A randomized trial of everolimus-based quadruple therapy vs standard triple therapy early after lung transplantation

Everolimus Personalized Therapy: Second Consensus Report by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology

ABSTRACT

The Immunosuppressive Drugs Scientific Committee of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology established the second consensus report to guide therapeutic drug monitoring (TDM) of everolimus (EVR) and its optimal use in clinical practice 7 years after the first version was published in 2016. This version provides information focused on new developments that have arisen in the last 7 years. For the general aspects of the pharmacology and TDM of EVR that have retained their relevance, readers can refer to the 2016 document. This edition includes new evidence from the literature, focusing on the topics updated during the last 7 years, including indirect pharmacological effects of EVR on the mammalian target of rapamycin complex 2 with the major mechanism of direct inhibition of the mammalian target of rapamycin complex 1. In addition, various concepts and technical options to monitor EVR concentrations, improve analytical performance, and increase the number of options available for immunochemical analytical methods have been included. Only limited new pharmacogenetic information regarding EVR has emerged; however, pharmacometrics and model-informed precision dosing have been constructed using physiological parameters as covariates, including pharmacogenetic information. In clinical settings, EVR is combined with a decreased dose of calcineurin inhibitors, such as tacrolimus and cyclosporine, instead of mycophenolic acid. The literature and recommendations for specific organ transplantations, such as that of the kidneys, liver, heart, and lungs, as well as for oncology and pediatrics have been updated. EVR TDM for pancreatic and islet transplantation has been added to this edition. The pharmacodynamic monitoring of EVR in organ transplantation has also been updated. These updates and additions, along with the previous version of this consensus document, will be helpful to clinicians and researchers treating patients receiving EVR.

[Risk analysis applied to the monitoring of immunosuppressor concentrations in lung transplant recipients]

Mastering and monitoring immunosuppressant concentrations is central to the care of lung transplant patients and involves multiple stakeholders. The objective is to conduct a risk analysis to evaluate the impact of various actions taken. The lung transplantation team was convened to carry out a failure mode effect analysis. The process was divided into stages where different risks were identified. The risk priority number (RPN) (severity, frequency, detectability) and risk level of criticality (frequency, severity) were established before implementation of actions (before 2009) and then after (in 2022) to classify risks according to four levels of criticality. The implemented actions included the establishment of a quality assurance process, computerization of monitoring, and double analysis by a physician/pharmacist pair. Thirty-two risks were identified during the four stages of the process: biological sampling (n=13), reception (n=3), analysis and treatment of levels (n=5), transmission of information/prescriptions to the patient (n=11). The total raw RPN (before 2009) was 839, with 12 major risks. The current total RPN (in 2022) was 452 (a decrease of 46.1%), with 7 major risks identified. The analysis enabled the objective evaluation of the effectiveness of the actions taken. The most secure stage of the process is the reception of residual level results. Efforts should focus on empowering and involving patients, as well as engaging local stakeholders in collaboration with the specialized transplantation team.

The Favorable impact of everolimus on Chronic lung allograft dysfunction in lung transplant recipients

Standard immunosuppressive therapy for lung transplant recipients combines a calcineurin inhibitor, an antimetabolite, and corticosteroids. In an observational, retrospective, monocentric study, we sought to compare the development of chronic lung allograft dysfunction (CLAD) between 37 patients who received this standard therapy (triple-therapy group) and 59 patients who received the mammalian target of rapamycin (mTOR) inhibitor everolimus in addition to the standard therapy (quadruple-therapy group). In the quadruple-therapy group, the time elapsed from transplantation to everolimus introduction (median [25th-75th percentile]) was 12 [7-25] months. In 46/59 cases, the indication for everolimus introduction was renal function sparing. Median follow-up durations were 36 [20-62] months and 84 [52-123] months in the triple-therapy and quadruple-therapy groups, respectively (p = 0.004). The incidence of CLAD was lower in patients receiving everolimus than in those who did not with an adjusted odds ratio of 0.303 [0.118-0.775]. In addition, the median time from transplantation to CLAD was longer in patients receiving quadruple therapy comprising everolimus than in those who did not (63 [30-92] vs. 29 [12-44] months; p = 0.025). This suggests that the addition of everolimus to a standard triple could result in a lower incidence of CLAD in lung transplant recipients.

Kidney Biopsy Findings After Lung Transplantation

Introduction

The early diagnosis of histological kidney damage after lung transplantation (LT) is of paramount importance given the negative prognostic implications of kidney disease.

Methods

Three pathologists analyzed all kidney biopsies (KBs) (N = 100) performed from 2010 to 2021 on lung transplant patients in 4 Paris transplantation centers.

Results

The main indication for biopsy was chronic renal dysfunction (72% of patients). Biopsies were performed at a median of 26.3 months after transplantation and 15 months after a decline in estimated glomerular filtration rate (eGFR) or the onset of proteinuria. Biopsies revealed a wide spectrum of chronic lesions involving the glomerular, vascular, and tubulointerstitial compartments. The 4 most frequent final diagnoses, observed in 18% to 49% of biopsies, were arteriosclerosis, acute calcineurin inhibitor (CNI) toxicity, thrombotic microangiopathy (TMA) and acute tubular necrosis (ATN). TMA was significantly associated with a combination of mTOR inhibitors (mTORi) or CNIs with biological signs present in only 50% of patients. The eGFR was poorly correlated with most lesions, particularly percent glomerulosclerosis, and with the risk of end-stage renal disease (ESRD). Thirty-four patients progressed to ESRD at an average of 20.1 months after biopsy. Three factors were independently associated with the risk of ESRD: postoperative dialysis, proteinuria >3 g/g and percent glomerulosclerosis >4%.

