagnosis, 7 received oral steroids, 7 received hydroxychloroquine, 5 received azithromycin, and 2 received azathioprine. The median (IQR) duration of follow-up (n = 6) was 6 (1.5, 9.5) months. Median (IQR) number of pulmonary exacerbations in follow-up was 2 (1, 5).

Conclusion:

PIBO is still an under-recognized entity with substantial delay in diagnosis and unnecessary use of antibiotics. Clinical course with imaging findings may help to diagnose and manage this entity.

Macrolide combination therapy for patients hospitalised with community-acquired pneumonia? An individualised approach supported by machine learning

BACKGROUND

The role of macrolide/β-lactam combination therapy in community-acquired pneumonia (CAP) of moderate severity is a matter of debate. Macrolides expand the coverage to atypical pathogens and attenuate pulmonary inflammation, but have been associated with cardiovascular toxicity and drug interactions. We developed a decision tree based on aetiological and clinical parameters, which are available ex ante to support a personalised decision for or against macrolides for the best clinical outcome of the individual patient.

METHODS

We employed machine learning in a cross-validation scheme based on a well-balanced selection of 4898 patients after propensity score matching to data available on admission of 6440 hospitalised patients with moderate severity (non-intensive care unit patients) from the observational, prospective, multinational CAPNETZ study. We aimed to improve the primary outcome of 180-day survival.

RESULTS

We found a simple decision tree of patient characteristics comprising chronic cardiovascular and chronic respiratory comorbidities as well as leukocyte counts in the respiratory secretion at enrolment. Specifically, we found that patients without cardiovascular or patients with respiratory comorbidities and high leukocyte counts in the respiratory secretion benefit from macrolide treatment. Patients identified to be treated in compliance with our treatment suggestion had a lower mortality of 27% (OR 1.83, 95% CI 1.48-2.27; p<0.001) compared to the observed standard of care.

CONCLUSION

Stratifying macrolide treatment in patients following a simple treatment rule may lead to considerably reduced mortality in CAP. A future randomised controlled trial confirming our result is necessary before implementing this rule into the clinical routine.

Long-term effect of azithromycin in bronchiolitis obliterans syndrome

Introduction

Azithromycin stabilises and improves lung function forced expiratory volume in one second (FEV₁) in lung transplantation patients with bronchiolitis obliterans syndrome (BOS). A post hoc analysis was performed to assess the long-term effect of azithromycin on FEV₁, BOS progression and survival .

Methods

Eligible patients recruited for the initial randomised placebo-controlled trial received open-label azithromycin after 3 months and were followed up until 6 years after inclusion (n=45) to assess FEV₁, BOS free progression and overall survival.

Results

FEV₁ in the placebo group improved after open-label azithromycin and was comparable with the treatment group by 6 months. FEV₁ decreased after 1 and 5 years and was not different between groups. Patients (n=18) with rapid progression of BOS underwent total lymphoid irradiation (TLI). Progression-free survival (log-rank test p=0.40) and overall survival (log-rank test p=0.28) were comparable. Survival of patients with early BOS was similar to late-onset BOS (log-rank test p=0.74).

Discussion

Long-term treatment with azithromycin slows down the progression of BOS, although the effect of TLI may affect the observed attenuation of FEV₁ decline. BOS progression and long-term survival were not affected by randomisation to the placebo group, given the early cross-over to azithromycin and possibly due to TLI in case of further progression. Performing randomised placebo-controlled trials in lung transplantation patients with BOS with a blinded trial duration is feasible, effective and safe.

Detection, classification, and management of rejection after lung transplantation

Rejection is a major complication following lung transplantation. Acute cellular rejection, lymphocytic bronchiolitis, and antibody-mediated rejection (AMR) are all risk factors for the subsequent development of chronic lung allograft dysfunction (CLAD). Acute cellular rejection and lymphocytic bronchiolitis have well defined histopathologic diagnostic criteria and grading. Diagnosis of AMR requires a multidisciplinary approach. CLAD is the major barrier to long-term survival following lung transplantation. The most common phenotype of CLAD is bronchiolitis obliterans syndrome (BOS) which is defined by a persistent obstructive decline in lung function. Restrictive allograft dysfunction (RAS) is a second phenotype of CLAD and is associated with a worse prognosis. This article will review the diagnosis, staging, clinical presentation, and treatment of acute rejection, AMR, and CLAD following lung transplantation.

