The metabolic effects of cyclosporin and tacrolimus

Chronic kidney disease combined with metabolic syndrome is a non-negligible risk factor

Metabolic syndrome (MetS) is a group of conditions characterized by hypertension (HTN), hyperglycaemia or insulin resistance (IR), hyperlipidaemia, and abdominal obesity. MetS is associated with a high incidence of cardiovascular events and mortality and is an independent risk factor for chronic kidney disease (CKD). MetS can cause CKD or accelerate the progression of kidney disease. Recent studies have found that MetS and kidney disease have a cause-and-effect relationship. Patients with CKD, those undergoing kidney transplantation, or kidney donors have a significantly higher risk of developing MetS than normal people. The present study reviewed the possible mechanisms of MetS in patients with CKD, including the disorders of glucose and fat metabolism after kidney injury, IR, HTN and the administration of glucocorticoid and calcineurin inhibitors. In addition, this study reviewed the effect of MetS in patients with CKD on important target organs such as the kidney, heart, brain and blood vessels, and the treatment and prevention of CKD combined with MetS. The study aims to provide strategies for the diagnosis, treatment and prevention of CKD in patients with MetS.

Tacrolimus Related Acute Pancreatitis: An Observational, Retrospective, Pharmacovigilance Study

PURPOSE

Recent case reports have drawn attention to the emergence of acute pancreatitis, a potentially life-threatening complication associated with tacrolimus. This study uses the Food and Drug Administration Adverse Event Reporting System (FAERS) to investigate the risk signal of acute pancreatitis associated with calcineurin inhibitors (CNIs), with a focus on tacrolimus.

METHODS

We conducted an observational retrospective pharmacovigilance study utilizing the FAERS database, encompassing data from its inception to the third quarter of 2023. The assessment of the association between CNIs and acute pancreatitis was carried out using the Information Component (IC) and Reporting Odds Ratio (ROR). Logistic regression analysis was employed to elucidate factors contributing to fatal outcomes. All analyses were performed using R version 3.2.5.

FINDING

We identified 221 cases of acute pancreatitis linked to CNIs. The median age of individuals experiencing acute pancreatitis induced by tacrolimus was 43, with a predominant occurrence among male patients. Our study showed a significant association between CNIs and acute pancreatitis (ROR 1.82 [1.60-2.08], IC 0.85 [3.66-3.92]). Comparing tacrolimus and cyclosporine, the signal for tacrolimus seemed to be higher. Further analysis revealed that, with the exception of patients aged 60 and above, the signal for tacrolimus remained stable. Contrastingly, the signal for cyclosporine was unstable and limited to the male group and individuals aged less than 20 years. In cases of CNIs-related acute pancreatitis, the mortality rate was 31.67% (70/221 cases). Logistic regression analysis indicated that a younger age acts as a protective factor for death due to CNIs-related acute pancreatitis (OR 0.943, 95% CI 0.915-0.972, P = 0.000).

IMPLICATIONS

Our study has identified a safety signal for tacrolimus in relation to acute pancreatitis. Additionally, we observed advanced age as a significant risk factor for tacrolimus-related acute pancreatitis, leading to mortality. Given the widespread use of tacrolimus, it is crucial for healthcare providers to be vigilant and informed about the potential association with acute pancreatitis.

Association of Abdominal Aortic Calcification With the Postoperative Metabolic Syndrome Components After Liver Transplantation

BACKGROUND

This study aimed to assess the risk factors for components of metabolic syndrome, such as diabetes mellitus, hypertension, and dyslipidemia, more than a year after liver transplantation.

METHODS

This study included 164 patients with liver failure secondary to acute and chronic liver disease or hepatocellular carcinoma who underwent liver transplantation between 2000 and 2019. Univariate and multivariate analyses were performed to identify the risk factors associated with metabolic syndrome components after liver transplantation.

RESULTS

The median follow-up period was 10.5 years. Of the 164 patients who underwent liver transplantation, 144 (87.8%) developed components of metabolic syndrome after liver transplantation. The most common cause of liver failure was hepatitis C virus infection (34.1%). The incidence of hepatocellular carcinoma was 36.0%. In univariate analysis, preoperative diabetes mellitus was a significantly more common component of metabolic syndrome than the others. In multivariate analysis, preoperative abdominal aortic calcification was a risk factor for the new onset of all components of metabolic syndrome after liver transplantation, despite the varying degree of calcification at risk of development (odds ratio for diabetes mellitus = 3.487, P = .0069; odds ratio for hypertension = 2.914, P = .0471; odds ratio for dyslipidemia = 3.553, P = .0030).

CONCLUSIONS

Preoperative abdominal aortic calcification was significantly associated with the development of each metabolic syndrome component after liver transplantation.

Statins in Kidney Transplant Recipients: Usage, All-Cause Mortality, and Interactions with Maintenance Immunosuppressive Agents

SIGNIFICANCE STATEMENT

Cardiovascular diseases account for 32% of deaths among kidney transplant recipients. Statin therapy is common in this population. However, its effect on mortality prevention remains unclear among kidney transplant recipients, whose clinical risk profile might be unique because of concomitant immunosuppressive therapy. In this national study of 58,264 single-kidney transplant recipients, statin use was associated with a 5% decrease in mortality. More importantly, this protective association was stronger among those who used a mammalian target of rapamycin (mTOR) inhibitor for immunosuppression (27% decrease in mTOR inhibitor users versus 5% in nonusers). Our results suggest that statin therapy may reduce mortality in kidney transplant recipients and that the strength of this protective association may vary by immunosuppression regimen.

BACKGROUND

Cardiovascular diseases are the leading cause of mortality in kidney transplant (KT) recipients, accounting for 32% of deaths. Statins are widely used in KT recipients, but effectiveness for preventing mortality remains unclear in this population, especially because of interaction between statins and immunosuppressive agents. We analyzed a national cohort to assess the real-world effectiveness of statins for reducing all-cause mortality in KT recipients.

METHODS

We studied statin use and mortality among 58,264 adults (18 years or older) who received single kidneys between 2006 and 2016 and had Medicare part A/B/D. Statin use was ascertained from Medicare prescription drug claims and deaths from Center for Medicare and Medicaid Services records. We estimated the association of statin use with mortality using multivariable Cox models, with statin use as a time-varying exposure and immunosuppression regimen as effect modifiers.

RESULTS

Statin use increased from 45.5% at KT to 58.2% at 1-year post-KT to 70.9% at 5-year post-KT. We observed 9785 deaths over 236,944 person-years. Overall, statin use was significantly associated with lower mortality (adjusted hazard ratio [aHR], 0.95; 95% confidence interval [CI], 0.90 to 0.99). The strength of this protective association varied by calcineurin inhibitor use (among tacrolimus users, aHR, 0.97; 95% CI, 0.92 to 1.03 versus among calcineurin nonusers, aHR, 0.72; 95% CI, 0.60 to 0.87; interaction P =0.002), mammalian target of rapamycin (mTOR) inhibitor use (among mTOR inhibitor users, aHR, 0.73; 95% CI, 0.57 to 0.92 versus among nonusers, aHR, 0.95; 95% CI, 0.91 to 1.00; interaction P =0.03), and mycophenolate use (among mycophenolate users, aHR, 0.96; 95% CI, 0.91 to 1.02 versus among nonusers, aHR, 0.76; 95% CI, 0.64 to 0.89; interaction P =0.002).

