Tacrolimus versus cyclosporin for immunosuppression in renal transplantation: meta-analysis of randomised trials

Tacrolimus After rATG and Infliximab Induction Immunosuppression-RIMINI Trial

BACKGROUND

Infliximab selectively targets recently activated effector cells and, as an induction agent, might enable the safe elimination of mycophenolate from maintenance immunosuppression in kidney transplantation.

METHODS

This is a phase II international multicenter open-label single-arm confidence interval (CI)-based clinical trial of the BIO-DrIM EU consortium aimed at assessing the efficacy and safety of rabbit antithymocyte globulin and infliximab induction in kidney transplantation. Sixty-seven primary kidney transplant recipients at low risk (panel-reactive antibodies <20%, no donor-specific antibodies [DSA]) received rabbit antithymocyte globulin (2 × 1.5 mg/kg, postoperative days 0 and 1) and infliximab (5 mg/kg, postoperative day 2), followed by mycophenolate-free tacrolimus-based immunosuppression for 12 mo. The primary endpoint was efficacy failure, defined as a composite of acute rejection, graft loss, or poor graft function (estimated glomerular filtration rate <40 mL/min) at 12 mo and was based on the endpoint of the comparator study. Additionally, a historical propensity-matched control cohort was established.

RESULTS

Primary endpoint occurred in 22 of 67 patients (32.84%), with upper bound of an exact 1-sided 95% CI of 43.47%, which met the predefined criteria (efficacy failure of <40% and upper-bound 95% CI of <50%) and was similar in the historical matched cohort. By 12 mo, 79.1% of patients remained on the study protocol. Lower rates of BK replication (6% versus 22.4%; P  = 0.013) but higher rates of de novo DSAs (11.9% versus 1.5%; P  = 0.039) were observed in the study cohort.

CONCLUSIONS

A similar efficacy of the study immunosuppression regimen to the comparator study and the historical matched cohort was found. However, a higher de novo DSA emergence points to an increased risk of antibody-mediated rejection (NCT04114188).

Impact of obesity on the conversion of immediate-release tacrolimus to extended-release tacrolimus in kidney transplant recipients

Outcomes analyzing conversion from IR-tacrolimus (IR) to LCP-tacrolimus (LCP) in obesity are limited. This was a retrospective longitudinal cohort study of patients converted from IR to LCP from June 2019 to October 2020. Primary outcomes were conversion ratios for weight-based dose at a steady-state therapeutic level and identification of appropriate dosing weight. Other outcomes included tacrolimus coefficient of variation (CV), time in therapeutic range (TITR), adverse events, infections, donor specific antibodies (DSAs), and acute rejection. A total of 292 patients were included; 156 and 136 patients with a BMI < 30 and BMI ≥ 30 kg/m2 , respectively. Baseline characteristics were similar, except for pancreas transplant, diabetes, and HLA mismatch. IR to LCP conversion ratio ranged from .73 to .79. Mean LCP dose was similar (.08 vs. .07 mg/kg/day for BMI < 30 and BMI ≥ 30 kg/m2 , respectively); there was a significant difference in IR and LCP mg/kg dosing at steady state with TBW (.11 mg/kg vs.09 mg/kg and .08 mg/kg vs. .06 mg/kg, respectively). The most appropriate dosing weight was adjusted body weight (AdjBW), consistent across IR and LCP steady-state doses, and might yield more accurate steady-state dosing requirements. In multivariable modeling, BMI was a significant predictor of steady state mg/kg dosing at therapeutic goal for total body weight (TBW), but not ideal body weight (IBW) or AdjBW.

The effect of calcineurin inhibitors on anthropometric measurements in kidney transplant recipients

Background

This study was designed to investigate the effect of calcineurin inhibitors (CNIs), cyclosporine (CsA), and tacrolimus (Tac) on anthropometrics in kidney transplant recipients.

Methods

111 of 128 adult kidney transplant recipients who received post-transplant CNIs were included in this retrospective study. Anthropometrics were recorded in the pre-transplant and post-transplant 4-year follow-up periods (1st, 3rd, 6th, 12th, 24th, 36th and 48th months).

Results

Compared to pre-transplant values, significant increases in body weight and body mass index (between 3rd and 48th months), waist and hip circumferences (between 1st and 48th months), waist-to-hip ratio (between 1st and 3rd or 6th months) and neck circumference (between 1st and 12th or 24th months) were observed in both CsA and Tac groups. A significant increase was noted in post-transplant body fat percentage values for the 3rd to 24th months in the CsA group, whereas for the 24th to 48th months in both CsA and Tac groups. Hip circumferences percentage changes from the pre-transplant period to the 1st, 12th and 24th months were significantly higher in CsA than in the Tac group. At each time point, there was no significant difference in percentage changes for other anthropometric parameters between the CsA and Tac groups. De novo diabetes mellitus developed in 8.3% of the CsA group and 19.1% of the Tac group.

Conclusions

After a successful kidney transplant, anthropometric measurements increase in most recipients. Although the effect of calcineurin inhibitor type on weight gain is unclear, a regression analysis showed that CNI type was not a risk factor for the development of obesity in the 48th month. However, it is helpful to be cautious about its dyslipidemic effect in patients using CsA and the potential hazards of using Tac in patients with a diabetic predisposition.

Cardiovascular Risk Following Conversion to Belatacept From a Calcineurin Inhibitor in Kidney Transplant Recipients: A Randomized Clinical Trial

Rationale & Objective

In kidney transplant recipients (KTRs), a belatacept-based immunosuppressive regimen is associated with beneficial effects on cardiovascular (CV) risk factors compared with calcineurin inhibitor (CNI)-based regimens. Our objective was to compare the calculated CV risk between belatacept and CNI (predominantly tacrolimus) treatments using a validated model developed for KTRs.

Study Design

Prospective, randomized, open-label, parallel-group, investigator-initiated, international multicenter trial.

Setting & Participants

KTRs aged 18-80 years with a stable graft function (estimated glomerular filtration rate > 20 mL/min/1.73 m²), 3-60 months after transplantation, treated with tacrolimus or cyclosporine A, were eligible for inclusion.

Intervention

Continuation with a CNI-based regimen or switch to belatacept for 12 months.

Outcomes

Comparison of the change in the estimated 7-year risk of major adverse CV events and all-cause mortality, changes in traditional markers of CV health, as well as measures of arterial stiffness.

Results

Among the 105 KTRs randomized, we found no differences between the treatment groups in the predicted risk for major adverse CV events or mortality. Diastolic blood pressure, measured both centrally by using a SphygmoCor device and peripherally, was lower after the belatacept treatment than after the CNI treatment. The mean changes in traditional cardiovascular (CV) risk factors, including kidney transplant function, were otherwise similar in both the treatment groups. The belatacept group had 4 acute rejection episodes; 2 were severe rejections, of which 1 led to graft loss.

Limitations

The heterogeneous baseline estimated glomerular filtration rate and time from transplantation to trial enrollment in the participants. A limited study duration of 1 year.

Conclusions

We found no effects on the calculated CV risk by switching to the belatacept treatment. Participants in the belatacept group had not only lower central and peripheral diastolic blood pressure but also a higher rejection rate.

Funding

The trial has received a financial grant from Bristol-Myers Squibb.

Trial Registration

EudraCT no. 2013-001178-20.

