Immunosuppression for delayed or slow graft function in primary cadaveric renal transplantation: use of low dose tacrolimus therapy with post-operative administration of anti-CD25 monoclonal antibody

A Randomized Controlled Trial of Envarsus Versus Immediate Release Tacrolimus in Kidney Transplant Recipients With Delayed Graft Function

BACKGROUND

The incidence of delayed graft function (DGF) among kidney transplant recipients (KTRs) in the United States continues to increase. The effect of immediate-release tacrolimus (tacrolimus) compared with extended-release tacrolimus (Envarsus) among recipients with DGF is unknown.

METHODS

This was a single-center open-label randomized control trial among KTRs with DGF (ClinicalTrials. gov, NCT03864926). KTRs were randomized either to continue on tacrolimus or switch to Envarsus at a 1:1 ratio. Duration of DGF (study period), number of dialysis treatments, and need for adjustment of calcineurin inhibitor (CNI) doses during the study period were outcomes of interest.

RESULTS

A total of 100 KTRs were enrolled, 50 in the Envarsus arm and 50 in the tacrolimus arm; of those, 49 in the Envarsus arm and 48 in the tacrolimus arm were included for analysis. There were no differences in the baseline characteristics, all P > .5, except donors in the Envarsus arm had higher body mass index (mean body mass index 32.9 ± 11.3 vs 29.4 ± 7.6 kg/m2 [P = .007]) compared with the tacrolimus arm. The median duration of DGF (5 days vs 4 days, P = .71) and the number of dialysis treatments (2 vs 2, P = .83) were similar between the groups. However, the median number of CNI dose adjustments during the study period in the Envarsus group was significantly lower (3 vs 4, P = .002).

CONCLUSIONS

Envarsus patients had less fluctuation in the CNI level, requiring fewer CNI dose adjustments. However, there were no differences in the DGF recovery duration or number of dialysis treatments.

Late-onset allograft rejection, cytomegalovirus infection, and renal allograft loss: Is anti-CMV prophylaxis required following late-onset allograft rejection?

Renal transplant recipients remain at risk of delayed-onset cytomegalovirus (CMV) infection occurring beyond a complete course of prophylaxis. In this retrospective cohort, all 278 patients who received renal allografts from deceased donors from 2014 to 2016 were followed until September 1, 2019. We determined the effect of early-vs late-onset acute rejection (EAR vs LAR [ie, occurring beyond 12 months after transplantation]) on CMV infection and subsequently long-term allograft outcome. Median (IQR) duration of follow-up was 1186.0 (904.7-1531.2) days. Seventy patients including 49 patients with EAR and 21 with LAR received augmented immunosuppression. In the same interval, 40 patients developed CMV infection (36 patients beyond 90 days after transplantation [90%]). In logistic regression analysis, D+/R- CMV serostatus (OR: 5.5, 95% CI: 2.5-12.2) and LAR (OR: 7.9, 95% CI: 2.8-22.2) significantly increased the risk of CMV infection. In Cox proportional hazard model, delayed-onset CMV infection (HR: 2.51, 95% CI: 1.08-5.86) and LAR (HR: 5.46, 95% CI: 2.26-13.14) significantly increased the risk of allograft loss. Patients with LAR are at risk of late-onset CMV infection. Post-LAR, targeted prophylaxis may reduce the risk of CMV infection and subsequently allograft loss. Further studies are required to demonstrate the effect of targeted prophylaxis following LAR.

The predictive value of urinary kidney injury molecular-1 for long-term graft function in kidney transplant patients: a prospective study

Background

Monitoring allograft function during the early stages is crucial, and therefore requires biomarkers more sensitive than serum creatinine (Scr). Kidney injury molecular-1 (KIM-1) is a potent biomarker; however, disparities exist in the literature concerning its predictive value in allograft function. Therefore, this study aimed to evaluate its predictive value for the long-term prognosis of kidney transplantation patients.

