Calcineurin inhibitors and post-transplant hyperlipidaemias

Haematological Drugs Affecting Lipid Metabolism and Vascular Health

Many drugs affect lipid metabolism and have side effects which promote atherosclerosis. The prevalence of cancer-therapy-related cardiovascular (CV) disease is increasing due to development of new drugs and improved survival of patients: cardio-oncology is a new field of interest and research. Moreover, drugs used in transplanted patients frequently have metabolic implications. Increasingly, internists, lipidologists, and angiologists are being consulted by haematologists for side effects on metabolism (especially lipid metabolism) and arterial circulation caused by drugs used in haematology. The purpose of this article is to review the main drugs used in haematology with side effects on lipid metabolism and atherosclerosis, detailing their mechanisms of action and suggesting the most effective therapies.

The triglyceride to HDL-cholesterol ratio and chronic graft failure in renal transplantation

BACKGROUND

Transplant vasculopathy (TV) is a major contributing factor to chronic graft failure in renal transplant recipients (RTR). TV lesions resemble atherosclerosis in several ways, and it is plausible to believe that some risk factors influence both atherosclerotic plaque formation and formation of TV.

OBJECTIVE

The objective of this prospective longitudinal study was to determine if dyslipidemia reflected by the triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) ratio is prospectively associated with death censored chronic graft failure in RTR.

METHOD

454 prospectively included RTR with a functioning graft for at least one year, were followed for a median of 7 years. RTR were matched based on propensity scores to avoid potential confounding and subsequently the association of the TG/HDL-C ratio with the endpoint chronic graft failure, defined as return to dialysis or re-transplantation, was investigated.

RESULTS

Linear regression analysis showed that concentration of insulin, male gender, BMI and number of antihypertensives predict the TG/HDL-C ratio. Cox regression showed that the TG/HDL-C ratio is associated with chronic graft failure (HR = 1.43, 95%CI = 1.12-1.84, p = 0.005) in competing risk analysis for mortality. Interaction testing indicated that the relationship of the TG/HDL-C ratio with graft failure is stronger in subjects with a higher insulin concentration.

CONCLUSION

Our results demonstrate that the TG/HDL-C ratio has the potential to act as a predictive clinical biomarker. Furthermore, there is a need for closer attention to lipid management in RTR in clinical practice with a focus on triglyceride metabolism.

Interferon-γ-induced HLA Class II expression on endothelial cells is decreased by inhibition of mTOR and HMG-CoA reductase

In organ transplantation, donor‐specific HLA antibody (DSA) is considered a major cause of graft rejection. Because DSA targets primarily donor‐specific human leukocyte antigen (HLA) expressed on graft endothelial cells, the prevention of its expression is a possible strategy for avoiding or salvaging DSA‐mediated graft rejection. We examined the effect of various clinically used drugs on HLA class II expression on endothelial cells. Interferon‐γ (IFN‐γ)‐induced HLA class II DR (HLA‐DR) was downregulated by everolimus (EVR, 49.1% ± 0.8%; P < 0.01) and fluvastatin (FLU, 33.8% ± 0.6%; P < 0.01). Moreover, the combination of EVR and FLU showed a greater suppressive effect on HLA‐DR expression. In contrast, cyclosporine, tacrolimus, mycophenolic acid, and prednisolone did not exhibit any significant suppressive effect. FLU, but not EVR, suppressed mRNA of HLA‐DR. Imaging analysis revealed that HLA‐DR expressed in cytosol or on the cell surface was repressed by EVR (cytosol: 58.6% ± 4.9%, P < 0.01; cell surface: 80.9% ± 4.0%, P < 0.01) and FLU (cytosol: 19.0% ± 3.4%, P < 0.01; cell surface: 48.3% ± 4.8%, P < 0.01). These data indicated that FLU and EVR suppressed IFN‐γ‐induced HLA‐DR expression at the transcriptional and post‐translational level, respectively, suggesting a potential approach for alleviating DSA‐related issues in organ transplantation.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern

BACKGROUND

Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC.

SUMMARY

This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

New frontiers in immunosuppression

Immunosuppressive therapy is arguably the most important component of medical care after lung transplantation. The goal of immunosuppression is to prevent acute and chronic rejection while maximizing patient survival and long-term allograft function. However, the benefits of immunosuppressive therapy must be balanced against the side effects and major toxicities of these medications. Immunosuppressive agents can be classified as induction agents, maintenance therapies, treatments for acute rejection and chronic rejection and antibody directed therapies. Although induction therapy remains an area of controversy in lung transplantation, it is still used in the majority of transplant centers. On the other hand, maintenance immunosuppression is less contentious; but, unfortunately, since the creation of three-drug combination therapy, including a glucocorticoid, calcineurin inhibitor and anti-metabolite, there have been relatively modest improvements in chronic maintenance immunosuppressive regimens. The presence of HLA antibodies in transplant candidates and development of de novo antibodies after transplantation remain a major therapeutic challenge before and after lung transplantation. In this chapter we review the medications used for induction and maintenance immunosuppression along with their efficacy and side effect profiles. We also review strategies and evidence for HLA desensitization prior to lung transplantation and management of de novo antibody formation after transplant. Finally, we review immune tolerance and the future of lung transplantation to limit the toxicities of conventional immunosuppressive therapy.

