The International Thoracic Organ Transplant Registry of the International Society for Heart and Lung Transplantation: Thirty-eighth adult lung transplantation report - 2021; Focus on recipient characteristics

Perioperative fluid balance and early acute kidney injury after lung transplantation

BACKGROUND

Postoperative acute kidney injury (AKI) after lung transplantation (LTx) is an important factor affecting the short-term outcomes. The focus item of transplantation centers is how to improve the incidence of AKI through optimal management during the perioperative period.

OBJECTIVE

The purpose of the study is to investigate the influence of perioperative volume in the development of early AKI following LTx.

METHOD

The study involved patients who had undergone LTx between October 2018 to December 2021 at China-Japan Friendship Hospital in Beijing. The patients were monitored for AKI occurring within 72 hours after LTx, as well as the renal outcomes within 30 days. The perioperative volumes were compared and analyzed to determine the impact on various clinical outcomes.

RESULTS

248 patients were enrolled in the study ultimately, with almost half of them (49.6 %) experiencing AKI. 48.8 % of AKI patients received continuous renal replacement therapy (CRRT), with 57.7 % recovered by the end of the 30-day follow-up period. A J-shaped relationship was demonstrated between perioperative volume and AKI incidence. Moreover, maintaining a positive fluid balance would increase the 30-day mortality and lead to poor renal outcomes.

CONCLUSION

Perioperative volume is an independent risk factor of early AKI after LTx. Positive fluid balance increases the risk of AKI, 30-day mortality, and adverse renal prognosis. The LTx recipients may benefit from a relatively restrict fluid strategy during and after the lung transplantation.

Pulmonary bacterial infection after lung transplantation: risk factors and impact on short-term mortality

OBJECTIVE

To explore the risk factors for pulmonary bacterial infection (PBI) after lung transplantation (LTX) and to evaluate the impact of PBI on short-term postoperative mortality.

METHODS

We retrospectively analyzed data on 549 recipients who underwent LTX at the Affiliated Wuxi People's Hospital of Nanjing Medical University, China, between January 2018 and December 2021. The risk factors for PBI after LTX were explored by univariate analysis and multivariate logistic regression. Cox proportional hazards regression models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) of one-, two-, and three-year mortality. Subgroup analysis was performed by the time of postoperative PBI (≤7 days or 8-30 day after surgery).

RESULTS

The incidence of postoperative PBI in 549 recipients was 82.70% (454/549). Preoperative history of infections with multidrug-resistant bacteria (OR 12.34, 95% CI 1.69-1572.39), Acinetobacter baumannii infection in donor (OR 3.08, 95% CI 1.26-9.66), and longer cold ischemia time (OR 1.16, 95% CI 1.03-1.32) were risk factors for postoperative PBI. Postoperative PBI was associated with one-year (HR 1.80, 95% CI 1.09-2.96), two-year (HR 1.91, 95% CI 1.20-3.04), and three-year mortality (HR 2.03, 95% CI 1.29-3.19). Subgroup analysis showed that PBI within 7 days after surgery was associated with one-year (HR 1.86, 95% CI 1.12-3.08), two-year (HR 1.99, 95% CI 1.25-3.17), and three-year mortality (HR 2.13, 95% CI 1.35-3.36), while PBI at 8-30 days after surgery was not associated with short-term mortality (one-year: HR 1.36, 95% CI 0.69-2.69; two-year: HR 1.48, 95% CI 0.80-2.76; three-year: HR 1.51, 95% CI 0.82-2.77).

CONCLUSIONS

Donor-recipient and surgical factors are risk factors for PBI after LTX. Active prevention and treatment of PBI within the first 7 days after surgery may improve short-term survival.

Diagnosis and management of hypersensitivity pneumonitis in adults: A position statement from the Thoracic Society of Australia and New Zealand

Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease (ILD) relating to specific occupational, environmental or medication exposures. Disease behaviour is influenced by the nature of exposure and the host response, with varying degrees of lung inflammation and fibrosis seen within individuals. The differentiation of HP from other ILDs is important due to distinct causes, pathophysiology, prognosis and management implications. This Thoracic Society of Australia and New Zealand (TSANZ) position statement aims to provide an up-to-date summary of the evidence for clinicians relating to the diagnosis and management of HP in adults, in the Australian and New Zealand context. This document highlights recent relevant findings and gaps in the literature for which further research is required.

Impact of Long-Term Atorvastatin Therapy on the Development of Chronic Lung Allograft Dysfunction in Patients with Azithromycin Prophylaxis after Lung Transplantation

OBJECTIVE

To assess the impact of long-term atorvastatin (ATO) therapy on reducing recipient inflammation and immune response, thus lowering the risk of chronic lung allograft dysfunction (CLAD) in lung transplant recipients. This study aimed to investigate the effects of ATO on overall survival, lung function recovery, and its influence on inflammatory factors alongside azithromycin (AZI) prophylaxis.

METHODS

This retrospective single-center study included lung transplant recipients from January 2017 to December 2022. Patients who survival >1 year after lung transplantation and who were receiving AZI prophylaxis for >6 months were selected. Outcome measures involved pulmonary function assessments at various time points after AZI treatment, complete blood cell analysis, and inflammatory factor evaluations.

RESULTS

The incidence of CLAD was significantly lower in the long-term ATO group compared with those not on ATO (P = .011). Long-term ATO treatment significantly delayed CLAD onset after lung transplantation (850 days vs. 630 days; P = .041), with patients showing notably enhanced lung function recovery within 6 months of AZI therapy compared with the non-ATO group. Neutrophil levels decreased in patients with CLAD, and interleukin-6 concentrations significantly decreased in the AZI + ATO group compared with the AZI group. Overall patient survival was significantly better in the AZI+ATO group than in the AZI group (P = .02).

CONCLUSION

In cases where CLAD develops despite AZI prophylaxis, long-term ATO treatment may lead to short-term improvements in lung function. It could also decrease inflammation levels in lung transplant recipients and enhance overall survival. The combination of AZI and long-term ATO therapy may be beneficial for CLAD prevention.

Impact of Tacrolimus vs. Cyclosporine on CLAD Incidence and Allograft Survival in the ISHLT Registry

PURPOSE

The ScanCLAD study reported a lower incidence of CLAD with the use of once-daily tacrolimus vs. twice-daily cyclosporine. Using the ISHLT Thoracic Organ Transplant (TTX) Registry data, we evaluated the hypothesis that tacrolimus is superior to cyclosporine in real world clinical practice.

METHODS

This study is a retrospective cohort study of adult lung transplant recipients in the ISHLT Registry from January 1, 2000 through June 30, 2018 with known CLAD status. The primary exposure variable was patients' maintenance calcineurin inhibitor (CNI) regimen captured at post-transplant discharge. The primary outcome variables were time to CLAD development (with death/retransplantation analyzed as a competing risk) and allograft survival (i.e., time to death/retransplant).

RESULTS

Of the 57,403 adult lung transplant recipients in the registry, 22,222 had both CNI and CLAD data available. Of these, 19,698 (88.6%) received tacrolimus immediate release (IR), 2,477 (11.2%) received cyclosporine, and 47 (0.2%) received tacrolimus extended release (XR) for maintenance CNI. Receiving cyclosporine for maintenance immunosuppression (vs. tacrolimus IR) was associated with an increased risk of developing CLAD (HR 1.16, 95% CI 1.08-1.23, p<0.001) and with an increased overall risk for death/retransplant (HR 1.16, 95% CI 1.09-1.23, p<0.001). Receiving tacrolimus XR vs. tacrolimus IR was not associated with differences in long-term post-transplant outcomes, although these analyses were limited by a small sample size.

CONCLUSIONS

Patients receiving cyclosporine vs. tacrolimus IR for maintenance calcineurin inhibition had an increased risk of CLAD and decreased overall allograft survival in the ISHLT TTX registry.

ISHLT consensus statement on the perioperative use of ECLS in lung transplantation: Part II: Intraoperative considerations

The use of extracorporeal life support (ECLS) throughout the perioperative phase of lung transplantation requires nuanced planning and execution by an integrated team of multidisciplinary experts. To date, no multidisciplinary consensus document has examined the perioperative considerations of how to best manage these patients. To address this challenge, this perioperative utilization of ECLS in lung transplantation consensus statement was approved for development by the International Society for Heart and Lung Transplantation Standards and Guidelines Committee. International experts across multiple disciplines, including cardiothoracic surgery, anesthesiology, critical care, pediatric pulmonology, adult pulmonology, pharmacy, psychology, physical therapy, nursing, and perfusion, were selected based on expertise and divided into subgroups examining the preoperative, intraoperative, and postoperative periods. Following a comprehensive literature review, each subgroup developed recommendations to examine via a structured Delphi methodology. Following 2 rounds of Delphi consensus, a total of 39 recommendations regarding intraoperative considerations for ECLS in lung transplantation met consensus criteria. These recommendations focus on the planning, implementation, management, and monitoring of ECLS throughout the entire intraoperative period.

