A comparison of tacrolimus and cyclosporine in liver transplantation: effects on renal function and cardiovascular risk status

Minimizing Metabolic and Cardiac Risk Factors to Maximize Outcomes After Liver Transplantation

Cardiovascular disease (CVD) is a leading complication after liver transplantation and has a significant impact on patients' outcomes posttransplant. The major risk factors for post-liver transplant CVD are age, preexisting CVD, nonalcoholic fatty liver disease, chronic kidney disease, and metabolic syndrome. This review explores the contemporary strategies and approaches to minimizing cardiometabolic disease burden in liver transplant recipients. We highlight areas for potential intervention to reduce the mortality of patients with metabolic syndrome and CVD after liver transplantation.

Immunosuppressive calcineurin inhibitor cyclosporine A induces proapoptotic endoplasmic reticulum stress in renal tubular cells

Current immunosuppressive strategies in organ transplantation rely on calcineurin inhibitors cyclosporine A (CsA) or tacrolimus (Tac). Both drugs are nephrotoxic, but CsA has been associated with greater renal damage than Tac. CsA inhibits calcineurin by forming complexes with cyclophilins, whose chaperone function is essential for proteostasis. We hypothesized that stronger toxicity of CsA may be related to suppression of cyclophilins with ensuing endoplasmic reticulum (ER) stress and unfolded protein response (UPR) in kidney epithelia. Effects of CsA and Tac (10 µM for 6 h each) were compared in cultured human embryonic kidney 293 (HEK 293) cells, primary human renal proximal tubule (PT) cells, freshly isolated rat PTs, and knockout HEK 293 cell lines lacking the critical ER stress sensors, protein kinase RNA-like ER kinase or activating transcription factor 6 (ATF6). UPR was evaluated by detection of its key components. Compared with Tac treatment, CsA induced significantly stronger UPR in native cultured cells and isolated PTs. Evaluation of proapoptotic and antiapoptotic markers suggested an enhanced apoptotic rate in CsA-treated cells compared with Tac-treated cells as well. Similar to CsA treatment, knockdown of cyclophilin A or B by siRNA caused proapoptotic UPR, whereas application of the chemical chaperones tauroursodeoxycholic acid or 4-phenylbutyric acid alleviated CsA-induced UPR. Deletion of protein kinase RNA-like ER kinase or ATF6 blunted CsA-induced UPR as well. In summary, inhibition of cyclophilin chaperone function with ensuing ER stress and proapoptotic UPR aggravates CsA toxicity, whereas pharmacological modulation of UPR bears potential to alleviate renal side effects of CsA.

Calcineurin Inhibitors Nephrotoxicity Prevention Strategies With Stress on Belatacept-Based Rescue Immunotherapy: A Review of the Current Evidence

BACKGROUND

A traditional narrative review was performed to evaluate clinical studies that have examined the clinical implications, risk factors, and prevention of calcineurin inhibitors (CNIs) nephrotoxicity with stress on a belatacept-based rescue regimen.

METHODS

The Cochrane Library, PubMed/MEDLINE, EBSCO (Academic Search Ultimate), ProQuest (Central), and Excerpta Medical databases and Google scholar were searched using the keywords (CNI AND Nephrotoxicity prevention) OR ("Calcineurin inhibitor" AND Nephrotoxicity) OR (Tacrolimus AND Nephrotoxicity) OR (Ciclosporin AND Nephrotoxicity) OR (cyclosporine AND Nephrotoxicity) OR (Belatacept) OR (CNI Conversion) for the period from 1990 to 2020. Fifty-five related articles and reviews were found.

CONCLUSION

A better understanding of the mechanisms underlying calcineurin inhibitor nephrotoxicity could help in the individualization of therapy for and prevention of CNI nephrotoxicity. Identification of high-risk patients for CNI nephrotoxicity before renal transplantation enables better use and selection of immunosuppression with reduced adverse effects and, eventually, successful treatment of the kidney recipients. Belatacept conversion is a good and safe option in patients with deteriorating renal function attributed to CNI nephrotoxicity.

Metabolic syndrome following liver transplantation in nonalcoholic steatohepatitis

Metabolic syndrome is a major clinical disorder involving metabolic dysregulation characterized clinically with features of central obesity, insulin resistance (IR), type 2 diabetes, hypertension, and dyslipidemia. Metabolic syndrome is strongly associated with the rising prevalence nonalcoholic steatohepatitis, a leading indication for orthotopic liver transplantation in the Western world. The presence or recurrence of metabolic syndrome following liver transplantation can contribute to the development and recurrence of nonalcoholic fatty liver disease (NAFLD) in the liver allograft. In this review, we discuss the endogenous and exogenous drivers of post-transplant metabolic syndrome, role of chronic immunosuppression, and the prevalence and clinical significant of post-transplant metabolic syndrome on nonalcoholic steatohepatitis.

Clinical significance of personalized tacrolimus dosing by adjusting to donor CYP3A-status in liver transplant recipients

Donor's CYP3A-status (CYP3A5 genotype and CYP3A4 expression) can provide prognostic information regarding tacrolimus-metabolizing capacity of the liver graft and initial tacrolimus dosing for therapeutic blood concentrations in liver transplants. The present work prospectively investigated whether CYP3A-status guided tacrolimus therapy has any potential clinical benefit for recipients in the early postoperative period.

METHODS

The contribution of preliminary assaying of donor CYP3A-status to the optimization of initial tacrolimus therapy and to the reduction of adverse events (acute rejection, infection, nephrotoxicity) was investigated in 112 liver transplant recipients (CYPtest group) comparing to 101 control patients on tacrolimus concentration guided therapy.

RESULTS

The time for achieving therapeutic tacrolimus concentration was significantly reduced, confirming potential benefit of initial tacrolimus therapy adjusted to donor's CYP3A-status over classical clinical practice of tacrolimus concentration guided treatment (4 vs 8 days, P < 0.0001). Acute rejection episodes (3.6 vs 23.8%, P < 0.0001) and tacrolimus induced nephrotoxicity (8 vs 27%, P = 0.0004) were less frequent in CYPtest group than in control patients, whereas occurrence of infectious disease was not influenced by tacrolimus dosing strategy (3.6 vs 5.9% in CYPtest and control groups, P > 0.05). Acute rejection was often accompanied with tacrolimus blood concentrations lower than 10 ng mL^-1 (20/24 of control and 2/4 of CYPtest patients), while nephrotoxicity was associated with high tacrolimus concentrations (>20 ng mL^-1 ) in the first week after transplantation (13/27 of control and 2/9 of CYPtest patients).

CONCLUSION

CYP3A-status guided therapy significantly improved the risk of misdosing induced early adverse effects (acute rejection, nephrotoxicity).