Conclusion

Given the great diversity of renal lesions observed in lung transplant recipients, early referral to nephrologists for KB should be considered for these patients when they present with signs of kidney disease.

mTOR inhibitors after lung transplantation: a real-life experience

Background

The mammalian target of rapamycin (mTOR) inhibitors in combination with calcineurin inhibitors (CNIs), antimetabolites and corticosteroids for immunosuppression after lung transplantation (TPL) have gained importance in patients with chronic kidney disease (CKD). The goal of this study was to characterize lung transplant recipients (LTR) treated with mTOR inhibitors, with a special focus on kidney function.

Methods

LTR transplanted at the University Hospital Zurich between December 1992 and April 2022 were analyzed. Demographics, estimated glomerular filtration rate (eGFR) before and after mTOR initiation, TPL circumstances, immunosuppressive regimens, and allograft function were recorded. We used linear regression to calculate the Mitch curves and a linear mixed-effects model to compare the eGFR.

Results

Of all LTR, 70/593 (12%) received mTOR inhibitors. Intolerance or adverse events of antimetabolites were the most common indications for mTOR inhibitor introduction. Discontinuation in 34/70 (49%) was often related to planned or urgent surgery to prevent impaired wound healing. The majority of patients had a preserved baseline eGFR at mTOR inhibitor introduction with CKD Kidney Disease Improving Global Outcomes (KDIGO) stage G1 or 2. The mean annual eGFR decline changed significantly from -16.19 mL/min/1.73 m2/year [95% confidence interval (CI): -22.27 to -10.11] 12 months before to -6.16 mL/min/1.73 m2/year (95% CI: -13.37 to 1.05) 12 months after mTOR initiation (P=0.009) showing better outcomes with earlier mTOR inhibitor initiation after lung TPL.

Conclusions

This retrospective study suggests stabilization of kidney function after mTOR inhibitor initiation in LTR documented by a slower eGFR decline after mTOR inhibitor introduction with better outcomes early after lung TPL. Intolerance or adverse events of antimetabolites are important indications for the introduction of mTOR inhibitors. A relatively high discontinuation rate (49%) can be explained by planned discontinuation of mTOR inhibitors prior to surgery to avoid impaired wound healing.

Everolimus Treatment for Chronic Lung Allograft Dysfunction in Lung Transplantation

Our study aims to evaluate the effect of everolimus treatment on lung function in lung transplant (LT) patients with established chronic lung allograft dysfunction (CLAD).

METHODS

This retrospective study included LT patients in two reference LT units who started everolimus therapy to treat CLAD from October 2008 to October 2016. We assessed the variation in the maximum forced expiratory volume in the first second (FEV1) before and after the treatment.

RESULTS

Fifty-seven patients were included in this study. The variation in the FEV1 was -102.7 (149.6) mL/month before starting everolimus compared to -44.7 (109.6) mL/month within the first three months, +1.4 (63.5) mL/month until the sixth month, and -7.4 (46.2) mL/month until the twelfth month (p < 0.05). Glomerular filtrate remained unchanged after everolimus treatment [59.1 (17.5) mL/min per 1.73 m2 at baseline and 60.9 (19.6) mL/min per 1.73 m2, 57.7 (20.5) mL/min per 1.73 m2, and 57.3 (17.8) mL/min per 1.73 m2, at 1, 3, and 6 months, respectively] (p > 0.05). Everolimus was withdrawn in 22 (38.6%) patients. The median time to withdrawal was 14.1 (5.5-25.1) months.

CONCLUSIONS

This study showed an improvement in FEV1 decline in patients with CLAD treated with everolimus. However, the drug was withdrawn in a high proportion of patients.

Sirolimus Long-Term Tolerability and Impact on Kidney Function in Lung Transplantation: A Single-Center Experience

BACKGROUND

After lung transplant, 2 common complications are calcineurin inhibitor (CNI) induced nephrotoxicity and bronchiolitis obliterans syndrome. The objective of this study was to investigate the long-term effects of sirolimus conversion after lung transplantation.

METHODS

This was a retrospective cohort study of patients who had undergone lung transplantation at a single center from June 2003 to December 2016. We compared patients converted to a sirolimus-based regimen to those maintained on our standard tacrolimus-based regimen. Kidney function, pulmonary function, and immunosuppression concentrations were compared between the groups. Additionally, indications, toxicity monitoring parameters, and discontinuation rates for sirolimus were collected.