The negative impact of T cell-mediated rejection on renal allograft survival in the modern era

The prevalence and long-term impact of T cell-mediated rejection (TCMR) is poorly defined in the modern era of tacrolimus/mycophenolate-based maintenance therapy. This observational study evaluated 775 kidney transplant recipients with serial histology and correlated TCMR events with the risk of graft loss. After a ~30% incidence of a first Banff Borderline or greater TCMR detected on for-cause (17%) or surveillance (13%) biopsies, persistent (37.4%) or subsequent (26.3%) TCMR occurred in 64% of recipients on follow-up biopsies. Alloimmune risk categories based on the HLA-DR/DQ single molecule eplet molecular mismatch correlated with the number of TCMR events (p = .002) and Banff TCMR grade (p = .007). Both a first and second TCMR event correlated with death-censored and all-cause graft loss when adjusted for baseline covariates and other significant time-dependent covariates such as DGF and ABMR. Therefore, a substantial portion of kidney transplant recipients, especially those with intermediate and high HLA-DR/DQ molecular mismatch scores, remain under-immunosuppressed, which in turn identifies the need for novel agents that can more effectively prevent or treat TCMR.

Effectiveness and safety of cyclophosphamide or tacrolimus therapy for idiopathic membranous nephropathy

BACKGROUND

Guidelines recommend classical combined therapy of steroid and cyclophosphamide (CYC) for patients with idiopathic membranous nephropathy (IMN), while it is associated with severe adverse effects.

AIMS

We conducted an observational and retrospective study to evaluate the effectiveness and safety of steroids plus tacrolimus (TAC) versus steroids plus CYC for IMN.

METHODS

A total of 203 kidney-biopsy-proven IMN patients was enrolled in this study. One group (n = 142) received steroid combined with intravenous CYC (750 mg/m² body surface) and the other group (n = 61) received steroid combined with oral TAC (target blood concentration of 4-8 ng/mL). The primary outcomes were achievement of remission. The secondary end-points included incidence of adverse events, relapse rates, 24 h urinary protein (UP), serum albumin, serum creatinine and estimated glomerular filtration rate.

RESULTS

Over the 18-month observation period, the study suggested that the remission rates at the first 3 months were significantly higher in TAC group than in CYC group (72.1% vs 54.9%, P < 0.05). Although the cumulative incidence of serious and non-serious adverse events was not different significantly between the two groups, the incidence after first 3 months was lower in TAC group. Levels of 24-h UP and serum albumin improved in the TAC group more than in the CYC group (P < 0.05) over the observed period.

CONCLUSIONS

Because of its short-term effectiveness and long-term safety profile, steroid plus TAC might be a better option for IMN.

Acute rejection in pediatric renal transplantation: Retrospective study of epidemiology, risk factors, and impact on renal function

AR is a major relevant and challenging topic in pediatric kidney transplantation. Our objective was to evaluate cumulative incidence of AR in pediatric kidney transplant patient, risk factors for this outcome, and impact on allograft function and survival. A retrospective cohort including pediatric patients that underwent kidney transplantation between 2011 and 2015 was designed. Risk factors for AR were tested by competing risk analysis. To estimate its impact, graft survival and difference in GFR were evaluated. Two hundred thirty patients were included. As a whole, the incidence of AR episodes was 0.16 (95% CI = 0.12-0.20) per person-year of follow-up. And cumulative incidence of AR was 23% in 1 year and 39% in 5 years. Risk factors for AR were number of MM (SHR 1.36 CI 1.14-1.63 P = .001); ISS with CSA, PRED, and AZA (SHR 2.22 CI 1.14-4.33 P = .018); DGF (SHR 2.49 CI 1.57-3.93 P < .001); CMV infection (SHR 5.52 CI 2.27-11.0 P < .001); and poor adherence (SHR 2.28 CI 1.70-4.66 P < .001). Death-censored graft survival in 1 and 5 years was 92.5% and 72.1%. Risk factors for graft loss were number of MM (HR 1.51 CI 1.07-2.13 P = .01), >12 years (HR 2.66 CI 1.07-6.59 P = .03), and PRA 1%-50% (HR 2.67 CI 1.24-5.73 P = .01). Although occurrence of AR did not influence 5-year graft survival, it negatively impacted GFR. AR was frequent in patients assessed and associated with number of MM, ISS regimen, DGF, CMV infection, and poor adherence, and had deleterious effect on GFR.

Effects of Late Conversion from Twice-Daily to Once-Daily Slow Release Tacrolimus on the Insulin Resistance Indexes in Kidney Transplant Patients

The use of tacrolimus (Tac) may be involved in the development of new-onset diabetes after transplantation (NODAT) in a dose-related manner. This study aimed to evaluate the effects of a standard twice-daily formulation of Tac (TacBID) vs. the once-daily slow-release formulation (TacOD) on the basal insulin resistance indexes (Homa and McAuley), and related metabolic parameters, in a cohort of kidney transplant patients. We retrospectively evaluated 20 stable renal transplant recipients who were switched from TacBID to TacOD. Blood levels of Tac were analyzed at one-month intervals from 6 months before to 8 months after conversion. Moreover, Homa and McAuley indexes, C-peptide, insulin, HbA1c, uric acid, triglycerides, low-density lipoprotein (LDL) and high-density lipoprotein (HDL)-cholesterol serum levels and their associations with Tac levels were evaluated. We observed a significant decrease in Tac exposure (8.5 ± 2 ng/mL, CV 0.23 vs. 6.1 ± 1.9 ng/mL, CV 0.31, TacBID vs. TacOD periods, p < 0.001) and no significant changes in Homa (1.42 ± 0.4 vs. 1.8 ± 0.7, p > 0.05) and McAuley indexes (7.12 ± 1 vs. 7.58 ± 1.4, p > 0.05). Similarly, blood levels of glucose, insulin, HbA1c, lipids, and uric acid were unchanged between the two periods, while C-peptide resulted significantly lower after conversion to TacOD. These data suggest that in kidney transplant recipients, reduced Tac exposure has no significant effects on basal insulin sensitivity indexes and metabolic parameters.

Effectiveness and safety of cyclophosphamide or tacrolimus therapy for idiopathic membranous nephropathy

Background: Guidelines recommend combined therapy of glucocorticoid and cyclophosphamide (CYC) for patients with idiopathic membranous nephropathy (IMN), while it is associated with severe adverse effects. We conducted a retrospective study to evaluate the effectiveness and safety of glucocorticoid plus tacrolimus (TAC) for IMN.

Methods: Two hundred and three kidney-biopsy-proven IMN patients were enrolled in this study. One group (n = 142) received glucocorticoid combined with intravenous CYC (750 mg/m² body surface) and the other group (n = 61) received glucocorticoid combined with oral TAC (target blood concentration of 4–8 ng/mL). The primary outcomes were achievement of remission and incidence of adverse events. The secondary end points included relapse rates, 24 h urinary protein (UP), serum albumin, serum creatinine and estimated glomerular filtration rate.

Results: Over the 18-month observation period, the study suggested that the remission rates at the first 3 months were significantly higher in TAC group than in CYC group (72.1% versus 54.9%, p < .05). Although the cumulative incidence of serious and non-serious adverse events was not different significantly between the two groups, the incidence after first 3 months was lower in TAC group. 24hUP and serum albumin improved in TAC group more than the CYC group (p < .05) over the observed period.

Conclusion: Because of its short-term effectiveness and long-term safety profile, glucocorticoid plus TAC might be a better option for IMN.