Neurologic Toxicities Associated with Tumor Necrosis Factor Inhibitors and Calcineurin Inhibitors

The calcineurin inhibitors cyclosporine and tacrolimus are used for their immunosuppressive effects. Neurotoxic side effects include tremor, paresthesia, and headache. Rarer neurotoxicities include seizure, posterior reversible encephalopathy syndrome, and encephalopathy. Tacrolimus tends to be more neurotoxic than cyclosporine. Management of toxicities associated with calcineurin inhibitors includes dose reduction, switching between calcineurin inhibitors, or switching to a calcineurin-free regimen. Tumor necrosis factor (TNF) inhibitors are used in autoimmune diseases. Management of demyelinating conditions among patients treated with anti-TNF should follow standard of care and withdrawal of the anti-TNF. This drug class should be avoided in patients with a history of demyelinating conditions.

Correlation between Cyclosporine Blood Levels and Area under Blood Concentration Time Curve in Iraqi Bone Marrow Transplant Patients Treated with Neoral® Oral Solution

Cyclosporine is a potent immunosuppressive drug. It has a narrow therapeutic index, and therefore the measurement of cyclosporine’s blood concentration is essential to obtain optimal therapy. Measurement of the area under the blood concentration-time curve (AUC) is reflective of total drug exposure. However, for organ transplant patients, the measurement of AUC involves many problems and difficulties. Thus, it is more clinically acceptable to use a single blood sample as a surrogate index of total drug exposure. Fifty-four adults bone marrow transplant Iraqi patients were given cyclosporine every 12 h as prophylaxis using Neoral® oral solution. Steady-state blood concentrations were monitored for each patient at zero time and then at 1, 2, 3, 4, 6, 8, 10, and at 12 h post-dosing. Cyclosporine blood levels were determined by using AXSYM automated immuno-analyzer which is a fluorescence polarization immunoassay (FPIA). The present investigation demonstrated the best correlation between C2 and the corresponding AUC0–4h and AUC0–12h compared to other concentrations. After two months of cyclosporine therapy, no unexpected biochemical changes and adverse effects were registered. It is concluded from this study that a single blood sample obtained at 2 h post-dosing (C2) and possibly at 3 h post dosing (C3) are ideal surrogate indexes for reflecting total drug exposure, and therefore may be used in clinical practice for predicting therapeutic and toxic effects of cyclosporine.

High prevalence of early atherosclerotic and cardiac damage in patients undergoing liver transplantation: Preliminary results

Liver transplanted patients are at high risk of metabolic syndrome and its complications. We aimed to prospectively evaluate the early onset of cardiovascular alterations in patients submitted to the transplant waiting list. From January 2014 to January 2016, 54 out of 79 patients on the waiting list with decompensated cirrhosis or hepatocellular-carcinoma received the transplant, 50 were followed for 24 months, 2 died post-surgery and 2 were lost to follow-up. A significantly increased prevalence of visceral adiposity (epicardial adipose tissue thickness (p = 0.001) and worsening of carotid damage (p = 0.003) and diastolic dysfunction (E/A p = 0.001) was observed at 6 months after transplant and remained stable at 24 months, corresponding to an increased prevalence of diabetes, metabolic syndrome, hypertension and dyslipidemia. The duration of steroid therapy, withdrawn in the majority of patients at 3 months, did not influence cardiovascular damage. No significant difference in early progression of cardiovascular damage was observed between patients who did or did not receive a graft with steatosis. CONCLUSION: The occurrence of early cardiovascular alterations in the first 6 months after OLT accounts for the reported cardiovascular events in the first years after transplant. In light of these results, new strategies aimed at preventing or delaying cardiovascular alterations should be provided, starting from the first weeks after transplant.

Antitumor pharmacotherapy of colorectal cancer in kidney transplant recipients

Renal transplantation has become the sole most preferred therapy modality for end-stage renal disease patients. The growing tendency for renal transplants, and prolonged survival of renal recipients, have resulted in a certain number of post-transplant colorectal cancer patients. Antitumor pharmacotherapy in these patients is a dilemma. Substantial impediments such as carcinogenesis of immunosuppressive drugs (ISDs), drug interaction between ISDs and anticancer drugs, and toxicity of anticancer drugs exist. However, experience of antitumor pharmacotherapy in these patients is limited, and the potential risks and benefits have not been reviewed systematically. This review evaluates the potential impediments, summarizes current experience, and provides potential antitumor strategies, including adjuvant, palliative, and subsequent regimens. Moreover, special pharmaceutical care, such as ISDs therapeutic drug monitoring, metabolic enzymes genotype, and drug interaction, are also highlighted.

Clinical aspects of tacrolimus use in paediatric renal transplant recipients

The calcineurin inhibitor tacrolimus, cornerstone of most immunosuppressive regimens, is a drug with a narrow therapeutic window: underexposure can lead to allograft rejection and overexposure can result in an increased incidence of infections, toxicity and malignancies. Tacrolimus is metabolised in the liver and intestine by the cytochrome P450 3A (CYP3A) isoforms CYP3A4 and CYP3A5. This review focusses on the clinical aspects of tacrolimus pharmacodynamics, such as efficacy and toxicity. Factors affecting tacrolimus pharmacokinetics, including pharmacogenetics and the rationale for routine CYP3A5*1/*3 genotyping in prospective paediatric renal transplant recipients, are also reviewed. Therapeutic drug monitoring, including pre-dose concentrations and pharmacokinetic profiles with the available "reference values", are discussed. Factors contributing to high intra-patient variability in tacrolimus exposure and its impact on clinical outcome are also reviewed. Lastly, suggestions for future research and clinical perspectives are discussed.

Risk factors for arterial hypertension after liver transplantation

Arterial hypertension represents a common complication of immunosuppressive therapy after liver transplantation (LT). The aim of the study is to evaluate the prevalence and risk factors associated with hypertension after LT. From a cohort of 323 cirrhotic patients who underwent LT from 2008 to 2012, 270 patients were retrospectively evaluated, whereas 53 (16.4%) patients deceased. Hypertension was defined as blood pressure ≥140/90 mm Hg in at least two visits and/or the need for antihypertensive therapy. The prevalence of hypertension was 15% before LT and significantly increased up to 53% after LT (P < .001). Mean follow-up was 43 ± 19 months. In normotensive (NT) subjects at baseline, 35.9% developed sustained hypertension after LT, whereas 15.2% developed transient hypertension within the first month after LT, and then returned NT. The development of sustained hypertension after LT was related to the mammalian target of rapamycin inhibitor treatment (odds ratio [OR], 4.02; 95% confidence interval [CI], 1.26-13.48; P = .02), alcoholic cirrhosis before LT (OR, 3.38; 95% CI, 1.44-8.09; P = .005), and new-onset hepatic steatosis after LT (OR, 2.13; 95% CI, 1.10-4.11; P = .02). Tacrolimus, the etiology and severity of liver disease, and other immunosuppressive regimens were not related to the development of hypertension after LT. In our cohort, the prevalence of arterial hypertension has increased up to 53% after LT, and metabolic comorbidities and immunosuppressive treatment with mammalian target of rapamycin inhibitors are the risk factors for the development of hypertension after LT.

