Long-term outcomes of thoracic transplant recipients following conversion to everolimus with reduced calcineurin inhibitor in a multicenter, open-label, randomized trial

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 Everolimus was withdrawn in 22 (38.6%) patients.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 However, the drug was withdrawn in a high proportion of patients.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.

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-inhibitor free immunosuppression after lung transplantation - a single center case-control study in 51 patients converted to Mechanistic Target of Rapamycin (mTOR) inhibitors

BACKGROUND

Data on calcineurin-inhibitor (CNI) free immunosuppression after lung transplantation (LTx) are limited. Aim of this study was to investigate CNI-free immunosuppression using mechanistic target of rapamycin (mTOR) inhibitors.

METHODS

This retrospective analysis was performed at a single center. Adult patients after LTx without CNI during the follow-up period were included. Outcome was compared to those LTx patients with malignancy who continued CNI.

RESULTS

Among 2,099 patients in follow-up, fifty-one (2.4%) were converted median 6.2 years after LTx to a CNI-free regimen combining mTOR inhibitors with prednisolone and an antimetabolite, two patients were switched to mTOR inhibitors with prednisolone only. In 25 patients, malignancies without curative treatment options were the reason of the conversion, with a 1-year survival of 36%. The remaining patients had a 1-year survival of 100%. Most common non-malignant indication was neurological complications (n = 9). Fifteen patients were re-converted to a CNI-based regimen. The median duration of CNI-free immunosuppression was 338 days. No acute rejections were detected in 7 patients with follow-up biopsies. In multivariate analysis, CNI-free immunosuppression were not associated with improved survival after malignancy. The majority of patients with neurological diseases improved 12 months after conversion. Glomerular filtration rate increased by median 5 (25 and 75% percentiles -6; +18) ml/min/1.73 m2.

CONCLUSIONS

mTOR inhibitor based CNI-free immunosuppression may be safely performed in selected patients after LTx. This approach was not associated with improved survival in patients with malignancy. Significant functional improvements were observed in patients with neurological diseases.

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.

CKD in Recipients of Nonkidney Solid Organ Transplants: A Review

Chronic kidney disease (CKD) after solid organ transplant is a common clinical presentation, affecting 10% to 20% of liver, heart and lung transplant recipients and accounting for approximately 5% of the kidney transplant waiting list. The causes of CKD are different for different types of transplants and are not all, or even predominantly, due to calcineurin inhibitor toxicity, with significant heterogeneity particularly in liver transplant recipients. Many solid organ transplant recipients with advanced CKD benefit from kidney transplantation, but have a higher rate of death while waitlisted and higher mortality following transplant than the general kidney failure population. Recent organ allocation policies and proposals have attempted to address the appropriate identification and prioritization of candidates in need of a kidney transplant, either simultaneous with or following non-kidney transplant. Future research should focus on predictive factors for individuals identified at high risk for progression to kidney failure and death, and strategies to preserve kidney function and minimize the CKD burden in this unique patient population.

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.

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.

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.

Conversion to everolimus in pediatric heart transplant recipients is a safe treatment option with an impact on cardiac allograft vasculopathy and renal function

BACKGROUND

Cardiac allograft vasculopathy (CAV) and nephrotoxicity affect long-term survival after heart transplantation (HTX). Studies, mostly conducted in adults, showed a positive effect of everolimus (EVL) on these problems. We describe the effects of conversion of the immunosuppressive therapy to an everolimus including regime on CAV, renal function, and safety in heart transplanted children/adolescents.

METHODS

This retrospective single-center study included 36 participants (mean time after HTX 6.3 ± 4.7 years). Descriptive pre/post-comparisons were performed with an observation period partially up to 4 years. Impact on CAV was assessed based on intravascular imaging and Stanford grading. Safety analysis included cytomegalovirus (CMV)-infection and acute rejection.

RESULTS

In terms of CAV (9 out of 36 patients) four showed no progression, three an improvement, one a worsening; one new diagnosis. The average CrCl showed a significant improvement 6, 12, and 24 months after conversion regarding all patients (n = 29). There was no acute rejection or CMV-infection.