Transplant Recipients Using Tacrolimus Had Higher Utilization of Healthcare Services Than Those Receiving Cyclosporine in Taiwan

To date, population-based studies on the healthcare service utilization among stable heart, kidney, and liver transplant recipients with different calcineurin inhibitors are still scarce. Therefore, we used the Taiwan National Health Insurance Research Database to conduct a nationwide cross-sectional study to estimate the healthcare utilization of stable transplant recipients with tacrolimus or cyclosporine (n = 3,482). The sampled patients in this study comprised 377 heart, 1,693 kidney, and 1,412 liver transplant recipients between 1 January 2011 and 31 December 2011. Each subject was followed for a 1-year period to evaluate his/her healthcare service utilization. Outcome variables of the healthcare service utilization were stated as below: numbers of outpatient visits, outpatient costs, numbers of inpatient days, inpatients costs, and total costs of all healthcare services. As for all healthcare service utilization, stable transplant recipients on tacrolimus had significantly more outpatient visits (40.7 vs. 38.6), outpatient costs (US$10,383 vs. US$8,155), and total costs (US$12,516 vs. US$10,372) of all healthcare services than those on cyclosporine during the 1-year follow-up period. Additionally, further analysis showed that heart transplant recipients receiving tacrolimus incurred 1.7-fold higher inpatient costs compared to patients receiving cyclosporine. We concluded that transplant recipients using tacrolimus had significantly higher utilization of all healthcare services than those receiving cyclosporine as immunosuppressive therapy.

Mechanistic analyses in kidney transplant recipients prospectively randomized to two steroid free regimen-Low dose Tacrolimus with Everolimus versus standard dose Tacrolimus with Mycophenolate Mofetil

Calcineurin inhibitors (CNI), the cornerstone of immunosuppression after transplantation are implicated in nephrotoxicity and allograft dysfunction. We hypothesized that combined low doses of CNI and Everolimus (EVR) may result in better graft outcomes and greater tolerogenic milieu. Forty adult renal transplant recipients were prospectively randomized to (steroid free) low dose Tacrolimus (TAC) and EVR or standard dose TAC and Mycophenolate (MMF) after Alemtuzumab induction. Baseline characteristics were statistically similar. EVR levels were maintained at 3-8 ng/ml. TAC levels were 4.5±1.9 and 6.4±1.5 ng/ml in the TAC+EVR and TAC+MMF group respectively. Follow up was 14±4 and 17±5 months respectively and included protocol kidney biopsies at 3 and 12 months post-transplantation. Rejection-rate was lower in the TAC+EVR group. However patient and overall graft survival, eGFR and incidence of adverse events were similar. TAC+EVR induced expansion of CD4+CD25hiFoxp3+ regulatory T cells as early as 3 months and expansion of IFN-γ+CD4+CD25hiFoxp3+ regulatory T cells at 12 months post-transplant. Gene expression profile showed a trend toward decreased inflammation, angiogenesis and connective tissue growth in the TAC+EVR Group. Thus, greater tolerogenic mechanisms were found to be operating in patients with low dose TAC+EVR and this might be responsible for the lower rejection-rate than in patients on standard dose TAC+MMF. However, further studies with longer follow up and evaluating impact on T regulatory cells are warranted.

Pretransplant Homeostasis Model Assessment of Insulin Resistance and Fasting Plasma Glucose Predict New-Onset Diabetes After Renal Transplant in Chinese Patients

BACKGROUND AND AIM

The present study aims to determine if homeostasis model assessment of insulin resistance (HOMA-IR) index, fasting plasma glucose (FPG), and plasma insulin (Ins) are able to predict development of new onset diabetes after transplant (NODAT) for kidney recipients.

METHODS

We performed a single-center retrospective study of 123 nondiabetic patients receiving a first renal transplant. The NODAT was diagnosed between 1 month and 1 year post transplant. Both univariate and multivariable analyses, including logistic regression analysis and Cox proportional hazards model, were applied to dissect potential pretransplant risk factors of NODAT.

RESULTS

A total of 26.8% (33/123) of recipients developed NODAT in the first year post transplant. The NODAT patients showed higher HOMA-IR index and increased levels of FPG and Ins than non-NODAT. Interestingly, we consistently revealed that both FPG (logistic: odds ratio [OR], 3.17 [1.41-6.45]; P = .01; Cox: OR, 2.75 [1.26-4.56]; P = .02) and HOMA-IR index (logistic: OR, 1.73 [1.21-2.87]; P = .02; Cox: OR, 1.72 [1.21-2.46]; P = .002) robustly predicted the development of NODAT. However, these analyses showed that neither plasma Ins nor hemoglobin A_1c was associated with NODAT.

CONCLUSION

Our findings suggest that pretransplant HOMA-IR and FPG are independent predictors for the development of NODAT in Chinese nondiabetic patients receiving a first renal transplant.

Pretransplant metabolic syndrome and its components predict post-transplantation diabetes mellitus in Chinese patients receiving a first renal transplant

Background

Post-transplantation diabetes mellitus (PTDM) remains a major clinical challenge following renal transplant. Identification of pretransplant modifiable risk factors may allow timely interventions to prevent PTDM. This study aims to determine whether pretransplant metabolic syndrome and its components are able to predict PTDM in Chinese patients receiving their first renal transplant.

Patients and methods

We conducted a single-center retrospective study of 633 non-diabetic patients receiving a first kidney transplant. PTDM was diagnosed between 1 month and 1 year post-transplant. Multivariable logistic regression and Cox proportional hazards model were applied to detect potential pretransplant risk factors for PTDM.

Results

One year post-transplant, 26.2% of recipients had developed PTDM. PTDM patients had significantly higher fasting plasma glucose (FPG) (P=0.026) and body mass index (BMI) (P=0.006) than non-PRDM patients, and lower levels of high-density lipoprotein cholesterol (P=0.015). The presence of metabolic syndrome was an independent risk factor for PTDM, as assessed by multivariable logistic regression analysis (OR 1.28, 95% CI 1.04–1.51, P=0.038) and Cox proportional hazards model (OR 2.75, 95% CI 1.45–6.05, P=0.021). Moreover, both FPG >5.6 mmol/L and BMI >28 kg/m² (obesity) were able to predict PTDM.

Conclusion

Our results suggest that the presence of metabolic syndrome and its components, impaired fasting glycemia and obesity, are independent risk factors for PTDM in Chinese non-diabetic patients receiving a first renal transplant. Interventions aimed at improving pretransplant metabolic syndrome may reduce the incidence of PTDM.

Onset and progression of diabetes in kidney transplant patients receiving everolimus or cyclosporine therapy: an analysis of two randomized, multicenter trials

Background

Conversion from calcineurin inhibitor (CNI) therapy to a mammalian target of rapamycin (mTOR) inhibitor following kidney transplantation may help to preserve graft function. Data are sparse, however, concerning the impact of conversion on posttransplant diabetes mellitus (PTDM) or the progression of pre-existing diabetes.

Methods

PTDM and other diabetes-related parameters were assessed post hoc in two large open-label multicenter trials. Kidney transplant recipients were randomized (i) at month 4.5 to switch to everolimus or remain on a standard cyclosporine (CsA)-based regimen (ZEUS, n = 300), or (ii) at month 3 to switch to everolimus, remain on standard CNI therapy or convert to everolimus with reduced-exposure CsA (HERAKLES, n = 497).

Results

There were no significant differences in the incidence of PTDM between treatment groups (log rank p = 0.97 [ZEUS], p = 0.90 [HERAKLES]). The mean change in random blood glucose from randomization to month 12 was also similar between treatment groups in both trials for patients with or without PTDM, and with or without pre-existing diabetes. The change in eGFR from randomization to month 12 showed a benefit for everolimus versus comparator groups in all subpopulations, but only reached significance in larger subgroups (no PTDM or no pre-existing diabetes).