Impact of comorbidity on waiting list and post-transplant outcomes in patients undergoing liver retransplantation

AIM

To determine the impact of Charlson comorbidity index (CCI) on waiting list (WL) and post liver retransplantation (LRT) survival.

METHODS

Comparative study of all adult patients assessed for primary liver transplant (PLT) (n = 1090) and patients assessed for LRT (n = 150), 2000-2007 at our centre. Demographic, clinical and laboratory variables were recorded.

RESULTS

Median age for all patients was 53 years and 66% were men. Median model for end stage liver disease (MELD) score was 15. Median follow-up was 7-years. For retransplant patients, 84 (56%) had ≥ 1 comorbidity. The most common comorbidity was renal impairment in 66 (44.3%). WL mortality was higher in patients with ≥ 1 comorbidity (76% vs 53%, P = 0.044). CCI (OR = 2.688, 95%CI: 1.222-5.912, P = 0.014) was independently associated with WL mortality. Patients with MELD score ≥ 18 had inferior WL survival (Log-Rank 6.469, P = 0.011). On multivariate analysis, CCI (OR = 2.823, 95%CI: 1.563-5101, P = 0.001), MELD score ≥ 18 (OR 2.506, 95%CI: 1.044-6.018, P = 0.04), and requirement for organ support prior to LRT (P < 0.05) were associated with reduced post-LRT survival. Donor/graft parameters were not associated with survival (P = NS). Post-LRT mortality progressively increased according to the number of transplanted grafts (Log-Rank 18.455, P < 0.001). Post-LRT patient survival at 1-, 3- and 5-years were significantly inferior to those of PLT at 88% vs 73%, P < 0.001, 81% vs 71%, P = 0.018 and 69% vs 55%, P = 0.006, respectively.

CONCLUSION

Comorbidity increases WL and post-LRT mortality. Patients with MELD ≥ 18 have increased WL mortality. Patients with comorbidity or MELD ≥ 18 may benefit from earlier LRT. LRT for ≥ 3 grafts may not represent appropriate use of donated grafts.

A Review of Organ Transplantation: Heart, Lung, Kidney, Liver, and Simultaneous Liver-Kidney

Heart, lung, kidney, liver, and simultaneous liver-kidney transplants share many features. They all follow the same 7-step process, the same 3 immunosuppressant medications, and the same reason for organ transplantation. Organs are transplanted because of organ failure. The similarities end there. Each organ has its unique causes for failure. Each organ also has its own set of criteria that must be met prior to transplantation. Simultaneous liver-kidney transplant criteria vary per transplant center but are similar in nature. Both the criteria required and the 7-step process are described by the United Network of Organ Sharing, which is a private, nonprofit organization, under contract with the US Department of Health and Human Services. Its function is to increase the number of transplants, improve survival rates after transplantation, promote safe transplant practices, and endorse efficiency. The purpose of this article is to review the reasons transplant is needed, specifically heart, lung, kidney, liver, and simultaneous liver-kidney, and a brief overview of the transplant process including criteria used, contraindications, and medications prescribed.

Cardiovascular morbidity and mortality after liver transplantation: The protective role of mycophenolate mofetil

Cardiovascular (CV) diseases are recognized longterm causes of death after liver transplantation (LT). The objective of this multicenter study was to analyze the prevalence and the evolution of CV risk factors and CV morbidity and mortality in 1819 LT recipients along 5 years after LT. The influence of baseline variables on survival, morbidity, and mortality was studied. There was a continuous and significant increase of the prevalence of all the CV risk factors (except smoking) after LT. CV diseases were the fourth cause of mortality in the 5 years after LT, causing 12% of deaths during the follow-up. Most CV events (39%) occurred in the first year after LT. Preexisting CV risk factors such as age, pre-LT CV events, diabetes, metabolic syndrome, and hyperuricemia, and mycophenolate-free immunosuppressive therapy, increased post-LT CV morbidity and mortality. The development of new-onset CV risk factors after LT, such as dyslipidemia and obesity, independently affected late CV morbidity and mortality. Tacrolimus and steroids increased the risk of posttransplant diabetes, whereas cyclosporine increased the risk of arterial hypertension, dyslipidemia, and metabolic syndrome. In conclusion, CV complications and CV mortality are frequent in LT recipients. Preexisting CV risk factors, immunosuppressive drugs, but also the early new onset of obesity and dyslipidemia after LT play an important role on late CV complications. A strict metabolic control in the immediate post-LT period is advisable for improving CV risk of LT recipients. Liver Transplantation 23 498-509 2017 AASLD.

Impact of Cardiovascular Risk Factors on Long-Term Mortality After Liver Transplantation

Immunosuppression with calcineurin inhibitors has contributed to an increased prevalence of hypertension, diabetes, and hypercholesterolemia in patients receiving liver transplantation. This study evaluated the prevalence of cardiovascular risk factors, their management, and long-term mortality after liver transplantation. Medical records were reviewed in 333 adult patients who underwent orthotopic liver transplantation. Data were collected on medical diagnoses before and after transplantation, medication use, and on long-term mortality. The 333 patients in the study included 223 men and 110 women, mean age 59 ± 10 years. The mean follow-up was 50 ± 28 months. After transplantation, there was a high prevalence of hypertension (67%), hypercholesterolemia (46%), diabetes mellitus (42%), and chronic kidney disease (45%). Out of 333 patients in the study, 96 patients (29%) died during follow-up. Stepwise logistic regression was performed to identify the risk factors that might influence long-term mortality outcomes. Based on pretransplant characteristics, positive independent risk factors that increased mortality were age at transplant and hepatitis C. After transplantation, positive predictive factors were diabetes mellitus and cancer. A negative predictive risk factor for mortality was hypercholesterolemia. Analysis of medication after transplantation showed that positive predictive factors were the use of insulin, steroids, and antibiotics. Negative predictors for mortality were tacrolimus and mycophenolate. Our data suggest that diabetes mellitus and hepatitis C play an important role in worsening posttransplant mortality.

Immunosuppression for kidney transplantation: Where are we now and where are we going?

Advances in immunosuppression have propelled kidney transplantation from a scientific curiosity to the optimal treatment for patients with end stage kidney disease. Declining rates of acute rejection have led to improvements in short term kidney transplant survival, culminating in incrementally better long term patient and allograft outcomes. Contextualized around established immune-suppressing drug targets, this review summarizes the history of the clinical science and highlights the pivotal trials that have led to present-day treatment standards at the level of both individual agents and multidrug regimens for kidney recipients. Finally, recently approved and emerging therapies are discussed, with an emphasis on challenges faced by clinicians managing this increasingly complex patient population.