The Korean Organ Transplant Registry (KOTRY): Third Official Adult Heart Transplant Report

BACKGROUND AND OBJECTIVES

The Korean Organ Transplant Registry (KOTRY) provided data for this third official report on adult heart transplantation (HT), including information from 709 recipients.

METHODS

Data from HTs performed at seven major centers in Korea between March 2014 and December 2020 were analyzed, focusing on immunosuppression, acute rejection, cardiac allograft vasculopathy (CAV), post-transplant survival, and mechanical circulatory support (MCS) usage.

RESULTS

The median ages of the recipients and donors were 56.0 and 43.0 years, respectively. Cardiomyopathy and ischemic heart disease were the most common preceding conditions for HT. A significant portion of patients underwent HT at waiting list status 1 and 0. In the multivariate analysis, a predicted heart mass mismatch was associated with a higher risk of 1-year mortality. Patients over 70 years old had a significantly increased risk of 6-year mortality. The risk of CAV was higher for male donors and donors older than 45 years. Acute rejection was more likely in patients with panel reactive antibody levels above 80%, while statin use was associated with a reduced risk. The employment of left ventricular assist device as a bridge to transplantation increased from 2.17% to 22.4%. Pre-transplant extra-corporeal membrane oxygenation was associated with worse post-transplant survival.

CONCLUSIONS

In this third KOTRY report, we analyzed changes in the characteristics of adult HT recipients and donors and their impact on post-transplant outcomes. The most notable discovery was the increased use of MCS before HT and their impact on post-transplant outcomes.

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Patterns and Risk Factors for Rehospitalizations Within the First 90 Days Following Discharge After Heart Transplantation

BACKGROUND

Heart transplantation (HT) recipients are at risk for urgent rehospitalizations following discharge. However, data on prevalence, risk factors and clinical outcomes associated with post-HT rehospitalization are limited.

METHODS

This study aims to describe patterns of urgent rehospitalizations in HT recipients at a cardiology reference center in Brazil. Rehospitalizations and deaths occurring within the first 90 days following hospital discharge were identified. Regression models were used to identify variables associated with urgent rehospitalizations.

RESULTS

A total of 239 patients were included. Of those, 118 (49.4%) presented with a rehospitalization within 90 days following hospital discharge and 5 (2.01%) died. Most patients who were rehospitalized had one new hospital admission (86.0%). The main cause of urgent rehospitalization was infection (55.0%). In the multivariate analysis, elevated C-reactive protein at discharge and the occurrence of intracranial bleeding at index hospitalization were associated with an increased risk of readmission. Longer duration of index hospitalization and use of lower doses of azathioprine were associated with a lower risk of rehospitalization.

CONCLUSION

Around half of HT recipients were rehospitalized within the first 90 days after hospital discharge. Understanding factors associated with post-HT rehospitalization may help the implementation of strategies to avoid patient morbidity and hospital costs.

Future directions for xenotransplantation in lungs

PURPOSE OF REVIEW

Advancements in preclinical xenotransplant studies have opened doors for clinical heart and kidney xenotransplantation. This review assesses recent progress in lung xenotransplantation research and its potential clinical implications.

RECENT FINDINGS

The efficacy of the humanized von Willebrand factor in reducing platelet sequestration in ex-vivo and in-vivo lung xenotransplant models was showcased. Combining human tissue factor pathway inhibitor and CD47 expression with selectin and integrin inhibition delayed neutrophil and platelet sequestration. Enhanced expression of human complement regulatory proteins and thrombomodulin in genetically engineered pig lungs improved graft survival by reducing platelet activation and modulating coagulation disruptions. Knocking out the CMAH gene decreased antibody-mediated inflammation and coagulation activation, enhancing compatibility for human transplantation. Furthermore, CMAH gene knockout in pigs attenuated sialoadhesin-dependent binding of human erythrocytes to porcine macrophages, mitigating erythrocyte sequestration and anemia. Meanwhile, in-vivo experiments demonstrated extended survival of xenografts for up to 31 days with multiple genetic modifications and comprehensive treatment strategies.

SUMMARY

Experiments have uncovered vital insights for successful xenotransplantation, driving further research into immunosuppressive therapy and genetically modified pigs. This will ultimately pave the way for clinical trials designed to improve outcomes for patients with end-stage lung disease.

Effect of revised organ transplant law in Japan on lung transplantation

PURPOSE

To investigate how revision of the organ transplant law in Japan affected lung transplantation in this country.

METHODS

Lung transplant candidates registered between January, 2000 and December, 2009 were designated as the pre-revision group (n = 396) and those registered between January, 2011 and December, 2020, as the post-revision group (n = 1326). Both groups were analyzed retrospectively using data collected by the Japanese Society of Lung and Heart-Lung Transplantation.

RESULTS

The number of patients who underwent brain-dead donor lung transplantation (BDLT) increased significantly after the law amendment (32.2 vs. 13.8%, p < 0.01). The median waiting time for BDLT was significantly reduced (708 days vs. 1163 days, p < 0.01) and the mortality rate while waiting for BDLT improved significantly after the law amendment (33.1 vs. 42.6%, p < 0.01). In the post-revision group, 18 pediatric patients underwent BDLT. The 5-year survival rates after BDLT were comparable between the groups (73.5% in the pre-revision group vs. 73.2% in the post-revision group, p = 0.32).

CONCLUSIONS

The organ transplant law revision shortened the waiting time for BDLT significantly and decreased the mortality rate while waiting for BDLT. The posttransplant outcomes in Japan remained favorable throughout the study period.

Experiences and Understanding of Well-Being in Lung Transplant Recipients in China: A Phenomenological Qualitative Study

AIM

To explore lung transplant recipients' perceptions of well-being when they are facing uncertain health outcomes, including identifying the factors to enhance well-being.

DESIGN

A qualitative descriptive study.

METHODS

A purposive sample of 11 lung transplantation recipients who were hospitalised in the Department of Organ Transplantation of a tertiary university hospital was recruited in China. A descriptive qualitative study using thematic analysis of semistructured interviews. Themes were organised within a PERMA model. Colaizzi's qualitative analysis was used to analyse the data.

RESULTS

Five major themes and 11 categories were generated: (1) mindset shift [optimism and hope and living in the moment]; (2) meaning in life [self-care, priority change and value realisation]; (3) health benefits [improved health and behavioural changes]; (4) perceived support [support from family, the health care team and others]; (5) unmet support needs.

CONCLUSION

Lung transplant recipients could perceive well-being from five aspects that caused significantly favourable transformation across a variety of aspects in patients' lives. These findings may support nursing staff when caring for this patient group, making them aware of multifaceted nature of well-being. They could offer insight into potential pathways for the development of nurse-led tailored interventions, based on specific elements of PERMA model.

IMPACT

This work adds to a growing body of knowledge about well-being amongst lung transplant patients. These findings may support nursing staff when caring for this patient group, making them aware of multifaceted nature of well-being and illustrating factors that promote positive well-being in this group, based on specific elements of PERMA model.

REPORTING METHOD

This study followed the Consolidated Criteria for Reporting Qualitative Research checklist.

PATIENT OR PUBLIC CONTRIBUTION

Two lung transplant recipients were involved in the early phases of this study. They helped in formulating the interview outline.

High-Risk HLA-DQ Mismatches Are Associated With Adverse Outcomes After Lung Transplantation

Human leukocyte antigen (HLA) mismatches (MM) between donor and recipient lead to eplet MM (epMM) in lung transplantation (LTX), which can induce the development of de-novo donor-specific HLA-antibodies (dnDSA), particularly HLA-DQ-dnDSA. Aim of our study was to identify risk factors for HLA-DQ-dnDSA development. We included all patients undergoing LTX between 2012 and 2020. All recipients/donors were typed for HLA 11-loci. Development of dnDSA was monitored 1-year post-LTX. EpMM were calculated using HLAMatchmaker. Differences in proportions and means were compared using Chi2-test and Students' t-test. We used Kaplan-Meier curves with LogRank test and multivariate Cox regression to compare acute cellular rejection (ACR), chronic lung allograft dysfunction (CLAD) and survival. Out of 183 patients, 22.9% patients developed HLA-DQ-dnDSA. HLA-DQ-homozygous patients were more likely to develop HLA-DQ-dnDSA than HLA-DQ-heterozygous patients (p = 0.03). Patients homozygous for HLA-DQ1 appeared to have a higher risk of developing HLA-DQ-dnDSA if they received a donor with HLA-DQB1*03:01. Several DQ-eplets were significantly associated with HLA-DQ-dnDSA development. In the multivariate analysis HLA-DQ-dnDSA was significantly associated with ACR (p = 0.03) and CLAD (p = 0.01). HLA-DQ-homozygosity, several high-risk DQ combinations and high-risk epMM result in a higher risk for HLA-DQ-dnDSA development which negatively impact clinical outcomes. Implementation in clinical practice could improve immunological compatibility and graft outcomes.

