Proteinuria following sirolimus conversion is associated with deterioration of kidney function in liver transplant recipients. Transplantation. 2012;93:1006-1012. [PMID: 22357174 DOI: 10.1097/tp.0b013e31824bbd01]

Management of long-term complications from immunosuppression

This review discusses long-term complications from immunosuppressants after liver transplantation and the management of these complications. Common complications of calcineurin inhibitors include nephrotoxicity and metabolic diseases. Nephrotoxicity can be managed by targeting a lower drug level and/or adding an immunosuppressant of a different class. Metabolic disorders can be managed by treating the underlying condition and targeting a lower drug level. Gastrointestinal adverse effects and myelosuppression are common complications of antimetabolites that are initially managed with dose reduction or discontinuation if adverse events persist. Mammalian targets of rapamycin inhibitors are associated with myelosuppression, proteinuria, impaired wound healing, and stomatitis, which may require dose reduction or discontinuation. Induction agents and agents used for steroid-refractory rejection or antibody-mediated rejection are reviewed. Other rare complications of immunosuppressants are discussed as well.

Essentials of Liver Transplantation in the Setting of Acute Kidney Injury and Chronic Kidney Disease

Kidney dysfunction is common among liver transplant candidates with decompensated cirrhosis and has a major impact on pre- and post-liver transplant survival. Updated definitions of acute kidney injury and criteria for the diagnosis of hepatorenal syndrome allow for early recognition and intervention, including early initiation of vasoconstrictor therapy for hepatorenal syndrome. The rise of the metabolic syndrome and nonalcoholic fatty liver disease as a cause of cirrhosis has coincided with an increase in intrinsic chronic kidney disease recognized in transplant candidates and recipients. Ultimately, the ability to accurately assess kidney function and associated risk is essential to decision-making in the context of transplantation, including selection of candidates for simultaneous liver and kidney transplantation.

Clinical efficacy and safety of sirolimus in systemic lupus erythematosus: a real-world study and meta-analysis

Objective:

To provide real-world data and summarize current clinical evidence on the efficacy and safety of sirolimus in active systemic lupus erythematosus (SLE) patients.

Methods:

This was a prospective real-world clinical study. Included SLE patients should have Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) ⩾ 2. They were treated with sirolimus and followed up regularly. The SLEDAI-2K, Physician Global Assessment (PGA), serological activity indices, and remission of organ manifestations were evaluated. We also performed a meta-analysis to integrate current evidence of sirolimus in SLE.

Results:

A total of 49 patients were included in the final analysis. After treatment, the SLEDAI-2K (6.2 ± 3.1 versus 4.0 ± 3.4, p = 0.001) decreased significantly, and the prednisone dosage was tapered successfully (9.9 ± 8.8 mg/day versus 5.9 ± 4.0 mg/day, p = 0.002). Serological activity indices also improved [complement 3 (C3): 0.690 ± 0.209 g/l versus 0.884 ± 0.219 g/l, p < 0.001; complement 4: 0.105 ± 0.059 g/l versus 0.141 ± 0.069 g/l, p < 0.001; anti-dsDNA antibody, 200 ± 178 IU/ml versus 156 ± 163 IU/ml, p = 0.022]. The remission proportions of arthritis, skin rash, and thrombocytopenia were 100%, 88.8%, and 46.2%, respectively. A total of 41.2% of lupus nephritis (LN) patients achieved renal remission, but the average 24-h urine protein level was not significantly changed. Meta-analysis enrolled five studies with 149 patients included, and revealed similar results regarding the changes of SLEDAI-2K [−3.5 (−5.0, −2.1)], C3 [0.224 (0.136, 0.311) g/l] and daily dosage of prednisone [−12.7 (−19.9, −5.6) mg/day].

Conclusion:

Sirolimus might be effective and tolerated in SLE. The role of sirolimus in LN requires further study.

Everolimus and long-term decline in renal function after liver transplantation: real-life experience with measured GFR

Switching from calcineurin-inhibitors (CNI) to everolimus >6-12-months after liver transplantation (LT) seems inefficient in improving renal function, but whether everolimus halts further renal-function decline compared to low-dose CNI remains unclear. In a retrospective single-center study of everolimus after LT (2008-2016) with routine measured glomerular filtration rates (mGFR; ⁵¹Cr-EDTA- or iohexol clearance), we compared by propensity-score matching everolimus therapy to low-dose CNI therapy. The study comprised 36 patients with everolimus introduced on average 22 months post-LT (range 2-105 months, median follow-up 3.4 years), and 36 matched controls. Everolimus introduction was associated with a mean improvement in mGFR of 7 mL/min up to 1 year (p = .003), restricted to patients switched <1-year post-transplant and at tacrolimus trough levels >5 ng/mL. The differences between the everolimus group and controls in delta-mGFR from baseline to 1 year (7.3 vs 4.3 mL/min, p = .25) or 1-year to last follow-up (-0.8 vs -0.2 mL/min/year, p = .71) were non-significant. Proportions with mGFR decline >3 mL/min/year were similar between groups (11% and 14%, p = 1.00). Everolimus was stopped in three patients (8%), and acute rejection occurred in 17%. In conclusion, despite an early improvement in renal function after everolimus introduction, we found no evidence that everolimus halts the long-term mGFR decline compared to continued low-dose CNI therapy. Due to retrospective design, small sample size and heterogenous characteristics, definite conclusions require prospective studies.