Efficacy and Safety of Everolimus and Mycophenolic Acid With Early Tacrolimus Withdrawal After Liver Transplantation: A Multicenter Randomized Trial

SIMCER was a 6-mo, multicenter, open-label trial. Selected de novo liver transplant recipients were randomized (week 4) to everolimus with low-exposure tacrolimus discontinued by month 4 (n = 93) or to tacrolimus-based therapy (n = 95), both with basiliximab induction and enteric-coated mycophenolate sodium with or without steroids. The primary end point, change in estimated GFR (eGFR; MDRD formula) from randomization to week 24 after transplant, was superior with everolimus (mean eGFR change +1.1 vs. -13.3 mL/min per 1.73 m² for everolimus vs. tacrolimus, respectively; difference 14.3 [95% confidence interval 7.3-21.3]; p < 0.001). Mean eGFR at week 24 was 95.8 versus 76.0 mL/min per 1.73 m² for everolimus versus tacrolimus (p < 0.001). Treatment failure (treated biopsy-proven acute rejection [BPAR; rejection activity index score >3], graft loss, or death) from randomization to week 24 was similar (everolimus 10.0%, tacrolimus 4.3%; p = 0.134). BPAR was more frequent between randomization and month 6 with everolimus (10.0% vs. 2.2%; p = 0.026); the rate of treated BPAR was 8.9% versus 2.2% (p = 0.055). Sixteen everolimus-treated patients (17.8%) and three tacrolimus-treated patients (3.2%) discontinued the study drug because of adverse events. In conclusion, early introduction of everolimus at an adequate exposure level with gradual calcineurin inhibitor (CNI) withdrawal after liver transplantation, supported by induction therapy and mycophenolic acid, is associated with a significant renal benefit versus CNI-based immunosuppression but more frequent BPAR.

Does African American Race Impact Statin Efficacy in Renal Transplant Outcomes?

There is a lack of studies assessing if race impacts the efficacy of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR) inhibitor ("statin") therapy on renal transplantation (RTx) outcomes. We examined the association between statin therapy and RTx outcomes, while concurrently quantifying the effect modification African American (AA) race has on statin efficacy.This was a retrospective longitudinal cohort study of solitary adult RTx (n = 1176) between June 2005 and May 2013. The Cox proportional hazard model was used to examine the impact of statin therapy on graft loss, death, and acute rejection and determine if significant interactions exist between statin therapy and race. Models were adjusted for demographics, socioeconomic status, cardiovascular history, medication use, and transplant characteristics.AAs (n = 624) and non-African Americans (n = 552) were equally likely to receive statin therapy (P = 0.922). Mean LDL and TGs in AA were 94 mg/dL and 133 mg/dL compared to 90 mg/dL and 163 mg/dL in non-AA, respectively. After adjusting for confounders, high statin users had 52% lower risk of developing graft loss (HR 0.48, 95% CI 0.29-0.80) and a nonstatistically significant reduction in death (HR 0.50, 95% CI 0.23-1.06) compared to low statin users. Acute rejection was not significantly influenced by statin use (HR 0.77 95% CI 0.46-1.27). There was a significant interaction between race and statin therapy for death (P = 0.007), but not for graft loss (P = 0.121) or rejection (P = 0.605). After stratifying by race, high statin use reduced the risk of death in AAs (HR 0.43, 95% CI 0.20-0.94), but not in non-AAs (HR 1.09, 95% CI 0.49-2.44).High statin use reduces the risk of graft loss in RTx, with a mortality benefit in AAs compared to non-AA, despite similar LDL levels. These results suggest a compelling reason to optimize statin therapy in renal transplant recipients (RTR), especially in AAs.

Immunosuppression in lung transplantation

Lung transplantation can be a life-saving procedure for those with end-stage lung diseases. Unfortunately, long term graft and patient survival are limited by both acute and chronic allograft rejection, with a median survival of just over 6 years. Immunosuppressive regimens are employed to reduce the rate of rejection, and while protocols vary from center to center, conventional maintenance therapy consists of triple drug therapy with a calcineurin inhibitor (cyclosporine or tacrolimus), antiproliferative agents [azathioprine (AZA), mycophenolate, sirolimus (srl), everolimus (evl)], and corticosteroids (CS). Roughly 50% of lung transplant centers also utilize induction therapy, with polyclonal antibody preparations [equine or rabbit anti-thymocyte globulin (ATG)], interleukin 2 receptor antagonists (IL2RAs) (daclizumab or basiliximab), or alemtuzumab. This review summarizes these agents and the data surrounding their use in lung transplantation, as well as additional common and novel therapies in lung transplantation. Despite the progression of the management of lung transplant recipients, they continue to be at high risk of treatment-related complications, and poor graft and patient survival. Randomized clinical trials are needed to allow for the development of better agents, regimens and techniques to address above mentioned issues and reduce morbidity and mortality among lung transplant recipients.