Progression of Incidental Intraductal Papillary Mucinous Neoplasms of the Pancreas in Liver Transplant Recipients

OBJECTIVES

Intraductal papillary mucinous neoplasms (IPMNs) are premalignant pancreatic cysts commonly found incidentally. Immunosuppression accelerates carcinogenesis.Thus, we aimed to compare IPMN progression in liver transplant (LT) recipients on chronic immunosuppression to progression among an immunocompetent population.

METHODS

We retrospectively assessed adult LT recipients between 2008 and 2014 for imaging evidence of IPMN. Diagnosis of IPMN was based on history, imaging, and cyst fluid analysis. The immunocompetent control group consisted of nontransplant patients from our pancreatic cyst surveillance program with IPMN under surveillance for greater than 12 months between 1997 and 2013. Four hundred fifty-four patients underwent LT in the study period and had cross-sectional imaging.

RESULTS

The prevalence of suspected IPMN was 6.6% (30 of 454). Compared with 131 controls, the transplant cohort was younger, with increased prevalence of diabetes and smoking. The prevalence of other risk factors for IPMN progression (history of pancreatitis, family history of pancreatic cancer) was similar. After an average follow-up of 31 months, most cysts increased in diameter, with a similar increase of dominant cyst (0.4 cm vs 0.5 cm; P = 0.6). Type of immunosuppression was not associated with the increased rate of cyst growth.

CONCLUSIONS

Our findings suggest that LT recipients with incidental IPMN can be managed under similar guidelines as immunocompetent patients.

Cardiovascular risk 10 years after liver transplant

OBJECTIVES

We sought to evaluate the frequency of cardiovascular risk factors in a cohort of patients 10 years after a liver transplant, and to assess their 10-year risk of fatal cardiovascular disease using Systematic COronary Risk Evaluation (SCORE) charts.

MATERIALS AND METHODS

Between January 1990 and June 1996, one hundred eighty-nine adults underwent a first liver transplant in our center. Fifty-nine patients (31%) died before reaching their tenth year, and 115 patients were available with complete clinical data at 10 years.

RESULTS

The main indications for liver transplant were alcoholic (38%) and viral cirrhosis (40%). The median age of patients was 56 (range, 29-73 y), 80% were men, 23% were obese, 16% were active smokers, 18% were diabetic, 40% had hypercholesterolemia, and 77% had hypertension. Before the tenth year after transplant, 6 deaths were because of cardiovascular diseases, which represents the third cause of late death (> 1 year after liver transplant). After liver transplant, 5% of the surviving patients underwent ischemic cardiovascular events during the first decade. At a 10-year assessment, the median estimated 10-year risk of fatal cardiovascular disease was 1% (range, 0%-9%) and 10% of the patients had a high risk (ie, SCORE ≥ 5%).

CONCLUSIONS

Our results suggest that the frequency of cardiovascular events is relatively low after a liver transplant, even if most of the patients had 1 or more cardiovascular risk factors. Nevertheless, clinicians should perform a similar evaluation 15 or 20 years after the liver transplant because cardiovascular risk exponentially increases with age.

A randomized cross-over comparison of short-term exposure of once-daily extended release tacrolimus and twice-daily tacrolimus on renal function in healthy volunteers

Calcineurin inhibitor nephrotoxicity remains an issue for transplant recipients. The pharmacokinetic profile (PK) of the once-daily tacrolimus extended release (Tac-ER) includes equivalent exposure [AUC(0-24 h) ] but lower Cmax versus twice-daily tacrolimus immediate release (Tac-IR). We hypothesized that the unique PK profiles would result in pharmacodynamic differences in renal function. Nineteen healthy male subjects were allocated to once-daily Tac-ER and twice-daily Tac-IR in a prospective, randomized, two period, cross-over study. Tacrolimus was titrated to achieve trough levels of 8-12 ng/ml. Twenty four hours ERPF and GFR estimated by para-aminohippurate and sinistrin clearance were performed at baseline and at the end of each 10-day dosing period. Mean Tac C0 was 11.0 ± 2.2 and 11.3 ± 1.8 ng/ml for Tac-ER and Tac-IR, respectively. The mean Effective 24 h renal plasma flow (ERPF) was significantly higher with Tac-ER compared with Tac-IR (658 ± 127 vs. 610 ± 93 ml/min/1.73 m(2) , P = 0.046). There was a trend to a greater mean GFR over 24 h for Tac-ER at 114.5 ± 13.6 ml/min/1.73 m(2) compared with 108.9 ± 9.7 ml/min/1.73 m(2) for Tac-IR, P = 0.116. Under controlled physiological conditions, ERPF was significantly improved with Tac-ER compared with Tac-IR, likely owing to the differing PKs of these tacrolimus preparations (ClinicalTrials.gov Identifier: NCT01681134).

Effect of low-dose tacrolimus with mycophenolate mofetil on renal function following liver transplantation

AIM: To determine whether low-dose tacrolimus (TAC) combined with mycophenolate mofetil (MMF) is a safe approach to decrease the incidence of chronic kidney disease (CKD) in liver transplantation (LT) recipients.

METHODS: We analyzed the medical records of 689 patients who underwent LT between March 1999 and December 2012 in a single Chinese center. Immunosuppression was initiated with a calcineurin inhibitor (TAC or CSA) and prednisone with or without MMF. CKD is defined by the glomerular filtration rate (GFR), estimated by an abbreviated Modification of Diet in Renal Disease formula, < 60 mL/min per 1.73 m² for at least 3 consecutive months after LT. Individuals with TAC trough concentrations ≤ 8 ng/mL at 3 mo after LT were defined as the low-dose group. The incidence of CKD within 5 years was compared between the TAC group and the CSA group, as well as between four subgroups (low-dose and high-dose TAC groups with or without MMF).

RESULTS: No difference regarding the occurrence of pre-LT renal dysfunction or that of post-LT rejection was found between the TAC and CSA groups or between the four subgroups. With a definition of GFR < 60 mL/min per 1.73 m², the overall incidence of CKD was significantly higher in the CSA group than in the TAC group. The incidence of CKD in the low-dose TAC + MMF group (7.7%) was significantly lower than that observed in the low-dose TAC group (15.9%), high-dose TAC group (24.6%) and high-dose TAC + MMF group (18.5%). The cumulative 1-, 3- and 5-year incidence rates of CKD were 12.7%, 14.5% and 16.7%, respectively. The cumulative 5-year survival rates were 61.7% and 82.2% in patients with or without CKD, respectively.

CONCLUSION: In LT patients, the choice of immunosuppressive therapy appears to affect renal function and patient survival.