CONCLUSION

Conversion to an EVL-based therapy after pediatric HTX is a safe immunosuppressive regime without increasing risk of acute rejection or CMV-infection. There was some evidence of reduction in progression of CAV and a significant improvement of the renal function.

Quadritherapy vs standard tritherapy immunosuppressant regimen after heart transplantation: A propensity score-matched cohort analysis

After heart transplant, adding everolimus (EVL) to standard immunosuppressive regimen mostly relies on converting calcineurin inhibitors (CNIs) into EVL. The aim of this study was to describe the effects of combining low-dose EVL and CNIs in maintenance immunosuppression regimen (quadritherapy) and compare it with standard tritherapy associating standard-dose CNIs, mycophenolate mofetil, and corticosteroids. In the 3-year registry cohort of heart transplanted patients, those who received quadritherapy were compared with those who received tritherapy. EVL was added after 3 months posttransplant. Three analyses were performed to control for confounders: propensity score matching, multivariable survival, and inverse probability score weighting analyses. Among 213 patients who were included (75 with quadritherapy), propensity score matching selected 64 unique pairs of patients with similar characteristics. In the matched cohort (n = 128), quadritherapy was associated with fewer deaths (3 [4.7%] vs 17 [21.9%], P = .007) and biopsy-proven acute rejections (15 [23.4%] vs 31 [48.4%], P = .002). These results were confirmed in the overall cohort (n = 213), after multivariable and inverse probability score weighting analyses. Renal function and donor-specific HLA-antibodies remained similar in both groups. Low-dose combination quadritherapy was associated with fewer deaths and rejections, compared with standard immunosuppression tritherapy.

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.

Many developments have taken place in lung transplantation over the last decade: indications have broadened, donor criteria expanded, allocations systems changed, and novel therapeutic interventions implemented, leading to improved long-term survivalhttp://bit.ly/2vnpwc1

Interventions to Prevent Nonmelanoma Skin Cancers in Recipients of a Solid Organ Transplant: Systematic Review of Randomized Controlled Trials

BACKGROUND

Organ transplant recipients are at high risk of developing skin cancer. The benefits and harms of interventions to prevent nonmelanoma skin cancer in solid organ transplant recipients have not been summarized.

METHODS

We searched MEDLINE, Embase, and CENTRAL through April 2018. Risk of bias was assessed using the Cochrane tool, and evidence certainty was evaluated using the Grades of Recommendation, Assessment, Development, and Evaluation process. Prespecified outcomes were nonmelanoma skin cancer, clearance and prevention of keratotic skin lesions, and intervention-specific adverse events.

RESULTS

Ninety-two trials (20 012 participants) were included. The evaluated treatments were cancer-specific interventions (acitretin, imiquimod, photodynamic therapy, nicotinamide, topical diclofenac, and selenium) and immunosuppression regimes (azathioprine, mycophenolate mofetil, calcineurin inhibitors, mammalian target of rapamycin [mTOR] inhibitors, belatacept, induction agents, and withdrawal of calcineurin inhibitors or corticosteroids). Effects on nonmelanoma skin cancer were uncertain for photodynamic therapy (3 trials, 93 participants, risk ratio [RR] 1.42 [95% confidence interval (CI), 0.65-3.11]; low certainty evidence), nicotinamide (2 trials, 60 participants), acitretin (2 trials, 61 participants), and imiquimod (1 trial, 20 participants) compared to control. mTOR inhibitors probably reduced skin cancer compared to calcineurin inhibitors (12 trials, 2225 participants, RR 0.62 [95% CI, 0.45-0.85]; moderate certainty evidence). Photodynamic therapy may cause pain at the treatment site (4 trials, 95 patients, RR 17.09 [95% CI, 4.22-69.26]; low certainty evidence).

CONCLUSIONS

There is limited evidence for the efficacy and safety of specific treatments to prevent nonmelanoma skin cancers among solid organ transplant recipients.