A comparative study of femoral artery and combined femoral and axillary artery cannulation in veno-arterial extracorporeal membrane oxygenation patients

Objective

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a critical support technique for cardiac surgery patients. This study compares the outcomes of femoral artery cannulation vs. combined femoral and axillary artery cannulation in post-cardiotomy VA-ECMO patients. This study aimed to compare the clinical outcomes of critically ill patients post-cardiac surgery under VA-ECMO support using different cannulation strategies. Specifically, the focus was on the impact of femoral artery (FA) cannulation vs. combined femoral artery and axillary artery (FA+AA) cannulation on patient outcomes.

Methods

Through a retrospective analysis, we compared 51 adult patients who underwent cardiac surgery and received VA-ECMO support based on the cannulation strategy employed-FA cannulation in 27 cases vs. FA+AA cannulation in 24 cases.

Results

The FA+AA group showed significant advantages over the FA group in terms of the incidence of chronic renal failure (CRF) (37.50% vs. 14.81%, p = 0.045), preoperative blood filtration requirement (37.50% vs. 11.11%, p = 0.016), decreased platelet count (82.67 ± 44.95 vs. 147.33 ± 108.79, p = 0.014), and elevated creatinine (Cr) levels (151.80 ± 60.73 vs. 110.26 ± 57.99, p = 0.041), although the two groups had similar 30-day mortality rates (FA group 40.74%, FA+AA group 33.33%). These findings underscore that a combined approach may offer more effective hemodynamic support and better clinical outcomes when selecting an ECMO cannulation strategy.

Conclusion

Despite the FA+AA group patients presenting with more preoperative risk factors, this group has exhibited lower rates of complications and faster recovery during ECMO treatment. While there has been no significant difference in 30-day mortality rates between the two cannulation strategies, the FA+AA approach may be more effective in reducing complications and improving limb ischemia. These findings highlight the importance of individualized treatment strategies and meticulous monitoring in managing post-cardiac surgery ECMO patients.

An integrated sampling strategy for therapeutic mycophenolic acid monitoring in lung transplant recipients

BACKGROUND

Mycophenolic Acid (MPA) is the most used anti-proliferative in lung transplantation, but its pharmacokinetic (PK) variability has precluded therapeutic drug monitoring. Both genetic and clinical factors have been implicated in MPA variability. This study aimed to integrate genetic and clinical factors with PK measurements to quantify MPA exposure.

METHODS

We performed 12-hour pharmacokinetic analysis on 60 adult lung transplant recipients maintained on MPA for immunosuppression. We genotyped a SLCO1B3 polymorphisms previously associated MPA metabolism and collected relevant clinical data. We calculated area under the curve (AUC0-12) and performed univariate linear regression analysis to evaluate its association with genetic, clinical, and pharmacokinetic variables. We performed lasso regression analysis to create final AUC estimation tools.

RESULTS

PK-only measurements obtained 2, 3, and 8 hours after MPA administration (C2, C3, and C8) were strongly associated with MPA AUC0-12 (R267%, 67% and 68% respectively). Clinical and genetic factors associated with MPA AUC0-12 included the MPA dose (p = 0.001), transplant diagnosis (p = 0.015), SLCO1B3 genotype (p = 0.049), and body surface area (p = 0.050). The best integrated single-sampling strategy included C2 and achieved an R2 value of 80%. The best integrated limited-sampling strategy included C0, C0.25, and C2 and achieved an R2 value of 90%.

CONCLUSIONS

An integrated limited sampling strategy (LSS) for MPA allows increased accuracy in prediction of MPA AUC0-12 compared to PK-only modeling. Validation of this model will allow for clinically feasible MPA therapeutic drug monitoring and help advance precision management of MPA.

Post-lung transplant outcomes of connective tissue disease-related interstitial lung diseases compared with idiopathic interstitial pneumonia: a single-center experience in Japan

OBJECTIVES

The aim of this study was to investigate the outcomes of lung transplantation for connective tissue disease-related interstitial lung disease (CTD-ILD) conducted at our institution, compared with those for idiopathic interstitial pneumonias (IIPs).

METHODS

We retrospectively reviewed patients with CTD-ILD and IIPs who underwent lung transplantation at our hospital from July 2015 to October 2023. We compared patients' backgrounds, early complications within 28 days post-transplant (CTCAE grade 3 or higher), postoperative courses, and prognoses between the two groups.

RESULTS

The CTD-ILD group (n = 19) and the IIPs group (n = 56) were compared. The CTD-ILD group had significantly higher preoperative use of corticosteroids and antifibrotic agents, mean pulmonary arterial pressure, anti-human leukocyte antigen antibody positivity, and donor age (p < 0.05). In addition, the CTD-ILD group had significantly longer operation times (579.0 vs 442.5 min), longer stays in the intensive care unit (17.0 vs 9.0 days) and hospital (58.0 vs 44.0 days); required more tracheostomies (57.9 vs 25.0%); and experienced more respiratory (52.6 vs 25.0%) and gastrointestinal (42.1 vs 8.9%) complications (p < 0.05). However, there were no significant differences in overall survival, nor chronic lung allograft dysfunction (CLAD)-free survival between the two groups.

CONCLUSION

Perioperative complications, notably respiratory and gastrointestinal complications, were prevalent after lung transplantation among CTD-ILD patients. Despite this, long-term survival rates were comparable to those observed in IIP cases.

Accuracy of Ultralow-Dose Photon-counting CT in the Detection of Lung Changes after Lung Transplant

Background Data on the diagnostic accuracy of ultralow-dose (ULD) CT protocols for periodic surveillance in recipients of lung transplant are lacking. Purpose To assess the potential for radiation dose reduction using ULD photon-counting CT (PCT) to detect lung abnormalities in recipients of lung transplant during repeat CT follow-up. Materials and Methods Consecutive adult recipients of lung transplant undergoing same-day standard-of-care low-dose (LD) and ULD PCT from March 2023 to May 2023 were prospectively included. The ULD protocols were performed with two target effective doses comprising 20% (hereafter, ULD1) and 10% (hereafter, ULD2) of the standard LD protocol. The 1-mm reconstructions were reviewed by three readers. Subjective image quality, the visibility of certain anatomic structures (using a five-point Likert scale), and the presence of lung abnormalities were independently assessed. The χ2 or t tests were used to evaluate differences between the ULD1 and ULD2 protocols. Results A total of 82 participants (median age, 64 years [IQR, 54-69 years]; 47 male) were included (41 participants for each ULD protocol). The mean effective doses per protocol were 1.41 mSv ± 0.44 (SD) for LD, 0.26 mSv ± 0.08 for ULD1, and 0.17 mSv ± 0.04 for ULD2. According to three readers, the subjective image quality of the ULD images was deemed diagnostic (Likert score ≥3) in 39-40 (ULD1) and 40-41 (ULD2) participants, and anatomic structures could be adequately visualized (Likert score ≥3) in 33-41 (ULD1) and 34-41 (ULD2) participants. The detection accuracy for individual lung anomalies exceeded 70% for both ULD protocols, except for readers 1 and 3 detecting proximal bronchiectasis and reader 3 detecting bronchial wall thickening and air trapping. No evidence of a statistically significant difference in noise (P = .96), signal-to-noise ratio (P = .77), or reader accuracy (all P ≥ .05) was noted between the ULD protocols. Conclusion ULD PCT was feasible for detecting lung abnormalities following lung transplant, with a tenfold radiation dose reduction. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Ciet in this issue.

Thirty years of surgical management of pediatric pulmonary hypertension: Mid-term outcomes following reverse Potts shunt and transplantation

BACKGROUND

Reverse Potts shunt (RPS) and lung or heart-lung transplantation are life-extending surgical interventions for pediatric patients with severe pulmonary arterial hypertension (PAH). Robust criteria for identifying patients who will benefit from these procedures remain elusive. Based on 30 years of experience, we sought to refine the surgical indications.

METHODS

This single-center retrospective cohort study included 61 consecutive pediatric patients with PAH managed by RPS (2004-2020) or transplantation (1988-2020). Their mid-term outcomes were assessed.

RESULTS

Compared with the 20 patients managed by RPS, the 41 transplant waitlist patients, of whom 28 were transplanted, were older (14.9 vs 8.0 years, P = .0001), had worse right ventricular impairment (tricuspid annular plane systolic excursion, 12.5 mm vs 18.0 mm, P = .03), and were managed later in the evolution of the disease (6.0 vs 1.7 years, P = .002). After implementation of a high-priority allocation program in 2007, waitlist mortality decreased from 52.6% to 13.6% (P = .02) and 5-year survival increased from 57.1% to 74.7% after RPS and 55.6% to 77.2% after transplantation. At a median follow-up of 8.6 years after RPS and 5.9 years after transplantation, functional capacity had improved significantly, and PAH-specific drug requirements had diminished markedly in the RPS group. Two patients successfully underwent double-lung transplant 6 and 9 years after RPS.