Methods

A prospective study with a cohort comprising 160 patients scheduled for kidney transplantation was conducted to evaluate the predictive power of urinary KIM-1 (uKIM-1) and other renal ischemia-reperfusion biomarkers including urinary L-type fatty acid binding protein (uL-FABP), urinary N-acetyl-β-D glucosaminidase (uNAG), and urinary neutrophil gelatinase-related lipoprotein (uNGAL) for allograft prognosis.

Results

One hundred and forty kidney recipients who were admitted to our hospital between September 2014 and December 2017 with a median follow-up of 30.3 months were included. Thirty-seven recipients had functional delayed graft function (fDGF) in the first week post transplantation, and 42 recipients had progressed to allograft dysfunction [estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m²] by the end of the study, while nine recipients deteriorated into allograft loss (defined by the initiation of dialysis). The levels of uKIM-1 in the fDGF group were higher than those in the immediate graft function (IGF) recipients (P<0.05) at 0 hour post transplantation [5.885 (4.420–7.913) vs. 4.605 (3.417–5.653) ng/mmol], and on the first day post transplantation [5.569 (4.181–6.722) vs. 4.002 (3.222–6.488) ng/mmol]. The levels of uL-FABP in the fDGF group were also higher than those in the IGF group at 0 hour post transplantation (89.818±39.332 vs. 69.187±37.926 µg/mmol) and on the third day post transplantation [77.835 (60.368–100.678) vs. 66.841 (28.815–89.783) µg/mmol]. Multivariate Cox regression analysis demonstrated that recipients with higher uKIM-1 levels on the first day post transplantation had a 23.5% increase in the risk of developing fDGF and a 27.3% increase in the risk of prolonged renal allograft dysfunction.

Conclusions

uKIM-1 on the first day post transplantation can predict short-term graft function and is a potent biomarker for the long-term prognosis of graft function.

Phase 3 trial Design of the Hepatocyte Growth Factor Mimetic ANG-3777 in Renal Transplant Recipients With Delayed Graft Function

Introduction

One-third of kidney transplantation patients experience acute kidney injury (AKI) resulting in delayed graft function (DGF), associated with increased risk of graft failure and mortality. Preclinical and phase 2 data indicate that treatment with ANG-3777 (formerly BB3), a hepatocyte growth factor (HGF) mimetic, may improve long-term kidney function and reduce health care resource use and cost, but these data require validation in a phase 3 randomized controlled trial.

Methods

The Graft Improvement Following Transplant (GIFT) trial is a multicenter, double-blind randomized controlled trial, designed to determine the efficacy and safety of ANG-3777 in renal transplantation patients showing signs of DGF. Subjects are randomized 1:1 to ANG-3777 (2 mg/kg) administered intravenously once daily for 3 consecutive days starting within 30 hours after transplantation, or to placebo.

Results

The primary endpoint is estimated glomerular filtration rate (eGFR) at 12 months. Secondary endpoints include proportion of subjects with eGFR >30 at days 30, 90, 180, and 360; proportion of subjects whose graft function is slow, delayed, or primary nonfunction; length of hospitalization; and duration of dialysis through day 30. Adverse events are assessed throughout the study.

Conclusion

GIFT will generate data that are important to advancing treatment of DGF in this medically complex population.

No Significant Influence of Reduced Initial Tacrolimus Dose on Risk of Underdosing and Early Graft Function in Older and Overweight Kidney Transplant Recipients

BACKGROUND

Nowadays, a reduced initial daily dose of tacrolimus (Tac) (0.1-0.15 mg/kg) is recommended for the majority of kidney transplant recipients (KTRs). The aim of the study was to analyze the safety of such a regimen, including the risk of first inadequately low Tac blood level, acute rejection (AR) occurrence, or early graft dysfunction.

METHODS

In 2011, we introduced a modified (0.1-0.15 mg/kg/d) initial Tac dosing regimen in older (>55 years) and/or overweight KTRs. To assure the safety of this protocol, we monitored the risk of inadequately low blood Tac level (<6 ng/mL) and incidence of AR or delayed graft function (DGF). The historical cohort with the higher Tac dosing regimen (0.2 mg/kg/d, n = 208) served as a control group.