Tacrolimus versus cyclosporin as primary immunosuppression for lung transplant recipients

BACKGROUND

Lung transplantation is a well-accepted treatment for people with most end-stage lung diseases. Although both tacrolimus and cyclosporin are used as primary immunosuppressive agents in lung transplant recipients, it is unclear which of these drugs is better in reducing rejection and death without causing adverse effects.

OBJECTIVES

To assess the benefits and harms of tacrolimus versus cyclosporin for primary immunosuppression in lung transplant recipients.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 10 April 2013 through contact with the Trials Search Co-ordinator using search terms relevant to this review. We also searched Science Citation Index Expanded and the Transplant Library to 20 April 2013.

SELECTION CRITERIA

We included all randomised controlled trials (RCT) that compared any dose and duration of administration of tacrolimus versus cyclosporin as primary immunosuppressive treatment in lung transplant recipients. Our selection criteria required that all included patients received the same additional immunosuppressive therapy within each study.

DATA COLLECTION AND ANALYSIS

Three authors extracted data. For dichotomous data we used risk ratio (RR) and used mean difference (MD) for continuous data, each with 95% confidence intervals (CI). Methodological components of the included studies were used to assess risk of systematic errors (bias). Trial sequential analysis was used to assess risk of random errors (play of chance).

MAIN RESULTS

We included three studies that enrolled a total of 413 adult patients that compared tacrolimus with microemulsion or oral solution cyclosporin. All studies were found to be at high risk of bias. Tacrolimus seemed to be significantly superior to cyclosporin regarding the incidence of bronchiolitis obliterans syndrome (RR 0.46, 95% CI 0.29 to 0.74), lymphocytic bronchitis score (MD -0.60, 95% CI -1.04 to -0.16), treatment withdrawal (RR 0.27, 95% CI 0.16 to 0.46), and arterial hypertension (RR 0.67, 95% CI 0.50 to 0.89). However, the finding for arterial hypertension was not confirmed when analysed using a random-effects model (RR 0.54, 95% CI 0.17 to 1.73). Furthermore, trial sequential analysis found that none of the meta-analyses reached the required information sizes and cumulative Z-curves did not cross trial sequential monitoring boundaries. Diabetes mellitus occurred more frequently among people in the tacrolimus group compared with the cyclosporin group when the fixed-effect model was applied (RR 4.24, 95% CI 1.58 to 11.40), but no difference was found when the random-effects model was used for analysis (RR 4.43, 95% CI 0.75 to 26.05). Again, trial sequential analysis found that the required information threshold was not reached and cumulative Z-curve did not cross the trial sequential monitoring boundary. No significant difference between treatment groups was observed regarding mortality (RR 1.06, 95% CI 0.75 to 1.49), incidence of acute rejection (RR 0.89, 95% CI 0.77 to 1.03), numbers of infections/100 patient-days (MD -0.15, 95% CI -0.30 to 0.00), cancer (RR 0.21, 95% CI 0.04 to 1.16), kidney dysfunction (RR 1.41, 95% CI 0.93 to 2.14), kidney failure (RR 1.57, 95% CI 0.28 to 8.94), neurotoxicity (RR 7.06, 95% CI 0.37 to 135.19), and hyperlipidaemia (RR 0.60, 95% CI 0.30 to 1.20). Trial sequential analysis showed the required information thresholds were not reached for any of these outcome measures.

AUTHORS' CONCLUSIONS

Tacrolimus may be superior to cyclosporin regarding bronchiolitis obliterans syndrome, lymphocytic bronchitis, treatment withdrawal, and arterial hypertension, but may be inferior regarding development of diabetes. No difference in mortality and acute rejection was observed between patients treated with tacrolimus and cyclosporin. There were few studies comparing tacrolimus and cyclosporin after lung transplantation, and the numbers of patients and events in the included studies were limited. Furthermore, the included studies were deemed to be at high risk of bias. Hence, more RCTs are needed to assess the results of the present review. Such studies ought to be conducted with low risks of systematic errors (bias) and of random errors (play of chance).

Severe rhabdomyolysis associated with concurrent use of simvastatin and sirolimus after cisplatin-based chemotherapy in a kidney transplant recipient

OBJECTIVES

Cardiovascular disease is the most common cause of sickness and death for long-term kidney transplant recipients, and dyslipidemia is an important risk factor for developing cardiovascular disease. Lipid-lowering strategies, with the use of statins, have been shown to reduce the cardiovascular risks related to dyslipidemia, but concomitant use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors and immunosuppressive agents may increase the risk of rhabdomyolysis owing to a drug-drug interaction. We report a case of simvastatin-induced rhabdomyolysis and acute kidney injury triggered by addition of sirolimus and cisplatin-based chemotherapy to a kidney transplant recipient who had previously tolerated chronic statin therapy.