RESULTS

During the study period, 176 of the 205 patients who underwent lung transplants were converted to a sirolimus-containing regimen (86%). The most common reason for sirolimus initiation was impairment of kidney function or CNI-associated neurotoxicity. Sirolimus was initiated at a median of 150 days post-transplantation and continued for a medium time of 5.02 (2.27-7.85) years. Of those patients converted to sirolimus, 39 (22%) had sirolimus subsequently discontinued secondary to an adverse event. No difference in pulmonary function was found between the groups at 1- and 3-years post-transplantation. In the sirolimus group, the median estimated glomerular filtration rate improved by 8.6 mL/min/1.73 m2 at 3 months post-conversion (P < .001), which was maintained at both 1 and 3 years (P = .014 and .025, respectively).

CONCLUSION

Sirolimus is a viable immunosuppressant option after lung transplant, which successfully allows for the reduction or withdrawal of the CNI, resulting in sustained improvement in kidney function.

Lymphocyte Depleting and Modulating Therapies for Chronic Lung Allograft Dysfunction

Chronic lung rejection, also called chronic lung allograft dysfunction (CLAD), remains the major hurdle limiting long-term survival after lung transplantation, and limited therapeutic options are available to slow the progressive decline in lung function. Most interventions are only temporarily effective in stabilizing the loss of or modestly improving lung function, with disease progression resuming over time in the majority of patients. Therefore, identification of effective treatments that prevent the onset or halt progression of CLAD is urgently needed. As a key effector cell in its pathophysiology, lymphocytes have been considered a therapeutic target in CLAD. The aim of this review is to evaluate the use and efficacy of lymphocyte depleting and immunomodulating therapies in progressive CLAD beyond usual maintenance immunosuppressive strategies. Modalities used include anti-thymocyte globulin, alemtuzumab, methotrexate, cyclophosphamide, total lymphoid irradiation, and extracorporeal photopheresis, and to explore possible future strategies. When considering both efficacy and risk of side effects, extracorporeal photopheresis, anti-thymocyte globulin and total lymphoid irradiation appear to offer the best treatment options currently available for progressive CLAD patients. SIGNIFICANCE STATEMENT: Effective treatments to prevent the onset and progression of chronic lung rejection after lung transplantation are still a major shortcoming. Based on existing data to date, considering both efficacy and risk of side effects, extracorporeal photopheresis, anti-thymocyte globulin, and total lymphoid irradiation are currently the most viable second-line treatment options. However, it is important to note that interpretation of most results is hampered by the lack of randomized controlled trials.

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.

Everolimus Based Immunosuppression Strategies in Adult Lung Transplant Recipients: Calcineurin Inhibitor Minimization Versus Calcineurin Inhibitor Elimination

Everolimus (EVE) provides an alternative to maintenance immunosuppression when conventional immunosuppression cannot be tolerated. EVE can be utilized with a calcineurin inhibitor (CNI) minimization or elimination strategy. To date, clinical studies investigating EVE after lung transplant (LTx) have primarily focused on the minimization strategy to preserve renal function. The primary aim was to determine the preferred method of EVE utilization for lung transplant recipients (LTR). To undertake this aim, we compared the safety and efficacy outcomes of EVE as part of minimization and elimination immunosuppressant regimens. Single center retrospective study of 217 LTR initiated on EVE (120 CNI minimization and 97 CNI elimination). Survival outcomes were calculated from the date of EVE commencement. On multivariate analysis, LTR who received EVE as part of the CNI elimination strategy had poorer survival outcomes compared to the CNI minimization strategy [HR 1.61, 95% CI: 1.11-2.32, p=0.010]. Utilization of EVE for renal preservation was associated with improved survival compared to other indications [HR 0.64, 95% CI: 0.42-0.97, p=0.032]. EVE can be successfully utilized for maintenance immunosuppression post LTx, particularly for renal preservation. However, immunosuppressive regimens containing low dose CNI had superior survival outcomes, highlighting the importance of retaining a CNI wherever possible.

Rescue Everolimus Post Lung Transplantation is Not Associated With an Increased Incidence of CLAD or CLAD-Related Mortality

Everolimus (EVE) has been used as a calcineurin inhibitor (CNI) minimization/ elimination agent or to augment immunosuppression in lung transplant recipients (LTR) with CNI-induced nephrotoxicity or neurotoxicity. The long-term evidence for survival and progression to chronic lung allograft dysfunction (CLAD) is lacking. The primary aim was to compare survival outcomes of LTR starting EVE-based immunosuppression with those remaining on CNI-based regimens. The secondary outcomes being time to CLAD, incidence of CLAD and the emergence of obstructive (BOS) or restrictive (RAS) phenotypes. Single center retrospective study of 91 LTR starting EVE-based immunosuppression matched 1:1 with LTR remaining on CNI-based immunosuppression. On multivariate analysis, compared to those remaining on CNI-based immunosuppression, starting EVE was not associated with poorer survival [HR 1.04, 95% CI: 0.67-1.61, p = 0.853], or a statistically significant faster time to CLAD [HR 1.34, 95% CI: 0.87-2.04, p = 0.182]. There was no difference in the emergence of CLAD (EVE, [n = 57, 62.6%] vs. CNI-based [n = 52, 57.1%], p = 0.41), or the incidence of BOS (p = 0.60) or RAS (p = 0.16) between the two groups. Introduction of EVE-based immunosuppression does not increase the risk of death or accelerate the progression to CLAD compared to CNI-based immunosuppression.