RESULTS

The mean Tac daily dose in 78 KTRs (group with reduced dosing) was 0.133 (95% confidence interval [CI], 0.130-0.136) mg/kg and was significantly lower than the standard, previously prescribed dose of 0.195 (95% CI, 0.194-0.197) mg/kg. Of note, induction therapy was employed twice more often in the reduced Tac dosing group. The dose reduction resulted in a slight, nonsignificant decrease in first Tac trough level. The percentages of patients with first Tac troughs <6 ng/mL (5.1% vs 4.8%), AR (6.4% vs 5.8%), and DGF (25.6% vs 31.2%) were similar in the reduced and standard dosing groups.

CONCLUSION

The currently recommended reduction in Tac initial dosing does not increase the risk of inadequate immunosuppression and does not affect the early graft function. Regardless of Tac dose reduction, there is still a substantial risk of Tac overdosing in older or overweight KTRs.

The Lifetime Health Burden of Delayed Graft Function in Kidney Transplant Recipients in the United States

Background. Although delayed graft function (DGF) is associated with an increased risk of acute rejection and decreased graft survival, there are no estimates of the long-term or lifetime health burden of DGF. Objectives. To estimate the long-term and lifetime health burden of DGF, defined as the need for at least one dialysis session within the first week after transplantation, for a cohort representative of patients who had their first kidney transplant in 2014. Methods. Data from the United States Renal Data System (USRDS; 2001–2014) were used to estimate a semi-Markov parametric multi-state model with three disease states. Maximum length of follow-up was 13.7 years, and a microsimulation model was used to extrapolate results over a lifetime. The impact of DGF was assessed by simulating the model for each patient in the cohort with and without DGF. Results. At the end of 13.7 years of follow-up, DGF reduces the probability of having a functioning graft from 52% to 32%, increases the probability of being on dialysis from 10% to 19%, and increases the probability of death from 38% to 50% relative to transplant recipients who do not experience DGF. A typical transplant recipient with DGF (median age = 53) is observed to lose 0.87 quality-adjusted life-years (QALYs). Extrapolated over a lifetime, the same 53-year-old DGF patient is projected to lose 3.01 (95% confidence interval: 2.33, 3.70) QALYs relative to a transplant recipient with the same characteristics who does not experience DGF. Conclusions. The lifetime health burden of DGF is substantial. Understanding these consequences will help health care providers weigh kidney transplant decisions and inform policies for patients in the context of varying risks of DGF.

Association of Slow Graft Function with Long-Term Outcomes in Kidney Transplant Recipients

Background

Whether slow graft function (SGF) represents an intermediate phenotype between immediate graft function (IGF) and delayed graft function (DGF) in kidney transplant recipients is unknown.

Material/Methods

In a retrospective cohort analysis of 1,222 kidney transplant recipients, we classified patients as having IGF, SGF, and DGF using two different schemas. SGF was defined as serum creatinine (Cr) ≥3.0 mg/dL by postoperative day 5 in Schema 1, and in Schema 2, SGF was defined as Cr >1.5 mg/dL plus a creatinine reduction ratio <20% between postoperative days 1 and 3. A complementary log-log model was used to examine the association of graft function with graft survival and patient survival.

Results

Mean age of study patients was 51.5±13.3 years, 59.9% were male, and 66.7% were white. In Schema 1, SGF and DGF were associated with comparable increases in risk of graft failure compared to IGF (hazard ratio (HR) 1.46, 95% confidence intervals (CI) 1.02–2.10 for SGF and HR 1.56, CI 1.11–2.22 for IGF); estimates were similar for Schema 2 (HR 1.52, CI 1.05–2.20 for SGF and HR 1.54, CI 1.10–2.17 for IGF). However, for mortality, outcomes for SGF were similarly to IGF, both SGF and IGF were associated with lower risk relative to DGF (HR 0.54, CI 0.36–0.80 for SGF in Schema 1; HR 0.58, CI 0.39–0.85 for SGF in Schema 2).