CONCLUSIONS

In selected children with suprasystemic PAH, RPS is associated with functional capacity improvements and decreased pharmacotherapy needs over the midterm. RPS deserves consideration earlier in the course of pediatric PAH, with transplantation being performed in the event of refractory RV failure.

Approach to the patient with Childhood Interstitial and Diffuse Lung Disease

Childhood Interstitial and Diffuse Lung Disease (chILD) encompasses a group of rare, chronic lung disorders in infants and children with overlapping clinical features but diverse etiologies. The clinical presentation of chILD is of chronic or recurring respiratory signs and symptoms, often including increased work of breathing and hypoxia, with diffuse radiographic abnormalities on chest imaging. Recognition can be challenging since some clinical features overlap with those of more common pediatric respiratory diseases including asthma and recurrent viral infections, among others. chILD should be considered as an underlying diagnosis when a patient's respiratory symptoms seem disproportionate to the clinical scenario and/or persist. The diagnostic process involves multiple steps and is tailored to the individual patient. Nearly all children will undergo imaging and pulmonary function testing, many will undergo bronchoscopy with bronchoalveolar lavage, many will receive genetic testing, and some will require lung biopsy. Treatment includes preventive care, evaluation for comorbidities, pharmacotherapy according to diagnosis, and ongoing disease surveillance, including revisiting genetic and histopathologic results as new clinical information becomes available and as our understanding of these rare disorders improves. The purpose of this review is to provide a broad approach to the diagnosis and management of patients with chILD.

Results from randomized trial of pirfenidone in patients with chronic rejection (STOP-CLAD study)

BACKGROUND

Chronic lung allograft dysfunction (CLAD) is the leading long-term cause of poor outcomes after transplant and manifests by fibrotic remodeling of small airways and/or pleuroparenchymal fibroelastosis. This study evaluated the effect of pirfenidone on quantitative radiographic and pulmonary function assessment in patients with CLAD.

METHODS

We performed a single-center, 6-month, randomized, placebo-controlled trial of pirfenidone in patients with CLAD. Randomization was stratified by CLAD phenotype. The primary outcome for this study was change in radiographic assessment of small airways disease, quantified as percentage of lung volume using parametric response mapping analysis of computed tomography scans (PRMfSAD); secondary outcomes included change in forced expiratory volume in 1 second (FEV1), change in forced vital capacity (FVC), and change in radiographic quantification of parenchymal disease (PRMPD). Linear mixed models were used to evaluate the treatment effect on outcome measures.

RESULTS

The goal enrollment of 60 patients was not met due to the coronavirus disease of 2019 pandemic, with 23 patients included in the analysis. There was no significant difference over the study period between the pirfenidone vs placebo groups with regards to the observed change in PRMfSAD (+4.2% vs -0.4%; p = 0.22), FEV1 (-3.5% vs -3.6%; p = 0.97), FVC (-1.9% vs -4.6%; p = 0.41), or PRMPD (-0.6% vs -2.5%; p = 0.30). The study treatment tolerance and adverse events were generally similar between the pirfenidone and placebo groups.

CONCLUSIONS

Pirfenidone had no apparent impact on radiographic evidence of allograft dysfunction or pulmonary function decline in a single-center randomized trial of CLAD patients that did not meet enrollment goals but had an acceptable tolerance and side-effect profile.

Analysis of the waitlist performance and post-transplant outcomes of lung transplant in elderly recipients in Korea: A nationwide cohort study

BACKGROUND

There is a lack of information on the waitlist performance and post-transplant outcomes of lung transplants in elderly recipients in Korea.

METHODS

We retrospectively reviewed and analyzed data from the Korean Network for Organ Sharing database between March 2010 and August 2023.

RESULTS

In total, 2574 patients were listed for lung transplantation during the study period, with 511 (19.9%) of them being over 65 years of age. Among these, 188 patients (36.8%) underwent transplantation, while 184 patients (36%) passed away without undergoing transplantation at the time of data extraction. The most prevalent underlying disease on the waitlist was idiopathic pulmonary fibrosis, accounting for 68.1%. The 1-year survival rate was significantly lower in the elderly compared to that in the nonelderly (65.4 vs. 75.4%; p = .004). In the multivariate Cox analysis, elderly (hazard ratio [HR], 1.49; 95% CI, 1.14-1.97; p = .004) and a high urgent status at registration (HR, 1.83; 95% CI, 1.40-2.40; p < .001) were significantly associated with post-transplant 1-year mortality. Kaplan-Meier curves demonstrated a significant difference in post-transplant mortality based on the urgency status at enrollment (χ2 = 8.302, p = .016). Even with the same highly urgent condition at the time of transplantation, different prognoses were observed depending on the condition at listing (χ2 = 9.056, p = .029).

CONCLUSION

The elderly exhibited worse transplant outcomes than nonelderly adults, with a highly urgent status at registration identified as a significant risk factor. Unprepared, highly urgent transplantation was associated with poor outcomes.

Risk factors and prognostic modeling in bridging extracorporeal membrane oxygenation patients before lung transplantation

Background

The increased use of preoperative extracorporeal membrane oxygenation (ECMO) as a life support system before lung transplantation demands a better understanding of the associated prognostic factors. This study aims to discern the critical factors influencing the survival outcomes of ECMO patients and design a prognostic model tailored to this patient group.

Methods

We retrospectively gathered and analyzed baseline and clinical data of patients who underwent preoperative bridging ECMO before lung transplantation from the United Network for Organ Sharing (UNOS) database. Univariate and multivariate Cox regression analyses were conducted and a prognostic model was generated to identify the independent factors influencing survival outcomes in these patients. The predictive model was cross-validated using the k-fold method where k=5.

Results

Our study included 1,202 patients. Both single and multiple analyses showed that age over 51 years, high body mass index (BMI), a history of dialysis before transplantation, donor hypertension, prolonged cold ischemia time, and high serum total bilirubin are adverse prognostic factors for the survival of ECMO-bridged lung transplant patients. Using the multivariate analysis, we created a prognosis model and a nomogram to predict 1-year post-transplant survival, with a receiver operating characteristic (ROC) curve area of 0.760 in internal validation. The 1-year survival rate calibration curve supported the nomogram's accuracy.

Conclusions

This study involved the development of a survival prognosis model for patients undergoing lung transplantation with preoperative ECMO bridging, which was validated through extensive data analysis. The prognosis model exhibited high accuracy and predictive capability, effectively predicting the survival outcomes of patients both pre- and post-surgery.

Prevention and rehabilitation after heart transplantation: A clinical consensus statement of the European Association of Preventive Cardiology, Heart Failure Association of the ESC, and the European Cardio Thoracic Transplant Association, a section of ESOT

Little is known either about either physical activity patterns, or other lifestyle-related prevention measures in heart transplantation (HTx) recipients. The history of HTx started more than 50 years ago but there are still no guidelines or position papers highlighting the features of prevention and rehabilitation after HTx. The aims of this scientific statement are (i) to explain the importance of prevention and rehabilitation after HTx, and (ii) to promote the factors (modifiable/non-modifiable) that should be addressed after HTx to improve patients' physical capacity, quality of life and survival. All HTx team members have their role to play in the care of these patients and multidisciplinary prevention and rehabilitation programmes designed for transplant recipients. HTx recipients are clearly not healthy disease-free subjects yet they also significantly differ from heart failure patients or those who are supported with mechanical circulatory support. Therefore, prevention and rehabilitation after HTx both need to be specifically tailored to this patient population and be multidisciplinary in nature. Prevention and rehabilitation programmes should be initiated early after HTx and continued during the entire post-transplant journey. This clinical consensus.

Machine learning model predicts airway stenosis requiring clinical intervention in patients after lung transplantation: a retrospective case-controlled study

BACKGROUND

Patients with airway stenosis (AS) are associated with considerable morbidity and mortality after lung transplantation (LTx). This study aims to develop and validate machine learning (ML) models to predict AS requiring clinical intervention in patients after LTx.

METHODS

Patients who underwent LTx between January 2017 and December 2019 were reviewed. The conventional logistic regression (LR) model was fitted by the independent risk factors which were determined by multivariate LR. The optimal ML model was determined based on 7 feature selection methods and 8 ML algorithms. Model performance was assessed by the area under the curve (AUC) and brier score, which were internally validated by the bootstrap method.

RESULTS

A total of 381 LTx patients were included, and 40 (10.5%) patients developed AS. Multivariate analysis indicated that male, pulmonary arterial hypertension, and postoperative 6-min walking test were significantly associated with AS (all P < 0.001). The conventional LR model showed performance with an AUC of 0.689 and brier score of 0.091. In total, 56 ML models were developed and the optimal ML model was the model fitted using a random forest algorithm with a determination coefficient feature selection method. The optimal model exhibited the highest AUC and brier score values of 0.760 (95% confidence interval [CI], 0.666-0.864) and 0.085 (95% CI, 0.058-0.117) among all ML models, which was superior to the conventional LR model.

CONCLUSIONS

The optimal ML model, which was developed by clinical characteristics, allows for the satisfactory prediction of AS in patients after LTx.