The novel calcineurin inhibitor CN585 has potent immunosuppressive properties in stimulated human T cells

The Ca2+/calmodulin-dependent protein phosphatase calcineurin is a key mediator in antigen-specific T cell activation. Thus, inhibitors of calcineurin, such as cyclosporin A or FK506, can block T cell activation and are used as immunosuppressive drugs to prevent graft-versus-host reactions and autoimmune diseases. In this study we describe the identification of 2,6- diaryl-substituted pyrimidine derivatives as a new class of calcineurin inhibitors, obtained by screening of a substance library. By rational design of the parent compound we have attained the derivative 6-(3,4-dichloro-phenyl)-4-(N,N-dimethylaminoethylthio)-2-phenyl-pyrimidine (CN585) that noncompetitively and reversibly inhibits calcineurin activity with a K(i) value of 3.8 mum. This derivative specifically inhibits calcineurin without affecting other Ser/Thr protein phosphatases or peptidyl prolyl cis/trans isomerases. CN585 shows potent immunosuppressive effects by inhibiting NFAT nuclear translocation and transactivation, cytokine production, and T cell proliferation. Moreover, the calcineurin inhibitor exhibits no cytotoxicity in the effective concentration range. Therefore, calcineurin inhibition by CN585 may represent a novel promising strategy for immune intervention.

Incidence of adverse events with HMG-CoA reductase inhibitors in liver transplant patients

Transplant patients are at increased risk of developing dyslipidemia, which contributes to coronary artery disease and cardiovascular events. The purpose of this study was to explore documented adverse effects of liver transplant recipients receiving lipid-lowering therapies.

METHODS

A retrospective chart review of 69 liver transplant patients was conducted to evaluate the incidence of adverse effects, especially rhabdomyolysis and liver function abnormalities, in liver transplant patients treated with a lipid lowering agent (LLA). Data were collected from the time of initiation of LLA to 12 months later, looking at the type, dose, and duration of LLA, concurrent cytochrome P450 inhibitors, immunosuppression used, and laboratory parameters.

RESULTS

For HMG-CoA reductase inhibitor therapy, simvistatin was used in five (7.8%) patients, pravastatin in 40 (62.5%), fluvastatin in one (1.6%), atorvastatin in five (7.8%), and lovastatin in three (4.7%). Gemfibrozil, a fibric acid derivative, was employed as monotherapy in 10 (15.6%) of patients. There were five patients who received combination therapy with a fibric acid derivative, four (80%) with gemfibrozil + pravastatin, and one (20%) with gemfibrozil + simvastatin. Six patients studied had adverse effects, five (7.2%) with myalgia and one (1.4%) with myopathy. LLA monotherapy with either pravastatin or atorvastatin was used in these patients. The five patients with myalgia were on concurrent therapy with cyclosporin, and the patient with myopathy was on concurrent cyclosporin + diltiazem therapy, both of which are P450 inhibitors. One out of 23 patients on a non-immunosuppressant P450 inhibitor developed adverse effects. No significant elevation of alanine aminotransferase, aspartate aminotransferase, or alkaline phosphatase was noted in any patient.

CONCLUSIONS

Overall, there was a general tolerability with a low incidence of adverse events, no incidence of severe complications, and no alterations in liver function tests in the study population with the use of LLA.

Genetic analysis of fluvastatin response and dyslipidemia in renal transplant recipients

The Assessment of Lescol in Renal Transplantation clinical trial demonstrated the efficacy of fluvastatin in reducing cardiovascular (CV) disease in renal transplant recipients. The study included a voluntary pharmacogenetic component, enrolling 1,404 patients, which allowed association testing of baseline measures and longitudinal analysis of the 707 fluvastatin-treated and 697 placebo-treated individuals. A candidate gene approach, examining 42 polymorphisms in 18 genes, was used to test for association between selected polymorphisms and major adverse cardiac events, graft failure, change in LDL and HDL cholesterol, and baseline LDL and HDL cholesterol. Reported associations between cholesteryl ester transfer protein (CETP) and baseline HDL cholesterol were replicated, with four previously implicated single nucleotide polymorphisms significantly associated in males and one in females; tests of reported associations between CETP and CV disease yielded varying results. We found no evidence for genetic factors affecting fluvastatin response. Polymorphisms in 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) previously reported to affect the efficacy of pravastatin did not show a similar effect on the reduction of LDL cholesterol by fluvastatin.

Beneficial effect of dl-α-lipoic acid on cyclosporine A induced hyperlipidemic nephropathy in rats

Cyclosporine A (CsA)-induced dyslipidemia is one of the most important risk factors for morbidity and mortality after solid organ transplantation. Reducing this side effect of CsA by dietary agents may be safe, cost-effective, and attractive to both patients and health professionals. Hence the present study was designed to evaluate the role of DL-alpha-Lipoic acid (LA) in deteriorating the lipid abnormalities induced by CsA in rat kidney. Male albino Wistar rats were divided into four groups. CsA administered at a dose of 25 mg/kg body weight, orally for 21 days showed abnormal changes in the levels of lipoprotein fractions (LDL, HDL and VLDL) and lipid profile in both plasma and renal tissue. Significant alterations were also observed in the activities of lipid metabolizing enzymes. Co-treatment with LA (20 mg/kg body weight, oral gavage, for 21 days) reverted the levels of lipid profile (P < 0.001, P < 0.01) and lipoprotein fractions (P < 0.001, P < 0.01) to near control. The activities of lipid metabolizing enzymes also showed considerable restoration on LA supplementation. The outcome of this study provides evidence that LA (a natural metabolic antioxidant) treatment acts as a potent antilipemic agent against CsA-induced lipid abnormalities.