Conclusions

These findings suggest that SGF may be a marker for graft failure but not for mortality, and SGF may therefore represent a phenotype separate from IGF and DGF.

Risk of peritoneal dialysis catheter-associated peritonitis following kidney transplant

OBJECTIVE

Peritoneal dialysis (PD) patients have equivalent or slightly better kidney transplant outcomes when compared to hemodialysis (HD) patients. However, given the risk for postoperative infection, we sought to determine the risk factors for PD catheter-associated infections for patients who do not have the PD catheter removed at the time of engraftment.

METHODS

Demographic and outcomes data were collected from 313 sequential PD patients who underwent kidney transplant from 2000 to 2015. Risk factors for postoperative peritonitis were analyzed using logistical regression.

RESULTS

Of 329 patients with PD catheters at transplant, 16 PD catheters were removed at engraftment. Of the remaining 313 patients, 8.9% suffered post-transplant peritonitis. On univariate analysis, patients with peritonitis were significantly more likely to have used the PD catheter or HD within 6 weeks after transplant. Multivariate analysis had similar findings, with increased risk for those using the PD catheter after transplant, with a trend for those who underwent HD only within 6 weeks of transplant.

CONCLUSION

These results suggest that delayed graft function requiring any type of dialysis is associated with increased post-transplant peritonitis risk.

Center-level variation in the development of delayed graft function after deceased donor kidney transplantation

BACKGROUND

Patient-level risk factors for delayed graft function (DGF) have been well described. However, the Organ Procurement and Transplantation Network definition of DGF is based on dialysis in the first week, which is subject to center-level practice patterns. It remains unclear if there are center-level differences in DGF and if measurable center characteristics can explain these differences.

METHODS

Using the 2003 to 2012 Scientific Registry of Transplant Recipients data, we developed a hierarchical (multilevel) model to determine the association between center characteristics and DGF incidence after adjusting for known patient risk factors and to quantify residual variability across centers after adjustment for these factors.

RESULTS

Of 82,143 deceased donor kidney transplant recipients, 27.0% developed DGF, with a range across centers of 3.2% to 63.3%. A center's proportion of preemptive transplants (odds ratio [OR], 0.83; per 5% increment; 95% confidence interval [95% CI], 0.74-;0.93; P = 0.001) and kidneys with longer than 30 hr of cold ischemia time (CIT) (OR, 0.95; per 5% increment; 95% CI, 0.92-;0.98; P = 0.001) were associated with less DGF. A center's proportion of donation after cardiac death donors (OR, 1.12; per 5% increment; 95% CI, 1.03-;1.17; P < 0.001) and imported kidneys (OR, 1.06; per 5% increment; 95% CI, 1.03-;1.10; P < 0.001) were associated with more DGF. After patient-level and center-level adjustments, only 41.8% of centers had DGF incidences consistent with the national median and 28.2% had incidences above the national median.

CONCLUSION

Significant heterogeneity in DGF incidences across centers, even after adjusting for patient-level and center-level characteristics, calls into question the generalizability and validity of the current DGF definition. Enhanced understanding of center-level variability and improving the definition of DGF accordingly may improve DGF's utility in clinical care and as a surrogate endpoint in clinical trials.

Basiliximab induction and delayed calcineurin inhibitor initiation in liver transplant recipients with renal insufficiency

BACKGROUND

Renal insufficiency (RI) is common after liver transplantation (LT) and may worsen due to calcineurin inhibitor (CNI) use. We compared LT outcomes using basiliximab induction and delayed CNI initiation to controls with a standard CNI regimen in patients with peri-LT RI.

METHODS

All adults transplanted January 2004 to December 2007 with peri-LT RI (hemodialysis or creatinine ≥1.5 within 1 week of LT) were included in a retrospective nonrandomized cohort. Outcomes including 30-day and 1-year patient and graft survival and renal function were compared between basiliximab and control groups.