CONCLUSION

Real-world evidence supports statin therapy for reducing all-cause mortality in KT recipients. Effectiveness might be greater when combined with mTOR inhibitor-based immunosuppression.

Synthetic Pharmacotherapy for Systemic Lupus Erythematosus: Potential Mechanisms of Action, Efficacy, and Safety

The pharmacological treatment of systemic lupus erythematosus (SLE) aims to decrease disease activity, progression, systemic compromise, and mortality. Among the pharmacological alternatives, there are chemically synthesized drugs whose efficacy has been evaluated, but which have the potential to generate adverse events that may compromise adherence and response to treatment. Therapy selection and monitoring will depend on patient characteristics and the safety profile of each drug. The aim of this review is to provide a comprehensive understanding of the most important synthetic drugs used in the treatment of SLE, including the current treatment options (mycophenolate mofetil, azathioprine, and cyclophosphamide), review their mechanism of action, efficacy, safety, and, most importantly, provide monitoring parameters that should be considered while the patient is receiving the pharmacotherapy.

Clinical trials for renal allograft tolerance induction through combined hematopoietic stem cell transplantation: A narrative review

During the last four decades, development of effective immunosuppressants has significantly improved short-term results of organ transplantation. However, long-term results have not been satisfactory due to chronic rejection or complications caused by immunosuppressive drugs. Therefore, induction of immunological tolerance of the transplanted organ is considered essential to improve the long-term results. Despite numerous tolerance strategies that have been successful in murine models, inducing hematopoietic chimerism through donor hematopoietic stem cell transplantation is the only method that reproducibly induces kidney allograft tolerance in nonhuman primates or humans. Combining kidney and hematopoietic stem cell transplantation to achieve allograft tolerance has now been attempted with different chimerism strategies. This review summarizes the status of current clinical trials on the induction of allograft tolerance. We also summarize recent studies to extend the chimerism approach to deceased donor transplant recipients.

Tacrolimus-induced acute pancreatitis and diabetic ketoacidosis (DKA) in pediatric kidney transplant recipient

BACKGROUND

Calcineurin inhibitors (CNIs) are often associated with abnormalities in glucose and lipid metabolism. Tacrolimus is the most potent CNI which is nowadays used almost universally as a part of triple-drug immunosuppression after kidney transplantation. Tacrolimus can cause islet cell damage and decrease in insulin secretion which can lead to post-transplant diabetes mellitus and rarely diabetic ketoacidosis. Although rare, acute pancreatitis has also been implicated by a few case reports to be associated with tacrolimus. However, tacrolimus-induced acute pancreatitis has not been reported in pediatric kidney transplant recipient till date.

CASE DESCRIPTION

We report the first case of tacrolimus-induced acute pancreatitis in association with hypertriglyceridemia and DKA in a child early after kidney transplant. The patient was managed with supportive treatment, and tacrolimus was stopped for three days and then switched to cyclosporine-based regimen. The patient became euglycemic within 8 weeks of switching to cyclosporine and did not have any recurrence of pancreatitis.

CONCLUSION

Tacrolimus-induced pancreatitis is rare in the setting of kidney transplants and prompt diagnosis and management can lead to a successful outcome.

Branched Chain Amino Acids are associated with Metabolic Complications in Liver Transplant Recipients

BACKGROUND

Obesity, dyslipidemia and type 2 diabetes (T2D) contribute substantially to increased cardiovascular morbidity and mortality in patients after orthotopic liver transplantation (OLTx). Elevated plasma branched chain amino acids (BCAA) are linked to metabolic disturbances and cardiovascular disease (CVD) risk profiles in several non-OLTx populations.

METHODS

Cross-sectional analysis of liver transplant recipients from TransplantLines, a single-center biobank and cohort study. BCAA plasma levels were measured by means of nuclear-magnetic resonance spectroscopy. CVD and cardiometabolic factors were collected by using data from electronic patient records. Associations were determined between BCAA plasma levels and T2D, Metabolic Syndrome (MetS), CVD as well as mTOR inhibition in liver transplant recipients.

RESULTS

336 Patients were divided into sex-stratified tertiles of total BCAA. MetS (P<0.001) and T2D (P=0.002) were significantly more frequent in subjects in the highest BCAA tertile. In logistic regression analyses, the multivariable adjusted odds ratio (OR) per 1 standard deviation increase in BCAA was 1.68 (95%CI: 1.18-2.20, P=0.003) for MetS and 1.60 (95%CI: 1.14-2.23, P=0.006) for T2D. Use of Sirolimus (mTOR inhibitor) was significantly associated with higher BCAA plasma levels, independent of age, sex, time after OLTx, MetS and other immunosuppressive medication (adjusted P=0.002).

CONCLUSION

Elevated BCAA plasma levels are associated with T2D, MetS and use of Sirolimus in liver transplant recipients. BCAA plasma levels may represent a valuable biomarker for cardiometabolic complications after OLTx.

Non-alcoholic steatohepatitis in liver transplant recipients diagnosed by serum cytokeratin 18 and transient elastography: A prospective study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) seem common after liver transplantation.

AIM

To investigate incidence and predictors of NAFLD and NASH by employing noninvasive testing in liver transplant recipients, namely controlled attenuation parameter (CAP) and the serum biomarker cytokeratin 18 (CK-18). We also evaluated the diagnostic accuracy of CK-18 and CAP compared to liver histology.

METHODS

We prospectively recruited consecutive adult patients who received liver transplant at the McGill University Health Centre between 2015-2018. Serial measurements of CK-18 and CAP were recorded. NAFLD and NASH were diagnosed by CAP ≥ 270 dB/m, and a combination of CAP ≥ 270 dB/m with CK-18 > 130.5 U/L, respectively. Incidences and predictors of NAFLD and NASH were investigated using survival analysis and Cox proportional hazards.

RESULTS

Overall, 40 liver transplant recipients (mean age 57 years; 70% males) were included. During a median follow-up of 16.8 mo (interquartile range 15.6-18.0), 63.0% and 48.5% of patients developed NAFLD and NASH, respectively. On multivariable analysis, after adjusting for sex and alanine aminotransferase, body mass index was an independent predictor of development of NAFLD [adjusted hazard ratio (aHR): 1.21, 95% confidence interval (CI): 1.04-1.41; P = 0.01] and NASH (aHR: 1.26, 95%CI: 1.06-1.49; P < 0.01). Compared to liver histology, CAP had a 76% accuracy to diagnose NAFLD, while the accuracy of CAP plus CK-18 to diagnose NASH was 82%.

CONCLUSION

NAFLD and NASH diagnosed non-invasively are frequent in liver transplant recipients within the first 18 mo. Close follow-up and nutritional counselling should be planned in overweight patients.

Ameliorating Metabolic Profiles After Kidney Transplantation: A Protocol for an Open-Label, Prospective, Randomized, 3-Arm, Controlled Trial

Aim: High prevalence of metabolic disorders causes higher risk of cardiovascular diseases after kidney transplantation (KT), which remains the main burden impairing short-term and long-term survival. This open-label, prospective, randomized, 3-arm, controlled trial will evaluate the safety, tolerability and efficacy of metformin and empagliflozin in ameliorating metabolic profiles after KT.

Methods: After a screening assessment, eligible patients with an estimated glomerular filtration rate (eGFR) >45 mL/min/1.73m2 are randomly assigned to standard triple immunosuppression alone, standard immunosuppression plus metformin (500 mg twice daily), standard immunosuppression plus empagliflozin (25 mg once daily) from discharge. The primary endpoint is the differences in the visceral-to-subcutaneous fat area ratio over 12 months, evaluated by magnetic resonance imaging (MRI). Secondary outcomes include kidney graft function, glycometabolism, lipid metabolism, and inflammatory parameters. The trial will enroll 105 kidney transplant recipients, providing 90% power to detect the difference at 5% significance.