Extracorporeal Photopheresis for Bronchiolitis Obliterans Syndrome After Lung Transplantation

BACKGROUND

Lung transplantation is a therapeutic option for select patients with end-stage lung disease. However, successful lung transplantation is hampered by chronic lung allograft dysfunction, in particular bronchiolitis obliterans syndrome (BOS). Although there is no approved or standard treatment for BOS, which may have several distinct phenotypes, extracorporeal photopheresis (ECP) has shown promising results in patients who develop BOS refractory to azithromycin treatment.

METHODS

We reviewed all relevant clinical data indexed on PubMed from 1987 to 2017 to evaluate the role of ECP in patients with BOS.

RESULTS

Seven small studies investigated the immunomodulatory effects of ECP in patients after solid organ transplant, and 12 studies reported clinical data specific to ECP therapy for BOS. Studies indicate that ECP triggers an apoptotic cellular cascade that exerts various immunomodulatory effects mediated via increases in anti-inflammatory cytokines, a decrease in proinflammatory cytokines, and an increase in tolerogenic regulatory T cells. Clinical evidence derived from relatively small single-center studies suggests that ECP therapy is associated with improvement or stabilization in lung function and sustainable, statistically significant, decreases in the rate of lung function decline in patients with BOS. Additionally, when adverse event data were reported, ECP was generally well tolerated. None of the comparative studies were randomized.

CONCLUSIONS

Immunomodulation mediated via ECP is a rational therapeutic option that may improve clinical outcomes in patients with BOS, particularly in the context of in-depth patient phenotyping as part of a stratified approach to treatment; good quality randomized controlled trials are needed to confirm observational findings.

Technique and Outcomes of Less Invasive Lung Retransplantation

BACKGROUND

Lung retransplantation is a demanding procedure with outcomes lagging primary transplantation. We implemented less invasive surgical techniques aiming at improving early outcomes. Here, we wish to describe these techniques and analyze the clinical outcomes.

METHODS

Since April 2010, a protocol of less invasive techniques was applied to all lung retransplantations. This protocol comprises bilateral lung retransplantation via sternum-sparing anterolateral thoracotomies, off-pump surgery, and empiric administration of 2 g fibrinogen and 2 platelet concentrates. Patient charts were retrospectively reviewed starting in April 2010 until May 2016 for this study and compared with a cohort of patients undergoing lung retransplantation between January 2005 and March 2010.

RESULTS

From April 2010 through March 2016, 774 total lung transplantations were performed at our center, 49 were retransplantations. In the era January 2005 to March 2010, a total of 480 lung transplantations were performed, 38 of those being retransplantations. Mean operation time in the era April 2010 to May 2016 was significantly longer as compared with the era January 2005 to March 2010, median time until extubation was significantly shorter in the era April 2010 to May 2016 (1 [1-2] days vs 11.5 [1-24] days; P = 0.0009). Similarly, median intensive care unit stay time was shorter in the era April 2010 to May 2016 (4 [2-5.5] days vs 12.5 [3-30.5] days; P = 0.003). Patient survival was significantly better in the era starting in April 2010 at 30 days (98% vs 76.3%, P = 0.002) as well as at 1 year (80.6% vs 63.2%; P = 0.01).

CONCLUSIONS

Less invasive retransplantation of the lung via sternum-sparing anterolateral thoracotomies and off-pump is a safe procedure with low associated morbidity and favorable midterm survival.

Association of methacholine challenge test with diagnosis of chronic lung allograft dysfunction in lung transplant patients

BACKGROUND

Chronic lung allograft dysfunction (CLAD) is a complication of lung transplantation. We sought to determine whether bronchial hyperresponsiveness detected by the methacholine challenge test (MCT) at 3 months after lung transplant (LT) predicts the development of CLAD.

METHODS

We performed a retrospective cohort study of 140 LT patients between 1/2008 and 6/2014 who underwent MCT at 3 months after LT. Pearson's chi-squared test and Kruskal-Wallis test were used to compare categorical and continuous variables, respectively. Cox proportional hazards modeling was used to evaluate the association between CLAD and MCT.