Simvastatin enhances learning and memory independent of amyloid load in mice

OBJECTIVE

Normal aging is often associated with a decline in learning and memory functions. This decline is manifested to a much greater extent in Alzheimer's disease. Recent studies have indicated statins, a class of cholesterol-lowering drugs, as a potential therapy for Alzheimer's disease. Our objective was to determine whether administering a statin drug (simvastatin) would protect against the development of behavioral deficits in an established mouse model of Alzheimer's disease.

METHODS

Tg2576 mice and their nontransgenic littermates were treated with simvastatin and assessed by behavioral tests and biochemical analyses.

RESULTS

Simvastatin treatment not only reversed learning and memory deficits in the Tg2576 mice, but also enhanced learning and memory in the nontransgenic mice. Moreover, levels of amyloid beta protein in the brains of treated mice did not differ from those of untreated mice. Simvastatin treatment was associated with increased expression levels of protein kinase B (Akt) and endothelial nitric oxide synthase in the mouse brain.

INTERPRETATION

Our findings demonstrate that the effects of simvastatin on learning and memory are independent of amyloid beta protein levels. The mechanisms by which simvastatin exerts its beneficial effects may be related to modulation of signaling pathways in memory formation.

Cyclosporine A withdrawal during follow-up after pediatric liver transplantation

It is unclear whether cyclosporine A (CsA) can be withdrawn safely during follow-up after pediatric liver transplantation. In our transplant program we have been using a strict protocol to withdraw CsA. The aim of this study was to retrospectively assess the effects of CsA withdrawal after pediatric liver transplantation on the incidence of rejection and renal function. Between 1986 and 2001, 91 children received CsA for at least 2 yr after liver transplantation. Specific criteria for eligibility to withdraw CsA were set. In 53 of the 91 children CsA was withdrawn. In 35 patients (66%) withdrawal of CsA did not cause rejection. In these patients the renal function improved compared with baseline values (glomerular filtration rate (GFR) at 1 yr, +16 mL/minute/1.73 m3, P < 0.001; at 2 yr, +10 mL/minute/1.73 m3, P < 0.05). After CsA withdrawal, 18 patients developed rejection (34%), which could be effectively treated by methylprednisolone and restarting CsA. Failure to withdraw CsA was not associated with increased incidence of graft loss. A body weight below 10 kg at the time of transplantation correlated significantly with successful withdrawal of CsA (<10 kg, 85% vs. > 10 kg, 60%; P < 0.05). In conclusion CsA can successfully be withdrawn in a major proportion of selected pediatric liver transplantation patients during follow-up. The success rate is the highest in children with a body weight below 10 kg at the time of transplantation. Successful withdrawal improves renal function, whereas failure to withdraw is not associated with graft loss or persisting morbidity.

Efficacy of mycophenolic acid combined with KRP-203, a novel immunomodulator, in a rat heart transplantation model

BACKGROUND

To explore a more effective and less toxic immunosuppressive strategy in organ transplantation, we recently developed the novel sphingosine-1-phosphate receptor agonist KRP-203. This study examined the efficacy of KRP-203 combined with mycophenolic acid (MPA), an active metabolite of mycophenolate mofetil, in rat heart allografts.

METHODS

Heterotopic heart transplantation was performed in a rat combination of DA (MHC haplotype: RT1(a)) to Lewis (RT1). The recipients were divided into 12 groups (n = 5-7): Syngeneic (Lewis to Lewis), Vehicle, KRP-203 (0.3 and 1 mg/kg), MPA (10 and 20 mg/kg), 10 mg/kg MPA with KRP-203 (0.03, 0.3, 1, and 3 mg/kg), and 20 mg/kg MPA with KRP-203 (0.3 and 1 mg/kg). MPA, KRP-203, and vehicle were given orally.

RESULTS

The mean days of survival were 5.8 (vehicle), 7 and 7.9 (0.3 and 1 mg/kg KRP-203, respectively), 12.7 and >54.4 (10 and 20 mg/kg MPA), >39.6 and >30.5 (10 mg/kg MPA with 1 and 3 mg/kg KRP-203), >100 and >87.8 (20 mg/kg MPA with 0.3 and 1 mg/kg KRP-203). Histologic and immunohistochemical analysis revealed that diffuse mononuclear cell infiltration (macrophages and T cells), hemorrhage, myocardial necrosis and fibrosis, and expression of endothelin-1, transforming growth factor-beta1, monocyte chemoattractant protein-1, interleukin-8, and E-selectin were markedly diminished in the allografts treated with MPA combined with KRP-203. Pharmacokinetic experiments indicated no interaction between MPA and KRP-203, and both combination regimens were well tolerated.

CONCLUSIONS

Combination therapy of MPA with KRP-203 has a therapeutic potential as a novel immunosuppressant strategy in clinical transplantation.