Impact of Tacrolimus Daily Dose Limitation in Renal Transplant Recipients Expressing CYP3A5: A Retrospective Study

The pharmacokinetic variability of tacrolimus can be partly explained by CYP3A5 activity. Our objective was to evaluate a tacrolimus sparing policy on renal graft outcome according to CYP3A5 6986A>G genetic polymorphism. This retrospective study included 1114 recipients with a median follow-up of 6.3 years. Genotyping of the 6986A>G allelic variant corresponding to CYP3A5*3 was systematically performed. One year after transplantation, tacrolimus blood trough concentration (C0) target range was 5–7 ng/mL. However, daily dose was capped to 0.10 mg/kg/day regardless of the CYP3A5 genotype. A total 208 CYP3A5*1/- patients were included. Despite a higher daily dose, CYP3A5*1/- recipients exhibited lower C0 during follow-up (p < 0.01). Multivariate analysis did not show any significant influence of CYP3A5*1/- genotype (HR = 0.70, 0.46–1.07, p = 0.10) on patient-graft survival. Glomerular Filtration Rate (GFR) decline was significantly lower for the CYP3A5*1/- group (p = 0.02). The CYP3A5*1/- genotype did not significantly impact the risk of biopsy-proven acute rejection (BPAR) (HR = 1.01, 0.68–1.49, p = 0.97) despite significantly lower C0. Based on our experience, a strategy of tacrolimus capping is associated with a better GFR evolution in CYP3A5*1/- recipients without any significant increase of BPAR incidence. Our study raised some issues about specific therapeutic tacrolimus C0 targets for CYP3A5*1/- patients and suggests to set up randomized control studies in this specific population.

The Tacrolimus Metabolism Rate and Dyslipidemia after Kidney Transplantation

Fast tacrolimus (Tac) metabolism is associated with reduced survival rates after renal transplantation (RTx), mainly due to cardiovascular events. Because dyslipidemia is a leading cause of cardiovascular death, we hypothesized that most RTx patients do not achieve recommended target low-density lipoprotein cholesterol (LDL-C) levels (European cardiology society guidelines) and that fast Tac metabolizers have higher dyslipidemia rates. This study included RTx recipients who received initial immunosuppression with immediate-release tacrolimus (IR-Tac), mycophenolate, and prednisolone. Patients were grouped according to their Tac concentration-to-dose ratio (C/D ratio) 3 months after RTx. Dyslipidemia parameters were analyzed at RTx, 3 months, and 12 months after RTx. Statin use and renal function were documented in a 12-month follow-up, and death was documented in a 60-month follow-up. Ninety-six RTx recipients were divided into two groups: 31 fast Tac metabolizers (C/D ratio < 1.05 ng/mL·1/mg) and 65 slow metabolizers (C/D ratio ≥ 1.05 ng/mL·1/mg). There were no differences in triglyceride or cholesterol levels between groups at RTx, 3, and 12 months after RTx. A total of 93.5% of fast and 95.4% of slow metabolizers did not achieve target LDL-C levels (p = 0.657). Fast metabolizers developed lower renal function compared to slow metabolizers 12 months after RTx (p = 0.009). Fast metabolizers showed a 60 month survival rate of 96.8% compared to 94.7% in the slow metabolizer group (p = 0.811). As most RTx recipients do not reach recommended target LDL-C levels, individualized nutritional counseling and lipid-lowering therapy must be intensified. Fast Tac metabolism is associated with lower renal function after RTx, but does not play a significant role in dyslipidemia.

Obesity and Post-Transplant Diabetes Mellitus in Kidney Transplantation

Worldwide, the prevalence obesity, diabetes, and chronic kidney disease is increasing apace. The relationship between obesity and chronic kidney disease is multidimensional, especially when diabetes is also considered. The optimal treatment of patients with chronic kidney disease includes the need to consider weight loss as part of the treatment. The exact relationship between obesity and kidney function before and after transplantation is not as clear as previously imagined. Historically, patients with obesity had worse outcomes following kidney transplantation and weight loss before surgery was encouraged. However, recent studies have found less of a correlation between obesity and transplant outcomes. Transplantation itself is also a risk factor for developing diabetes, a condition known as post-transplant diabetes mellitus, and is related to the use of immunosuppressive medications and weight gain following transplantation. Newer classes of anti-diabetic medications, namely SGLT-2 inhibitors and GLP-1 agonists, are increasingly being recognized, not only for their ability to control diabetes, but also for their cardio and renoprotective effects. This article reviews the current state of knowledge on the management of obesity and post-transplant diabetes mellitus for kidney transplant patients.

NEAT1/hsa-miR-372-3p axis participates in rapamycin-induced lipid metabolic disorder

Rapamycin is a crucial immunosuppressive regimen for patients that have undergone liver transplantation (LT). However, one of the major side effects of rapamycin include metabolic disorders such as dyslipidemia, and the mechanism remains unknown. This study aims to explore the biomolecules that are responsible for rapamycin-induced dyslipidemia and the control strategies that can reverse the lipid metabolism disorder. In this study, data collected from LT patients, cell and mouse models treated with rapamycin were analyzed. Results showed an increase of triglycerides (TGs) induced by rapamycin. MicroRNAs (miRNAs) play important roles in many vital biological processes including TG metabolism. hsa-miR-372-3p was filtered using RNA sequencing and identified as a key regulator in rapamycin-induced TGs accumulation. Using bioinformatics and experimental analyses, target genes of hsa-miR-372-3p were predicted. These genes were alkylglycerone phosphate synthase (AGPS) and apolipoprotein C4 (APOC4), which are reported to be involved in TG metabolism. LncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) was also identified as an upstream regulatory factor of hsa-miR-372-3p. From the results of this study, NEAT1/hsa-miR-372-3p/AGPS/APOC4 axis plays a vital role in rapamycin-disruption of lipid homeostasis. Therefore, targeting this axis is a potential therapeutic target combating rapamycin-induced dyslipidemia after LT.

Metabolic Surgery to Treat Obesity in Diabetic Kidney Disease, Chronic Kidney Disease, and End-Stage Kidney Disease; What Are the Unanswered Questions?

Obesity is a major factor in contemporary clinical practice in nephrology. Obesity accelerates the progression of both diabetic and non-diabetic chronic kidney disease and, in renal transplantation, both recipient and donor obesity increase the risk of allograft complications. Obesity is thus a major driver of renal disease progression and a barrier to deceased and living donor kidney transplantation. Large observational studies have highlighted that metabolic surgery reduces the incidence of albuminuria, slows chronic kidney disease progression, and reduces the incidence of end-stage kidney disease over extended follow-up in people with and without type 2 diabetes. The surgical treatment of obesity and its metabolic sequelae has therefore the potential to improve management of diabetic and non-diabetic chronic kidney disease and aid in the slowing of renal decline toward end-stage kidney disease. In the context of patients with end-stage kidney disease, although complications of metabolic surgery are higher, absolute event rates are low and it remains a safe intervention in this population. Pre-transplant metabolic surgery increases access to kidney transplantation in people with obesity and end-stage kidney disease. Metabolic surgery also improves management of metabolic complications post-kidney transplantation, including new-onset diabetes. Procedure selection may be critical to mitigate the risks of oxalate nephropathy and disruption to immunosuppressant pharmacokinetics. Metabolic surgery may also have a role in the treatment of donor obesity, which could increase the living kidney donor pool with potential downstream impact on kidney paired exchange programmes. The present paper provides a comprehensive coverage of the literature concerning renal outcomes in clinical studies of metabolic surgery and integrates findings from relevant mechanistic pre-clinical studies. In so doing the key unanswered questions for the field are brought to the fore for discussion.