RESULTS

Methacholine challenge test+ was associated with the development of overall CLAD (adjusted hazards ratio [aHR]: 3.47; 95% confidence interval [95% CI]: 1.71, 7.03; P = 0.001) and CLAD within 3 years (aHR: 4.98; 95%CI: 1.84, 13.48; P = 0.002). Subgroup analysis showed that MCT (+) is associated with overall CLAD in single lung transplant (SLT) (aHR: 8.18; 95% CI: 2.22, 30.09; P = 0.002), double lung transplant (DLT) (aHR: 3.27; 95% CI: 1.22, 8.78; P = 0.02) and CLAD within 3 years in DLT patients (aHR: 6.76; 95% CI: 1.71, 26.74; P = 0.01).

CONCLUSION

Methacholine challenge test+ at 3 months after LT is associated with the development of overall CLAD. Positive MCT could predict the development of early CLAD within 3 years in DLT patients.

Lobe-wise assessment of lung volume and density distribution in lung transplant patients and value for early detection of bronchiolitis obliterans syndrome

PURPOSE

To evaluate quantitative computed tomography (CT) measurements of the lung parenchyma in lung transplant (LTx) patients for early detection of the bronchiolitis obliterans syndrome (BOS).

MATERIALS AND METHODS

359 CT scans of 122 lung transplant patients were evaluated. Measurements of lung volume and density were performed for the whole lung and separately for each lobe. For longitudinal analysis the difference between the baseline at 6 months after LTx and follow-up examinations was calculated. Patients with and without BOS (matched 1:2) were compared at two different time points, the last examination before the BOS onset and the first examination within one year after BOS onset.

RESULTS

30 patients developed BOS during the follow-up period. Longitudinal changes in the lung volume and lung density measured on CT differed significantly between those patients with and without early BOS, in particular the difference of the inspiratory and expiratory lung volume (p < 0.001), the ratio of the expiratory and inspiratory lung volume (p < 0.001-p = 0.001) and MLD (p < 0.001-p = 0.001), the volume on expiration (p < 0.001-p = 0.007), the MLD on expiration (p < 0.001-p = 0.007), and the percentiles on expiration (p < 0.001-p = 0.002) with an increase of lung volume and a decrease of lung density. Changes were pronounced in the lower lobes. Before BOS onset, patients with and without future development of BOS showed no significant differences.

CONCLUSION

Longitudinal changes of lung volume and lung density measured on CT start markedly at BOS onset with increased lung volume and decreased lung density indicating increased inflation levels. Even though this method may help to diagnose BOS at onset it is not useful as a predictor for BOS before disease onset.

Cystic Fibrosis and gastroesophageal reflux disease

Gastroesophageal reflux is common in children and adults with cystic fibrosis (CF). Pathological gastroesophageal reflux disease (GERD) is also frequent in patients of all ages with CF. This article reviews the pathophysiology, diagnostic work-up, management options, complications, and future directions in the evaluation and management of GERD - unique to and pertinent for - patients with CF in particular.

Breath volatile organic compounds of lung transplant recipients with and without chronic lung allograft dysfunction

INTRODUCTION

Chronic lung allograft dysfunction with its clinical correlative of bronchiolitis obliterans syndrome (BOS) remains the major limiting factor for long-term graft survival. Currently there are no established methods for the early diagnosis or prediction of BOS. To assess the feasibility of breath collection as a non-invasive tool and the potential of breath volatile organic compounds (VOC) for the early detection of BOS, we compared the breath VOC composition between transplant patients without and different stages of BOS.

METHODS

75 outpatients (25 BOS stage 0, 25 BOS stage 1 + 2, 25 BOS stage 3) after bilateral lung transplantation were included. Exclusion criteria were active smoking, oxygen therapy and acute infection. Patients inhaled room air through a VOC and sterile filter and exhaled into an aluminum reservoir tube. Breath was loaded directly onto Tenax^® TA adsorption tubes and was subsequently analyzed by gas-chromatography/mass-spectrometry.

RESULTS

The three groups were age and gender matched, but differed with respect to time since transplantation, the spectrum of underlying disease, and treatment regimes. Relative to patients without BOS, BOS stage 3 patients showed a larger number of different VOCs, and more pronounced differences in the level of VOCs as compared to BOS stage 1 + 2 patients. Logistic regression analysis found no differences between controls and BOS 1 + 2, but four VOCs (heptane, isopropyl-myristate, ethyl-acetate, ionone) with a significant contribution to the discrimination between controls and BOS stage 3. A combination of these four VOCs separated these groups with an area under the curve of 0.87.