Impact of tacrolimus versus cyclosporin A on renal function during the first year after heart transplant

AIMS

Nephrotoxicity of calcineurin inhibitors (CNIs) is associated with adverse events in patients undergoing heart transplant (HTx), although studies directly comparing tacrolimus (TAC) versus cyclosporin A (CsA), especially in combination with everolimus and low-dose CNIs approach, are limited. Thus, we sought to investigate the associations of TAC and CsA with clinical outcomes in HTx recipients, with specific focus on renal function.

METHODS AND RESULTS

From August 2007 to February 2017, 72 consecutive patients (39 treated with TAC vs. 33 with CsA) receiving de novo HTx in a single transplant centre were retrospectively evaluated. We used the instrumental variable method to account for unmeasured confounding. The study outcomes were percentage change in estimated glomerular filtration rates (eGFR) (safety endpoint) and biopsy-proven acute rejection (efficacy endpoint) within the first year after HTx. The enrolled patients (median age 40 years) were predominantly men (68%). There were no significant differences in baseline characteristics, including eGFR (64.8 [45.7-96.4] mL/min/1.73 m² in TAC vs. 65.6 [57.9-83.0] mL/min/1.73 m² for CsA; P = 0.48), other than sex (male, 49% for TAC vs. 91% for CsA; P < 0.001) between the two groups. Within the first year after HTx, 23 (59%) in the TAC group switched mycophenolate mofetil to everolimus, whereas 16 (48%) in the CsA group (P = 0.52). At 12 months, the rates of mortality and end-stage renal disease requiring renal replacement therapies were both 0%. In the instrumental variable analysis, no differences in renal function as well as graft rejection for 1 year after HTx existed between the TAC and CsA groups. These results were similar when taking into account of everolimus use.

CONCLUSIONS

Irrespective of everolimus use with low-dose CNIs, our analysis using the instrumental variable method showed no differences in renal function as well as graft rejection during the first year after HTx between HTx recipients who received TAC or CsA.

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.

The advantage of Sirolimus in amplifying regulatory B cells and regulatory T cells in liver transplant patients

Sirolimus has been shown to ameliorate steroid-resistant rejection and induce long-term immune tolerance among liver transplant patients. However, the detailed mechanism of how Sirolimus achieve these advantages is still lacking. This study attempts to reveal some possible mechanisms by investigating regulatory B cells (Bregs), regulatory T cells (Tregs) and some cytokines in liver transplant recipients whose Tacrolimus was partially converted to Sirolimus. The results showed that CD19⁺CD24⁺CD38⁺Bregs and CD4⁺CD25⁺FoxP3⁺Tregs increased significantly during the first month after drug conversion (P < 0.01 and P < 0.05). The percentages of IL-10⁺Bregs and TGF-β₁⁺Bregs were also elevated (P < 0.05 and P < 0.01), and the same trend was observed in the levels of IL-10 and TGF-β₁ (P < 0.01 and P < 0.01). However, in the observation period, these investigated lymphocyte subsets and cytokines didn't change significantly in patients without Sirolimus usage. The incidence of biliary stenosis in the conversion group were significantly lower than that in the control group (P < 0.05). At the same time, in vitro experiments showed that Sirolimus could significantly amplify Bregs and Tregs (P < 0.01 and P < 0.01) while Tacrolimus did not show the amplifications effects. Sirolimus' function of amplifying Bregs was weakened, and its function of amplifying Tregs even disappeared after IL-10 and TGF-β₁ were neutralized. In conclusion, Sirolimus could amplify Bregs and Tregs among liver transplant recipient, which might be benefit to mitigate the immune response, decrease chances of rejection and alleviate biliary complication. IL-10 and TGF-β₁ may play important roles during this process.