Importance of Hematopoietic Mixed Chimerism for Induction of Renal Allograft Tolerance in Nonhuman Primates

BACKGROUND

Although induction of durable mixed chimerism is required for murine skin allograft tolerance (TOL), renal allograft TOL has been achieved after induction of only transient mixed chimerism in nonhuman primates (NHPs) and humans. To better define the level/duration of chimerism required for stable renal allograft TOL, we retrospectively analyzed these parameters and compared them with transplant outcomes in NHP combined kidney and bone marrow transplant recipients.

METHODS

Peripheral blood levels and duration of myeloid or lymphoid chimerism were retrospectively analyzed in 34 NHP combined kidney and bone marrow transplantation recipients which were divided into 3 groups: TOL, n = 10; chronic antibody-mediated rejection (CAMR), n = 12; and T cell-mediated rejection (TCMR), n = 12.

RESULTS

All 4 of the recipients that failed to develop any chimerism lost their allografts due to TCMR after discontinuation of immunosuppression (56 ± 3 d). Among 30 recipients who successfully developed multilineage chimerism, 10 achieved long-term immunosuppression-free survival without rejection (1258 ± 388 d), 12 eventually developed CAMR (932 ± 155 d), and 8 developed TCMR (82 ± 10 d). The maximum level but not duration of lymphoid chimerism was significantly higher in TOL recipients compared with both CAMR (P = 0.0159) and TCMR (P = 0.0074). On the other hand, the maximum myeloid chimerism was significantly higher in TOL than in TCMR (P = 0.0469), but not in CAMR. Receiver operating characteristic analyses revealed that lymphoid chimerism levels of 3.1% or greater could reliably predict long-term immunosuppression-free renal allograft survival (P < 0.0001).

CONCLUSIONS

This retrospective study confirmed that induction of chimerism is essential for long-term immunosuppression-free survival, which best correlates with lymphoid chimerism levels higher than 3.1%.

Metabolic Pathway of Cyclosporine A and Its Correlation with Nephrotoxicity

Background:

Cyclosporine A (CsA) is widely used for organ transplantation and autoimmune disorders. However, CsA nephrotoxicity is a serious side effect that limits the clinical use of CsA. The metabolism of CsA has a close relationship with this disease in renal-transplant patients. However, the metabolic pathways of CsA and its metabolizing enzymes have rarely been comprehensively reviewed. In this review, we have summarized the specific metabolic profiles of CsA in humans, especially renal-transplant patients. Moreover, the specific metabolizing enzymes and the potential roles that CsA metabolism plays in CsA nephrotoxicity were summarized and discussed.

Methods:

Electronic databases including PubMed, Web of Science, and Scifinder were searched with the keywords "Cyclosporine A and metabolism", and "Cyclosporine A and nephrotoxicity", "Cyclosporine A metabolism and nephrotoxicity". All these studies published until 2018 were included in this review.

Results:

The major metabolic pathways of CsA in humans are hydroxylation and N-demethylation. Normally, these metabolites are relatively less toxic than CsA. However, the metabolism of CsA in the kidneys is much weaker than that in the liver, which explains why CsA is so toxic to the kidneys. CYP3A families, especially CYP3A4 and CYP3A5, play an important role in the biotransformation of CsA. Moreover, increased lines of evidence show that some metabolites (including AM19) associate directly with nephrotoxicity in CsA-treated organ-transplant patients.

Conclusion:

The findings of this review help to further understand the metabolic activities of CsA in renal-transplant patients and cast some light on the mechanisms of CsA nephrotoxicity.

Clinical Profile of Patients With Diabetes Mellitus and Liver Transplantation: Results After a Multidisciplinary Team Intervention

BACKGROUND

Over the years, survival after liver transplantation has increased and metabolic complications are becoming more common, contributing to patients' morbidity and mortality. The objectives of this study were to describe a population of patients with hepatic transplantation and diabetes mellitus (DM), evaluate the frequency of metabolic complications, and assess the impact of a multidisciplinary team on DM management.

MATERIALS AND METHODS

This was a retrospective study involving interview and medical record analysis of 46 consecutive patients followed at the diabetes mellitus and liver transplantation unit of a tertiary university hospital, all evaluated by a multidisciplinary team.

RESULTS

Of all patients, 76.1% were men, with a median age 60 years old (interquartile range: 56 to 65 years) and liver transplantation time of 5 years (interquartile range: 0.6-9 years). Hypertension, hypercholesterolemia, hypertriglyceridemia, alcoholism, and smoking were present in 47.8%, 34.8%, 23.9%, 34.8%, and 30.4% of the patients, respectively. The most frequent immunosuppressant in use was tacrolimus (71.1%). Regarding nutritional status, 37.9% of patients were classified as overweight according to body mass index, and 41.2% were considered overweight according to the triceps skin fold. The median glycosylated hemoglobin and weight before and after intervention of the multidisciplinary team in all 46 patients were, respectively, 7.6% (5.7% to 8.8%) versus 6.5% (5.7% to 7.7%); P = .022 and 70.5 kg (64.7 to 82.0 kg) versus 71.6 kg (65.0 to 85.0 kg); P = .18.

CONCLUSIONS

Hypertension and dyslipidemia were common in transplanted patients with DM. Intervention of the multidisciplinary team resulted in a significant improvement in glycosylated hemoglobin without significant weight gain.

Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis in Liver Transplantation

The number of transplants caused by nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NASH) has been progressively increasing and this is expected to become the most common indication for liver transplant in the United States. Patients with NASH show many features of the metabolic syndrome and, as a result, are at higher risk for postoperative cardiovascular morbidity and mortality. Despite this, patients with NASH have long-term graft and patient survival rates comparable with other causes of chronic liver disease. Posttransplant metabolic syndrome is a common occurrence that increases the risk of steatosis in the graft liver.

Performance of transient elastography and serum fibrosis biomarkers for non-invasive evaluation of recurrent fibrosis after liver transplantation: A meta-analysis

Recurrent fibrosis after liver transplantation (LT) impacts on long-term graft and patient survival. We performed a meta-analysis to compare the accuracy of non-invasive methods to diagnose significant recurrent fibrosis (stage F2-F4) following LT. Studies comparing serum fibrosis biomarkers, namely AST-to-platelet ratio index (APRI), fibrosis score 4 (FIB-4), or transient elastography (TE) with liver biopsy in LT recipients were systematically identified through electronic databases. In the meta-analysis, we calculated the weighted pooled odds ratio and used a fixed effect model, as there was no significant heterogeneity between studies. Eight studies were included for APRI, four for FIB-4, and twelve for TE. The mean prevalence of significant liver fibrosis was 37.4%. The summary odds ratio was significantly higher for TE (21.17, 95% CI confidence interval 14.10–31.77, p = 1X10^-30) as compared to APRI (9.02, 95% CI 5.79–14.07; p = 1X10^-30) and FIB-4 (7.08, 95% CI 4.00–12.55; p = 1.93X10^-11). In conclusion, TE performs best to diagnose recurrent fibrosis in LT recipients. APRI and FIB-4 can be used as an estimate of significant fibrosis at centres where TE is not available. Longitudinal assessment of fibrosis by means of these non-invasive tests may reduce the need for liver biopsy.