Conclusions

Within the restrictions of this post hoc analysis, including non-standardized diagnostic criteria and limited glycemia laboratory parameters, these data do not indicate any difference in the incidence or severity of PTDM with early conversion from a CsA-based regimen to everolimus, or in the progression of pre-existing diabetes.

Trial registration

clinicaltrials.gov, NCT00154310 (registered September 2005) and NCT00514514 (registered August 2007); EudraCT (2006-007021-32 and 2004-004346-40).

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1031-1) contains supplementary material, which is available to authorized users.

New-Onset Diabetes After Transplantation: Comparison Between a Cyclosporine-Based and a Tacrolimus-Based Immunosuppressive Regimen

INTRODUCTION

New-onset diabetes after transplantation (NODAT) is a complication of renal transplantation (RT) with an adverse effect on graft survival.

OBJECTIVES

The purpose of the present study was to compare modifiable or non-modifiable clinical and laboratory parameters as well as the course of patients and transplants between 2 groups of RT recipients with NODAT in relation to the use of either a cyclosporine-based (group A) or a tacrolimus-based immunosuppressive regimen (group B).

MATERIALS AND METHODS

Retrospectively comparing 66 renal transplant recipients with NODAT, multiple clinical, and laboratory parameters were investigated. For statistical analysis, the χ² test, the Student t test, and the patient and graft survival or the Kaplan-Meier analysis from the statistical software SPSS 22.0 for Windows were used.

RESULTS

There was no statistically significant difference in association with the majority of the investigated parameters. In group B (tacrolimus [Tac]), more patients had HbA1c >7.2% at 3 years after RT. The mean value of systolic blood pressure was higher in group A (cyclosporine [CsA]) at 6 months and at 1 year after RT. More patients in group A (CsA) experienced at least one acute rejection episode. Finally, greater levels of cold ischemia time were recorded in group B (Tac) and statistically significant difference was found in connection with the patient and graft survival in the fourth year after RT.

CONCLUSIONS

NODAT in patients on tacrolimus requires the adjustment of modifiable clinical and metabolic parameters and possible change of the immunosuppressive regimen to a cyclosporine-based one.

Ten-year observational follow-up of a randomized trial comparing cyclosporine and tacrolimus therapy combined with steroid withdrawal in living-donor renal transplantation

Although various strategies for steroid withdrawal after transplantation have been attempted, there are few reports of the long-term results of steroid withdrawal regimens in kidney transplantation. Earlier, we reported on a 5-year prospective, randomized, single-center trial comparing the safety and efficacy of cyclosporine (CsA) plus mycophenolate mofetil (MMF) with that of tacrolimus (TAC) plus MMF, when steroids were withdrawn 6 months after kidney transplantation in low-risk patients. We now report the 10-year observational data on the study population. We collected data from the database of the Organ Transplantation Center, Samsung Medical Center for 5 years after completion of the original study (TAC group n = 62; CsA group n = 55). The 10-year patient survival, death-censored graft survival, and acute rejection-free survival did not differ between groups (98% vs 96%; P = 0.49, 78% vs 85%; P = 0.75 and 84% vs 76%; P = 0.14 in the TAC group vs CsA group, respectively). In low-risk patients, there was no difference in long-term patient and graft survival between TAC- and CsA-based late steroid withdrawal regimens that included MMF treatment. More long-term randomized clinical trials are needed to clarify the benefits of late steroid withdrawal in kidney transplantation.

Genetic and clinic predictors of new onset diabetes mellitus after transplantation

New Onset Diabetes after Transplantation (NODAT) is a frequent complication after solid organ transplantation, with higher incidence during the first year. Several clinical and genetic factors have been described as risk factors of Type 2 Diabetes (T2DM). Additionally, T2DM shares some genetic factors with NODAT. We investigated if three genetic risk scores (w-GRS) and clinical factors were associated with NODAT and how they predicted NODAT development 1 year after transplantation. In both main (n = 725) and replication (n = 156) samples the clinical risk score was significantly associated with NODAT (OR_main: 1.60 [1.36-1.90], p = 3.72*10^-8 and OR_replication: 2.14 [1.39-3.41], p = 0.0008, respectively). Two w-GRS were significantly associated with NODAT in the main sample (OR_{w-GRS 2}:1.09 [1.04-1.15], p = 0.001 and OR_{w-GRS 3}:1.14 [1.01-1.29], p = 0.03) and a similar OR_{w-GRS 2} was found in the replication sample, although it did not reach significance probably due to a power issue. Despite the low OR of w-GRS on NODAT compared to clinical covariates, when integrating w-GRS 2 and w-GRS 3 in the clinical model, the Area under the Receiver Operating Characteristics curve (AUROC), specificity, sensitivity and accuracy were 0.69, 0.71, 0.58 and 0.68, respectively, with significant Likelihood Ratio test discrimination index (p-value 0.0004), performing better in NODAT discrimination than the clinical model alone. Twenty-five patients needed to be genotyped in order to detect one misclassified case that would have developed NODAT 1 year after transplantation if using only clinical covariates. To our knowledge, this is the first study extensively examining genetic risk scores contributing to NODAT development.

Update on the Management of High-Risk Penetrating Keratoplasty

PURPOSE OF REVIEW

In this article, we review the indications and latest management of high-risk penetrating keratoplasty.

RECENT FINDINGS

Despite the immune-privilege status of the cornea, immune-mediated graft rejection still remains the leading cause of corneal graft failure. This is particularly a problem in the high-risk graft recipients, namely patients with previous graft failure due to rejection and those with inflamed and vascularized corneal beds. A number of strategies including both local and systemic immunosuppression are currently used to increase the success rate of high-risk corneal grafts. Moreover, in cases of limbal stem cell deficiency, limbal stem cells transplantation is employed.

SUMMARY

Corticosteroids are still the top medication for prevention and treatment in cases of corneal graft rejection. Single and combined administration of immunosuppressive agents e.g. tacrolimus, cyclosporine and mycophenolate are promising adjunctive therapies for prolonging graft survival. In the future, cellular and molecular therapies should allow us to achieve immunologic tolerance even in high-risk grafts.

Tacrolimus confers lower acute rejection rates and better renal allograft survival compared to cyclosporine

AIM

To compare the impact of tacrolimus (FK) and cyclosporine (CYA) on acute rejection and graft survival and to assess the predominant causes of graft loss between patients receiving these two calcineurin inhibitors (CNIs).

METHODS

Retrospective review of 1835 patients who received a kidney transplant (KTX) between 1999-2012. Patients were grouped based on initial CNI utilized: 1195 in FK group, 640 in CYA group. Data on baseline characteristics, clinical outcomes, and causes of graft loss in both groups were analyzed.

RESULTS

Cumulative acute rejection rates were 14% in the FK vs 24% in the CYA group. Despite more marginal donor characteristics in the FK group, these patients had better graft survival rates compared to the CYA group. Three and five year graft survival rates were 88% and 84% respectively in the FK group compared to 79% and 70% respectively in the CYA group (P < 0.001). After multivariate analysis, which controlled for confounders, FK use was a strong predictor for lower acute rejection rates [odds ratio (OR) 0.60, 95%CI: 0.45-0.79] and better renal allograft survival (OR 0.740, 95%CI: 0.58-0.94). Death with a functioning graft was the most common cause of graft loss in both groups. Common causes of death included cardiovascular disease, infections, and malignancies. Chronic allograft nephropathy was also found to be an important cause of graft loss, being more prevalent in the CYA group.

CONCLUSION

The use of FK-based maintenance immunosuppression therapy is associated with a significantly lower rate of acute rejection and better graft survival compared to CYA-based regimen. Individualizing immunosuppression through risk-stratified CNI choice may lead to improved outcomes across all spectra of KTX patients.