Long-term cardiac outcomes in renal transplant recipients receiving fluvastatin: the ALERT extension study

Renal transplant recipients (RTR) have an increased risk of premature cardiovascular disease. The ALERT study is the first trial to evaluate the effect of statin therapy on cardiac outcomes following renal transplantation. Patients initially randomized to fluvastatin or placebo in the 5-6 year ALERT study were offered open-label fluvastatin XL 80 mg/day in a 2-year extension to the original study. The primary endpoint was time to first major adverse cardiac event (MACE). Of 1787 patients who completed ALERT, 1652 (92%) were followed in the extension. Mean total follow-up was 6.7 years. Mean LDL-cholesterol was 98 mg/dL (2.5 mmol/L) at last follow-up compared to a pre-study level of 159 mg/dL (4.1 mmol/L). Patients randomized to fluvastatin had a reduced risk of MACE (hazards ratio [HR] 0.79, 95% CI 0.63-0.99, p = 0.036), and a 29% reduction in cardiac death or definite non-fatal MI (HR 0.71, 95% CI 0.55-0.93, p = 0.014). Total mortality and graft loss did not differ significantly between groups. Fluvastatin produces a safe and effective reduction in LDL-cholesterol associated with reduced risk of MACE in RTR. The lipid-lowering and cardiovascular benefits of fluvastatin are comparable to those of statins in other patient groups, and support use of fluvastatin in RTR.

Fluvastatin in the treatment of dyslipidemia associated with chronic kidney failure and renal transplantation

Premature atherosclerotic coronary heart disease driven by multiple risk factors is a major cause of morbidity and mortality among the 6 million patients in the United States with chronic renal failure. Consensus is that kidney failure and renal transplantation patients should be treated aggressively for dyslipidemia. Major medical literature databases were searched for published information about fluvastatin, a HMG-CoA reductase inhibitor, used in patients with impaired renal function. This article characterizes the dyslipidemia observed in these clinical settings and reviews the clinical experience with fluvastatin.

Role of apolipoprotein E epsilon 4 allele on chronic allograft nephropathy after renal transplantation

Lipid abnormalities may contribute to chronic allograft nephropathy (CAN). Apolipoprotein E (ApoE) gene polymorphism regulates lipoprotein metabolism, but little is known about an association between CAN and this polymorphism. The ApoE gene (E3/E4) polymorphism was typed by PCR assay (99 E3/E3, 28 E3/E4, 1 E4/E4) on 128 consecutive renal transplant patients with functioning grafts for more than 3 years (6.7 +/- 2.8 years). Twenty-eight patients with histological CAN were compared with 100 patients who had no clinical evidence of chronic rejection (no proteinuria and sCr < 2.5 mg%). As expected, univariate analysis revealed that patients with CAN experienced a greater acute rejection rate (78% vs 21%; P=.001), a higher serum creatinine (3.6 +/- 1.7 vs 1.4 +/- 0.5 mg%; P=.0001), and an older organ donor (43 +/- 20 vs 29 +/- 13 years; P=.0001). The lipid profiles (total cholesterol and triglycerides levels) were similar in both groups with 60% in each group receiving anti-lipemic drugs. Interestingly, the ApoE epsilon 4 allele was overrepresented in the group with CAN (39% vs 17%, P=.019). Logistic regression analysis showed that the epsilon 4 allele was an independent predictor of CAN (OR: 3.4; CI 95%: 1.07 to 11; P=.040) as were donor age and acute rejection episodes. In conclusion, an interaction between risk factors and genetic factors may determine CAN in this population. This finding may help to target prophylactic interventions in these recipients.

Conversion from cyclosporine A to mycophenolate mofetil protects recipient kidney and prevents intimal hyperplasia in rat aortic allografts

BACKGROUND

Recent studies have demonstrated that complete conversion from cyclosporine A (CsA) to mycophenolate mofetil (MMF) prolongs graft survival in patients undergoing clinical organ transplantation. We investigated the effects of conversion from CsA to MMF on recipient kidneys and transplant arteriosclerosis in a rat aortic allograft model as a high responder combination.

METHODS

DA (MHC haplotype, RT1a) rat abdominal aortic grafts were orthotopically transplanted into Lewis (RT1l) rats. The recipients were divided into four oral treatment groups: (1) vehicle group, (2) CsA group (15 mg/kg/day), (3) CsA/MMF40 group (conversion from CsA 15 mg/kg/day to MMF 40 mg/kg/day on day 14), and (4) CsA/MMF20 group (conversion from CsA 15 mg/kg/day to MMF 20 mg/kg/day on day 14). On day 28 after transplantation, the rats were sacrificed and the hematoserological parameters were analyzed. The grafted aortas and recipient kidneys also were evaluated histologically and immunohistochemically.

RESULTS

The CsA group developed serological renal dysfunction, arteriolar hyalinosis, and apoptosis in the recipient kidneys, whereas the CsA/MMF40 and CsA/MMF20 groups did not. In the vehicle group, we observed remarkable intimal hyperplasia and marked inflammatory cell infiltration including macrophages and T cells. In the CsA group, intimal hyperplasia was evident without infiltration of macrophages or T cells. In the CsA/MMF40 and CsA/MMF20 groups, intimal hyperplasia was abrogated, while adventitial infiltration of and adhesion to the endothelium by macrophages and T cells occurred.