Risk factors for metabolic syndrome after liver transplantation: A systematic review and meta-analysis

INTRODUCTION

Metabolic syndrome is associated with increased risk of cardiovascular events, which contributes to the elevated mortality rate among liver transplant recipients. The objective of this systematic review and meta-analysis was to assess the prevalence and risk factors for metabolic syndrome after liver transplantation.

METHODS

The databases Medline and Scopus were searched for observational studies evaluating prevalence and risk factors for metabolic syndrome after liver transplantation. Meta-analyses were performed based on odds ratios (ORs) from multivariable analyses. The Newcastle-Ottawa Scale was used for assessment of bias.

RESULTS

The literature search generated 1815 records of which 16 articles were included comprising 3539 patients. The post-transplant prevalence of metabolic syndrome was 39%. Eight studies were eligible for meta-analyses, which showed that pre-transplant diabetes (OR=3.54, 95% confidence interval (CI): 2.51-4.98) and pre-transplant obesity (OR=2.44, 95% CI: 1.48-4.03) were risk factors for metabolic syndrome. Six out of seven studies reported that recipients with metabolic syndrome had a higher incidence of cardiovascular events. Four studies showed that survival was not affected by metabolic syndrome.

CONCLUSIONS

The prevalences of metabolic syndrome and new-onset metabolic syndrome were high after liver transplantation. Metabolic syndrome was associated with cardiovascular events, but not poorer survival. Patients with pre-transplant diabetes and -obesity are at high risk of metabolic syndrome and should be under careful surveillance in order to prevent, earlier diagnose, and treat metabolic syndrome and thereby limit the risk of cardiovascular events.

Chimerism-based tolerance in organ transplantation: preclinical and clinical studies

Induction of allograft tolerance has been considered the ultimate goal in organ transplantation. Although numerous protocols to induce allograft tolerance have been reported in mice, a chimerism-based approach through donor haematopoietic stem cell transplantation has been the only approach to date that induced allograft tolerance reproducibly following kidney transplantation in man. Renal allograft tolerance has been achieved by induction of either transient mixed chimerism or persistent full donor chimerism. Although the risk of rejection may be low in tolerance achieved via durable full donor chimerism, the development of graft-versus-host disease (GVHD) has limited the wider clinical application of this approach. In contrast, tolerance induced by transient mixed chimerism has not been associated with GVHD, but the risk of allograft rejection is more difficult to predict after the disappearance of haematopoietic chimerism. Current efforts are directed towards the development of more clinically feasible and reliable approaches to induce more durable mixed chimerism in order to widen the clinical applicability of these treatment regimens.

Cynomolgus monkeys are successfully and persistently infected with hepatitis E virus genotype 3 (HEV-3) after long-term immunosuppressive therapy

Epidemiological studies found that hepatitis E virus genotype 3 (HEV-3) infection was associated with chronic hepatitis and cirrhosis in immunocompromised patients. Our study aimed to investigate the relationship between the host immunosuppressive status and the occurrence of HEV-related chronic hepatitis. Here we describe a successful experimental study, using cynomolgus monkeys previously treated with tacrolimus, a potent calcineurin inhibitor immunosuppressant, and infected with a Brazilian HEV-3 strain isolated from naturally infected pigs. HEV infected monkeys were followed up during 160 days post infection (dpi) by clinical signs; virological, biochemical and haematological parameters; and liver histopathology. The tacrolimus blood levels were monitored throughout the experiment. Immunosuppression was confirmed by clinical and laboratorial findings, such as: moderate weight loss, alopecia, and herpes virus opportunistic infection. In this study, chronic HEV infection was characterized by the mild increase of liver enzymes serum levels; persistent RNA viremia and viral faecal shedding; and liver histopathology. Three out of four immunosuppressed monkeys showed recurrent HEV RNA detection in liver samples, evident hepatocellular ballooning degeneration, mild to severe macro and microvesicular steatosis (zone 1), scattered hepatocellular apoptosis, and lobular focal inflammation. At 69 dpi, liver biopsies of all infected monkeys revealed evident ballooning degeneration (zone 3), discrete hepatocellular apoptosis, and at most mild portal and intra-acinar focal inflammation. At 160 dpi, the three chronically HEV infected monkeys showed microscopic features (piecemeal necrosis) corresponding to chronic hepatitis in absence of fibrosis and cirrhosis in liver parenchyma. Within 4-months follow up, the tacrolimus-immunosuppressed cynomolgus monkeys infected with a Brazilian swine HEV-3 strain exhibited more severe hepatic lesions progressing to chronic hepatitis without liver fibrosis, similarly as shown in tacrolimus-immunosuppressed solid organ transplant (SOT) recipients. The cause-effect relationship between HEV infection and tacrolimus treatment was confirmed in this experiment.

Incidence and Predictors of Advanced Liver Fibrosis by a Validated Serum Biomarker in Liver Transplant Recipients

Background and Aims. Serum fibrosis biomarkers have shown good accuracy in the liver transplant (LT) population. We employed a simple serum biomarker to elucidate incidence and predictors of advanced fibrosis after LT over a long follow-up period. Methods. We included 440 consecutive patients who underwent LT between 1991 and 2013. Advanced liver fibrosis was defined as FIB-4 > 3.25 beyond 12 months after LT. Results. Over 2030.5 person-years (PY) of follow-up, 189 (43%) developed FIB-4 > 3.25, accounting for an incidence of 9.3/100 PY (95% confidence interval [CI], 8.1-10.7). Advanced fibrosis was predicted by chronic HCV infection (adjusted hazard ratio (aHR) = 3.96, 95% CI 2.92-5.36, p < 0.001), hypoalbuminemia (aHR = 2.31, 95% CI 1.72-3.09; p < 0.001), and hyponatremia (aHR = 1.48, 95% CI 1.09-2.01; p = 0.01). LT recipients with more than 1 predictor had a higher incidence of advanced fibrosis, the highest being when all 3 predictors coexisted (log-rank: p < 0.001). Conclusions. Chronic HCV infection, hypoalbuminemia, and hyponatremia predict progression to advanced liver fibrosis following LT. Patients with these risk factors should be serially monitored using noninvasive fibrosis biomarkers and prioritized for interventions.

Prospective Analysis of Metabolic Parameters in the Detection of Diabetes and Metabolic Syndrome in Liver Transplant Recipients

BACKGROUND

Liver transplant recipients are at increased risk of metabolic complications, including new-onset diabetes mellitus after transplantation (NODAT) and post-transplant metabolic syndrome (PTMS), both of which are associated with decreased patient survival. We prospectively monitored traditional and novel metabolic parameters in nondiabetic liver transplantation (LT) candidates to determine their role in detecting these conditions.

METHODS

Nondiabetic adults undergoing initial LT were prospectively identified. NODAT and PTMS were defined according to WHO and ATP III criteria. Metabolic measures were collected at pre-LT, 4, and 12 months post-LT.

RESULTS

Of 49 subjects enrolled, 24.5% were found to be diabetic pre-LT by 2-hr oral glucose tolerance test (OGTT) despite fasting glucose below the diabetic range. Two patients developed NODAT post-LT. A single patient was found to have MS at baseline, while PTMS developed in 26% and 31.3% of patients at 4 and 12 months. Novel metabolic markers did not detect these conditions.