RESULTS

Two hundred twenty-nine patients (102 basiliximab, 127 controls) were analyzed, mean age 54 years, 72% men, 54% with hepatitis C virus. Mean model for end-stage liver disease (28.2 vs. 20.0; P<0.001) and creatinine (1.9 vs. 1.6; P=0.001) were higher and more patients were on hemodialysis at LT (29% vs. 6%; P<0.001) in the basiliximab group. 30-day patient (99% vs. 97%; P=0.26) and graft survival (98% vs. 95%; P=0.17), 1-year patient (87% vs. 87%; P=0.89) and graft survival (86% vs. 82%; P=0.37), mean creatinine at 1-year (1.5 vs. 1.5 mg/dL; P=0.82), and treated acute rejection (6% vs. 6%; P=0.90) were similar between basiliximab and control groups, respectively. In multivariable logistic regression, basiliximab was not significantly associated with 30-day (odds ratio, 0.10; P=0.11) or 1-year (odds ratio, 0.97; P=0.94) survival, controlling for age, previous LT, model for end-stage liver disease, and hepatitis C virus.

CONCLUSIONS

Basiliximab induction resulted in 30-day and 1-year patient, graft and renal outcomes comparable with a control group receiving standard CNI-based immunosuppression. Antibody induction with delayed CNI should be further studied prospectively.

Association between delayed graft function and allograft and patient survival: a systematic review and meta-analysis

BACKGROUND

Delayed graft function (DGF) is a common complication of renal transplantation. The short-term consequences of DGF are well known, but the long-term relationship between DGF and patient and graft survival is controversial in the published literature. We conducted a systematic review and meta-analysis to precisely estimate these relationships.

METHODS

We performed a literature search for original studies published through March 2007 pertaining to long-term (>6 months) outcomes of DGF. The primary outcome was graft survival. Secondary outcomes were patient survival, acute rejection and kidney function.

RESULTS

When compared to patients without DGF, patients with DGF had a 41% increased risk of graft loss (RR 1.41, 95% CI 1.27-1.56) at 3.2 years of follow-up. There was no significant relationship between DGF and patient survival at 5 years (RR 1.14, 95% CI 0.94-1.39). The mean creatinine in the non-DGF group was 1.6 mg/dl. Patients with DGF had a higher mean serum creatinine (0.66 mg/dl, 95% CI 0.57-0.74) compared to patients without DGF at 3.5 years of follow-up. DGF was associated with a 38% relative increase in the risk of acute rejection (RR 1.38, 95% CI 1.29-1.47).

CONCLUSION

The results of this meta-analysis emphasize and quantify the long-term detrimental association between DGF and important graft outcomes like graft survival, acute rejection and renal function. Efforts to prevent and treat DGF should be aggressively investigated in order to improve graft survival given the deficit in the number of kidney donors.

Grossly delayed graft function in a living related kidney transplant recipient: a case report

Delayed graft function is a potentially challenging problem especially in cadaveric kidney transplant recipients. It adversely impacts long-term graft survival. It is rarely seen in living kidney transplants. Recovery of graft function usually occurs within a month. The chances of recovery of graft function diminish with further prolongation of delayed function. In fact, recovery of graft function after 3 months has rarely been described, we report herein recovery of graft function after 132 days of nonfunction in a living related kidney transplant.

Long-term renal outcomes after delayed graft function

Delayed graft function (DGF) describes dysfunction of the kidney allograft immediately after transplantation and is the most common complication in the immediate posttransplantation period. Although a standardized definition for DGF is lacking, it is most commonly defined as the need for dialysis within the first week after transplant. DGF is caused by a variety of factors related to the donor and recipient as well as organ procurement techniques. The occurrence of DGF affects both allograft and patient outcomes. In addition to prolonging hospital stay and increasing the costs associated with transplantation, DGF is associated with an increased incidence of acute rejection after transplantation and is associated with poorer long-term graft outcomes. Both immunologic and nonimmunologic mechanisms contribute to DGF. The risk factors for DGF that have been identified are reviewed as well as the impact of DGF on long-term outcomes.