Mammalian Target of Rapamycin Inhibitors and Kidney Function After Thoracic Transplantation: A Systematic Review and Recommendations for Management of Lung Transplant Recipients

BACKGROUND

Chronic kidney disease (CKD) after lung transplantation is common and limits the survival of transplant recipients. The calcineurin inhibitors (CNI), cyclosporine A, and tacrolimus being the cornerstone of immunosuppression are key mediators of nephrotoxicity. The mammalian target of rapamycin (mTOR) inhibitors, sirolimus and everolimus, are increasingly used in combination with reduced CNI dosage after lung transplantation.

METHODS

This systematic review examined the efficacy and safety of mTOR inhibitors after lung transplantation and explored their effect on kidney function.

RESULTS

mTOR inhibitors are often introduced to preserve kidney function. Several clinical trials have demonstrated improved kidney function and efficacy of mTOR inhibitors. The potential for kidney function improvement and preservation increases with early initiation of mTOR inhibitors and low target levels for both mTOR inhibitors and CNI. No defined stage of CKD for mTOR inhibitor initiation exists, nor does severe CKD preclude the improvement of kidney function under mTOR inhibitors. Baseline proteinuria may negatively predict the preservation and improvement of kidney function. Discontinuation rates of mTOR inhibitors due to adverse effects increase with higher target levels.

CONCLUSIONS

More evidence is needed to define the optimal immunosuppressive regimen incorporating mTOR inhibitors after lung transplantation. Not only the indication criteria for the introduction of mTOR inhibitors are needed, but also the best timing, target levels, and possibly discontinuation criteria must be defined more clearly. Current evidence supports the notion of nephroprotective potential under certain conditions.

Calcineurin inhibitors' impact on cardiovascular and renal function, a descriptive study in lung transplant recipients from the North of Spain

Patients undergoing lung transplantation (LTx) need administration of immunosuppressive therapy following the procedure to prevent graft rejection. However, these drugs are not exempt from potential risks. The development of cardiovascular risk factors and impaired renal function in the post-transplantation period are conditions that may be favoured by the use of calcineurin inhibitor (CNI) drugs which could have repercussions on the quality of life and the post-transplantation evolution. To evaluate the cardiovascular and renal toxicity following the administration of CNI as maintenance immunosuppression in lung transplant recipients (LTRs) we reviewed a total number of 165 patients undergoing LTx between 01/01/2015 and 08/12/2018. They were divided into two groups according to the CNI drug administrated: cyclosporine (CsA-group) with 11 patients or tacrolimus (Tac-group), with 154 patients. We evaluated the de novo occurrence of arterial hypertension (HTN), diabetes mellitus (DM), hyperlipidemia and impaired renal function after initiation of CNI administration. In addition to that, the time until each of these events was assessed. A higher rate for developing HTN (p < 0.001) and impaired renal function (p = 0.047) was observed within the CsA-group. The new onset of hyperlipidemia was similar between both CNI groups and de novo appearance of DM was only documented in those LTRs receiving tacrolimus. In this LTRs retrospective study, it was observed that having ≥ 4 tacrolimus trough levels above the upper limit of the proposed interval for each specific post-LTx period was associated with an increased risk for developing renal impairment. No other statistically significant association was found between supratherapeutic CNIs blood levels and the evaluated toxicities.

Everolimus Use in Lung Transplant Recipients

BACKGROUND

Most lung transplantation centers prefer triple immunosuppressive therapy with tacrolimus, mycophenolate mofetil, and corticosteroids. However, to prevent complications and comorbidities caused by tacrolimus, replacing the drug with everolimus has been considered.

METHODS

This is a retrospective observational study investigating everolimus switch for different reasons. The population was divided into 3 groups: chronic lung allograft dysfunction (CLAD), kidney impairment, and malignant neoplasm groups. We investigated whether we achieved the goal of the switch and the frequency of rejection, cytomegalovirus and fungal infections, and everolimus adverse effects.

RESULTS

Nineteen patients received everolimus therapy, and 5 of these were for CLAD, 7 for tacrolimus nephrotoxicity, and 7 for explant/de novo malignant neoplasm. The patients were followed up for a mean (SD) of 30 (16.7) months under the therapy. The number of acute cellular rejection, cytomegalovirus infection, and aspergillosis infection cases before switch were 7, 13, and 2, respectively, and 7, 2, and 3 after that. The mean values of creatinine and estimated glomerular filtration rate of the whole population after the switch improved with no statistical significance, whereas it was significant in tacrolimus nephrotoxicity group. Three patients in the CLAD group remained stable after switching, whereas 2 progressed. Only 1 of the 7 patients with malignant neoplasms had a recurrence during 31.1 (16.5) months of median follow-up. Eleven cases of everolimus adverse effects occurred in 9 patients (47.3%), with 2 (10.5%) withdrawal events. Kidney impairment (P = .02) and age (P = .05) stood out as significant risk factors for drug adverse effects.

CONCLUSIONS

After lung transplant, everolimus can be a safe alternative for immunosuppression with acceptable adverse effects.