Taste-masked tacrolimus-phospholipid nanodispersions: dissolution enhancement, taste masking and reduced gastric complications

Through the integration of orthogonal central composite design and desirability function, this work aimed to explore the potential of quality by design in understanding the formulation of phospholipid-stabilized tacrolimus nanodispersions by microfluidization. The influence of homogenization pressure, microfluidization time and phospholipid concentration (X1-X3) on nanodispersion performance was studied. Nanodispersions were characterized by differential scanning calorimetric (DSC), X-ray diffractometer (XRD) and Fourier transform infrared (FTIR) analysis. Moreover, masking the unpalatable taste of tacrolimus and reducing the gastric complications were also evaluated. FTIR analysis indicated its interaction with phospholipid. DSC and XRD analysis revealed the amorphous transformation of tacrolimus within nanodispersions. The dissolution was enhanced by 35 folds and 15 folds after 0.5 and 2 h, respectively. Maximum tacrolimus content, yield, polydispersity index, percentages dissolved after 0.5 and 2 h of 99.3%, 100%, 0.864, 39.7% and 95.3%, respectively, with particle size of 160 nm were obtained at X1, X2 and X3 values of 20 000 psi, 6 min and 30%, respectively. The Euclidean distance values demonstrated masking the unpalatable taste and taste perversion to stimuli of tacrolimus in its optimized nanodispersion. Moreover, the ulcerative indices following raw tacrolimus and its optimized nanodispersion oral administration were 6.73 and 2.45, respectively, to indicate that nanodispersion was significantly less irritating to the gastric mucosa.

Impact of Mycophenolate Mofetil Dose Reduction on Allograft Outcomes in Kidney Transplant Recipients on Tacrolimus-Based Regimens: A Systematic Review

OBJECTIVE

To systematically evaluate the clinical consequences of mycophenolate dose reduction in renal transplant recipients on tacrolimus-based regimens.

DATA SOURCES

PubMed (1949-July 2010), EMBASE (1980-July 2010), Cochrane Database of Systematic Reviews, International Pharmaceutical Abstracts, and Web of Science were searched using the terms mycophenolate mofetil, tacrolimus, dose reduction, and kidney and/or renal transplant. References from publications identified were reviewed.

STUDY SELECTION AND DATA EXTRACTION

Studies reporting on rejection rate, allograft survival, or renal function were included and ranked according to the US Preventive Services Task Force classification; excluded were studies that were dose-finding or used cyclosporine only, involved patients on enteric-coated mycophenolate sodium or those with multiorgan transplant, or provided no information on concomitant immunosuppressants. Data extracted were study design, sample size, immunosuppression regimen, type of transplant, and allograft outcomes.

DATA SYNTHESIS

Of 13 studies included, 1 was level I evidence, 3 were level II-2, 6 were level II-3, and 3 were level III evidence. Three focused on tacrolimus-based regimens, whereas 7 included either cyclosporine or tacrolimus. The only prospective, randomized, multicenter trial demonstrated that early taper of mycophenolate dosage to 1 g/day can be utilized without increased risk of rejection, compared with late tapering, but the rejection rate was high (30-40%). Overall, we found conflicting evidence regarding the impact of mycophenolate dose reduction on rejection rate and allograft loss and that discontinuing mycophenolate led to an increased risk of graft loss as high as 8 fold. Allograft survival was lowest in patients with gastrointestinal complications and those in whom mycophenolate was discontinued, compared with patients with neither gastrointestinal complications nor mycophenolate discontinuation.

CONCLUSIONS

Weak evidence suggests that mycophenolate dose modifications, either reduction or discontinuation, may increase rejection rate and graft loss; however, this is more apparent in cyclosporine-based regimens. Prospective, well-designed trials are necessary to definitively determine the impact of dose reduction in renal transplant recipients on tacrolimus-based regimens.

Advances in pharmacotherapy to treat kidney transplant rejection

INTRODUCTION

Current immunosuppressive combination therapy provides excellent prevention of T-cell-mediated rejection following renal transplantation; however, antibody-mediated rejection remains of high concern and accounts for a large number of long-term allograft losses. The recent development of protocol biopsies resulted in the definition of subclinical rejection (SCR), showing histologic evidence for rejection but unremarkable clinical course.

AREAS COVERED

This review describes the current knowledge and evidence of pharmacotherapy to treat kidney allograft rejections and covers SCR treatment options. Each substance is analyzed with regard to its classical indication and further discussed for the treatment of other forms of rejection.

EXPERT OPINION

Despite a lack of randomized trials, early acute T-cell-mediated rejection can be treated effectively in most cases without graft loss. The necessity to treat SCR is currently unclear. Due to a lack of effective therapies, new treatment approaches for antibody-mediated rejection are an urgent medical need to improve long-term outcomes. Future research should aim to better define pathophysiology and histology, stratify risk, and develop rational treatment strategies from randomized controlled trials, in order to establish the value of novel therapies in the arsenal of rejection pharmacotherapy. However, the effective prevention of rejection with minimal side effects still remains the goal in immunosuppression.

Efficacy and safety of systemic tacrolimus in high-risk penetrating keratoplasty after graft failure with systemic cyclosporine

PURPOSE

The aim of this study was to investigate the efficacy and safety of systemic tacrolimus for the treatment of eyes that developed graft failure despite treatment with cyclosporine (CsA).

METHODS

Ten eyes of 10 patients who underwent high-risk penetrating keratoplasty (PKP) and developed graft failure despite treatment with systemic CsA were included in this study. The patients underwent PKP and were treated with systemic tacrolimus according to the standardized protocol.

RESULTS

Treatment with tacrolimus was continued for 18.1 ± 13.9 months. The median duration of corneal graft clarity was 34.5 months. Graft rejection occurred in 2 of 10 eyes during a mean follow-up period of 48.9 ± 22.9 months. Kaplan-Meier survival plots showed significantly fewer graft rejection episodes (P = 0.033) and longer graft survival (P = 0.042) after treatment with tacrolimus compared those with CsA. Tacrolimus was discontinued in 2 patients; 1 had renal dysfunction and the other had muscle pain and fatigue. These side effects subsided after discontinuation of tacrolimus.

CONCLUSIONS

Treatment with systemic tacrolimus is possibly safe and effective in reducing graft rejection and prolonging graft survival in patients with high-risk PKP after graft failure with systemic CsA.

Is basiliximab induction, a novel risk factor for new onset diabetes after transplantation for living donor renal allograft recipients?

AIM

It was found that, by affecting populations of T lymphocytes and regulatory T cells, basiliximab also indirectly affects pancreatic β-cell function and glucose homeostasis.

METHODS

In this prospective observational study, we included all renal transplant recipients from 1 July 2007 to 31 July 2011. The overall incidence of hyperglycaemia (transient hyperglycaemia, impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and new onset diabetes after transplantation (NODAT)) was compared between patients with and without basiliximab induction.

RESULTS

Of the 439 eligible study patients, 105 patients received basiliximab induction and 334 patients did not. Overall hyperglycaemia (transient hyperglycaemia, IFG, IGT and NODAT) was detected in 102/334 (30.5%) patients without induction and 44/105 (41.9%) patients with induction (P = 0.03). Of the 102 patients with hyperglycaemia in patients without basiliximab, 46 (45.1%) patients improved, while only 10 (22.7%) of the 44 patients with basiliximab improved (P = 0.016) at the end of 3 months. Finally, NODAT was observed in 56/334 (16.7%) patients without induction and 102/334 (30.5%) patients with induction. Relative risk of NODAT with basiliximab was 2.3 (95% CI 1.4-3.9) compared to that of patients without induction. Basiliximab and hepatitis C virus infection were independent risk factors for NODAT. Risk of NODAT remained high with basiliximab despite adjusting the acute rejections episodes.