Marked variation in the definition and diagnosis of delayed graft function: a systematic review

BACKGROUND

The term delayed graft function (DGF) is commonly used to describe the need for dialysis after receiving a kidney transplant. DGF increases morbidity after transplantation, prolongs hospitalization and may lead to premature graft failure. Various definitions of DGF are used in the literature without a uniformly accepted technique to identify DGF.

METHODS

We performed a systematic review of the literature to identify all of the different definitions and diagnostic techniques to identify DGF.

RESULTS

We identified 18 unique definitions for DGF and 10 diagnostic techniques to identify DGF.

CONCLUSIONS

The utilization of heterogeneous clinical criteria to define DGF has certain limitations. It will lead to delayed and sometimes inaccurate diagnosis of DGF. Hence a diagnostic test that identifies DGF reliably and early is necessary. Heterogeneity, in the definitions used for DGF, hinders the evolution of a diagnostic technique to identify DGF, which requires a gold standard definition. We are in need of a new definition that is uniformly accepted across the kidney transplant community. The new definition will be helpful in promoting better communication among transplant professionals and aids in comparing clinical studies of diagnostic techniques to identify DGF and thus may facilitate clinical trials of interventions for the treatment of DGF.

Intraoperative hypotension and prolonged operative time as risk factors for slow graft function in kidney transplant recipients

BACKGROUND

Slow graft function (SGF) is an immediate post-operative complication of cadaveric kidney transplantation pre-disposing to acute rejection (AR) and lower graft survival. The objective of this study was to test whether intraoperative hypotension and/or prolonged operative time are risk factors for SGF in patients post-cadaveric kidney transplant.

METHODS

This was a single center retrospective case-control study of patients post-cadaveric kidney transplant performed at the University of Kansas Medical Center (KUMC) between January 2002 and February 2005. Data were retrieved from the United Network of Organ Sharing (UNOS) database.

RESULTS

One hundred and sixty patients underwent cadaveric kidney transplant. Intraoperative measurements including blood pressure and operative time were available in 94 patients of which 57 had immediate graft function (IGF) and 37 had SGF (defined as decline in serum creatinine (Cr) of <50% by day 3). In multivariate logistic regression analysis, intraoperative hypotension and prolonged operative time were additive independent risk factors for SGF. For every 5 mmHg increment decrease in blood pressure, the odds ratio (OR) for SGF was 1.28 (95% confidence interval (CI): 1.08-1.53) for systolic blood pressure (SBP), 1.38 (CI: 1.06-1.79) for diastolic blood pressure (DBP), and 1.51 (CI: 1.15-1.99) for mean arterial pressure (MAP). For every 30 min increase in operative time, the OR for SGF was 1.35 (CI: 1.07-1.71).

CONCLUSION

Intraoperative hypotension and prolonged operative time are independent risk factors for SGF in patients post-cadaveric kidney transplant.

Impact of initial exposure to calcineurin inhibitors on kidney graft function of patients at high risk to develop delayed graft function

We conducted a retrospective analysis of the influence of full doses of calcineurin inhibitors [8-10 mg kg-1 day-1 cyclosporine (N = 80), or 0.2-0.3 mg kg-1 day-1 tacrolimus (N = 68)] administered from day 1 after transplantation on the transplant outcomes of a high-risk population. Induction therapy was used in 13% of the patients. Patients also received azathioprine (2 mg kg(-1) day(-1), N = 58) or mycophenolate mofetil (2 g/day, N = 90), and prednisone (0.5 mg kg(-1) day(-1), N = 148). Mean time on dialysis was 79 +/- 41 months, 12% of the cases were re-transplants, and 21% had panel reactive antibodies > 10%. In 43% of donors the cause of death was cerebrovascular disease and 27% showed creatinine above 1.5 mg/dL. The incidence of slow graft function (SGF) and delayed graft function (DGF) was 15 and 60%, respectively. Mean time to last dialysis and to nadir creatinine were 18 +/- 15 and 34 +/- 20 days, respectively. Mean creatinine at 1 year after transplantation was 1.48 +/- 0.50 mg/dL (DGF 1.68 +/- 0.65 vs SGF 1.67 +/- 0.66 vs immediate graft function (IGF) 1.41 +/- 0.40 mg/dL, P = 0.089). The incidence of biopsy-confirmed acute rejection was 22% (DGF 31%, SGF 10%, IGF 8%). One-year patient and graft survival was 92.6 and 78.4%, respectively. The incidence of cytomegalovirus disease, post-transplant diabetes mellitus and malignancies was 28, 8.1, and 0%, respectively. Compared to previous studies, the use of initial full doses of calcineurin inhibitors without antibody induction in patients with SGF or DGF had no negative impact on patient and graft survival.