MNK-driven eIF4E phosphorylation regulates the fibrogenic transformation of mesenchymal cells and chronic lung allograft dysfunction

Tissue fibrosis remains unamenable to meaningful therapeutic interventions and is the primary cause of chronic graft failure after organ transplantation. Eukaryotic translation initiation factor (eIF4E), a key translational regulator, serves as convergent target of multiple upstream profibrotic signaling pathways that contribute to mesenchymal cell (MC) activation. Here, we investigate the role of MAP kinase-interacting serine/threonine kinase-induced (MNK-induced) direct phosphorylation of eIF4E at serine 209 (Ser209) in maintaining fibrotic transformation of MCs and determine the contribution of the MNK/eIF4E pathway to the pathogenesis of chronic lung allograft dysfunction (CLAD). MCs from patients with CLAD demonstrated constitutively higher eIF4E phosphorylation at Ser209, and eIF4E phospho-Ser209 was found to be critical in regulating key fibrogenic protein autotaxin, leading to sustained β-catenin activation and profibrotic functions of CLAD MCs. MNK1 signaling was upregulated in CLAD MCs, and genetic or pharmacologic targeting of MNK1 activity inhibited eIF4E phospho-Ser209 and profibrotic functions of CLAD MCs in vitro. Treatment with an MNK1/2 inhibitor (eFT-508) abrogated allograft fibrosis in an orthotopic murine lung-transplant model. Together these studies identify what we believe is a previously unrecognized MNK/eIF4E/ATX/β-catenin signaling pathway of fibrotic transformation of MCs and present the first evidence, to our knowledge, for the utility of MNK inhibitors in fibrosis.

Pollution exposure in the first 3 months post transplant is associated with lower baseline FEV1 and higher CLAD risk

BACKGROUND

Exposure to air pollution post-lung transplant has been shown to decrease graft and patient survival. This study examines the impact of air pollution exposure in the first 3 months post-transplant on baseline (i.e., highest) forced expiratory volume in 1 second (FEV1) achieved and development of chronic lung allograft dysfunction (CLAD).

METHODS

Double-lung transplant recipients (n = 82) were prospectively enrolled for comprehensive indoor and personal environmental monitoring at 6- and 12-week post transplant and followed for >4 years. Associations between clinical and exposure variables were investigated using an exposomics approach followed by analysis with a Cox proportional hazards model. Multivariable analyses were used to examine the impact of air pollution on baseline % predicted FEV1 (defined as the average of the 2 highest values post transplant) and risk of CLAD.

RESULTS

Multivariable analysis revealed a significant inverse relationship between personal black carbon (BC) levels and baseline % FEV1. The multivariable model indicated that patients with higher-than-median exposure to BC (>350 ng/m3) attained a baseline % FEV1 that was 8.8% lower than those with lower-than-median BC exposure (p = 0.019). Cox proportional hazards model analysis revealed that patients with high personal BC exposure had a 2.4 times higher hazard risk for CLAD than patients with low BC exposure (p = 0.045).

CONCLUSIONS

Higher personal BC levels during the first 3 months post-transplant decrease baseline FEV1 and double the risk of CLAD. Strategies to reduce BC exposure early following a lung transplant may help improve lung function and long-term outcomes.

Cystic fibrosis

Cystic fibrosis is a rare genetic disease caused by mutations in CFTR, the gene encoding cystic fibrosis transmembrane conductance regulator (CFTR). The discovery of CFTR in 1989 has enabled the unravelling of disease mechanisms and, more recently, the development of CFTR-directed therapeutics that target the underlying molecular defect. The CFTR protein functions as an ion channel that is crucial for correct ion and fluid transport across epithelial cells lining the airways and other organs. Consequently, CFTR dysfunction causes a complex multi-organ disease but, to date, most of the morbidity and mortality in people with cystic fibrosis is due to muco-obstructive lung disease. Cystic fibrosis care has long been limited to treating symptoms using nutritional support, airway clearance techniques and antibiotics to suppress airway infection. The widespread implementation of newborn screening for cystic fibrosis and the introduction of a highly effective triple combination CFTR modulator therapy that has unprecedented clinical benefits in up to 90% of genetically eligible people with cystic fibrosis has fundamentally changed the therapeutic landscape and improved prognosis. However, people with cystic fibrosis who are not eligible based on their CFTR genotype or who live in countries where they do not have access to this breakthrough therapy remain with a high unmet medical need.

Murine orthotopic lung transplant models: A comprehensive overview of genetic mismatch degrees and histopathological insights into chronic lung allograft dysfunction

Currently, lung transplantation outcome remains inferior compared to other solid organ transplantations. A major cause for limited survival after lung transplantation is chronic lung allograft dysfunction. Numerous animal models have been developed to investigate chronic lung allograft dysfunction to discover adequate treatments. The murine orthotopic lung transplant model has been further optimized over the last years. However, different degrees of genetic mismatch between donor and recipient mice have been used, applying a single, minor, moderate, and major genetic mismatch. This review aims to reassess the existing murine mismatch models and provide a comprehensive overview, with a specific focus on their eventual histopathological presentation. This will be crucial to leverage this model and tailor it according to specific research needs.

Chronic Postsurgical Pain Following Lung Transplantation: Characteristics, Risk Factors, Treatment, and Prevention: A Narrative Review

Chronic pain after lung transplantation (LTx) can substantially reduce quality of life (QoL), yet current consensus guidelines say little about how to prevent or manage it. Research on pain after LTx has tended to focus on acute rather than chronic pain, and it has not extensively examined the factors associated with onset or resolution of chronic pain, which differ from factors influencing chronic pain after general thoracic surgery. This narrative review explores what is known about the epidemiology and risk factors of chronic pain after LTx, as well as effective ways to treat or prevent it. The review identifies key questions and issues that should be the focus of future research.

Comparison of the safety and cost-effectiveness of nebulized liposomal amphotericin B and amphotericin B deoxycholate for antifungal prophylaxis after lung transplantation

INTRODUCTION

Fungal infection after lung transplantation can lead to poor clinical outcome, for which lung transplant recipients require prophylaxis. One of the antifungal agents used after lung transplantation is nebulized amphotericin B (AMB). Nebulized AMB causes adverse events such as dyspnea and airway irritation, and long-term use leads to high economic costs. So far, prophylactic regimens employing AMB deoxycholate (AMB-d) and liposomal AMB (L-AMB) have been developed. This study compared the efficacy, safety, and cost of AMB-d and L-AMB.

PATIENTS AND METHODS

Patients who underwent lung transplantation at Kyoto University Hospital from January 2021 to May 2023 were included in this study. Thirty-three patients received nebulized AMB-d, whereas 29 received nebulized L-AMB.

RESULTS

Both regimens maintained comparable prophylactic efficacy regarding the development of fungal infection in the AMB-d and L-AMB groups (3.0% vs. 3.4%, P = 0.877). Patients treated with nebulized L-AMB experienced fewer respiratory-related adverse reactions than those treated with nebulized AMB-d (6.9% vs. 30.3%, P < 0.05), leading to a longer treatment duration with L-AMB than with AMB-d. Additionally, the daily cost of administering L-AMB was lower than that of administering AMB-d (3609 Japanese yen vs. 1792.3 Japanese yen, P < 0.05).

DISCUSSION

These results suggest that nebulized L-AMB is safer and more cost-effective than nebulized AMB-d, with comparable efficacy.

Donor Fractions of Cell-Free DNA Are Elevated During CLAD But Not During Infectious Complications After Lung Transplantation

During the last few years, cell-free DNA (cfDNA) has emerged as a possible non-invasive biomarker for prediction of complications after lung transplantation. We previously published a proof-of-concept study using a digital droplet polymerase chain reaction (ddPCR)-based method for detection of cfDNA. In the current study, we aimed to further evaluate the potential clinical usefulness of detecting chronic lung allograft dysfunction (CLAD) using three different ddPCR applications measuring and calculating the donor fraction (DF) of cfDNA as well as one method using the absolute amount of donor-derived cfDNA. We analyzed 246 serum samples collected from 26 lung transplant recipients. Nine of the patients had ongoing CLAD at some point during follow-up. All four methods showed statistically significant elevation of the measured variable in the CLAD samples compared to the non-CLAD samples. The results support the use of ddPCR-detected cfDNA as a potential biomarker for prediction of CLAD. These findings need to be validated in a subsequent prospective study.

Long-term follow-up of the randomized, prospective Scandinavian heart transplant everolimus de novo study with early calcineurin inhibitors avoidance (SCHEDULE) trial

BACKGROUND

Early substitution of calcineurin inhibitor (CNI) with mammalian target of rapamycin inhibitors has been shown to improve kidney function and reduce intimal hyperplasia in heart transplant (HTx) recipients but data on long-term outcome of such a regime are still sparse.

METHODS

In the SCHEDULE trial, 115 de novo HTx recipients were randomized to (1) everolimus with reduced exposure of CNI followed by CNI withdrawal at week 7-11 post-transplant or (2) standard-exposure with CNI. Both groups received mycophenolate mofetil and corticosteroids. Herein we report on the 10-12-year long-term follow-up of the study.