Cytochrome P450 2J2: distribution, function, regulation, genetic polymorphisms and clinical significance

Cytochrome P450 2J2 (CYP2J2) is an enzyme mainly found in human extrahepatic tissues, with predominant expression in the cardiovascular systems and lower levels in the intestine, kidney, lung, pancreas, brain, liver, etc. During the past 15 years, CYP2J2 has attracted much attention for its epoxygenase activity in arachidonic acid (AA) metabolism. It converts AA to four epoxyeicosatrienoic acids (EETs) that have various biological effects, especially in the cardiovascular systems. In recent publications, CYP2J2 is shown highly expressed in various human tumor cells, and its EET metabolites are demonstrated to implicate in the pathologic development of human cancers. CYP2J2 is also a human CYP that involved in phase I xenobiotics metabolism. Antihistamine drugs and many other compounds were identified as the substrates of CYP2J2, and studies have demonstrated that these substrates have a broad structural diversity. CYP2J2 is found not readily induced by known P450 inducers; however, its expression could be regulated in some pathological conditions, might through the activator protein-1(AP-1), the AP-1-like element and microRNA let-7b. Several genetic mutations in the CYP2J2 gene have been identified in humans, and some of them have been shown to have potential associations with some diseases. With the increasing awareness of its roles in cancer disease and drug metabolism, studies about CYP2J2 are still going on, and various inhibitors of CYP2J2 have been determined. Further studies are needed to delineate the roles of CYP2J2 in disease pathology, drug development and clinical practice.

Mycophenolate mofetil enhances the negative effects of sirolimus and tacrolimus on rat kidney cell metabolism

Background and Purpose

Mycophenolate mofetil (MMF) per se is not known to have negative effects on the kidney. MMF alone or in combination with sirolimus, can be the basis of calcineurin inhibitor (CNI)-free, kidney sparing drug protocols. However, long-term outcomes in patients on MMF/SRL seem to be inferior to those treated with regimens that include the CNI tacrolimus (TAC) due to an increased risk of allo-immune reactions. Interestingly, potential enhancement of the negative effects of SRL and TAC on the kidney by MMF has never been considered.

Experimental Approach

It was our aim to study the effects of TAC, SRL and MMF alone and evaluate their interactions when combined on the rat kidney. For this purpose we used a comprehensive molecular marker approach including measurements of urinary 8-isoprostane concentrations (oxidative stress marker) and changes of urinary metabolite patterns (¹H-NMR spectroscopy) and comparing these markers to renal function (glomerular filtration rate (GFR)) and morphologic alterations (histology).

Key Results

While MMF alone did not impact GFR, its interaction with SRL and TAC led to a significant decrease of rats’ renal function. The decline went in parallel with a significant increase in urinary isoprostane concentrations and an enhancement of negative effects on urinary metabolite patterns.

Conclusions

In broad summary, the present study showed that MMF may enhance the negative effects of TAC on kidney function and may even display nephrotoxic properties when combined with SRL.

Prevention of hepatitis C recurrence after liver transplantation: An update

Hepatitis C related liver failure and hepatocarcinoma are the most common indications for liver transplantation in Western countries. Recurrent hepatitis C infection of the allograft is universal and immediate following liver transplantation, being associated with accelerated progression to cirrhosis, graft loss and death. Graft and patient survival is reduced in liver transplant recipients with recurrent Hepatitis C virus (HCV) infection compared to HCV-negative recipients. Many variables may impact on recurrent HCV liver disease. Overall, excess immunosuppression is believed to be a key factor; however, no immunosuppressive regimen has been identified to be more beneficial or less harmful. Donor age limitations, exclusion of moderately to severely steatotic livers and minimization of ischemic times could be a potential strategy to minimize the severity of HCV disease in transplanted subjects. After transplantation, antiviral therapy based on pegylated IFN alpha with or without ribavirin is associated with far less results than that reported for immunocompetent HCV-infected patients. New findings in the field of immunotherapy and genomic medicine applied to this context are promising.

Risk of post-lung transplant renal dysfunction in adults with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is one of the leading indications for lung transplantation. The incidence and pre-lung transplant risk factors for posttransplant renal dysfunction in the CF population remain undefined.

METHODS

We conducted a cohort study using adults (≥ 18 years old) in the CF Foundation Patient Registry from 2000 to 2008 to determine the incidence of post-lung transplant renal dysfunction, defined by an estimated glomerular filtration rate of < 60 mL/min/1.73 m(2). Multivariable Cox proportional hazards modeling was used to identify independent pretransplant risk factors for post-lung transplant renal dysfunction.

RESULTS

The study cohort included 993 adult lung transplant recipients with CF, with a median follow-up of 2 years. During the study period, 311 individuals developed renal dysfunction, with a 2-year risk of 35% (95% CI, 32%-39%). Risk of posttransplant renal dysfunction increased substantially with increasing age (25 to < 35 years vs 18 to < 25 years: hazard ratio [HR], 1.60; 95% CI, 1.15-2.23; vs ≥ 35 years: HR, 2.45; 95% CI, 1.73-3.47) and female sex (HR, 1.56; 95% CI, 1.22-1.99). CF-related diabetes requiring insulin therapy (HR, 1.30; 95% CI, 1.02-1.67) and pretransplant renal function impairment (estimated glomerular filtration rate, 60-90 mL/min/m(2) vs > 90 mL/min/m(2): HR, 1.58; 95% CI, 1.19-2.12) also increased the risk of posttransplant renal dysfunction.

CONCLUSIONS

Renal dysfunction is common following lung transplant in the adult CF population. Increased age, female sex, CF-related diabetes requiring insulin, and pretransplant renal impairment are significant risk factors.

Prophylaxis of chronic kidney disease after liver transplantation - experience from west China

AIM: To evaluate the prophylaxis of chronic kidney disease (CKD) after liver transplantation (LT) with low-dose calcineurin inhibitor (CNI) and mycophenolate mofetil (MMF).

METHODS: From March 1999 to December 2009, a total of 572 patients (478 males and 94 females) underwent LT enrolled in the study. Initial immunosuppression was by triple-drug regimens that included a CNI, MMF, and prednisone. The initial dose of CNI was 0.05-0.10 mg/kg per day for tacrolimus (TAC) and 5-10 mg/kg per d for cyclosporine A (CSA) respectively, and was gradually reduced based on a stable graft function. The serum trough level of CNI was 6-8 ng/mL for TAC and 120-150 ng/mL for CSA 3-mo post-operation, 4-6 ng/mL for TAC and 80-120 ng/mL for CSA 1-year after transplantation was expected with stable liver function. MMF was personalized between 1.0-1.5 g/d. Glomerular filtration rate (GFR) was estimated by an abbreviated Modification of Diet in Renal Disease formula. Risk factors of CKD were examined by univariate and multivariate logistic regression.