Chronic kidney disease after lung transplantation in a changing era

Lung transplant (LTx) physicians are responsible for highly complex post-LTx care, including monitoring of kidney function and responding to kidney function loss. Better survival of the LTx population and changing patient characteristics, including older age and increased comorbidity, result in growing numbers of LTx patients with chronic kidney disease (CKD). CKD after LTx is correlated with worse survival, decreased quality of life and high costs. Challenges lie in different aspects of post-LTx renal care. First, serum creatinine form the basis for estimating renal function, under the assumption that patients have stable muscle mass. Low or changes in muscle mass is frequent in the LTx population and may lead to misclassification of CKD. Second, standardizing post-LTx monitoring of kidney function and renal care might contribute to slow down CKD progression. Third, new treatment options for CKD risk factors, such as diabetes mellitus, proteinuria and heart failure, have entered clinical practice. These new treatments have not been studied in LTx yet but are of interest for future use. In this review we will address the difficult aspects of post-LTx renal care and evaluate new and promising future approaches to slow down CKD progression.

Lung transplantation and severe coronary artery disease: results from a single-centre experience

OBJECTIVES

The management of severe coronary artery disease at the time of lung transplantation remains a challenge. We analyzed the short- and long-term-outcomes of lung transplant recipients with severe coronary artery disease.

METHODS

Records of adult patients transplanted at our institution between April 2010 and February 2021 were retrospectively reviewed. Severe coronary artery disease was defined by coronary stenosis ≥70% (main stem ≥50%) at the coronary angiography performed before or at the time of listing. Patient characteristics, perioperative- and long-term-outcomes were compared between patients with and without severe coronary artery disease.

RESULTS

Among 896 lung-transplanted patients who had undergone a coronary angiography before transplantation, 77 (8.5%) showed severe coronary artery disease, the remaining 819 (91.5%) did not. Patients with severe coronary artery disease were older (p < 0.0001), more often male (p < 0.0001) and were transplanted more often for pulmonary fibrosis (p = 0.0007). The median (interquartile range) follow-up was 46 (20-76) months. At the Cox multivariable analysis severe coronary artery disease was not associated with mortality. Patients with pretransplant percutaneous transluminal coronary angioplasty and patients with coronary artery bypass graft surgery concomitant to transplantation had equivalent survival compared to patients without severe coronary artery disease (p = 0.513, p = 0.556).

CONCLUSIONS

Severe coronary artery disease was not associated with decreased survival after lung transplantation. Concomitant coronary artery bypass graft surgery and pretransplant percutaneous transluminal coronary angioplasty can be used for revascularization.

Early Postoperative Management of Lung Transplant Recipients

The early postoperative period after lung transplantation is a critical time. Prompt recognition and treatment of primary graft dysfunction can alter long-term allograft function. Cardiovascular, gastrointestinal, renal, and hematologic derangements are common and require close management to limit their negative sequelae.

Chronic Lung Allograft Dysfunction

Chronic lung allograft dysfunction (CLAD) is a syndrome of progressive lung function decline, subcategorized into obstructive, restrictive, and mixed phenotypes. The trajectory of CLAD is variable depending on the phenotype, with restrictive and mixed phenotypes having more rapid progression and lower survival. The mechanisms driving CLAD development remain unclear, though allograft injury during primary graft dysfunction, acute cellular rejection, antibody-mediated rejection, and infections trigger immune responses with long-lasting effects that can lead to CLAD months or years later. Currently, retransplantation is the only effective treatment.

Polyomavirus exerts detrimental effects on renal function in patients after lung transplantation

INTRODUCTION

Chronic kidney disease (CKD) is associated with significant morbidity and mortality after lung transplantation (LTX). Calcineurin inhibitor (CNI) nephrotoxicity is the leading cause of CKD. After kidney transplantation, polyomavirus-associated nephropathy (PyVAN) is a well-recognized problem. This study aims to evaluate the role of polyomavirus in patients after LTX.

METHODS

From January 2017 to January 2020, all lung transplant recipients who performed follow-up visits in our center were included in the study and retrospectively assessed. We measured renal function (creatinine levels before and after transplantation), JCPyV, and BKPyV load by polymerase chain reaction (PCR) in serum and urine samples after transplantation.

RESULTS

In total, 104 consecutive patients (59 males, 56.7%) with a mean age of 49.6 ± 11.1 years were identified. JCPyV was found in urine of 36 patients (34.6%) and serum of 3 patients (2.9%). BKPyV was found in urine of 40 patients (38.5%) and serum of 4 patients (3.8%), respectively. Urine evidence for JCPyV (p < 0.001, coefficient: +21.44) and BKPyV (p < 0.001, coefficient: +29.65) correlated highly with further kidney function decline.

CONCLUSION

Kidney function deterioration is associated with JCPyV and BKPyV viruria in patients after LTX. This might indicate a role of PyVAN in lung transplant recipients.

Immunosuppression in Lung Transplantation

Immunosuppression in lung transplantation is an area devoid of robust clinical data. This chapter will review the history of immunosuppression in lung transplantation. Additionally, it will evaluate the three classes of induction, maintenance, and rescue immunosuppression in detail. Induction immunosuppression in lung transplantation aims to decrease incidence of lung allograft rejection, however infectious risk must be considered when determining if induction is appropriate and which agent is most favorable. Similar to other solid organ transplant patient populations, a multi-drug approach is commonly prescribed for maintenance immunosuppression to minimize single agent drug toxicities. Emphasis of this review is placed on key medication considerations including dosing, adverse effects, and drug interactions. Clinical considerations will be reviewed per drug class given available literature. Finally, acute cellular, antibody mediated, and chronic rejection are reviewed.