RESULTS

A total of 78 patients attended the follow-up visit at a median time of 11 years post-transplant. In the everolimus intention to treat (ITT) group 87.5% (35/40 patients) still received everolimus and in the CNI ITT group 86.8% (33/38) still received CNI. Estimated glomerular filtration rate (eGFR) (least square mean (95% CI)) at the 10-12 years visit was 82.7 (74.2-91.1) ml/min/1.73 m2 and 61.0 (52.3-69.7) ml/min/1.73 m2 in the everolimus and CNI group, respectively (p < 0.001). Graft function measured by ejection fraction, ECG, NT-proBNP and drug safety were comparable between groups. During the study period there was a total of 28 deaths, but there was no difference in survival between the everolimus and the CNI group (aHR 0.61 (95% CI 0.29-1.30) p = 0.20). For the composite endpoint of death, re-transplantation, myocardial infarction, PCI, dialysis, kidney transplantation or cancer no between group differences were found (aHR 1.0 (95% CI 0.57-1.77) p = 0.99).

CONCLUSIONS

De novo HTx patients randomized to everolimus and low dose CNI followed by CNI free therapy sustained significantly better long-term kidney function than patients randomized to standard therapy. The graft function at 10-12 years was similar in both groups and there was no difference in survival.

Lung Transplant for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) carries a high burden of morbidity and mortality to patient and a high cost to health care systems. Lung transplantation is a last resort available for end-stage COPD patients interested in pursuing it and meeting the strict transplant requirements. It requires commitment from patients and their loved ones to support them through this tough process. This review will cover history of transplant, indications, candidate selection, evaluation testing, transplant listing, type of transplant (single versus bilateral), posttransplant complications, immunosuppression, and rejection. It is tailored to the COPD patient when applicable; however, many aspects of lung transplantation are shared amongst all lung diseases eligible for transplant.

Is Night Surgery a Nightmare for Lung Transplantation?

Night work is frequently associated with sleep deprivation and is associated with greater surgical and medical complications. Lung transplantation (LT) is carried out both at night and during the day and involves many medical healthcare workers. The goal of the study was to compare morbidity and mortality between LT recipients according to LT operative time. We performed a retrospective, observational, single-center study. When the procedure started between 6 AM and 6 PM, the patient was allocated to the Daytime group. If the procedure started between 6 PM and 6 AM, the patient was allocated to the Nighttime group. Between January 2015 and December 2020, 253 patients were included. A total of 168 (66%) patients were classified into the Day group, and 85 (34%) patients were classified into the Night group. Lung Donors' general characteristics were similar between the groups. The 90-day and one-year mortality rates were similar between the groups (90-days: n = 13 (15%) vs. n = 26 (15%), p = 0.970; 1 year: n = 18 (21%) vs. n = 42 (25%), p = 0.499). Daytime LT was associated with more one-year airway dehiscence (n = 36 (21%) vs. n = 6 (7.1%), p = 0.004). In conclusion, among patients who underwent LT, there was no significant association between operative time and survival.

Pseudomonas aeruginosa infection correlates with high MFI donor-specific antibody development following lung transplantation with consequential graft loss and shortened CLAD-free survival

BACKGROUND

Donor-specific antibodies (DSAs) are common following lung transplantation (LuTx), yet their role in graft damage is inconclusive. Mean fluorescent intensity (MFI) is the main read-out of DSA diagnostics; however its value is often disregarded when analyzing unwanted post-transplant outcomes such as graft loss or chronic lung allograft dysfunction (CLAD). Here we aim to evaluate an MFI stratification method in these outcomes.

METHODS

A cohort of 87 LuTx recipients has been analyzed, in which a cutoff of 8000 MFI has been determined for high MFI based on clinically relevant data. Accordingly, recipients were divided into DSA-negative, DSA-low and DSA-high subgroups. Both graft survival and CLAD-free survival were evaluated. Among factors that may contribute to DSA development we analyzed Pseudomonas aeruginosa (P. aeruginosa) infection in bronchoalveolar lavage (BAL) specimens.

RESULTS

High MFI DSAs contributed to clinical antibody-mediated rejection (AMR) and were associated with significantly worse graft (HR: 5.77, p < 0.0001) and CLAD-free survival (HR: 6.47, p = 0.019) compared to low or negative MFI DSA levels. Analysis of BAL specimens revealed a strong correlation between DSA status, P. aeruginosa infection and BAL neutrophilia. DSA-high status and clinical AMR were both independent prognosticators for decreased graft and CLAD-free survival in our multivariate Cox-regression models, whereas BAL neutrophilia was associated with worse graft survival.

CONCLUSIONS

P. aeruginosa infection rates are elevated in recipients with a strong DSA response. Our results indicate that the simultaneous interpretation of MFI values and BAL neutrophilia is a feasible approach for risk evaluation and may help clinicians when to initiate DSA desensitization therapy, as early intervention could improve prognosis.

[Relationship between frailty and functional status in lung transplant candidates]

INTRODUCTION

Lung transplant (LT) is one of the therapeutic options for patients with terminal respiratory diseases. It is highly important to incorporate the functional status and frailty assessment into the selection process of candidates for LT.

OBJECTIVES

Identify the prevalence of frailty in the LT waiting list. Study the relationship between frailty, functional status, Lung Allocation Score (LAS) and muscular dysfunction.

METHODOLOGY

Descriptive transversal study of patients on the waiting list for LT.

POPULATION

74 patients with chronic respiratory diseases assessed by the lung transplant committee and accepted to be transplanted in a university hospital in Barcelona. The outcome variables were frailty status was evaluate for SPPB test, functional capacity was evaluate for the six-minute walking test (6MWT) and muscular dysfunction. The results were analyzed with the statistical package STATA 12.

RESULTS

Sample of 48 men and 26 women, with a median age of 56.55 years (SD 10.87. The prevalence of frailty assessed with the SPPB was 33.8% (8.1% are in frailty and 25.7% are in a state of pre-frailty). There is a relationship between the SPPB, 6MWT and maximal inspiratory pressure, but not with others force values. There is a relationship between the risk of frailty (scores below 9 in SPPB) and the meters walked in 6 but not with the LAS.

CONCLUSIONS

The risk of frailty in patients with terminal chronic respiratory diseases is high. Frailty is related with functional capacity, but not with LAS.

An update of palliative care in lung transplantation with a focus on symptoms, quality of life and functional outcomes

PURPOSE OF REVIEW

Palliative care (PC) in lung transplantation is increasingly acknowledged for its important role in addressing symptoms, enhancing functionality, and facilitating advance care planning for patients, families, and caregivers. The present review provides an update in PC management in lung transplantation.

RECENT FINDINGS

Research confirms the effectiveness of PC for patients with advanced lung disease who are undergoing transplantation, showing improvements in symptoms and reduced healthcare utilization. Assessment tools and patient-reported outcome measures for PC are commonly used in lung transplant candidates, revealing discrepancies between symptom severity and objective measures such as exercise capacity. The use of opioids to manage dyspnea and cough in the pretransplant period is deemed safe and does not heighten risks posttransplantation. However, the integration of PC support in managing symptoms and chronic allograft dysfunction in the posttransplant period has not been as well described.

SUMMARY

Palliative care support should be provided in the pretransplant and select peri-operative and posttransplant periods to help support patient quality of life, symptoms, communication and daily function.

Predictors of Cytomegalovirus Recurrence Following Cessation of Posttransplant Prophylaxis

INTRODUCTION

Cytomegalovirus (CMV) infection is associated with a poor prognosis after lung transplantation, and donor and recipient CMV serostatus is a risk factor for reactivation. CMV prophylaxis is commonly administered in the first year following transplantation to reduce CMV infection; however, the risk factors for long-term reactivation remain unclear. We investigated the timing and risk factors of CMV infection after prophylactic administration.

METHODS

This study was a retrospective review of the institutional lung transplantation database from June 2014 to June 2022. Data on patient characteristics, pretransplantation laboratory values, postoperative outcomes, and CMV infection were collected. Donor CMV-IgG-positive and recipient CMV-IgG-negative groups were defined as the CMV mismatch group.

RESULTS

During the study period, 257 patients underwent lung transplantation and received a prophylactic dose of valganciclovir hydrochloride for up to 1 y. CMV infection was detected in 69 patients (26.8%): 40 of 203 (19.7%) in the non-CMV mismatch group and 29 of 54 (53.7%) in the CMV mismatch group (P < 0.001). CMV infection after prophylaxis occurred at a median of 425 and 455 d in the CMV mismatch and non-CMV mismatch groups, respectively (P = 0.07). Multivariate logistic regression analysis revealed that preoperative albumin level (odds ratio [OR] = 0.39, P = 0.04), CMV mismatch (OR = 15.7, P < 0.001), and donor age (OR = 1.05, P = 0.009) were significantly associated with CMV infection.