CONCLUSIONS

Basiliximab induction prevents acute rejection; however, it is associated with increased risk of NODAT.

The Cost of Kidney Transplant over Time

Background

Kidney transplant improves quality of life and survival compared with dialysis. Despite advances in immunosuppressant regimens and the prevention and treatment of acute rejection, graft survival rates have not improved significantly in the past decade. Although the clinical effectiveness of these regimens has been studied, the impact of changes over time on cost has not.

Methods

Costs of kidney transplant were compared between 2 periods demarcated by a programmatic change from cyclosporine (early) to tacrolimus (late) and from nonroutine induction (early) to routine induction (late) therapy in adult patients receiving a first kidney-only transplant in Calgary, Alberta, Canada, in an 8-year period.

Results

Complete costs for 3 years after transplant was available for 344 patients, including 161 adult recipients in the early period (April 1, 1998-December 31, 2001) and 183 adult recipients in the late period (January 1, 2002-March 31, 2006). The mean total 3-year cost of transplant for recipients was Can$100 034 in the early period and Can$144 712 in the late period largely attributed to increases in the cost of immunosuppressants ( P < .001).

Conclusions

Given that the cost of transplant has increased significantly over time, the cost-effectiveness of these and other immunosuppressive regimens should be evaluated carefully.

Interaction Study of an Amorphous Solid Dispersion of Cyclosporin A in Poly-Alpha-Cyclodextrin with Model Membranes by (1)H-, (2)H-, (31)P-NMR and Electron Spin Resonance

The properties of an amorphous solid dispersion of cyclosporine A (ASD) prepared with the copolymer alpha cyclodextrin (POLYA) and cyclosporine A (CYSP) were investigated by ¹H-NMR in solution and its membrane interactions were studied by ¹H-NMR in small unilamellar vesicles and by ³¹P ²H NMR in phospholipidic dispersions of DMPC (dimyristoylphosphatidylcholine) in comparison with those of POLYA and CYSP alone. ¹H-NMR chemical shift variations showed that CYSP really interacts with POLYA, with possible adduct formation, dispersion in the solid matrix of the POLYA, and also complex formation. A coarse approach to the latter mechanism was tested using the continuous variations method, indicating an apparent 1 : 1 stoichiometry. Calculations gave an apparent association constant of log Ka = 4.5. A study of the interactions with phospholipidic dispersions of DMPC showed that only limited interactions occurred at the polar head group level (³¹P). Conversely, by comparison with the expected chain rigidification induced by CYSP, POLYA induced an increase in the fluidity of the layer while ASD formation led to these effects almost being overcome at 298 K. At higher temperature, while the effect of CYSP seems to vanish, a resulting global increase in chain fluidity was found in the presence of ASD.

Keratoplasty postoperative treatment update

Immunosuppressive therapy is the main postoperative treatment for keratoplasty, but there are considerable differences in protocols for the use of steroids and other immunosuppressants. Therefore, we conducted 2 prospective randomized clinical trials and 1 prospective nonrandomized clinical trial on keratoplasty postoperative treatment. One study evaluated the efficacy and safety of long-term topical corticosteroids after a penetrating keratoplasty was performed. Patients who underwent keratoplasty and maintained graft clarity for >1 year were randomly assigned to either a steroid or a no-steroid group. At the 12-month follow-up, the no-steroid group developed significantly more endothelial rejection than did the steroid group. A second study elucidated the effectiveness and safety of systemic cyclosporine in high-risk corneal transplantation. The patients were assigned to a systemic cyclosporine or control group. At a mean follow-up of 42.7 months, no difference was observed in the endothelial rejection rates and graft clarity loss between the 2 groups. A third study elucidated the effectiveness and the safety of systemic tacrolimus in high-risk corneal transplantation. Of 11 consecutive eyes decompensated despite systemic cyclosporine treatment, there was no irreversible rejection in eyes treated with tacrolimus, which was significantly better than in previous penetrating keratoplasty with systemic cyclosporine treatment. Prognosis after keratoplasty in patients with keratoconus is relatively good, but special attention is required for patients with atopic dermatitis. Postkeratoplasty atopic sclerokeratitis (PKAS) is a severe form of sclerokeratitis after keratoplasty in atopic patients. Our retrospective study showed that 35 eyes of 29 patients from a total of 247 keratoconus eyes undergoing keratoplasty were associated with atopic dermatitis, of which 6 eyes of 5 patients developed PKAS. Eyes with PKAS had a significantly higher incidence of atopic blepharitis and preoperative corneal neovascularization, and therefore, we suggest systemic corticosteroids or cyclosporine to prevent PKAS in such high-risk cases.

Clinical outcomes after conversion from brand-name tacrolimus (prograf) to a generic formulation in renal transplant recipients: a retrospective cohort study

After kidney transplant recipients who received Prograf were switched to generic tacrolimus, most differences in the safety and effectiveness of the medications were not considered clinically relevant.

Trends in laboratory test volumes for Medicare Part B reimbursements, 2000-2010

CONTEXT

Changes in reimbursements for clinical laboratory testing may help us assess the effect of various variables, such as testing recommendations, market forces, changes in testing technology, and changes in clinical or laboratory practices, and provide information that can influence health care and public health policy decisions. To date, however, there has been no report, to our knowledge, of longitudinal trends in national laboratory test use.

OBJECTIVE

To evaluate Medicare Part B-reimbursed volumes of selected laboratory tests per 10,000 enrollees from 2000 through 2010.

DESIGN

Laboratory test reimbursement volumes per 10,000 enrollees in Medicare Part B were obtained from the Centers for Medicare & Medicaid Services (Baltimore, Maryland). The ratio of the most recent (2010) reimbursed test volume per 10,000 Medicare enrollees, divided by the oldest data (usually 2000) during this decade, called the volume ratio, was used to measure trends in test reimbursement. Laboratory tests with a reimbursement claim frequency of at least 10 per 10,000 Medicare enrollees in 2010 were selected, provided there was more than a 50% change in test reimbursement volume during the 2000-2010 decade. We combined the reimbursed test volumes for the few tests that were listed under more than one code in the Current Procedural Terminology (American Medical Association, Chicago, Illinois). A 2-sided Poisson regression, adjusted for potential overdispersion, was used to determine P values for the trend; trends were considered significant at P < .05.

RESULTS

Tests with the greatest decrease in reimbursement volumes were electrolytes, digoxin, carbamazepine, phenytoin, and lithium, with volume ratios ranging from 0.27 to 0.64 (P < .001). Tests with the greatest increase in reimbursement volumes were meprobamate, opiates, methadone, phencyclidine, amphetamines, cocaine, and vitamin D, with volume ratios ranging from 83 to 1510 (P < .001).

CONCLUSIONS

Although reimbursement volumes increased for most of the selected tests, other tests exhibited statistically significant downward trends in annual reimbursement volumes. The observed changes in reimbursement volumes may be explained by disease prevalence and severity, patterns of drug use, clinical or laboratory practices, and testing recommendations and guidelines, among others. These data may be useful to policy makers, health systems researchers, laboratory directors, and industry scientists to understand, address, and anticipate trends in laboratory testing in the Medicare population.

Tacrolimus in transplant rejection

INTRODUCTION

Renal transplantation is the best therapy for patients with end-stage renal disease. To avoid graft rejection, adequate immunosuppressive therapy is crucial. Tacrolimus is approved for prophylaxis of transplant rejection in liver, kidney or heart allograft recipients and for the treatment of allograft rejection resistant to treatment with other immunosuppressive medicinal products.