Mammalian Target of Rapamycin Inhibitors Vs Calcineurin Inhibitors in Chronic Graft Rejection After Lung Transplantation: A Systematic Review and Meta-Analysis

BACKGROUND

The number of lung transplantations has been rising constantly. However, use of this therapeutic resource is limited by several issues that are difficult to resolve, such as chronic graft rejection and complications secondary to immunosuppression.

METHODS

This systematic review compared mammalian target of rapamycin (mTOR) inhibitor immunosuppression associated with low-dose calcineurin inhibitors with isolated calcineurin inhibitor immunosuppression on the new-onset chronic rejection development and mortality 12 months after lung transplantation. Three controlled randomized clinical trials (SHITRIT, NOCTET, and 4EVERLUNG) were selected from electronic databases.

RESULTS

Meta-analysis of the data at 12 months postintervention showed that only 4EVERLUNG assessed chronic graft rejection, with a higher incidence in the control group; however, the difference was not statistically significant (P = .197). Significant data were related to an increase in the number of adverse events (P = .0064) and improved renal function (P < .0001) in the mTOR inhibitor-based scheme. The other outcomes indicated a trend toward greater risk of death and acute graft rejection with the use of mTORs.

CONCLUSIONS

The researchers suggest considering the use of mTOR inhibitors, whose greatest benefit is felt by patients with renal dysfunction, in association with the use of calcineurin inhibitors, because of the imminent risk of death among patients with renal failure.

Looking Beyond the Allograft Survival: Long-Term, 5-Year Renal Outcome in Lung Transplant Recipients

With the increased incidence and survival of lung transplant (LTx) recipients, the risk for chronic sequelae such as chronic kidney disease (CKD) is on the rise. Data on the long-term renal outcome are scarce. We performed a retrospective chart review of 171 adults with LTx from January 1, 2014, to January 1, 2019. Primary outcomes were prevalence of CKD/end-stage renal disease, acute kidney injury (AKI) as a risk factor for future CKD, and all-cause mortality in recipients with CKD compared with the non-CKD group. Secondary outcomes were frequency of utilization of modalities for CKD (urinalysis, imaging, biopsy, nephrology consultations). Baseline median creatinine and estimated glomerular filtration rate (eGFR) were 0.8 mg/dL and 90 mL/min/1.73 m², respectively. Of the participants, 60% (96 of 161), 67% (102 of 153), 79% (37 of 47), 86% (10 of 12) had CKD at the end of 6, 12, 36, and 60 months, respectively, and 16% were on dialysis at the end of the study period; 3% received a subsequent renal transplant, and 27% mortality was noted over a 5-year follow-up period. The odds of CKD development in patients with an AKI during index hospitalization vs no AKI was 6.22 (2.87 to 13.06, P < .0001). The odds ratio of all-cause mortality in patients with CKD compared with non-CKD was 3.36 (95% confidence interval, 1.44-8.64, P = .005). Measurement of hematuria/proteinuria, imaging, and renal biopsy were infrequently used. Given the high prevalence of AKI and CKD in this population, a multidisciplinary team approach with an early nephrology consultation will be key to improve the overall and renal outcomes in LTx recipients.

Letermovir in lung transplant recipients with cytomegalovirus infection: A retrospective observational study

Letermovir is a new antiviral drug approved for the prophylaxis of CMV infection in allogeneic stem cell transplants. The aim of the study was to assess the therapeutic efficacy of letermovir in difficult to treat CMV infections in lung transplant recipients. All lung transplant recipients between March 2018 and August 2020, who have been treated with letermovir for ganciclovir-resistant or refractory CMV infection were included in the study and analysed retrospectively. In total, 28 patients were identified. CMV disease was present in 15 patients (53.6%). In 23 patients (82.1%), rapid response was noticed, and CMV-viral load could be significantly decreased (>1 log₁₀ ) after a median of 17 [14-27] days and cleared subsequently in all of these patients. Five patients (17.9%) were classified as non-responder. Thereof, development of a mutation of the CMV UL56 terminase (UL-56-Gen: C325Y) conferring letermovir resistance could be observed in three patients (60%). Common side effects were mild and mostly of gastrointestinal nature. Mild adjustments of the immunosuppressive drugs were mandatory upon treatment initiation with letermovir. In addition to other interventions, letermovir was effective in difficult to treat CMV infections in lung transplant recipients. However, in patients with treatment failure mutation conferring letermovir, resistance should be taken into account.