RESULTS: With a definition of GFR < 60 mL/min per 1.73 m², the incidence of CKD was 17.3% 5-year after LT. There were 68.3% (293 of 429 cases) patients managed to control their TAC trough concentrations within 8 ng/mL and 58.0% (83 of 143 cases) patients’ CSA trough concentrations within 150 ng/mL. Of the 450 recipients followed-up over 1 year, 55.5% (183 of 330 cases) of which were treated with TAC had a trough concentration ≤ 6 ng/mL while 65.8% (79 of 120 cases) of which were treated with CSA had a concentration ≤ 120 ng/mL. The incidence of CKD in the groups of lower CNI trough concentrations was significantly lower than the groups with CNI concentrations above the ideal range. Patients with CKD had much higher CNI trough concentrations than that of patients without CKD. MMF was adopted in 359 patients (62.8%). Patients administrated with MMF had a relatively low CNI trough concentrations but with no significant difference. The graft function remained stable during follow-up. No difference was found between different groups of CNI trough concentrations. Pre-LT renal dysfunction, ages, acute kidney injury, high blood trough concentrations of CNI in 3 mo (TAC > 8 ng/mL, CSA > 150 ng/mL) and hypertension after operation were associated with CKD progression, while male gender and adoption of MMF were protection factors.

CONCLUSION: Low dose of CNI combined with MMF managed to prevent CKD after LT with stable graft function.

Arterial hypertension in liver transplant recipients

Hypertension is an important cardiovascular risk factor that influences patient survival. This study sought to evaluate hypertension incidence and circadian rhythms of blood pressure (BP) among liver transplant recipients during the first posttransplant month. We also compared hypertension incidence according to clinical and automated blood pressure monitoring methods. BP was determined by clinical blood pressure monitoring (CBPM) methods and by automated blood pressure monitoring (ABPM) using the SpaceLabs device. We also assessed blood biochemistry, particularly kidney function parameters and immunosuppressive drug blood trough levels, among 32 white subjects (10 women and 22 men) of average age 47.58±14.19 years. The leading cause for transplantation was liver insufficiency due to viral hepatitis B and/or C infection (43.75%). The majority (93.75%) of patients was prescribed immunosuppressive treatment with tacrolimus. Although we observed hypertension in 28 patients (87.5%) by ABPM measurements and in 25 (78.12%) using CBPM method, the difference did not reach statistical significance. However, BP control was inadequate in 28 patients (87.5%) by ABPM assessment versus 3 (9.38%) according to CBPM readings (P=.025). The BP circadian rhythm was altered in 30 patients (93.75%) including 15 with higher nighttime BP readings. There was no correlation between tacrolimus blood levels and BP values or with kidney function as assessed by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. We concluded that prevalence of arterial hypertension among liver transplant recipients within 1 month after transplantation is high. The majority of the patients show disturbed circadian rhythms in the early period after liver transplantation with loss or even reversal of the normal nocturnal decrease in BP. Owing to the fact that ABPM enables more adequate daily assessment of BP values, it is an optimal method to adjust antihypertensive therapy to optimal levels.

Renal function, efficacy and safety postconversion from twice- to once-daily tacrolimus in stable liver recipients: an open-label multicenter study

This multicenter, open-label, phase III study assessed renal function, safety, and efficacy in stable adult liver transplant recipients converted from tacrolimus twice-daily (BID) to once-daily (QD). Patients received tacrolimus BID for 6weeks before conversion to tacrolimus QD (1:1 [mg:mg] total daily dose basis) for 12weeks. Primary endpoint: change in steady state creatinine clearance (CrCl) between treatment phases. Of 112 patients enrolled, 98 were converted to QD dosing (full analysis set [FAS]). Mean (SD) tacrolimus dose was 3.7 (1.7) mg/day during BID and at conversion, and 3.9 (1.8) mg/day at Week 12. 74.5% of patients required no dose adjustment on conversion (FAS). Mean tacrolimus whole blood trough levels were at the lower end of the recommended range during tacrolimus BID and QD; the difference between mean steady-state trough levels was statistically significant (7.5ng/ml vs. 6.5ng/ml; P<0.0001). Following conversion, mean tacrolimus trough levels were reduced by 15% (about 1ng/ml) without any cases of acute rejection, remained stable during the remainder of the study, and were more consistent, showing reduced between- and within-patient variability in trough levels. Renal function remained stable, demonstrating noninferiority of tacrolimus QD versus BID (relative difference in mean calculated CrCl -0.1% [±6.3%]). Patient and graft survival were 100%. Adverse events incidence was low during both treatment phases.

Effect of tacrolimus on survival in hepatitis C-infected patients after liver transplantation

The observation that cyclosporine inhibits HCV replication in vitro has led some programs to use cyclosporine as the calcineurin inhibitor (CNI) of choice after orthotopic liver transplantation (OLT). Previous studies comparing outcomes with different CNIs used small HCV cohorts or had short-term follow-up. We examined patient survival and fibrosis progression in all HCV-infected adult primary OLT recipients from 1995 to 2004 at the Annette C. and Harold C. Simmons Transplant Institute (n = 516). Patients were categorized by their CNI on day 7 post-OLT, and they were excluded if they died before day 14. Patient and donor age, sex, race, and prevalence of cytomegalovirus infection post-OLT were similar in the tacrolimus and cyclosporine patients. As expected, acute cellular rejection and steroid-resistant rejection were less common in tacrolimus-treated patients. Although no difference in 1-year survival was seen, tacrolimus patients (n = 268) had superior 5-year survival compared to cyclosporine patients (n = 248) (75% vs. 67%; P = 0.02). Fibrosis progression was no different between the groups. In our retrospective analysis of 516 post-OLT patients, tacrolimus improved long-term survival compared to cyclosporine in HCV-infected patients, although it did not impact HCV fibrosis progression.

One thousand consecutive primary liver transplants under tacrolimus immunosuppression: a 17- to 20-year longitudinal follow-up

BACKGROUND

Tacrolimus has proven to be a potent immunosuppressive agent in orthotopic liver transplantation (OLT). The aim of this study is to examine its long-term efficacy and safety.

METHODS AND RESULTS

One thousand consecutive primary OLTs performed between August 1989 and December 1992 and maintained under tacrolimus-based immunosuppression were followed up until January 2009. Patient and graft survivals with corresponding causes of death and retransplantation, maintenance immunosuppression, and adverse effects were examined. The study population includes 600 males and 400 females comprising 166 children, 630 adults, and 204 seniors. The mean follow-up was 17.83 (range, 16.1-19.50) years. The overall 20-year actuarial patient and graft survivals were 35.8% and 32.6%, respectively. At the last follow-up, 442 patients were alive; 133 (77.1%) children, 265 (34.5%) adults, and 44 (16.1%) seniors (P=0.0001). After the first post-OLT year, cardiopulmonary events, recurrence of primary disease, and malignancy were the main causes of death. Overall, 183 recipients underwent retransplants; mainly for primary nonfunction, hepatic artery thrombosis, and recurrent primary disease, 180 required dialysis, and 45 underwent kidney transplant. A total of 97.7% of the survivors were on tacrolimus and 26.2% were also receiving adjunctive immunosuppressants at the last follow-up.