CONCLUSIONS

CMV mismatch may have increased the risk of CMV infection after lung transplantation, which decreased after prophylaxis. In addition to CMV mismatch, low preoperative albumin level and donor age were independent predictors of CMV infection.

Profile of patients referred for lung transplant and their transplant-free survival

INTRODUCTION

Lung transplant (LTx) is a potential treatment option for all patients with chronic, end-stage respiratory disease, who are refractory to optimal medical therapy or where no medical therapy exists. In India, LTx is still in its evolving stages and published literature is sparse. The current study was carried out to study the selection criteria for lung transplant and to evaluate the clinical and socio-economic profile of patients referred for the same at a tertiary health care facility.

METHODS

The study was a descriptive, prospective, observational study. All adults referred for lung transplant were evaluated for clinical and laboratory profiles. All enrolled patients were assessed for presence of referral criteria, listing criteria, contraindications, and willingness for lung transplant. These patients were followed up for 2 years for transplant-free survival, and the Cox proportional hazards model was used to determine independent predictors of all-cause mortality.

RESULTS

A total of 103 were included in study. The most common diagnosis was interstitial lung disease (57.2%), followed by bronchiectasis (17.5%) and COPD (13.6%). Most patients were referred for LTx at an advanced stage as 90% met listing criteria. Fifty-four (52.4%) patients had an absolute or relative contraindication to transplant; however, the majority of those contraindications were modifiable. Patients with a lower socio-economic status were less likely to be willing for LTx. The median survival was 757 days. A 6-minute walk distance (6MWD) lesser than 250 m was found to be an independent predictor of mortality.

CONCLUSION

Making patients aware about lung transplant early in their treatment may give them sufficient time to come to terms with their disease and understand the risk and benefits associated. Efforts should be focused on screening and early treatment of reversible contraindications for the eligible patients. Patients with 6MWD < 250 m are at increased risk of mortality.

Intravenous Immunoglobulins Alone for the Desensitization of Lung Transplant Recipients with Preformed Donor Specific Antibodies and Negative Flow Cytometry Crossmatch

BACKGROUND

The lack of evidence regarding optimal desensitization strategies for lung transplant candidates with preformed donor specific anti-human leukocyte antigen antibodies (DSAs) has led to varying approaches among centers towards this patient group. Our institution's desensitization protocol for recipients with preformed DSAs and negative flow cytometry crossmatch (FCXM) consists of intravenous immunoglobulin (IVIG) as the sole therapy. The study aimed to determine outcomes using this approach.

METHODS

This retrospective study included adults who underwent lung-only transplantation for the first time between January 2015 and March 2022 at a single center. We excluded patients with positive or missing FCXM results. Transplant recipients with any DSA ≥ 1000 MFI on latest testing within three months of transplant were considered DSA-positive, while recipients with DSAs <1000 MFI and those without DSAs were assigned to the low-level/negative group. Graft survival (time to death/retransplantation) and chronic lung allograft dysfunction (CLAD)-free times were compared between groups using Cox proportional hazards models.

RESULTS

Thirty-six out of 167 eligible patients (22%) were DSA-positive. At least 50% of preformed DSAs had documented clearance (decrease to <1000 MFI) within the first 6 months of transplant. Multivariable Cox regression analyses did not detect a significantly increased risk of graft failure (aHR 1.04 95%CI 0.55-1.97) or chronic lung allograft dysfunction (aHR 0.71 95%CI 0.34-1.52) in DSA-positive patients compared to patients with low-level/negative DSAs. Incidences of antibody-mediated rejection (p = 1.00) and serious thromboembolic events (p = 0.63) did not differ between study groups.

CONCLUSION

We describe a single-center experience of administering IVIG alone to lung transplant recipients with preformed DSAs and negative FCXM. Further studies are required to confirm the efficacy of this strategy against other protocols.

Macrophage and CD8 T cell discordance are associated with acute lung allograft dysfunction progression

BACKGROUND

Acute lung allograft dysfunction (ALAD) is an imprecise syndrome denoting concern for the onset of chronic lung allograft dysfunction (CLAD). Mechanistic biomarkers are needed that stratify risk of ALAD progression to CLAD. We hypothesized that single cell investigation of bronchoalveolar lavage (BAL) cells at the time of ALAD would identify immune cells linked to progressive graft dysfunction.

METHODS

We prospectively collected BAL from consenting lung transplant recipients for single cell RNA sequencing. ALAD was defined by a ≥10% decrease in FEV1 not caused by infection or acute rejection and samples were matched to BAL from recipients with stable lung function. We examined cell compositional and transcriptional differences across control, ALAD with decline, and ALAD with recovery groups. We also assessed cell-cell communication.

RESULTS

BAL was assessed for 17 ALAD cases with subsequent decline (ALAD declined), 13 ALAD cases that resolved (ALAD recovered), and 15 cases with stable lung function. We observed broad differences in frequencies of the 26 unique cell populations across groups (p = 0.02). A CD8 T cell (p = 0.04) and a macrophage cluster (p = 0.01) best identified ALAD declined from the ALAD recovered and stable groups. This macrophage cluster was distinguished by an anti-inflammatory signature and the CD8 T cell cluster resembled a Tissue Resident Memory subset. Anti-inflammatory macrophages signaled to activated CD8 T cells via class I HLA, fibronectin, and galectin pathways (p < 0.05 for each). Recipients with discordance between these cells had a nearly 5-fold increased risk of severe graft dysfunction or death (HR 4.6, 95% CI 1.1-19.2, adjusted p = 0.03). We validated these key findings in 2 public lung transplant genomic datasets.

CONCLUSIONS

BAL anti-inflammatory macrophages may protect against CLAD by suppressing CD8 T cells. These populations merit functional and longitudinal assessment in additional cohorts.

How do we expand the lung donor pool?

PURPOSE OF REVIEW

Lung transplantation activity continues to be limited by the availability of timely quality donor lungs. It is apparent though that progress has been made. The steady evolution of clinical practice, combined with painstaking scientific discovery and innovation are described.

RECENT FINDINGS

There have been successful studies reporting innovations in the wider use and broader consideration of donation after circulatory death donor lungs, including an increasing number of transplants from each of the controlled, uncontrolled and medically assisted dying donor descriptive categories. Donors beyond age 70 years are providing better than expected long-term outcomes. Hepatitis C PCR positive donor lungs can be safely used if treated postoperatively with appropriate antivirals. Donor lung perfusion at a constant 10 degrees appears capable of significantly improving donor logistics and ex-vivo lung perfusion offers the potential of an ever-increasing number of novel donor management roles. Bioartificial and xenografts remain distant possibilities only at present.

SUMMARY

Donor lungs have proved to be surprisingly robust and combined with clinical, scientific and engineering innovations, the realizable lung donor pool is proving to be larger than previously thought.

Adherence to the ISHLT Protocol for the Referral of Patients with Idiopathic Pulmonary Fibrosis to the Transplantation Center among of Czech Centers for Interstitial Lung Diseases

There are limited data on referral rates and the number of patients with idiopathic pulmonary fibrosis (IPF) who are eligible for lung transplantation. The aim of the present study was to assess adherence to the consensus of the International Society for Heart and Lung Transplantation (ISHLT) for the referral of patients with IPF among Czech interstitial lung disease (ILD) centers. Czech patients who were diagnosed with IPF between 1999 and 2021 (n = 1584) and who were less than 65 years old at the time of diagnosis were retrospectively selected from the Czech Republic of the European Multipartner Idiopathic Pulmonary Fibrosis Registry (EMPIRE). Nonsmokers and ex-smokers with a body mass index (BMI) of <32 kg/m2 (n = 404) were included for further analyses. Patients with a history of cancer <5 years from the time of IPF diagnosis, patients with alcohol abuse, and patients with an accumulation of vascular comorbidities were excluded. The trajectory of individual patients was verified at the relevant ILD center. From the database of transplant patients (1999-12/2021, n = 541), all patients who underwent transplantation for pulmonary fibrosis (n = 186) were selected, and the diagnosis of IPF was subsequently verified from the patient's medical records (n = 67). A total of 304 IPF patients were eligible for lung transplantation. Ninety-six patients were referred to the transplant center, 50% (n = 49) of whom were referred for lung transplantation. Thirty percent of potentially eligible patients not referred to the transplant center were considered to have too many comorbidities by the reporting physician, 19% of IPF patients denied lung transplantation, and 17% were not referred due to age. Among Czech patients with IPF, there may be a larger pool of potential lung transplant candidates than has been reported to the transplant center to date.

Lobar lung transplantation in the mouse

Background

As an important supplementary approach to clinical in orthotopic lung transplantation (LTx), lobar LTx currently lacks a stable animal model and in the orthotopic left LTx model, the right lung of the donor mouse is completely removed and discarded. We introduce a novel mouse lobar LTx model that potentially provides a mouse model for clinical lobar LTx and increase the utilization rate of the experimental donor.