An overview of the efficacy and safety of everolimus in adult solid organ transplant recipients

As the risk of graft loss due to acute rejection has declined, the goal of post-transplant management has switched to long-term preservation of organ function. Minimizing calcineurin inhibitor (CNI)-related nephrotoxicity is a key component of this objective. Everolimus is a mammalian target of rapamycin inhibitor/proliferation-signal inhibitor with potent immunosuppressive and anti-proliferative effects. It has been widely investigated in large randomized clinical studies that have shown it to have similar anti-rejection efficacy compared with standard-of-care regimens across organ transplant indications. With demonstrated potential to facilitate the reduction of CNI therapy and preserve renal function, everolimus is an alternative to the current standard-of-care CNI-based regimens used in de novo and maintenance solid organ transplantation recipients. Here, we provide an overview of the evidence from the everolimus clinical study program across kidney, liver, heart, and lung transplants, as well as other key data associated with its use in CNI reduction strategies in adult transplant recipients.

Association of CMV-specific T-cell immunity and risk of CMV infection in lung transplant recipients

BACKGROUND

Protecting against CMV infection and maintaining CMV in latent state are largely provided by CMV-specific T-cells in lung transplant recipients. The aim of the study was to assess whether a specific T-cell response is associated with the risk for CMV infection in seronegative patients who are at high risk for delayed CMV infection.

METHODS

All CMV-seronegative recipients (R-) from CMV-seropositive donors (D+) between January 2018 and April 2019 were included and retrospectively screened for CMV infection before and after assessment of CMV-specific cell-mediated immunity.

RESULTS

Thirty-one of the 50 patients (62%) developed early-onset CMV infection. Lower absolute neutrophil counts were significantly associated with early-onset CMV infection. Antiviral prophylaxis was ceased after 137.2 ± 42.8 days. CMV-CMI were measured at a median of 5.5 months after LTx. 19 patients experienced early and late-onset CMV infection after prophylaxis withdrawal within 15 months post transplantation. Positive CMV-CMI was significantly associated with lower risk of late-onset CMV infection after transplantation in logistic and cox-regression analysis (OR=0.05, p = .01; OR=2,369, p = .026).

CONCLUSION

D+/R- lung transplant recipients are at high risk of developing early and late-onset CMV infection. Measurement of CMV-CMI soon after transplantation might further define the CMV infection prediction risk in LTx recipients being at high risk for CMV viremia.

Real life experience with mTOR-inhibitors after lung transplantation

Mammalian target of rapamycin inhibitors (mTORi) are increasingly used after lung transplantation as part of a calcineurin inhibitor sparing regimen, aiming to preserve renal function. The aim of our study was to determine whether immunosuppressive therapy using mTORi in lung transplant recipients (LTR) is feasible in practice, or limited by intolerance and adverse events. Data were retrospectively assessed for all LTR transplanted between July 1991 and January 2020. Patients ever receiving mTORi (monotherapy or in combination with calcineurin inhibitor) as treatment of physicians' choice were included. 149/1184 (13%) of the LTR ever received mTORi. Main reasons to start were renal insufficiency (67%) and malignancy (21%). In 52% of the patients, mTORi was stopped due to side effects or drug toxicity after a median time of 159 days. Apart from death, main reasons for discontinuation were infection (19%) and edema (14%). Early discontinuation (<90 days) was mainly due to edema or gastrointestinal intolerance. As mTORi was stopped due to adverse events or drug intolerance in 52% of LTR, cautious consideration of advantages and disadvantages when starting mTORi is recommended.

Viral load-guided immunosuppression after lung transplantation (VIGILung)-study protocol for a randomized controlled trial

Background

Immunosuppression including high-dose calcineurin inhibitors (CNI) is essential after lung transplantation. Dosing is usually guided by therapeutic drug monitoring adjusted to target trough levels of CNIs to keep the balance between over-dose causing severe toxicity and increased risk of infections or under-dose with a risk of graft injury. Adaptation of CNI-based immunosuppression by monitoring of torque teno virus (TTV), a latent nonpathogenic DNA virus, measured in the whole blood in addition to conventional therapeutic drug monitoring may reduce the toxicity of immunosuppression with similar efficacy.

Methods/design

An open-label, randomized, controlled, parallel-group, multicenter trial in lung transplant recipients will be conducted to investigate the safety and efficacy of immunosuppression guided by TTV monitoring as an add-on to conventional therapeutic drug monitoring. Adult lung transplant recipients 21 to 42 days after transplantation are eligible to participate. Patients (N = 144) will be randomized 1:1 to the experimental intervention (arm 1: immunosuppression guided by TTV monitoring in addition to conventional therapeutic drug monitoring of tacrolimus trough levels) and control intervention (arm 2: conventional therapeutic drug monitoring). Outcomes will be assessed 12 months after randomization with the change in glomerular filtration rate as the primary endpoint. Secondary endpoints will be additional measurements of renal function, allograft function, incidence of acute rejections, incidence of chronic lung allograft dysfunction, graft loss, and infections.

Discussion

The results of this randomized controlled trial may reduce the toxicity of immunosuppression after lung transplantation while maintaining the efficacy of immunosuppression. Study results are transferable to all other solid organ transplantations.