CONCLUSION

Breath sample collection using our reservoir sampler in the clinical environment was feasible. Our results suggest that breath VOCs can discriminate severe BOS. However, convincing evidence for VOCs with a potential to detect early onset BOS is lacking.

Effect of Immunosuppression on Target Blood Immune Cells Within 1 Year After Lung Transplantation: Influence of Age on T Lymphocytes

Background

Lymphocytes are targeted by immunosuppressive therapy in solid organ transplantation and they influence allograft outcome.

Material/Methods

Peripheral blood lymphocyte subsets (PBLS) determined by flow cytometry during the first year post-transplant from patients who underwent a first lung transplantation in a French University Hospital between December 2011 and July 2013 were retrospectively analyzed according to recipient characteristics and allograft outcome.

Results

Fifty-seven recipients were enrolled and 890 PBLS were collected. T lymphocytes and NK cells were rapidly decreased, below normal range, from the first postoperative days. B cells decreased more gradually, remaining within normal range, with the lowest level reached after day 100. In multivariate analysis, greater T lymphopenia was found in older recipients (−414 [−709 to −119] cells/μL, p=0.007). According to the outcome, multivariate analysis evidenced lower levels of lymphocytes when bacterial and viral infection occurred (−177 [−310 to −44] cells/μL, p=0.009 and (−601 [−984 to −218] cells/μL, p=0.002, respectively), higher CD8+ T lymphocytes with BOS (+324 [+94 to +553] cells/μL, p=0.006), and higher leukocytes with restrictive allograft syndrome (+3770 [+418 to +7122] cells/μL, p=0.028).

Conclusions

Aging is associated in our cohort with more severe T lymphopenia after induction therapy for lung transplantation. The analysis of leukocytes and PBLS is associated with specific profile according to the allograft outcome.

Efficacy of Extracorporeal Photopheresis in Patients With Bronchiolitis Obliterans Syndrome After Lung Transplantation

BACKGROUND

Lung transplantation (LT) is only therapeutic option for patients affected by chronic respiratory failure. Chronic rejection, also known as bronchiolitis obliterans syndrome (BOS), is still the main cause of death and the most important factor that influences post-transplantation quality of life. Currently available therapies have not been proven to result in significant benefit in the prevention or treatment of BOS. Extracorporeal photopheresis (ECP) seems to reduce the rate of lung function decline in transplant recipients with progressive BOS.

METHODS

From 1991 until now, 239 LTs were performed at our center. Fifty-four patients (22.5%) developed BOS; 15 of these (27.7%) were treated with ECP. At the beginning of the treatment, all patients showed a mean decline of forced expiratory volume in 1 second (FEV₁) from baseline values of 45.8% ± 17.2%; 2 patients were in long-term oxygen therapy.

RESULTS

Mean follow-up from November 2013 to June 2016 was 11.6 ± 7 months. Twelve patients (80%) showed lung function stabilization with an FEV₁ range after treatment between -6% to +8% from the pre-treatment values. We did not report any adverse effects or increase of infections incidence.

DISCUSSION

ECP seems to be an effective and well-tolerated therapeutic option for LT patients with BOS in terms of stabilization of lung function and increased survival.

Effect of HMG CoA reductase inhibitors on the development of chronic lung allograft dysfunction

Lung transplant recipients (LRs) have a reduced median 5-year survival of approximately 55% primarily due to chronic lung allograft dysfunction (CLAD). Statins have anti-inflammatory and immunomodulatory effects that may facilitate CLAD prevention. This study sought to evaluate statin effect on CLAD development. Adult bilateral LRs from January 2004 to October 2013 were included. Statin group included recipients with early statin use and continued for minimum 6 months. Propensity score matching was performed for age, gender, and native lung disease to select matched nonstatin group. Competing risk approach was used to evaluate statin effect on CLAD development at 3 years while controlling for acute rejection and CMV pneumonitis. A total of 130 patients were included in each group. CLAD cumulative incidence at 3 years for statin and nonstatin groups was 20.6% (CI: 11.8%-33.5%) and 22.4% (CI: 12.2%-27.3%). Statin use was not associated with a decreased risk of CLAD (subdistribution hazard ratio [SHR]: 0.93, 95% CI: 0.55-1.59, P = .80) but was associated with a decreased risk of death (SHR: 0.45, CI: 0.22-0.90, P = .024). At 3 years, patient survival was 81.7% in statin group and 68.3% in nonstatin group (P = .012). Statins did not significantly delay the time to development of CLAD in LR but did demonstrate a benefit in patient survival.