CONCLUSIONS

Screening OGTT detected pre-LT diabetes in patients with normal fasting glucose. Serial measurement of metabolic parameters allowed earlier detection of PTMS. Novel metabolic parameters did not correspond to post-LT outcomes, but provided a baseline for future study. More frequent and intensive metabolic monitoring appears reasonable, but larger studies are needed to clarify its efficacy.

New-Onset Diabetes Mellitus Associated with Sirolimus Use in Renal Transplant Recipients

New-onset diabetes after transplantation and impaired glucose tolerance are very common in renal transplant patients. New-onset diabetes after transplantation (NODAT) is associated with increased cardiovascular morbidity and mortality, reduced graft and patient survival. Several risk factors for NODAT have been identified: age, obesity, family history of diabetes mellitus and HCV infection. In addition, steroid and calcineurin inhibitors also contribute to the development of NODAT. Sirolimus causes immunosuppressive effects by inhibiting mammalian target of rapamycin (mTOR), and has well known side effects. The effects of sirolimus on glucose metabolism and contribution to NODAT development are not clearly known. In this report, we presented five RTX patients who developed NODAT under the treatment of sirolimus.

Serum fibrosis biomarkers predict death and graft loss in liver transplantation recipients

Noninvasive serum fibrosis biomarkers predict clinical outcomes in pretransplant patients with chronic liver disease. We investigated the role of serum fibrosis biomarkers and of changes in biomarkers in predicting death and graft loss after liver transplantation (LT). We included 547 patients who underwent LT between 1991 and 2012 and who met the following criteria: patient and graft survival > 12 months; serum fibrosis biomarkers aspartate aminotransferase-to-platelet ratio index (APRI), fibrosis score 4 (FIB-4), and nonalcoholic fatty liver disease (NAFLD) fibrosis score available at 1 year after LT; and a minimum follow-up of 1 year. Delta of fibrosis biomarkers was defined as (end of follow-up score--baseline score)/follow-up duration. Baseline and delta fibrosis biomarkers were associated with death: APRI > 1.5 (adjusted hazard ratio [aHR], 2.2; 95% confidence interval [CI], 1.4-3.3; P < 0.001) and delta APRI > 0.5 (aHR, 5.3; 95% CI, 3.4-8.2; P < 0.001); FIB-4 > 3.3 (aHR, 1.9; 95% CI, 1.3-2.8; P = 0.002) and delta FIB-4 > 1.4 (aHR, 2.4; 95% CI, 1.4-4.1; P = 0.001); and NAFLD fibrosis score > 0.7 (aHR, 1.9; 95% CI, 1.3-2.9; P = 0.002) and delta NAFLD fibrosis score (aHR, 3.7; 95% CI, 2.6-5.4; P < 0.001). Baseline and delta fibrosis biomarkers were associated also with graft loss. In conclusion, serum fibrosis biomarkers 1 year after LT and changes in serum fibrosis biomarkers predict death and graft loss in LT recipients. They may help in risk stratification of LT recipients and identify patients requiring closer monitoring.

A retrospective 15-year review: survival advantage after switching to sirolimus in hepatitis C virus infected liver graft recipients

BACKGROUND

The use of sirolimus-based immune suppression in liver transplantation, particularly in hepatitis C virus (HCV)-infected recipients, remains contentious. There is some evidence that sirolimus retards hepatic fibrosis, is renal sparing and may be of benefit in preventing hepatocellular carcinoma (HCC) recurrence. Sirolimus has not been adopted by many transplant centres because of persistent concerns regarding an increased risk of hepatic artery thrombosis, graft loss and death with de novo sirolimus.

AIM

To review the impact of switching to sirolimus monotherapy in HCV-infected liver recipients with respect to survival, graft loss and hepatic fibrosis.

METHODS

A retrospective review of 190 patients from a single centre undergoing first liver transplantation for HCV over 15 years. 113 patients were switched from calcineurin inhibitor (CNI)-based therapy to low-dose sirolimus monotherapy at a median of 15 months after transplantation for HCV-related fibrosis (72%), renal impairment (14%) or high-risk HCC (5%).

RESULTS

Patients switched to sirolimus had improved survival (P < 0.001) and slower progression to cirrhosis (P = 0.001). In patients with HCC (n = 91), sirolimus duration rather than strategy was an independent predictor of survival (P = 0.001) and extended time to HCC recurrence (33 vs. 16 months). Patients switched for renal dysfunction showed improvement in serum creatinine (140-108 μmol/L, P = 0.001). Those remaining on CNI-therapy were more likely to develop post-transplant diabetes (P = 0.03).

CONCLUSION

These data suggest selective switching to low-dose sirolimus monotherapy in HCV-positive liver recipients improves clinical outcome.

Long-term results in recipients of combined HLA-mismatched kidney and bone marrow transplantation without maintenance immunosuppression

We report here the long-term results of HLA-mismatched kidney transplantation without maintenance immunosuppression (IS) in 10 subjects following combined kidney and bone marrow transplantation. All subjects were treated with nonmyeloablative conditioning and an 8- to 14-month course of calcineurin inhibitor with or without rituximab. All 10 subjects developed transient chimerism, and in seven of these, IS was successfully discontinued for 4 or more years. Currently, four subjects remain IS free for periods of 4.5-11.4 years, while three required reinstitution of IS after 5-8 years due to recurrence of original disease or chronic antibody-mediated rejection. Of the 10 renal allografts, three failed due to thrombotic microangiopathy or rejection. When compared with 21 immunologically similar living donor kidney recipients treated with conventional IS, the long-term IS-free survivors developed significantly fewer posttransplant complications. Although most recipients treated with none or two doses of rituximab developed donor-specific antibody (DSA), no DSA was detected in recipients treated with four doses of rituximab. Although further revisions of the current conditioning regimen are planned in order to improve consistency of the results, this study shows that long-term stable kidney allograft survival without maintenance IS can be achieved following transient mixed chimerism induction.

Strategies for the management of adverse events associated with mTOR inhibitors

Mammalian target of rapamycin (mTOR) inhibitors are used as potent immunosuppressive agents in solid-organ transplant recipients (everolimus and sirolimus) and as antineoplastic therapies for various cancers (eg, advanced renal cell carcinoma; everolimus, temsirolimus, ridaforolimus). Relevant literature, obtained from specific PubMed searches, was reviewed to evaluate the incidence and mechanistic features of specific adverse events (AEs) associated with mTOR inhibitor treatment, and to present strategies to effectively manage these events. The AEs examined in this review include stomatitis and other cutaneous AEs, wound-healing complications (eg, lymphocele, incisional hernia), diabetes/hyperglycemia, dyslipidemia, proteinuria, nephrotoxicity, delayed graft function, pneumonitis, anemia, hypertension, gonadal dysfunction, and ovarian toxicity. Strategies for selecting appropriate patients for mTOR inhibitor therapy and minimizing the risks of AEs are discussed, along with best practices for identifying and managing side effects. mTOR inhibitors are promising therapeutic options in immunosuppression and oncology; most AEs can be effectively detected and managed or reversed with careful monitoring and appropriate interventions.

Tolerance induction: hematopoietic chimerism

PURPOSE OF REVIEW

Although numerous experimental models to induce allograft tolerance have been reported, it has been difficult to translate these basic studies to clinical transplantation. However, successful induction of tolerance in HLA-mismatched kidney transplantation has recently been reported. In this review, recent progress in tolerance induction in preclinical (nonhuman primates) and clinical transplantation is summarized.