CONCLUSIONS

Conversion from CsA to MMF protected recipient kidneys and prevented transplant arteriosclerosis. However, insufficient immunosuppression by MMF might reactivate immune cells. This conversion therapy has preventive potential in transplant patients with CsA-associated nephrotoxicity and transplant arteriosclerosis.

Tacrolimus and steroids versus ciclosporin microemulsion, steroids, and azathioprine in children undergoing liver transplantation: randomised European multicentre trial

BACKGROUND

Results of studies in adult recipients of liver allograft suggest that tacrolimus is more efficacious than ciclosporin microemulsion in the prevention of acute rejection. We aimed to compare these drugs in children undergoing liver transplantation.

METHODS

This 12-month multicentre, open-label, parallel-group, randomised study compared a dual tacrolimus regimen (tacrolimus/corticosteroids, n=93) with a triple ciclosporin microemulsion regimen (ciclosporin microemulsion/corticosteroids/azathioprine, n=92) in children who had had liver transplants (age < or =16 years, bodyweight < or =40 kg). Initial oral daily doses were 0.30 mg/kg for tacrolimus and 10 mg/kg for ciclosporin microemulsion. Primary endpoint was the incidence of and time to first histologically proven acute rejection. We excluded patients from analysis if they did not receive the study drug, or were given incorrect medication. Otherwise patients were analysed in accordance with their random treatment allocation, irrespective of whether they switched medication during the trial.

FINDINGS

Median age was 22 months (IQR 9-56) in the tacrolimus group and 17 months (9-54) in the ciclosporin microemulsion group. We noted no difference between treatment groups with respect to patient survival (93.4% vs 92.2%; p=0.77) or graft survival (92.3% vs 85.4%; p=0.16) at month 12 after transplant. The acute rejection free rate at study end (Kaplan-Meier method) was 55.5% for patients on tacrolimus and 40.2% for patients on ciclosporin microemulsion (p=0.0288). The Kaplan-Meier estimate of patients free from corticosteroid-resistant acute rejection at study end was 94.0% for tacrolimus-treated patients and 70.4% for ciclosporin-microemulsion-treated patients (p<0.0001). Overall, incidence of adverse events did not differ between groups.

INTERPRETATION

Tacrolimus is a safe and effective treatment for the prevention of rejection after liver transplantation in children.

Janus kinase-3 (JAK3) inhibition: a novel immunosuppressive option for allogeneic transplantation

Current immunosuppressive therapy in clinical organ transplantation is based on drugs that suppress various functions of immunocompetent cells but still affect cells and organ compartments other than the immune system. Hence, these drugs have considerable side effects which lead to increased morbidity and reduced life-quality of transplant recipients. A major step forward in the rationale design of clinical immunosuppression resides in the elucidation of molecular targets that play a critical role specifically within the immune system. Recently, Janus kinase 3 (JAK3) has been identified as such a molecule. Genetic absence or ablation of this tyrosine kinase is associated with defective T-cell immunity that results in severe combined immunodeficiency (SCID) without apparent changes in other organ systems. Furthermore, pharmacological inhibition has significantly prolonged allograft survival in several experimental models of organ transplantation. The present review provides an overview of the emerging role of JAK3 in the immune system and the development of JAK3-inhibiting drugs. The potential clinical application of JAK3 inhibitors in organ transplantations is discussed in the light of a recent series of successful kidney transplantations in non-human primates immunosuppressed solely with a novel JAK3 inhibitor.

Mécanismes des hyperlipidémies dues aux immunosuppresseurs

This article summarises the mechanisms responsible for the hyperlipidaemia observed after immunosuppressive treatment. Much progress has been achieved in the treatment of organ transplantation over the last 10 years, in particular because of the use of new immunosuppressive drugs with less nephrotoxicity. However, hypercholesterolaemia and hypertriglyceridaemia persist among many patients, who are thus more likely to develop cardiovascular diseases. We first reviewed the effects of immunosuppressive drugs on biliary acid biosynthesis, which is the main pathway of cholesterol degradation. The inhibition of this biosynthesis pathway, and especially of some key cytochrome P450s (CYP) such as CYP27A1, could contribute to the increased cholesterolaemia. Immunosuppressive drugs may also modify the activity of lipoprotein receptors or the expression of different apolipoproteins involved in cholesterol and triglyceride transport by lipoproteins. Finally, the fact that hypertriglyceridaemia is more frequently observed after certain immunosuppressive treatments may be partly caused by changes in the synthesis and elimination of triglycerides involving lipoprotein lipase or some apolipoproteins which serve as its cofactors (apoCII or apoCIII).