Trial registration

ClinicalTrials.gov NCT04198506. Registered on 12 December 2019

Application of MR diffusion imaging for non-invasive assessment of acute kidney injury after lung transplantation

To assess whether MR diffusion imaging may be applied for non-invasive detection of renal changes correlating with clinical diagnosis of acute kidney injury (AKI) in patients after lung transplantation (lutx).Fifty-four patients (mean age 49.6, range 26-64 years) after lutx were enrolled in a prospective clinical study and underwent functional MR imaging of the kidneys in the early postoperative period. Baseline s-creatinine ranged from 39 to 112 μmol/L. For comparison, 14 healthy volunteers (mean age 42.1, range 24-59 years) underwent magnetic resonance imaging (MRI) using the same protocol. Renal tissue injury was evaluated using quantification of diffusion and diffusion anisotropy with diffusion-weighted (DWI) and diffusion-tensor imaging (DTI). Renal function was monitored and AKI was defined according to Acute-Kidney-Injury-Network criteria. Statistical analysis comprised one-way ANOVA and Pearson correlation.67% of lutx patients (36/54) developed AKI, 47% (17/36) had AKI stage 1, 42% (15/36) AKI stage 2, and 8% (3/36) severe AKI stage 3. Renal apparent diffusion coefficients (ADCs) were reduced in patients with AKI, but preserved in transplant patients without AKI and healthy volunteers (2.07 ± 0.02 vs 2.18 ± 0.05 vs 2.21 ± 0.03 × 10 mm/s, P < .05). Diffusion anisotropy was reduced in all lutx recipients compared with healthy volunteers (AKI: 0.27 ± 0.01 vs no AKI: 0.28 ± 0.01 vs healthy: 0.33 ± 0.02; P < .01). Reduction of renal ADC correlated significantly with acute loss of renal function after lutx (decrease of renal function in the postoperative period and glomerular filtration rate on the day of MRI).MR diffusion imaging enables non-invasive assessment of renal changes correlating with AKI early after lutx. Reduction of diffusion anisotropy was present in all patients after lutx, whereas marked reduction of renal ADC was observed only in the group of lutx recipients with AKI and correlated with renal function impairment.

Developments in lung transplantation over the past decade

With an improved median survival of 6.2 years, lung transplantation has become an increasingly acceptable treatment option for end-stage lung disease. Besides survival benefit, improvement of quality of life is achieved in the vast majority of patients. Many developments have taken place in the field of lung transplantation over the past decade. Broadened indication criteria and bridging techniques for patients awaiting lung transplantation have led to increased waiting lists and changes in allocation schemes worldwide. Moreover, the use of previously unacceptable donor lungs for lung transplantation has increased, with donations from donors after cardiac death, donors with increasing age and donors with positive smoking status extending the donor pool substantially. Use of ex vivo lung perfusion further increased the number of lungs suitable for lung transplantation. Nonetheless, the use of these previously unacceptable lungs did not have detrimental effects on survival and long-term graft outcomes, and has decreased waiting list mortality. To further improve long-term outcomes, strategies have been proposed to modify chronic lung allograft dysfunction progression and minimise toxic immunosuppressive effects. This review summarises the developments in clinical lung transplantation over the past decade.

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.

[Current developments in lung transplantation]

BACKGROUND

Lung transplantation is the established treatment of benign end-stage pulmonary diseases after failure of alternative surgical and medical treatment options. The aim of this paper is to provide an overview of current developments in selected fields of lung transplantation.

METHODS

A selective literature search was conducted.

RESULTS

Lung transplantation in Germany is currently limited by a donor organ shortage. Measures to increase organ donation rates and to optimize the use of available donor organs are required. Ex-vivo lung perfusion, currently mainly used to re-evaluate marginal donor organs, has the potential to increase the available donor pool and to serve as a platform for additional therapies.

CONCLUSIONS

Refinements in organ allocation, perioperative management, immunosuppression, and in the understanding of acute cellular and humoral rejection as well as chronic lung allograft dysfunction contributed to improvements in long-term outcome after lung transplantation.

A randomized trial of everolimus-based quadruple therapy vs standard triple therapy early after lung transplantation

Calcineurin inhibitor (CNI) therapy after lung transplantation increases risk of kidney failure. Early everolimus-based quadruple low CNI immunosuppression may improve renal function without compromising efficacy or safety. A prospective, randomized, open-label, 12-month multicenter trial was conducted at 8 German sites. Patients 3-18 months after lung transplantation were randomized (1:1), stratified by baseline estimated glomerular filtration rate (eGFR). In the quadruple low CNI regimen, patients received everolimus (target trough level 3-5 ng/mL) with reduced CNI (tacrolimus 3-5 ng/mL or cyclosporine 25-75 ng/mL) and a cell cycle inhibitor plus prednisone. In the standard triple CNI regimen, patients received tacrolimus (target trough level >5 ng/mL) or cyclosporine (>100 ng/mL) and a cell cycle inhibitor plus prednisone. Of the 180 patients screened, 130 were randomized: 67 in the quadruple low CNI group and 63 in the standard triple CNI group. The primary endpoint (eGFR after 12 months) demonstrated superiority of the quadruple low CNI regimen: 64.5 mL/min vs 54.6 mL/min for the standard triple group (least squares mean, analysis of covariance; P < .001). Key efficacy parameters (biopsy-proven acute rejection, chronic lung allograft dysfunction, and death) and safety endpoints were similar between both groups. Quadruple low CNI immunosuppression early after lung transplantation was demonstrated to be efficacious and safe. Clinical trials registry: ClinicalTrials.gov NCT01404325.