Prevention of chronic rejection after lung transplantation

Long-term survival after lung transplantation (LTx) is limited by chronic rejection (CR). Therapeutic strategies for CR have been largely unsuccessful, making prevention of CR an important and challenging therapeutic approach. In the current review, we will discuss current clinical evidence regarding prevention of CR after LTx.

Update in Chronic Lung Allograft Dysfunction

Chronic lung allograft dysfunction (CLAD) is the major limitation to posttransplant survival. This review highlights the evolving definition of CLAD, risk factors, treatment, and expected outcomes after the development of CLAD.

Chronic lung allograft dysfunction phenotypes and treatment

Chronic lung allograft dysfunction (CLAD) remains a major hurdle limiting long-term survival post lung transplantation. Given the clinical heterogeneity of CLAD, recently two phenotypes of CLAD have been defined [bronchiolitis obliterans syndrome (BOS) vs. restrictive allograft syndrome (RAS) or restrictive CLAD (rCLAD)]. BOS is characterized by an obstructive pulmonary function, air trapping on CT and obliterative bronchiolitis (OB) on histopathology, while RAS/rCLAD patients show a restrictive pulmonary function, persistent pleuro-parenchymal infiltrates on CT and pleuroparenchymal fibro-elastosis on biopsies. Importantly, the patients with RAS/rCLAD have a severely limited survival post diagnosis of 6-18 months compared to 3-5 years after BOS diagnosis. In this review, we will review historical evidence for this heterogeneity and we will highlight the clinical, radiological, histopathological characteristics of both phenotypes, as well as their risk factors. Treatment of CLAD remains troublesome, nevertheless, we will give an overview of different treatment strategies that have been tried with some success. Adequate phenotyping remains difficult but is clearly needed for both clinical and scientific purposes.

Association of Higher CD4+ CD25high CD127low , FoxP3+ , and IL-2+ T Cell Frequencies Early After Lung Transplantation With Less Chronic Lung Allograft Dysfunction at Two Years

Regulatory T cells (Treg) can regulate alloantigens and may counteract chronic lung allograft dysfunction (CLAD) in lung transplantation. We analyzed Treg in peripheral blood prospectively and correlated percentages of subpopulations with the incidence of CLAD at 2 years. Among lung-transplanted patients between January 2009 and July 2011, only patients with sufficient Treg measurements were included into the study. Tregs were measured immediately before lung transplantation, at 3 weeks and 3, 6, 12, and 24 months after transplantation and were defined as CD4⁺ CD25^high T cells and further analyzed for CTLA4, CD127, FoxP3, and IL-2 expressions. Between January 2009 and July 2011, 264 patients were transplanted at our institution. Among the 138 (52%) patients included into the study, 31 (22%) developed CLAD within 2 years after transplantation. As soon as 3 weeks after lung transplantation, a statistically significant positive association was detected between Treg frequencies and later absence of CLAD. At the multivariate analysis, increasing frequencies of CD4⁺ CD25^high CD127^low , CD4⁺ CD25^high FoxP3⁺ and CD4⁺ CD25^high IL-2⁺ T cells at 3 weeks after lung transplantation emerged as protective factors against development of CLAD at 2 years. In conclusion, higher frequencies of specific Treg subpopulations early after lung transplantation are protective against CLAD development.

How I treat bronchiolitis obliterans syndrome after hematopoietic stem cell transplantation

In past years, a diagnosis of bronchiolitis obliterans syndrome (BOS) after allogeneic hematopoietic cell transplant (HCT) conferred nearly universal mortality secondary to lack of consensus for diagnostic criteria, poorly understood disease pathogenesis, and very few studies of therapeutic or supportive care interventions. Recently, however, progress has been made in these areas: revised consensus diagnostic guidelines are now available, supportive care has improved, there is greater understanding of potential mechanisms of disease, and prospective trials are being conducted. This article describes these advances and provides suggestions to optimize therapy for patients with BOS after HCT.