IL-2-mediated apoptosis of kidney tubular epithelial cells is regulated by the caspase-8 inhibitor c-FLIP

BACKGROUND

Tubular epithelial cells (TECs) are essential in the maintenance of kidney function. Apoptosis of TECs occur during acute and chronic renal allograft rejection as well as other forms of renal injury, including autoimmune nephritis. The regulation of TEC apoptosis by proinflammatory cytokines associated with renal inflammation [e.g., interleukin (IL)-2 and interferon-gamma (IFN-gamma)] has not been extensively investigated.

METHODS

Apoptosis in murine TECs was determined by FACS with annexin-V or ligation-mediated-polymerase chain reaction (LM-PCR) and mRNA levels by reverse transcription (RT)-PCR or Northern blot. Protein expression was observed using Western blot.

RESULTS

IL-2R (CD25) was expressed by murine TECs and up-regulated by IL-2. Both IL-2 and IFN-gamma induced TEC apoptosis and activated caspase-8. Apoptosis with IL-2 was concentration-dependent and blocked by z-IETD-fmk, a specific caspase-8 inhibitor. Apoptosis with IFN-gamma was associated with increased surface expression of Fas, while IL-2 had no effect on Fas. IL-2 did not induce apoptosis in Fas-deficient TECs (M3.1-lpr) suggesting IL-2 regulation of caspase-8 activity requires Fas. Consistent with this, IL-2 but not IFN-gamma was found to decrease mRNA and protein expression of c-FLIP, an endogenous caspase-8 inhibitor in murine TECs. Overexpression of c-FLIP in TECs (CS3.7-FLIP) blocked apoptosis and caspase-8 activation with both IFN-gamma and IL-2. c-FLIP expression was found in kidney cortex, primary and cloned TECs, suggesting c-FLIP is likely a key regulator of caspase-8-mediated apoptosis in vivo.

CONCLUSION

This is the first report of c-FLIP regulation by IL-2 in renal TECs. Augmentation of c-FLIP in TECs may enhance an endogenous mechanism by which TECs normally resist injury to caspase-8-mediated apoptosis and thus may be a useful and novel strategy to prevent tubular injury in transplant rejection and autoimmune nephritis.

The Selective Use of Basiliximab Versus Thymoglobulin in Combination with Sirolimus for Cadaveric Renal Transplant Recipients at Low Risk Versus High Risk for Delayed Graft Function

BACKGROUND

We previously reported that the use of basiliximab together with sirolimus permits a window of recovery from delayed graft function before the introduction of reduced-dose cyclosporine. The present study reviews our experience with the substitution of thymoglobulin for basiliximab as induction therapy for recipients at increased risk for early acute rejection episodes.

METHODS

We retrospectively reviewed 145 cadaveric renal allograft recipients who received either basiliximab (n=115) or thymoglobulin (n=30) in combination with sirolimus and prednisone, followed by delayed introduction of reduced doses of cyclosporine. Recipients were stratified as high immune responders if they were African American, a retransplant recipient, or a recipient with a panel-reactive antibody greater than 50%. All other recipients were considered low immune responders.