Proteinuria and baseline renal function predict mortality and renal outcomes after sirolimus therapy in liver transplantation recipients

Background

Chronic kidney disease is a significant complication after liver transplantation (LT), but the role of pre-existing renal insufficiency and proteinuria remains unclear among LT recipients receiving sirolimus.

Methods

We assessed the effects of proteinuria and baseline renal function on long-term renal and survival outcomes among 576 LT recipients who received SRL in a medical center between 2005 and 2014. Renal outcomes were the incidences of >50% reduction in their baseline estimated glomerular filtration rate and end stage kidney disease requiring renal replacement therapy. Proteinuria was identified using morning dipstick results (≥30 mg/dL) at baseline and within the first year after the initiation of SRL therapy. A Kaplan-Meier analysis was performed to estimate time to event. Factors associated with the outcomes were determined using the Cox proportional hazards model with a significance level set at P <0.05.

Results

During the study period, renal function deteriorated in 135 (25.3%) patients and 68 (11.8%) patients died. Persistent and new onset proteinuria contributed to a high rate of mortality and the deterioration of renal function (both log-rank tests, P <0.0001). After adjustments, new onset proteinuria within the first year after the initiation of SRL therapy increased the risk of deteriorating renal function, regardless of baseline estimated glomerular filtration rate. Moreover, pre-existing (hazard ratio = 1.91; P <0.001) and new onset diabetes (hazard ratio = 2.34; P <0.0001) were significantly associated with new onset proteinuria among SRL users.

Conclusions

These findings support the effective monitoring and early management of the predictable risks for proteinuria among new SRL users in order to delay the progression of renal disease.

Acute Kidney Disease After Liver and Heart Transplantation

After transplantation of nonrenal solid organs, an acute decline in kidney function develops in the majority of patients. In addition, a significant number of nonrenal solid organ transplant recipients develop chronic kidney disease, and some develop end-stage renal disease, requiring renal replacement therapy. The incidence varies depending on the transplanted organ. Acute kidney injury after nonrenal solid organ transplantation is associated with prolonged length of stay, cost, increased risk of death, de novo chronic kidney disease, and end-stage renal disease. This overview focuses on the risk factors for posttransplant acute kidney injury after liver and heart transplantation, integrating discussion of proteinuria and chronic kidney disease with emphasis on pathogenesis, histopathology, and management including the use of mechanistic target of rapamycin inhibition and costimulatory blockade.

Safety of mTOR inhibitors in adult solid organ transplantation

INTRODUCTION

Mammalian target of rapamycin (mTOR) inhibitors (sirolimus and everolimus) are a class of immunosuppressive drugs approved for solid organ transplantation (SOT). By inhibiting the ubiquitous mTOR pathway, they present a peculiar safety profile. The increased incidence of serious adverse events in early studies halted the enthusiasm as a kidney sparing alternative to calcineurin inhibitors (CNI).

AREAS COVERED

Herein we review mTOR inhibitors safety profile for adult organ transplantation, ranging from acute side effects, such as lymphoceles, delayed wound healing, or cytopenias, to long-term ones which increase morbidity and mortality, such as cancer risk and metabolic profile. Infection, proteinuria, and cutaneous safety profiles are also addressed.

EXPERT OPINION

In the authors' opinion, mTOR inhibitors are a safe alternative to standard immunosuppression therapy with CNI and mycophenolate/azathioprine. Mild adverse events can be easily managed with an increased awareness and close monitoring of trough levels. Most serious side effects are dose- and organ-dependent. In kidney and heart transplantation mTOR inhibitors may be safely used as either low-dose de novo or through early-conversion. In the liver, conversion 4 weeks post-transplantation may reduce long-term chronic kidney disease secondary to calcineurin nephrotoxicity, without increasing hepatic artery/portal vein thrombosis.

Review on immunosuppression in liver transplantation

The optimal level of immunosuppression in solid organ transplantation, in particular for the liver, is a delicate balance between the benefit of preventing rejection and the adverse side effects of immunosuppression. There is uncertainty about when this level is achieved in any individual recipient. Immunosuppression regimens vary between individual centers and changes with time as new agents and data are available. Presently concerns about the adverse side effects of calcineurin inhibitor, the main class of immunosuppressive agents used in liver transplantation (LT), has led to consideration of the use of antibody induction therapies for patients at higher risk of developing adverse side effects. The longevity of the transplanted organ is potentially improved by better management of rejection episodes and special consideration for tailoring of immunosuppression to the individual with viral hepatitis C, hepatocellular carcinoma or pregnancy. This review provides an overview of the current strategies for post LT immunosuppression and discusses modifications to consider for special patient populations.