AREAS COVERED

The objective of this review is to summarize the clinical efficacy of tacrolimus in renal transplantation with special emphasis on acute rejection, refractory rejection and nephrotoxicity and post-transplant diabetes mellitus as typical adverse effects of the drug.

EXPERT OPINION

Since its approval in 1994, tacrolimus has proven its efficacy as a cornerstone of modern immunosuppressive therapy not only in numerous randomized clinical trials but also in standard clinical care. Compared with cyclosporine, the use of tacrolimus in renal transplant recipients is associated with a reduced risk for acute rejection, a reduction in the occurrence of steroid-resistant rejection and a better graft function. The avoidance of nephrotoxicity and especially post-transplant diabetes mellitus are of major interest in long-term care of renal transplant recipients.

[Diagnosis, prevention and treatment of cardiac allograft vasculopathy]

The major limitation of long-term survival after cardiac transplantation is allograft vasculopathy, which consists of concentric and diffuse intimal hyperplasia. The disease still has a significant incidence, estimated at 30% five years after cardiac transplantation. It is a clinically silent disease and so diagnosis is a challenge. Coronary angiography supplemented by intravascular ultrasound is the most sensitive diagnostic method. However, new non-invasive diagnostic techniques are likely to be clinically relevant in the future. The earliest possible diagnosis is essential to prevent progression of the disease and to improve its prognosis. A new nomenclature for allograft vasculopathy has been published in July 2010, developed by the International Society for Heart and Lung Transplantation (ISHLT), establishing a standardized definition. Simultaneously, the ISHLT published new guidelines standardizing the diagnosis and management of cardiac transplant patients. This paper reviews contemporary concepts in the pathophysiology, diagnosis, prevention and treatment of allograft vasculopathy, highlighting areas that are the subject of ongoing research.

Therapeutic effect of 0.03% tacrolimus ointment for ocular graft versus host disease and vernal keratoconjunctivitis

Purpose

To determine whether topical tacrolimus might prove effective in the treatment of refractory anterior segment inflammatory diseases, and to evaluate its efficacy in eyes with ocular graft versus host disease (GVHD), and vernal keratoconjunctivitis (VKC).

Methods

Twenty-eight eyes of 14 patients with anterior segment inflammation refractory to steroid treatment were treated with 0.03% tacrolimus ointment at the Samsung Medical Center, Seoul, Korea from March 2008 through August 2009. Seven patients had ocular GVHD and seven had VKC. We evaluated the conjunctival and corneal inflammatory change at one, two, four, and eight weeks after treatment with a scoring system. Time to initial response of treatment and therapeutic effect between GVHD and VKC was also analyzed. After the eight-week treatment period, patients were divided into two groups (maintenance group and discontinuance group). Eight patients maintained the treatment for an additional four months, and six patients discontinued the treatments. Therapeutic effect was also compared between the groups at eight weeks and six months after treatment.

Results

The mean conjunctival and corneal inflammation score was reduced significantly at eight weeks after treatment (p < 0.0001). The therapeutic effect in conjunctival inflammation was first noted at week two after the initial treatment (p = 0.002); reduction in corneal inflammation was first noted at one week (p = 0.0009). When compared according to diagnosis, no therapeutic difference was detected between the groups (p > 0.05). Six months after treatment, we noted no therapeutic differences between the maintenance group and discontinuance group (p > 0.05).

Conclusions

0.03% tacrolimus ointment was safe and effective for use in anterior segment inflammatory disease refractory to steroid.

Antibody induction therapy in adult kidney transplantation: A controversy continues

Antibody induction therapy is frequently used as an adjunct to the maintenance immunosuppression in adult kidney transplant recipients. Published data support antibody induction in patients with immunologic risk to reduce the incidence of acute rejection (AR) and graft loss from rejection. However, the choice of antibody remains controversial as the clinical studies were carried out on patients of different immunologic risk and in the context of varying maintenance regimens. Antibody selection should be guided by a comprehensive assessment of immunologic risk, patient comorbidities, financial burden as well as the maintenance immunosuppressives. Lymphocyte-depleting antibody (thymoglobulin, ATGAM or alemtuzumab) is usually recommended for those with high risk of rejection, although it increases the risk of infection and malignancy. For low risk patients, interleukin-2 receptor antibody (basiliximab or daclizumab) reduces the incidence of AR without much adverse effects, making its balance favorable in most patients. It should also be used in the high risk patients with other medical comorbidities that preclude usage of lymphocyte-depleting antibody safely. There are many patients with very low risk, who may be induced with intravenous steroids without any antibody, as long as combined potent immunosuppressives are kept as maintenance. In these patients, benefits with antibody induction may be too small to outweigh its adverse effects and financial cost. Rituximab can be used in desensitization protocols for ABO and/or HLA incompatible transplants. There are emerging data suggesting that alemtuzumab induction be more successful than other antibody for promoting less intensive maintenance protocols, such as steroid withdrawal, tacrolimus monotherapy or lower doses of tacrolimus and mycophenolic acid. However, the long-term efficacy and safety of these unconventional strategies remains unknown.

Pediatric renal transplantation in the jordanian population: the clinical outcome measures during long-term follow-up period

INTRODUCTION

Recently, many international studies have suggested that pediatric patients from diverse ethnic origins confront unique challenges for transplantation. Data concerning the efficacy and safety of transplantation for various pediatric renal transplant populations remains limited and are often confounded by immunosuppressive protocols. In one study, we aimed to evaluate the short- and long-term outcomes of renal transplants in Jordanian children in comparison with groups of different nationalities.

METHODS

We retrospectively retrieved data for 34 Jordanian children who received kidney transplants from living donors between January 2003 and January 2009. Subsequently, we continued to follow-up with these selected patients at scheduled clinic visits to prospectively collect long-term data for a period of approximately 22 months±15 months.

RESULTS

The patients included in this study ranged between 4 years and 19 years of age. The male/female ratio was 0.79. Glumerulonephritis (35.3%) was the most common cause of end-stage renal disease in the sample of this study; 23.5% had received a preemptive transplant. All patients also received triple immunosuppressive therapy, consisting of tacrolimus (TAC), prednisolone, and mycophenolate mofetil (n=26) or azathioprine (n=8). Furthermore, the rate of acute rejection episodes was lower in the sample of this study than the average rate of many previous studies. The patients' survival rate at 1 year, 2 years and 3 years posttransplant was nearly 100%. The corresponding graft survivals were 97.1%, 94.12% and 91.2% respectively. Beyond three years, one female patient died postgraft loss. This graft loss was mainly attributed to recurrent glomerulonephritis. Strikingly, the prevalence of posttransplant diabetes (PTD) and hypertension was higher than reported international figures. Other adverse events, such as infections, were manageable.

CONCLUSION

The average result of pediatric renal transplantation in Jordan is more successful than the average results of this procedure in many developed countries, especially in terms of early graft function, acute rejection episodes as well as long-term patient and graft survivals. However, additional studies are needed to better characterize pharmacokinetic of TAC and to fully understand those factors that lead to an increased probability of developing conditions like PTD and hypertension.

Belatacept: a new biologic and its role in kidney transplantation

OBJECTIVE

To review the pharmacology, efficacy, safety, and role of belatacept in maintenance immunosuppression in adult kidney transplant recipients (KTR).

DATA SOURCES

PubMed, EMBASE, International Pharmaceutical Abstracts, Web of Knowledge (1990-November 2011), and Google were searched using the terms belatacept, kidney or renal, and transplant.