RECENT FINDINGS

Among many clinical trials to induce renal allograft tolerance, success has so far been achieved only by combining donor bone marrow with organ transplantation. Induction of renal allograft tolerance by transient or durable mixed chimerism has been reported in HLA-matched or mismatched kidney transplant recipients. More recently, renal allograft tolerance by induction of full donor chimerism has also been reported using a more intensified preparative conditioning regimen.

SUMMARY

Durable allograft tolerance has been achieved by induction of hematopoietic chimerism in clinical kidney transplantation, with outstanding long-term results in successful cases. However, these approaches have been associated with higher early complications than are seen following transplantation with conventional immunosuppression. Improvements in the consistency and safety of tolerance induction and extension of successful protocols to other organs will be the next steps in bringing tolerance to a wider range of clinical applications.

Ablation of calcineurin Aβ reveals hyperlipidemia and signaling cross-talks with phosphodiesterases

Insulin resistance, hyperlipidemia, and cardiovascular complications are common dysregulations of metabolic syndrome. Transplant patients treated with immunosuppressant drugs such as cyclosporine A (CsA), an inhibitor of calcineurin phosphatase, frequently develop similar metabolic complications. Although calcineurin is known to mediate insulin sensitivity by regulating β-cell growth and adipokine gene transcription, its role in lipid homeostasis is poorly understood. Here, we examined lipid homeostasis in mice lacking calcineurin Aβ (CnAβ(-/-)). We show that mice lacking calcineurin Aβ are hyperlipidemic and develop age-dependent insulin resistance. Hyperlipidemia found in CnAβ(-/-) mice is, in part, due to increased lipolysis in adipose tissues, a process mediated by β-adrenergic G-protein-coupled receptor signaling pathways. CnAβ(-/-) mice also exhibit additional pathophysiological phenotypes caused by the potentiated GPCR signaling pathways. A cell autonomous mechanism with sustained cAMP/PKA activation is found in CnAβ(-/-) mice or upon CsA treatment to inhibit calcineurin. Increased PKA activation and cAMP accumulation in CnAβ(-/-) mice, however, are sensitive to phosphodiesterase inhibitor. Indeed, we show that calcineurin regulates degradation of phosphodiesterase 3B, in addition to phosphodiesterase 4D. These results establish a role for calcineurin in lipid homeostasis. These data also indicate that potentiated cAMP signaling pathway may provide an alternative molecular pathogenesis for the metabolic complications elicited by CsA in transplant patients.

Cholesterol metabolism altered and FGF21 levels high after pediatric liver transplantation despite normal serum lipids

Liver transplantation (LT) predisposes to metabolic derangements and increases the risk for cardiovascular disease. We conducted a national cross-sectional study of all pediatric recipients who underwent LT between 1987 and 2007. We measured serum levels of noncholesterol sterols (surrogate markers of cholesterol synthesis and intestinal absorption) and fibroblast growth factor 21 (FGF21) in 49 patients (74% of survivors) at a median of 10 years posttransplant and in 93 controls matched for age and gender. Although serum cholesterol levels were similar in patients and controls, patients displayed increased whole-body synthesis and decreased intestinal absorption of cholesterol compared with controls (lathosterol to cholesterol ratio 129 ± 55 vs. 96 ± 41, respectively, p < 0.001; campesterol to cholesterol ratio 233 ± 91 vs. 316 ± 107, respectively; p < 0.001). Azathioprine (r =-0.383, p = 0.007) and low-dose methylpredisolone (r =-0.492, p < 0.001) were negatively associated with lathosterol/sitosterol ratio reflecting a favorable effect on cholesterol metabolism. FGF21 levels were higher in patients than in controls (248 pg/mL vs. 77 pg/mL, p < 0.001). In healthy controls, FGF21 was associated with cholesterol metabolism, an association missing in LT recipients. Normal serum lipids are achievable in long-term survivors of pediatric LT, but changes in cholesterol metabolism and increased FGF21 levels may explicate later cardiovascular risk.

Focal fat masquerading as malignancy in the liver graft of a post-transplant patient

BACKGROUND AND AIMS

Liver failure from non-alcoholic fatty liver disease (NAFLD) is an increasing indication for liver transplant and recurrence of fatty liver in transplanted grafts has been documented. Herein is described an atypical recurrence of steatosis as a de novo focal fatty lesion that mimicked a more ominous cancerous lesion. This presentation of recurrent NAFLD has not previously been described in the literature.

METHODS

Chart review.

RESULTS

Biopsy of an atypical lesion was found to be focal fat with surrounding steatohepatitis.

CONCLUSIONS

Non-alcoholic fatty liver disease may recur after liver transplant and manifest as a focal fatty lesion. It is important to catalogue the atypical presentations of the increasingly common NAFLD developing in transplanted livers.

Metabolic syndrome in liver transplant recipients: prevalence, risk factors, and association with cardiovascular events

Features of metabolic syndrome are not uncommon in patients after liver transplantation. To examine the prevalence and risk factors of posttransplantation metabolic syndrome (PTMS), the files of 252 transplant recipients (mean age, 54.5 ± 2.8 years, 57.9% male) were reviewed for pretransplant and posttransplant clinical and laboratory parameters (mean follow-up, 6.2 ± 4.4 years). Rates of obesity (body mass index >30 kg/m(2) ), hypertriglyceridemia (>150 mg/dL), high-density lipoprotein cholesterol <40 mg/dL (men) or <50 mg/dL (women), hypertension, and diabetes were significantly higher after transplantation than before. Metabolic syndrome was diagnosed in 5.4% of patients before transplantation and 51.9% after. Besides significantly higher rates of the typical metabolic derangements (P < 0.0001), the patients with PTMS were older and heavier than those without PTMS, and they had a higher rate of pretransplant hepatitis C virus infection (P < 0.03) and more posttransplant major vascular and cardiac events (20 events in 15.2% of patients with PTMS versus 6 events in 4.9% of patients without PTMS; P < 0.007). There was no between-group difference in mortality or causes of death (mainly related to recurrent disease, graft failure, and sepsis). Significant independent predictors of PTMS on logistic regression analysis were age (odds ratio [OR] = 1.04), pretransplant nonalcoholic fatty liver disease (OR = 3.4), body mass index (OR = 1.13), diabetes (OR = 5.95), and triglycerides (OR = 1.01). The rate of metabolic syndrome in liver transplant recipients is more than twice that reported for the general population. PTMS is associated with cardiovascular morbidity but not mortality, and it may be predicted by pretransplantation conditions. Prospective studies are required to determine the significance and management of PTMS.

Evolutionarily conserved role of calcineurin in phosphodegron-dependent degradation of phosphodiesterase 4D

Calcineurin is a widely expressed and highly conserved Ser/Thr phosphatase. Calcineurin is inhibited by the immunosuppressant drug cyclosporine A (CsA) or tacrolimus (FK506). The critical role of CsA/FK506 as an immunosuppressant following transplantation surgery provides a strong incentive to understand the phosphatase calcineurin. Here we uncover a novel regulatory pathway for cyclic AMP (cAMP) signaling by the phosphatase calcineurin which is also evolutionarily conserved in Caenorhabditis elegans. We found that calcineurin binds directly to and inhibits the proteosomal degradation of cAMP-hydrolyzing phosphodiesterase 4D (PDE4D). We show that ubiquitin conjugation and proteosomal degradation of PDE4D are controlled by a cullin 1-containing E(3) ubiquitin ligase complex upon dual phosphorylation by casein kinase 1 (CK1) and glycogen synthase kinase 3beta (GSK3beta) in a phosphodegron motif. Our findings identify a novel signaling process governing G-protein-coupled cAMP signal transduction-opposing actions of the phosphatase calcineurin and the CK1/GSK3beta protein kinases on the phosphodegron-dependent degradation of PDE4D. This novel signaling system also provides unique functional insights into the complications elicited by CsA in transplant patients.