Update on Chronic Lung Allograft Dysfunction

Chronic lung allograft dysfunction (CLAD) encompasses a range of pathologies that cause a transplanted lung to not achieve or maintain normal function. CLAD manifests as airflow restriction and/or obstruction and is predominantly a result of chronic rejection. Three distinct phenotypes of chronic rejection are now recognized: bronchiolitis obliterans, neutrophilic reversible allograft dysfunction, and restrictive allograft syndrome. Recent investigations have revealed that each phenotype has a unique pathology and histopathological findings, suggesting that treatment regimens should be tailored to the underlying etiology. CLAD is poorly responsive to treatment once diagnosed, and therefore the prevention of the factors that predispose a patient to develop CLAD is critically important. Small and large animal models have contributed significantly to our understanding of CLAD and more studies are needed to develop treatment regimens that are effective in humans.

Therapeutic effect of budesonide/formoterol, montelukast and N-acetylcysteine for bronchiolitis obliterans syndrome after hematopoietic stem cell transplantation

Background

Bronchiolitis obliterans syndrome (BOS) after allogeneic hematopoietic stem cell transplantation (HSCT) is currently treated with systemic corticosteroids despite poor efficacy and side effects. This study investigated the therapeutic effect of budesonide/formoterol, montelukast and n-acetylcysteine, which are suggested as treatment options for BOS after HSCT.

Methods

After diagnosis of BOS, 61 patients were treated with budesonide/formoterol, montelukast and n-acetylcysteine for 3 months. Pulmonary function test and COPD assessment test (CAT) were performed before and after the combination therapy. Therapeutic response was evaluated by changes in forced expiratory volume in 1 s (FEV₁) or CAT score.

Results

After 3 months of combination treatment, mean FEV₁ increased by 220 mL (p < 0.001) and residual volume decreased by 200 mL (p =0 .005). Median CAT score also significantly decreased from 15.5 to 11.0 (p = 0.001). The overall response rate to combination therapy was 82 %. Comparing the no-response group and the response group, the forced vital capacity (% predicted) decline between pre-HSCT and BOS diagnosis was significantly greater in the response group (p = 0.036).

Conclusion

Combination treatment with budesonide/formoterol, montelukast and n-acetylcysteine significantly improved lung function and respiratory symptoms in patients with BOS after allogeneic HSCT without serious side effects.

Epithelial and Erythrocyte Microvesicles From Bronchoalveolar Lavage Fluid Are Elevated and Associated With Outcome in Chronic Lung Allograft Dysfunction

BACKGROUND

Chronic lung allograft dysfunction (CLAD) is the major outcome limitation for lung transplant recipients (LTR) after the first year, and therapies targeting immunological pathways show only limited success. Because microvesicles (MV) are biomarkers of endothelial dysfunction and coagulation but are also involved in immunological responses, we hypothesized that MV, found in bronchoalveolar lavage (BAL) fluids (BALF) of LTR at CLAD diagnosis, are elevated and potential prognostic biomarkers.

METHODS

The BALF was collected from 37 LTR at time point of CLAD diagnosis and 37 LTR without any complication at routinely performed BAL. The MV concentration and origin were determined by flow cytometry by detection of different antigens. Patient- and transplant-related risk factors were included in a retrospective statistical analysis.

RESULTS

The BALF-MV levels of epithelial and red blood cell (RBC) origin were significantly higher in CLAD patients (mean: 1533/μL and 158/μL) compared to controls (436/μL, 57/μL). The LTR with high levels of epithelial MV >580/μL showed a significantly shorter overall survival at 4 years after BAL (39.5%) compared to patients with low MV (66.4%) and this proofed to be an independent prognostic factor in multivariate Cox analysis (hazards ratio = 3.05). Furthermore, LTR with high levels of RBC MV ≥225/μL were also associated with worse disease-specific survival, with probabilities at 4 years after BAL of 85.8% vs. 36.0%.

CONCLUSIONS

Epithelial and RBC BALF-MV are elevated at CLAD diagnosis, have a potential as biomarkers, and support the hypothesis of a pathway, including activation of coagulation and complement, endothelial barrier dysfunction, and microangiopathy.