The Role of mTOR Inhibitors in Liver Transplantation: Reviewing the Evidence

Despite the success of liver transplantation, long-term complications remain, including de novo malignancies, metabolic syndrome, and the recurrence of hepatitis C virus (HCV) and hepatocellular carcinoma (HCC). The current mainstay of treatment, calcineurin inhibitors (CNIs), can also worsen posttransplant renal dysfunction, neurotoxicity, and diabetes. Clearly there is a need for better immunosuppressive agents that maintain similar rates of efficacy and renal function whilst minimizing adverse effects. The mammalian target of rapamycin (mTOR) inhibitors with a mechanism of action that is different from other immunosuppressive agents has the potential to address some of these issues. In this review we surveyed the literature for reports of the use of mTOR inhibitors in adult liver transplantation with respect to renal function, efficacy, safety, neurological symptoms, de novo tumors, and the recurrence of HCC and HCV. The results of our review indicate that mTOR inhibitors are associated with efficacy comparable to CNIs while having benefits on renal function in liver transplantation. We also consider newer dosing schedules that may limit side effects. Finally, we discuss evidence that mTOR inhibitors may have benefits in the oncology setting and in relation to HCV-related allograft fibrosis, metabolic syndrome, and neurotoxicity.

Renal function at two years in liver transplant patients receiving everolimus: results of a randomized, multicenter study

In a 24-month prospective, randomized, multicenter, open-label study, de novo liver transplant patients were randomized at 30 days to everolimus (EVR) + Reduced tacrolimus (TAC; n = 245), TAC Control (n = 243) or TAC Elimination (n = 231). Randomization to TAC Elimination was stopped prematurely due to a significantly higher rate of treated biopsy-proven acute rejection (tBPAR). The incidence of the primary efficacy endpoint, composite efficacy failure rate of tBPAR, graft loss or death postrandomization was similar with EVR + Reduced TAC (10.3%) or TAC Control (12.5%) at month 24 (difference -2.2%, 97.5% confidence interval [CI] -8.8%, 4.4%). BPAR was less frequent in the EVR + Reduced TAC group (6.1% vs. 13.3% in TAC Control, p = 0.010). Adjusted change in estimated glomerular filtration rate (eGFR) from randomization to month 24 was superior with EVR + Reduced TAC versus TAC Control: difference 6.7 mL/min/1.73 m(2) (97.5% CI 1.9, 11.4 mL/min/1.73 m(2), p = 0.002). Among patients who remained on treatment, mean (SD) eGFR at month 24 was 77.6 (26.5) mL/min/1.73 m(2) in the EVR + Reduced TAC group and 66.1 (19.3) mL/min/1.73 m(2) in the TAC Control group (p < 0.001). Study medication was discontinued due to adverse events in 28.6% of EVR + Reduced TAC and 18.2% of TAC Control patients. Early introduction of everolimus with reduced-exposure tacrolimus at 1 month after liver transplantation provided a significant and clinically relevant benefit for renal function at 2 years posttransplant.

Mechanistic target of rapamycin inhibitors in solid organ transplantation: from benchside to clinical use

PURPOSE OF REVIEW

Here, we review recent advances and new insights in mechanistic target of rapamycin (mTOR) biology (signalling pathway, kidney biology and immune system), and recent clinical data on mTOR inhibitors related to solid organ transplantation.

RECENT FINDINGS

The mTOR pathway is a major integrator of signals governing protein and lipid biosynthesis and growth factor-driven cell cycle progression. Recent findings have emphasized a critical role of mTOR in cellular homeostasis with a crucial role in podocyte function. Beyond CD8(+) and regulatory T-cell control, mTOR protein is involved in critical biological functions of T helper cells or dendritic cells. New specific inhibitors of mTORC1/C2 are available and shed new light on mTOR functions. Finally, clinical trials have better defined the use of mTOR inhibitors and emphasized their role in cancer prevention.

SUMMARY

The mTOR pathway is considered as a key integrator of multiple inputs that drives numerous biological processes in cell biology. mTOR inhibitors are potent immunosuppressive drugs for solid organ transplantation. Newly designed specific inhibitors of mTOR complex 1 and 2 offer promising therapeutic effects and a better understanding of the pathway. Many conditions may benefit from mTOR inhibition for a short period, but tolerance of treatment in a chronic setting remains a major concern.

The kidney in pediatric liver transplantation: an updated perspective

CKD continues to detract from the success of improved survival in pediatric liver transplantation, and its presence is likely under recognized. Here we review the literature regarding the prevalence, etiology, and management of renal dysfunction in pediatric liver transplant recipients. Long-term studies suggest the prevalence of CKD to be 25-38% by 5-10 yr post-transplant. While important, sole use of serum creatinine overestimates renal function in this population. Screening for and treatment of persistent proteinuria and hypertension as well as minimization of nephrotoxic insults are the mainstays to delay or prevent CKD progression. Office-based blood pressure measures are less sensitive than ABPM, which is specifically recommended by the American Heart Association for its ability to diagnose masked hypertension in pediatric liver transplant recipients. Long-term risk of CKD is predominantly secondary to CNI toxicity. CNI minimization protocols have shown promise in slowing progression of CKD while maintaining graft function, but large-scale randomized control trials with long-term follow-up are needed.