Different effects of FK506, rapamycin, and mycophenolate mofetil on glucose-stimulated insulin release and apoptosis in human islets

Pancreatic islet transplantation has the potential to be an effective treatment for type 1 diabetes mellitus. While recent improvements have improved 1-year outcomes, follow-up studies show a persistent loss of graft function/survival over 5 years. One possible cause of islet transplant failure is the immunosuppressant regimen required to prevent alloimmune graft rejection. Although there is evidence from separate studies, mostly in rodents and cell lines, that FK506 (tacrolimus), rapamycin (sirolimus), and mycophenolate mofetil (MMF; CellCept) can damage pancreatic beta-cells, there have been few side-by-side, multiparameter comparisons of the effects of these drugs on human islets. In the present study, we show that 24-h exposure to FK506 or MMF impairs glucose-stimulated insulin secretion in human islets. FK506 had acute and direct effects on insulin exocytosis, whereas MMF did not. FK506, but not MMF, impaired human islet graft function in diabetic NOD*scid mice. All of the immunosuppressants tested in vitro increased caspase-3 cleavage and caspase-3 activity, whereas MMF induced ER-stress to the greatest degree. Treating human islets with the GLP-1 agonist exenatide ameliorated the immunosuppressant-induced defects in glucose-stimulated insulin release. Together, our results demonstrate that immunosuppressants impair human beta-cell function and survival, and that these defects can be circumvented to a certain extent with exenatide treatment.

Tacrolimus and angiotensin receptor blockers associated with changes in serum adiponectin level in new-onset diabetes after renal transplantation: single-center cross-sectional analysis

We analysed whether pre- and post-transplant serum adiponectin levels in renal transplant patients were associated with new-onset diabetes after transplantation (NODAT). The mean post-transplant follow-up duration was 47.9 months. Of 98 previously non-diabetic renal transplant patients, 12 were diagnosed with NODAT and 86 without (non-NODAT). There was a significant inverse correlation between mean post-transplant serum adiponectin level and homeostasis model assessment for insulin resistance (HOMA-IR) (r = -0.22, P = 0.03), and a positive correlation between follow-up duration after transplantation and HOMA-IR (r = 0.28, P = 0.005). The mean pre- and post-transplant serum adiponectin levels in NODAT patients were significantly lower than those in non-NODAT patients (13.3 vs. 21.0 microg/ml and 13.0 vs. 16.4 microg/ml, P = 0.01 and 0.03 respectively). In addition, the post-transplant serum adiponectin level in patients treated with tacrolimus (TAC) was significantly lower than that in patients with cyclosporine (14.3 vs. 18.7 microg/ml, P = 0.01), while, that level in patients treated with angiotensin receptor blockers (ARB) was significantly higher than that in patients without treatment of ARB (17.9 vs. 14.7 microg/ml, P = 0.01). Our results indicate that post-transplant serum adiponectin levels are decreased after transplantation in association with insulin resistance in the development of NODAT, and that TAC and ARB influence the level of adiponectin in serum.

Metabolic syndrome in liver transplantation: relation to etiology and immunosuppression

Excessive weight gain, hypertension, hyperlipidemia, and diabetes are frequently observed in patients having undergone liver transplantation (LTx). These alterations are probably multifactorial in origin, and cluster to generate a metabolic syndrome (MS), increasing the risk of cardiovascular events. We assessed the prevalence of MS (National Cholesterol Education Program-Adult Treatment Panel III criteria) in 296 LTx patients in the course of regular follow-up, at least 6 months after transplantation (median, 38 months). Several pre-LTx and post-LTx data were collected to identify the factors associated with the presence of MS. In a subset of 99 patients, insulin resistance was measured by the homeostasis model assessment. High blood pressure was present in 53% of cases, hyperlipidemia in 51%, high glucose in 37%, and enlarged waist circumference in 32%. Overall, MS (defined as 3 or more of the above features) was present in 44.5% of cases. Insulin resistance (homeostasis model assessment > 2.7) was observed in 41% of cases. Hypertension and hyperlipidemia were more frequent in subjects on cyclosporine than in tacrolimus-treated cases, whereas the type of immunosuppressive drug had no effect on the prevalence of diabetes, enlarged waist, and MS. In a logistic regression analysis, only pre-LTx body mass index (odds ratio, 1.20), body mass index increase (odds ratio, 1.18), and pre-LTx diabetes (odds ratio, 2.36) predicted MS; age, gender, etiology of liver disease, time from LTx, type of immunosuppressive drug, and previous hepatocellular carcinoma were removed from the model. Disorders related to MS are frequent in LTx patients, and are related to both pre-LTx conditions and to weight gain. Weight control is mandatory in LTx patients to prevent risk factors of premature atherosclerosis.

Calcineurin inhibitor-associated oral inflammatory polyps after transplantation

Calcineurin inhibitors (cyclosporine and tacrolimus) have been used as the mainstay immunosuppressive therapy for solid organ and hematopoietic cell transplantations (HCT) to prevent allograft rejection and for prophylaxis and treatment of the chronic graft-versus-host disease. Adverse effects of these drugs include nephrotoxicity, hepatotoxicity, neurotoxicity, hypertension and gingival hyperplasia. Association of oral non-gingival soft tissue hyperplasia with calcineurin inhibitor therapy has only recently been recognized and is thought to occur infrequently. We present four cases of oral non-gingival inflammatory fibro-vascular hyperplasias attributed to the use of calcineurin inhibitors following solid organ transplantation and HCT. These lesions interfere with function and must be differentiated from other oral lesions, and therefore should be surgically excised.

De novo nonalcoholic fatty liver disease after liver transplantation

Hepatic steatosis is a recognized problem in patients after orthotopic liver transplant (OLT). However, de novo development of nonalcoholic fatty liver disease (NAFLD) has not been well described. The aim of this study was to determine the prevalence and predictors of de novo NAFLD after OLT. A retrospective analysis was performed on 68 OLT patients with donor liver biopsies and posttransplantation liver biopsies. Individual medical charts were reviewed for demographics, indication for OLT, serial histology reports, genotypes for hepatitis C, comorbid conditions, and medications. Liver biopsies were reviewed blindly and graded according to the Brunt Scoring System. Multivariate logistic regression analysis was used to study the risk factors for developing NAFLD. The interval time from OLT to subsequent follow-up liver biopsy was 28 +/- 18 months. A total of 12 patients (18%) developed de novo NAFLD, and 6 (9%) developed de novo NASH. The regression model indicated that the use of angiotensin-converting enzyme inhibitors (ACE-I) was associated with a reduced risk of developing NAFLD after OLT (odds ratio, 0.09; 95% confidence interval, 0.010-0.92; P = 0.042). Increase in body mass index (BMI) of greater than 10% after OLT was associated with a higher risk of developing NAFLD (odds ratio, 19.38; 95% confidence interval, 3.50-107.40; P = 0.001). In conclusion, de novo NAFLD is common in the post-OLT setting, with a significant association with weight gain after transplant. The use of an ACE-I may reduce the risk of developing post-OLT NAFLD.