CONCLUSIONS

The overall 20-year actuarial patient and graft survivals were 35.8% and 32.6%, respectively, with significantly better survival among children. Age-related complications, recurrence of primary disease, and malignancy were the major causes of late graft loss. Graft loss related to immunologic reasons was rare. The prevention of recurrent disease and newer immunosuppressive regimen will further improve these results.

Regression of new-onset diabetes mellitus after conversion from tacrolimus to cyclosporine in liver transplant patients: results of a pilot study

INTRODUCTION

New-onset diabetes mellitus (NODM) has important implications for long-term outcome following liver transplantation.

AIM

To evaluate the impact of conversion from tacrolimus to cyclosporine in liver transplant patients presenting NODM.

METHOD

In a 12-month pilot study, 39 liver transplant patients with NODM were converted from tacrolimus to cyclosporine. Most patients (59%) were receiving antidiabetic therapy (18% insulin, 41% oral) and all patients had received dietary advice prior to the study.

RESULTS

At month 12, NODM had significantly resolved (FBG<7 mmol/L without treatment) in 36% of patients (95% CI 20.8-51.0%). In the 16 patients not receiving antidiabetic drugs at baseline, mean FBG decreased from 8.1 mmol/L to 6.6 mmol/L (P=0.008) and mean HbA(1c) decreased from 6.4 to 6.0% (P=0.05). Steroids were stopped rapidly in the nine patients receiving steroids at inclusion but NODM resolution was observed in only one of these nine patients. No significant factors were identified that could have affected NODM resolution. There were three episodes of biopsy-proven acute rejection (7.7%), no graft losses and one death. Overall, cyclosporine tolerance was good with no significant change in creatinine clearance at month 12. Total cholesterol increased from 4.6 mmol/L to 5.1 mmol/L (P<0.001).

CONCLUSIONS

These results suggest that liver transplant patients with NODM may benefit from conversion to cyclosporine from tacrolimus through improved glucose metabolism. Confirmation in a prospective, randomized comparative study is required.

A comparison of short-term exposure of once-daily extended release tacrolimus and twice-daily cyclosporine on renal function in healthy volunteers

BACKGROUND

Calcineurin inhibitor nephrotoxicity remains an issue for recipients of solid organ transplants. After cyclosporine A (CsA) microemulsion administration, effective renal plasma flow (ERPF) and glomerular filtration rate(GFR) are decreased coincident with the maximal concentration (Cmax) of CsA. The pharmacokinetic (PK) profile of the once-daily formulation of tacrolimus extended release (Tac ER) includes an equivalent AUCPK 0-24 hr and a lower Cmax versus twice-daily Tac immediate release.

METHODS

Eighteen healthy subjects were allocated once-daily Tac ER and twice-daily CsA in a prospective, randomized,open-label, two-period, two-sequence single crossover study. CsA was targeted to C2 of 700 to 1400 ng/mL, and Tac ER was targeted to C0 of 5 to 10 ng/mL. Pharmacodynamic (PD) assessments were conducted preexposure, and PD and PK were assessed during a 6-hr postdose period after 10-day exposure.

RESULTS

The achieved mean C(o) Tac and CsA were 6.4 +/- 1.16 and 201 +/- 57 ng/mL, respectively. At Cmax, the change in ERPF was +30 +/- 127 vs. -70 +/- 96 mL/min/1.73 m2 relative to baseline for Tac ER and CsA (P=0.0085). The ERPF and GFR AUC (PD 0-6) hr were 3645 +/- 887 vs. 3210 +/- 582 mL/1.73 m2 (P=0.027) and 604 +/- 98 vs. 543+/- 79 mL/1.73 m2(P=0.023) for Tac ER versus CsA, respectively. Both systolic and diastolic blood pressures were significantly greater with exposure to CsA compared with Tac ER.

CONCLUSIONS

Acute reductions in ERPF and GFR are attenuated with Tac ER compared with CsA and may correlate with the differing PK profiles of these calcineurin inhibitors.

Cyclosporin A-induced gingival overgrowth is not associated with myofibroblast transdifferentiation

Cyclosporin A (CyA) induces gingival overgrowth via its stimulatory effects on expression of transforming growth factor-beta1 (TGF-beta1) and collagen. It is not known whether CyA has a direct effect on gingival fibroblasts or induces its effect indirectly via stimulation of myofibroblast transdifferentiation. The present study was undertaken to examine the in vivo and in vitro effect of CyA on myofibroblast transdifferentiation. Rats were treated for 60 days with a daily subcutaneous injection of CyA, and the gingival overgrowth tissue was analyzed by immunohistochemistry. In vitro, fibroblasts from normal gingiva (NG) were cultured in the presence of different concentrations of CyA, and subjected to semi-quantitative reverse transcriptase-polymerase chain reaction and western blot. Although CyA treatment stimulated TGF-beta1 expression by NG fibroblasts, it lacked to induce expression and production of isoform alpha of smooth muscle actin (alpha-SMA), the specific myofibroblast marker. The expression levels of connective tissue growth factor (CTGF), which has been considered a key molecule to promote the transdifferentiation of myofibroblasts via TGF-beta1 activation, were unaffected by CyA. Our results demonstrate that CyA-induced gingival overgrowth is not associated with activation of myofibroblast transdifferentiation, since CyA is not capable to increase CTGF expression.

Once-daily prolonged-release tacrolimus (ADVAGRAF) versus twice-daily tacrolimus (PROGRAF) in liver transplantation

The efficacy and safety of dual-therapy regimens of twice-daily tacrolimus (BID; Prograf) and once-daily tacrolimus (QD; Advagraf) administered with steroids, without antibody induction, were compared in a multicenter, 1:1-randomized, two-arm, parallel-group study in 475 primary liver transplant recipients. A double-blind, double-dummy 24-week period was followed by an open extension to 12 months posttransplant. The primary endpoint, event rate of biopsy-proven acute rejection (BPAR) at 24 weeks, was 33.7% for tacrolimus BID versus 36.3% for tacrolimus QD (Per-protocol set; p = 0.512; treatment difference 2.6%, 95% confidence interval -7.3%, 12.4%), falling within the predefined 15% noninferiority margin. At 12 months, BPAR episodes requiring treatment were similar for tacrolimus BID and QD (28.1% and 24.7%). Twelve-month patient and graft survival was 90.8% and 85.6% for tacrolimus BID and 89.2% and 85.3% for tacrolimus QD. Adverse event (AE) profiles were similar for both tacrolimus BID and QD with comparable incidences of AEs and serious AEs. Tacrolimus QD was well tolerated with similar efficacy and safety profiles to tacrolimus BID.