Cyclosporine A-induced reduction of bile salt synthesis associated with increased plasma lipids in children after liver transplantation

Hyperlipidemia is a common side effect of cyclosporine A (CsA) after solid organ transplantation. CsA also markedly reduces the synthesis rate of bile salts in rats and can inhibit biliary bile salt secretion. It is not known, however, whether CsA inhibits the synthesis of bile salts in humans, and whether the hyperlipidemic effects of CsA are related to bile salt metabolism. Our objective was to assess the effects of CsA on the synthesis rate of bile salts and on plasma triglycerides and cholesterol levels in pediatric liver transplant patients. Before and after discontinuation of CsA treatment after liver transplantation, synthesis rate and pool size of the primary bile salts cholate and chenodeoxycholate were determined using a stable isotope dilution technique and related to plasma lipids. In 6 children (age: 3-16 years) CsA treatment was discontinued at 2 years (median 2.3 years) after liver transplantation. Discontinuation of CsA increased synthesis rate of chenodeoxycholate (+38%, P <.001) and cholate (+21%, P <.05) and the pool size of chenodeoxycholate (+54%, P <.001). Discontinuation of CsA decreased plasma levels of cholesterol (-18%, P <.05) and triglycerides (-23%, P <.05). Bile salt synthesis rate appeared to be inversely correlated with plasma cholesterol (Spearman rank correlation coefficient [r(s)] = -0.82, P <.01) and plasma triglyceride levels (r(s) = -0.62, P <.05). In conclusion, CsA inhibits bile salt synthesis and increases plasma concentration of cholesterol and triglycerides in pediatric liver transplant patients. Suppression of bile salt synthesis by long-term CsA treatment may contribute to hyperlipidemia and thus to increased risk for cardiovascular disease.

Experience with cyclosporine in the Canary Islands

Cyclosporine (CsA) is currently the basis of most immunosuppressive protocols after solid organ transplantation. The introduction of Neoral, a new microemulsion formulation of CsA, and more recently a range of adjunctive immunosuppressants have further enhanced short-term efficacy and tolerability of CsA-based immunosuppression. In addition, Neoral C2 monitoring has been shown to have advantages not only in the early posttransplant period, but also for maintenance transplant patients. The major long-term disadvantage associated with CsA is the development of nephrotoxicity and chronic allograft nephropathy (CAN), which is the second major cause of graft failure. Thus, strategies to reduce the risk of CAN include CsA-sparing protocols, use of C2 level monitoring, introduction of non-nephrotoxic adjunctive immunosuppressants, and optimal management of additional risk factors. Other important side effects related to CsA-based immunosuppression include hypertension, diabetes, and hyperlipidemia. Optimal management of these conditions may lead to significant reduction of cardiovascular-related morbidity and mortality following solid organ transplantation.

Calreticulin is an upstream regulator of calcineurin

Ca(2+) is a signalling molecule involved in virtually every aspect of cell function. The endoplasmic reticulum (ER) is an important and dynamic organelle responsible for storage of the majority of intracellular Ca(2+). Within the ER lumen are proteins that function as Ca(2+) buffers and/or molecular chaperones including calreticulin, a multifunctional Ca(2+)-binding protein. Calreticulin-deficiency is lethal in utero due to impaired cardiac development. In the absence of calreticulin Ca(2+) storage capacity in the ER and InsP(3) receptor mediated Ca(2+) release from ER are compromised. Remarkably, over-expression of constitutively active calcineurin in the hearts of calreticulin deficient mice rescues them from embryonic lethality and produces live calreticulin deficient animals. These observations provide first evidence that calreticulin is a key upstream regulator of calcineurin in the Ca(2+)-signalling cascade and they highlight the importance of ER during early stages of cellular commitment and tissue development during organogenesis.

Cardiovascular risk profile in nondiabetic renal transplant patients: cyclosporine versus tacrolimus

Calcineurin inhibitors (CIs) contribute to cardiovascular risk (CR) in renal transplant (RT) patients. However, the CR profile in RT patients without preexistent diabetes is not well known. We compared CR factors in 191 nondiabetic RT recipients with functioning grafts beyond 1 year, receivingly either CsA (Neoral; n=100) or tacrolimus (Tac; n= 91). Clinical data and pretransplant CR profiles were similar in both groups. There were no differences in acute rejection episodes and graft survival rates during follow-up. The overall proportions of posttransplant diabetes (9% versus 6%), and of hypertension (73% vs 63%) were similar in both groups. Hyperlipidemia was more frequent in the CsA group (58% vs 31%; P=.0001). The cholesterol levels in the CsA group showed at 3 months (232+/-47 vs 202+/-42 m/dL; P=.0001), 6 months (232+/-49 vs 205+/-41 mg/dL; P=.0001), and 12 months (217+/-50 vs 202+/-40 mg/dL; P=.028), despite receiving a greater proportion of lipid-lowering drugs (49% vs 15%; P=.0001). Logistic regression analysis showed that CsA was an independent predictor of posttransplant hyperlipidemia (OR: 5.8, CI 95%; 3.3-10.7; P=.0001) as were age, female gender, pretransplant dyslipidemia, and body mass index (BMI). Interestingly, an interaction was observed between pretransplant BMI and CIs: Among pretransplant normal weight patients (BMI <25 kg/m2), CsA produced a greater incidence of hyperlipidemia than tacrolimus (58% vs 23%; P=.0001) while not among patients who were overweight (BMI >25 kg/m2: pretransplant 58% vs 42%; P=.341). In conclusion, CsA confers a higher risk of hyperlipidemia after RT in nondiabetic patients, particularly those with normal pretransplant weight.