Cardiac Allograft Vasculopathy: The Enduring Enemy of Cardiac Transplantation

Cardiac allograft vasculopathy remains a major limiting factor in the long-term survival of the heart transplant recipient. Our understanding of its pathogenesis is continuously evolving as advances in imaging modalities have allowed a direct window into the natural history of the disease. Innovation in diagnostic modalities has spurred the proliferation of prognostic tools and biomarkers. And in parallel, pharmacological advances have emerged that have helped ameliorate the disease's progressive course.

mTOR Inhibition and Clinical Transplantation: Heart

This brief overview discusses recent data on the use of mammalian target of rapamycin (mTOR) inhibitors in heart transplantation. Trials on de novo use have shown good efficacy of mTOR inhibitors; however, adverse events are often seen. Conversion protocols in long-term patients are mainly used in patients with renal insufficiency. Calcineurin inhibitor minimization and conversion to calcineurin inhibitor-free protocols have proven to stabilize renal function in recent trials. Lastly, beneficial effects of mTORs against the development of graft vasculopathy, cytomeglovirus infection and malignancy have been shown. Nevertheless, lower tolerability of the drug has affected the long-term use in patients. Future consideration of using mTORs will be individualized protocols in special subpopulation after heart transplantation.

Individualizing immunosuppression in lung transplantation

Immunosuppression management after lung transplantation continues to evolve, with an increasing number of agents available for use in various combinations allowing for more choice and individualization of immunosuppressive therapy. Therapeutic developments have led to improved outcomes including lower acute rejection rates and improved survival. However, a one size fits all approach for any immunosuppressive strategy may not be best suited to the individual patient and ultimately patient specific factors must be considered when designing the immunosuppressive regimen. Recipient factors including age, race, co-morbidities, immunologic risk, genetic polymorphisms, concomitant and previous pharmacotherapy, and overall immunosuppression burden should be considered. There are several significant drug-drug interactions with select immunosuppressive agents utilized in lung transplant pharmacotherapy that must be considered when choosing and devising a dosing strategy for an individual immunosuppressive agent. Herein, considerations for immunosuppression management in the individual patient will be reviewed.

Prevention of chronic rejection after lung transplantation

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

The CECARI Study: Everolimus (Certican®) Initiation and Calcineurin Inhibitor Withdrawal in Maintenance Heart Transplant Recipients with Renal Insufficiency: A Multicenter, Randomized Trial

In this 3-year, open-label, multicenter study, 57 maintenance heart transplant recipients (>1 year after transplant) with renal insufficiency (eGFR 30–60 mL/min/1.73 m²) were randomized to start everolimus with CNI withdrawal (N = 29) or continue their current CNI-based immunosuppression (N = 28). The primary endpoint, change in measured glomerular filtration rate (mGFR) from baseline to year 3, did not differ significantly between both groups (+7.0 mL/min in the everolimus group versus +1.9 mL/min in the CNI group, p = 0.18). In the on-treatment analysis, the difference did reach statistical significance (+9.4 mL/min in the everolimus group versus +1.9 mL/min in the CNI group, p = 0.047). The composite safety endpoint of all-cause mortality, major adverse cardiovascular events, or treated acute rejection was not different between groups. Nonfatal adverse events occurred in 96.6% of patients in the everolimus group and 57.1% in the CNI group (p < 0.001). Ten patients (34.5%) in the everolimus group discontinued the study drug during follow-up due to adverse events. The poor adherence to the everolimus therapy might have masked a potential benefit of CNI withdrawal on renal function.

Influence of tacrolimus metabolism rate on renal function after solid organ transplantation

The calcineurin inhibitor (CNI) tacrolimus (TAC) is an integral part of the immunosuppressive regimen after solid organ transplantation. Although TAC is very effective in prevention of acute rejection episodes, its highly variable pharmacokinetic and narrow therapeutic window require frequent monitoring of drug levels and dose adjustments. TAC can cause CNI nephrotoxicity even at low blood trough levels (4-6 ng/mL). Thus, other factors besides the TAC trough level might contribute to CNI-related kidney injury. Unfortunately, TAC pharmacokinetic is determined by a whole bunch of parameters. However, for daily clinical routine a simple application strategy is needed. To address this problem, we and others have evaluated a simple calculation method in which the TAC blood trough concentration (C) is divided by the daily dose (D). Fast TAC metabolism (C/D ratio < 1.05) was identified as a potential risk factor for an inferior kidney function after transplantation. In this regard, we recently showed a strong association between fast TAC metabolism and CNI nephrotoxicity as well as BKV infection. Therefore, the TAC C/D ratio may assist transplant clinicians in a simple way to individualize the immunosuppressive regimen.