Long-term glomerular filtration rate in liver allograft recipients according to the type of calcineurin inhibitors

The calcineurin inhibitors (CNI) cyclosporine micro emulsion (CyA-ME) and tacrolimus (Tac) both display renal and vascular toxicities. We undertook a single-center retrospective study among 149 surviving liver transplant recipients. The primary outcome was kidney function over 10 years posttransplant, evaluating the glomerular filtration rate (GFR) by the abbreviated Modification of Diet in Renal Disease formula with subsequent Kidney Disease Outcomes Quality Initiative staging. The secondary outcomes included correlations between CNI trough levels (C0), GFR, and items of cardiovascular toxicity. At 1 and 5 years, the mean GFRs were 74.2 and 76.9 mL/min/1.73 m(2) under Tac versus 62.8 and 66.0 mL/min/1.73 m(2) under CyA-ME (P < .001). The mean value in favor of Tac was + 10 mL/min/1.73 m(2). Distribution of GFR stages showed more Tac patients at stage 1 or 2 and more at stage 4 or 5 under CyA-ME. There was no significant correlation between CNI-C0 and GFR. Switches between CNI or to mycophenolate mofetil did not show any significant GFR improvement. Patients under CyA-ME displayed significantly higher blood pressures with 3 requiring dialysis versus none under Tac. In conclusion, we observed that liver transplant patients under Tac maintained significantly better renal function with less progression to dialysis as compared with CyA-ME, indicating a lower renal and vascular (lower BP) toxicity.

Management of arterial hypertension occurring early after living donor liver transplantation in children: report of three cases and review of the literature

Three pediatric patients with hypertension occurring early after liver transplantation are reviewed. The patients were all female, and underwent living donor liver transplantation at the age of 9 years, 1 month, and 7 months. The etiology of liver disease was cirrhosis due to biliary atresia in two patients and fulminant hepatitis in one patient. Antihypertensive therapy with calcium channel blocker alone was not effective. Blood pressure was eventually controlled after the administration of a beta-adrenergic blocker in addition to the calcium channel blocker to all patients. No end-organ damage was observed, except that two patients developed temporary left ventricular hypertrophy.

Renal function and cardiovascular risk profile after conversion from ciclosporin to tacrolimus: prospective study in 80 liver transplant recipients

BACKGROUND

Increased risk of cardiovascular and cerebrovascular disease in liver transplant recipients results in particular from the side effects of calcineurin inhibitor-based immunosuppressive therapy. Several studies have demonstrated a more favourable outcome for patients receiving tacrolimus (TAC) as compared with ciclosporin (CS).

AIM

To investigate the effects of conversion from CS to TAC on cardiovascular risk factors and renal function in liver transplant recipients.

METHODS

In a prospective study, all except two patients had chronic kidney disease stages 2-4 (n = 80), according to estimated glomerular filtration rate using the abbreviated Modification of Diet in Renal Disease equation.

RESULTS

Conversion was accompanied with a mean decrease of total cholesterol from 194.6 +/- 54.0 mg/dL to 175.8 +/- 44.2 mg/dL (P < 0.001), low density lipoprotein cholesterol from 106.7 +/- 39.2 mg/dL to 90.9 +/- 28.6 mg/dL (P < 0.001) and mean arterial blood pressure values from 102.2 +/- 13.2 mm Hg to 95.9 +/- 11.7 mm Hg (P < 0.001). Renal function remained stable. No cases of de novo diabetes mellitus were identified. The Framingham risk score was significantly reduced from 5.2 +/- 4.4 at baseline to 4.4 +/- 5.3 after 12 months (P = 0.006).

CONCLUSIONS

Conversion from CS to TAC has been shown to improve the cardiovascular risk profile and may retard further decline of renal function after liver transplantation.

Induction of allogeneic mixed chimerism by immature dendritic cells and bone marrow transplantation leads to prolonged tolerance to major histocompatibility complex disparate allografts

Mixed chimerism has been shown to lead to prolonged major histocompatibility complex (MHC) disparate allograft survival and immune-specific tolerance; however, traditional conditioning regimes often involve myeloablation, which may pose a significant safety risk. In this study we examined the use of donor C57BL/6 (H-2(b)) immature dendritic cells (imDCs) to tolerize the BALB/c (H-2(d)) recipient to bone marrow transplantation (BMT), allowing the induction of mixed chimerism without immunosuppression or myeloablation. We showed that successful mismatched bone marrow engraftment can be achieved using imDCs given up to 3 days prior to BMT and that mixed chimerism can be established and detected in excess of 100 days post-BMT without evidence of graft-versus-host disease. Furthermore, we showed that imDCs can suppress lymphocyte proliferation in response to mismatched MHC stimulation, leading to increased expression of interleukin (IL)-4 and IL-10 and decreased expression of IL-2 and interferon-gamma (IFN-gamma). The induction of stable chimeras through pre-conditioning of mice with donor imDCs followed by BMT led to tolerance, allowing the long-term survival (> 110 days) of mismatched cardiac allografts and the prolonged survival of mismatched skin allografts without the need for immunosuppression or myeloablation. Transplantation with third-party C3H allografts were rapidly rejected in this model, suggesting that immune-specific tolerance was achieved. The induction of immune-specific tolerance without the need for immunosuppression or myeloablation represents a significant advance in transplant immunology and may provide clinicians with a plausible alternative in combating organ rejection following transplantation.

Calcineurin inhibitor nephrotoxicity

The use of the calcineurin inhibitors cyclosporine and tacrolimus led to major advances in the field of transplantation, with excellent short-term outcome. However, the chronic nephrotoxicity of these drugs is the Achilles' heel of current immunosuppressive regimens. In this review, the authors summarize the clinical features and histologic appearance of both acute and chronic calcineurin inhibitor nephrotoxicity in renal and nonrenal transplantation, together with the pitfalls in its diagnosis. The authors also review the available literature on the physiologic and molecular mechanisms underlying acute and chronic calcineurin inhibitor nephrotoxicity, and demonstrate that its development is related to both reversible alterations and irreversible damage to all compartments of the kidneys, including glomeruli, arterioles, and tubulo-interstitium. The main question--whether nephrotoxicity is secondary to the actions of cyclosporine and tacrolimus on the calcineurin-NFAT pathway--remains largely unanswered. The authors critically review the current evidence relating systemic blood levels of cyclosporine and tacrolimus to calcineurin inhibitor nephrotoxicity, and summarize the data suggesting that local exposure to cyclosporine or tacrolimus could be more important than systemic exposure. Finally, other local susceptibility factors for calcineurin inhibitor nephrotoxicity are reviewed, including variability in P-glycoprotein and CYP3A4/5 expression or activity, older kidney age, salt depletion, the use of nonsteroidal anti-inflammatory drugs, and genetic polymorphisms in genes like TGF-beta and ACE. Better insight into the mechanisms underlying calcineurin inhibitor nephrotoxicity might pave the way toward more targeted therapy or prevention of calcineurin inhibitor nephrotoxicity.