STUDY SELECTION AND DATA EXTRACTION

Relevant articles (English language and human subjects) were reviewed. Selected studies included 3 Phase 2 and 2 Phase 3 trials. Data were compared with Food and Drug Administration (FDA) briefing documents and belatacept full prescribing information.

DATA SYNTHESIS

Belatacept, a cytotoxic T-lymphocyte-associated antigen 4-immunoglobulin, is the first marketed intravenous maintenance immunosuppressant. It is approved for use in combination with basiliximab induction, mycophenolate mofetil, and corticosteroids to prevent rejection in adult KTR. Belatacept exhibits linear pharmacokinetics and first-order elimination. The less intensive regimen used in Phase 3 trials is approved by the FDA. In low-moderate immunologic risk KTR, short-term patient and allograft survival appear comparable with that seen with cyclosporine, with improved renal function despite more frequent and severe early acute rejection. Preliminary data from Phase 2 corticosteroid-avoidance and conversion trials suggest that better renal function, acceptable rejection rates, and comparable patient and allograft survival may be achieved with belatacept compared with calcineurin inhibitors (CNIs). Common adverse effects of belatacept include anemia, neutropenia, urinary tract infection, headache, and peripheral edema. While a more favorable cardiovascular and metabolic profile and lack of requirement for therapeutic drug monitoring are attractive, a higher frequency of posttransplant lymphoproliferative disorder is concerning. Belatacept drug costs are significantly higher than those of standard CNI- or sirolimus-based regimens.

CONCLUSIONS

Belatacept provides a new option for maintenance immunosuppression in adult KTR. Further research is needed to compare its efficacy and safety with standard tacrolimus-based regimens, to evaluate whether increased drug costs are offset by long-term improvements in patient and allograft survival, and to establish its role in the immunosuppression armamentarium.

Successful conversion from twice-daily to once-daily tacrolimus in liver transplantation: observational multicenter study

BACKGROUND

Compliance with immunosuppressive therapy in liver transplant patients is critical to prevent acute organ rejection and/or late graft loss. Strategies to simplify the therapeutic regimen may improve adherence.

AIM

To evaluate the safety and efficacy of conversion from a twice-daily to once-daily tacrolimus formulation in adult liver transplant patients.

PATIENTS AND METHODS

This prospective observational multicenter study included 187 liver transplant patients with at least 10 months post-transplant follow-up, no rejection episodes in the last three months, and creatinine levels <2 mg/dL. Conversion from a twice-daily to a once-daily formulation was based on a 1:1 proportion.

RESULTS

Median age was 61 yr (range: 28-80 yr); 64% were men and 36% women. The main indications for liver transplant were alcoholic cirrhosis in 30%. Median conversion time was 55 months (range: 10-215 months). Serum tacrolimus levels decreased at one month after conversion (pre-conversion levels = 5.4 ± 3.0 ng/mL vs. post-conversion levels = 4.4 ± 2.4 ng/mL, p = 0.013); however, these values normalized at six months post-conversion with no changes in liver function and rejection episodes were observed only in two patients.

CONCLUSION

Conversion from a twice-daily to a once-daily tacrolimus formulation is a safe, effective strategy in the management of stable liver transplant patients.

Incidence and risk factors of glucose metabolism disorders in kidney transplant recipients: role of systematic screening by oral glucose tolerance test

BACKGROUND

New-onset diabetes after transplantation (NODAT) increases infectious and cardiovascular complications and reduces patient and graft survival. We assessed the incidence and the risk factors for glucose metabolism abnormalities before and after kidney transplantation using an oral glucose tolerance test (OGTT). The purpose of the study was to better identify patients at risk for NODAT to adapt their immunosuppressive treatment and their management after transplantation.

METHODS

OGTT was performed before transplantation in 243 patients placed on the kidney waiting list between January 1, 2005, and December 31, 2008. Of these 243 patients, 120 received a kidney transplant and also had an OGTT after transplantation.

RESULTS

Impaired glucose tolerance (IGT) was identified in 22 of 120 patients (18%) before transplantation. After transplantation, diabetes developed in 31 patients and 16 patients had IGT. According to univariate analyses, risk factors for NODAT were age more than 50 years, body mass index more than 25 kg/m, pretransplant IGT, autosomal dominant polycystic kidney disease, and acute rejection. According to multivariate analyses, pretransplant IGT (relative risk=2.4), autosomal dominant polycystic kidney disease (relative risk=3), and acute rejection (RR, 2.8) remained significantly associated with NODAT. Patients were stratified by age, primary kidney disease, and pretransplant OGTT. The risk of developing NODAT increased 2.4-, 5-, and 14-fold, depending on the number of risk factors.

CONCLUSION

Pretransplant OGTT, together with age and nephropathy, is a helpful tool for identifying patients at risk for NODAT. For patients with two or three of these risk factors, the adjustment of immunosuppression may be recommended.

The impact of tacrolimus on vascular endothelial growth factor in experimental corneal neovascularization

PURPOSE

To investigate the impact of tacrolimus on vascular endothelial growth factor (VEGF) in experimental corneal neovascularization (NV) immunohistochemically.

MATERIAL AND METHODS

Five groups of seven Wistar albino rats were formed. A silver nitrate cauterization technique was used to induce corneal NV in the study groups, excluding Group 1 (Control Group). Rats in group 1 did not receive any treatment. Rats in group 2 (sham 1) were administered 1 ml of saline intraperitoneally once a day and those in group 3 (sham 2) received one drop of saline four times a day. Rats in group 4 were administered 0.3 mg/kg tacrolimus intraperitoneally once a day. For group 5, 0.3 mg/ml tacrolimus was installed four times a day. Digital photography for each cornea was performed and the percentage area of the NV on the total corneal surface was calculated. The intensity of VEGF immunostaining in the epithelial, the stromal, and endothelial layers was performed in a semi quantitative fashion.

RESULTS

The mean percentages of the neovascularized areas of intraperitoneally and topically tacrolimus-treated groups were lesser than those of the sham groups (p = 0.002, p = 0.038, respectively). The mean intensity of the epithelial VEGF immunostaining of the intraperitoneally tacrolimus-treated group was less than that of its sham group (p = 0.002), while the mean intensity of the stromal VEGF staining of the topically tacrolimus-treated group was lesser than that of its sham group (p = 0.042). The intensities of the endothelial VEGF immunostaining of the intraperitoneally and topically tacrolimus-treated groups were less than those of the sham groups (p = 0.038, p = 0.032).

CONCLUSION

Systemic and topical administration of tacrolimus may be beneficial in the prevention of corneal NV because of its effect on VEGF.

Tacrolimus Pharmacokinetic and Pharmacogenomic Differences between Adults and Pediatric Solid Organ Transplant Recipients

Tacrolimus is a calcineurin inhibitor immunosuppressant that has seen considerable use in both adult and pediatric solid organ transplant recipients. Though there is much pharmacokinetic data available for tacrolimus in the adult population, the literature available for children is limited. Furthermore, very little is known about the pharmacogenomic differences in the two patient groups. Based on what information is currently available, clinically significant differences may exist between the two populations in terms of absorption, distribution, metabolism and elimination. In addition, inherent physiological differences exist in the young child including: less effective plasma binding proteins, altered expression of intestinal P-glycoprotein, and increased expression of phase 1 metabolizing enzymes, therefore one would expect to see clinically significant differences when administering tacrolimus to a child. This paper examines available literature in an attempt to summarize the potential pharmacokinetic and pharmacogenomic variability that exists between the two populations.