Methods

Lobar and orthotopic left LTx were performed in syngeneic strain combinations. We performed micro-computed tomography and tested arterial blood gases to assess the graft function 28 days after transplantation. Hematoxylin-eosin and Masson's trichrome staining were used to evaluate pathological changes.

Results

We performed ten lobar LTx with an operation success rate of 90%, accompanied by ten orthotopic left LTx from the same donors with an operation success rate of 100%. The graft preparation for lobar LTx was longer than that of the orthotopic left LTx (42.11±3.79 vs. 30.10±3.14 minutes, P<0.001). The recipient procedure for lobar LTx was nearly equivalent to the orthotopic left LTx. The graft function and histopathological changes for lobar LTx were comparable to those of orthotopic left LTx 28 days after transplantation.

Conclusions

We describe a lobar LTx model in the mouse, which potentially provides a model for clinical lobar LTx and effectively addresses the issue of resource wastage in the orthotopic left LTx model.

Impact of Pre-Transplant Left Ventricular Diastolic Pressure on Primary Graft Dysfunction after Lung Transplantation: A Narrative Review

Lung transplantation (LT) constitutes the last therapeutic option for selected patients with end-stage respiratory disease. Primary graft dysfunction (PGD) is a form of severe lung injury, occurring in the first 72 h following LT and constitutes the most common cause of early death after LT. The presence of pulmonary hypertension (PH) has been reported to favor PGD development, with a negative impact on patients' outcomes while complicating medical management. Although several studies have suggested a potential association between pre-LT left ventricular diastolic dysfunction (LVDD) and PGD occurrence, the underlying mechanisms of such an association remain elusive. Importantly, the heterogeneity of the study protocols and the various inclusion criteria used to define the diastolic dysfunction in those patients prevents solid conclusions from being drawn. In this review, we aim at summarizing PGD mechanisms, risk factors, and diagnostic criteria, with a further focus on the interplay between LVDD and PGD development. Finally, we explore the predictive value of several diastolic dysfunction diagnostic parameters to predict PGD occurrence and severity.

Prevention and Rehabilitation After Heart Transplantation: A Clinical Consensus Statement of the European Association of Preventive Cardiology, Heart Failure Association of the ESC, and the European Cardio Thoracic Transplant Association, a Section of ESOT

Little is known either about either physical activity patterns, or other lifestyle-related prevention measures in heart transplantation (HTx) recipients. The history of HTx started more than 50 years ago but there are still no guidelines or position papers highlighting the features of prevention and rehabilitation after HTx. The aims of this scientific statement are (i) to explain the importance of prevention and rehabilitation after HTx, and (ii) to promote the factors (modifiable/non-modifiable) that should be addressed after HTx to improve patients' physical capacity, quality of life and survival. All HTx team members have their role to play in the care of these patients and multidisciplinary prevention and rehabilitation programmes designed for transplant recipients. HTx recipients are clearly not healthy disease-free subjects yet they also significantly differ from heart failure patients or those who are supported with mechanical circulatory support. Therefore, prevention and rehabilitation after HTx both need to be specifically tailored to this patient population and be multidisciplinary in nature. Prevention and rehabilitation programmes should be initiated early after HTx and continued during the entire post-transplant journey. This clinical consensus statement focuses on the importance and the characteristics of prevention and rehabilitation designed for HTx recipients.

Impact of Acute Exacerbation of Idiopathic Pulmonary Fibrosis on Lung Transplant Outcomes

BACKGROUND

Acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF) are acute, significant respiratory deteriorations in patients with IPF and can lead to increased morbidity and mortality. It remains unclear how AE-IPF impacts lung transplant (LTX) outcomes.

METHODS

All adult patients who were listed for LTX between July 2005 and October 2020 at the Loyola University Medical Center with a diagnosis of IPF were included. Pretransplant characteristics and posttransplant outcomes were gathered via retrospective chart review. The primary outcome was short- and long-term survival for patients transplanted during stable IPF versus those with AE-IPF.

RESULTS

One hundred fifty-nine patients were included in this study, 17.6% of whom were transplanted during AE-IPF. AE-IPF patients were more likely to have higher oxygen needs pretransplant, have higher lung allocation score, and were more likely to be intubated or be on extracorporeal membrane oxygenation as compared with stable IPF patients. Survival by AE status at transplant did not differ at 90 d or 1 y posttransplantation. There were also no significant differences in rates of severe primary graft dysfunction or acute rejection within 1 y.

CONCLUSIONS

Patients with AE-IPF were more likely to have higher oxygenation requirements and higher lung allocation score at the time of LTX than those with stable IPF. Despite this, there were no differences in survival at 90 d, 1 y, or 3 y, or differences in incidence of severe primary graft dysfunction or acute cellular rejection. Transplantation of patients with AE-IPF has clinical outcomes comparable with transplantation of patients with stable IPF. This contrasts with previous studies examining LTX in patients with AE-IPF.

Early extracorporeal photopheresis treatment is associated with better survival in patients with chronic or recurrent acute lung allograft dysfunction

BACKGROUND

Due to development of chronic lung allograft dysfunction (CLAD), prognosis for patients undergoing lung transplantation (LTx) is still worse compared to other solid organ transplant recipients. Treatment options for slowing down CLAD progression are scarce with extracorporeal photopheresis (ECP) as an established rescue therapy. The aim of the study was to identify characteristics of responders and non-responders to ECP treatment, assess their survival, lung function development and by that define the subset of patients who should receive early ECP treatment.

METHODS

We performed a retrospective study of all LTx patients receiving ECP treatment at the University Hospital Zurich between January 2010 and March 2020. Patients were followed-up for a maximum period of 5 years. Mortality and lung function development were assessed by CLAD stage and by CLAD subtype before initiation of ECP treatment.

RESULTS

Overall, 105 patients received at least one ECP following LTx. A total of 57 patients (61.3%) died within the study period with a median survival of 15 months. Mortality was 57% for patients who started ECP at CLAD1, 39% for CLAD2, 93% for CLAD3, and 90% for CLAD4 (p < 0.001). Survival and lung function development was best in young patients at early CLAD stages 1 and 2. Response to ECP treatment was worst in patients with CLAD-RAS/mixed subtype (14.3%) and patients with ECP initiation in CLAD stages 3 (7.1%) and 4 (11.1%). Survival was significantly better in a subset of patients with recurrent acute allograft dysfunction and earlier start of ECP treatment (105 vs 15 months).

CONCLUSION

In this retrospective analysis of a large group of CLAD patients treated with ECP after LTx, early initiation of ECP was associated with better long-term survival. Besides a subset of patients suffering of recurrent allograft dysfunction, especially a subset of patients defined as responders showed an improved response rate and survival, suggesting that ECP should be initiated in early CLAD stages and young patients. ECP might therefore prevent long-term disease progression even in patients with CLAD refractory to other treatment options and thus prevent or delay re-transplantation.

Advances in lung transplantation: 60 years on

Lung transplantation is a well-established treatment for advanced lung disease, improving survival and quality of life. Over the last 60 years all aspects of lung transplantation have evolved significantly and exponential growth in transplant volume. This has been particularly evident over the last decade with a substantial increase in lung transplant numbers as a result of innovations in donor utilization procurement, including the use donation after circulatory death and ex-vivo lung perfusion organs. Donor lungs have proved to be surprisingly robust, and therefore the donor pool is actually larger than previously thought. Parallel to this, lung transplant outcomes have continued to improve with improved acute management as well as microbiological and immunological insights and innovations. The management of lung transplant recipients continues to be complex and heavily dependent on a tertiary care multidisciplinary paradigm. Whilst long term outcomes continue to be limited by chronic lung allograft dysfunction improvements in diagnostics, mechanistic understanding and evolutions in treatment paradigms have all contributed to a median survival that in some centres approaches 10 years. As ongoing studies build on developing novel approaches to diagnosis and treatment of transplant complications and improvements in donor utilization more individuals will have the opportunity to benefit from lung transplantation. As has always been the case, early referral for transplant consideration is important to achieve best results.

Fibrotic progression from acute cellular rejection is dependent on secondary lymphoid organs in a mouse model of chronic lung allograft dysfunction

Chronic lung allograft dysfunction (CLAD) remains one of the major limitations to long-term survival after lung transplantation. We modified a murine model of CLAD and transplanted left lungs from BALB/c donors into B6 recipients that were treated with intermittent cyclosporine and methylprednisolone postoperatively. In this model, the lung allograft developed acute cellular rejection on day 15 which, by day 30 after transplantation, progressed to severe pleural and peribronchovascular fibrosis, reminiscent of changes observed in restrictive allograft syndrome. Lung transplantation into splenectomized B6 alymphoplastic (aly/aly) or splenectomized B6 lymphotoxin-β receptor-deficient mice demonstrated that recipient secondary lymphoid organs, such as spleen and lymph nodes, are necessary for progression from acute cellular rejection to allograft fibrosis in this model. Our work uncovered a critical role for recipient secondary lymphoid organs in the development of CLAD after pulmonary transplantation and may provide mechanistic insights into the pathogenesis of this complication.