RESULTS

Basiliximab-treated high immune responders exhibited a higher incidence of acute rejection episodes (26%) than either basiliximab-treated low immune responders (10%, P=0.04) or thymoglobulin-treated high immune responders (3%, P=0.01). The median time to initiation of cyclosporine was 12 days; cyclosporine was initiated when the serum creatinine level was 2.5 mg/dL or less. Patients with early return of renal function displayed a lower incidence of acute rejection episodes than those with later recovery of function (P=0.003). High immune responders treated with basiliximab expressed a higher mean serum creatinine level at 3 months (P<0.01), 6 months (P=0.02) and 12 months (P=0.01) than either low immune responders treated with basiliximab or high immune responders treated with thymoglobulin.

CONCLUSION

A strategy combining sirolimus with basiliximab for low-immunologic risk recipients and thymoglobulin for high-risk recipients leads to prompt recovery of renal function with a low risk of acute rejection episodes.

Acute Nephrotoxicity of Tacrolimus and Sirolimus in Renal Isografts: Differential Intragraft Expression of Transforming Growth Factor-??1 and ??-Smooth Muscle Actin

BACKGROUND

Renal dysfunction early after kidney transplantation has multiple causes including ischemia-reperfusion (I/R) injury and drug-induced nephrotoxicity. This study assesses the acute nephrotoxicity of tacrolimus (Tac) and sirolimus (Sir) in a rat renal isograft model.

METHODS

Lewis renal isografts and uninephrectomized rats that did not undergo transplantation were treated with various doses of Tac (0.5-5.0 mg/kg/d) or Sir (0.5-6.5 mg/kg/d). Kidneys were examined on day 14 by routine histology and immunohistochemistry for transforming growth factor (TGF)-beta1 and alpha-smooth muscle actin (SMA).

RESULTS

Both Tac and Sir demonstrated evidence of nephrotoxicity in the early posttransplant period including increased serum creatinine and morphologic changes in the graft including interstitial inflammation, fibrosis, and tubular vacuolization. Nephrotoxicity was most prominent in the high-dose treatment groups for both drugs and was more severe in transplanted kidneys than in uninephrectomized animals that did not undergo transplantation, suggesting an additive effect of I/R injury and drug nephrotoxicity. Both Tac and Sir increased intragraft TGF-beta1 and alpha-SMA, but there were distinct differences in the patterns of TGF-beta1 expression. Both demonstrated TGF-beta1 in tubular epithelial cells, but Sir was associated with proximal tubular TGF-beta1 localization in a bright granular pattern, whereas Tac was associated with diffuse distal tubular staining.

CONCLUSIONS

Both Tac and Sir may be nephrotoxic in the early posttransplant period, especially at high doses and when combined with I/R injury. Immunohistochemical localization of TGF-beta1 in the tubular cells was distinctly different with each drug, suggesting possible differences in the mechanism(s) of nephrotoxicity requiring further study.

Creatinine reduction ratio on post-transplant day two as criterion in defining delayed graft function

Delayed graft function (DGF) is a common complication after renal transplant, affecting its outcome. A common definition of DGF is the need for dialysis within the first week of transplantation, but this criterion has its drawbacks. We tried to validate an earlier and better defined parameter of DGF based on the creatinine reduction ratio on post-transplant day 2 (CRR2). We analyzed the clinical charts of 291 cadaver kidney recipients to compare the outcome of patients with immediate graft function (IGF), dialyzed patients (D-DGF) and nondialyzed CRR2-defined DGF patients (ND-DGF) and to identify risk factors for D-DGF and ND-DGF. Creatinine reduction ratio on post-transplant day 2 correlates significantly with renal function during the first year. Patients with IGF have significantly better renal function throughout the first year and better graft survival than patients with D-DGF and ND-DGF, while we found no differences either in renal function from days 30-365 or in graft survival between D-DGF and ND-DGF patients. Defining DGF by CRR2 allows an objective and quantitative diagnosis after transplantation and can help to improve post-transplant management. Creatinine reduction ratio on post-transplant day 2 correlates with renal function throughout the first year. The worse survival in the ND-DGF group is an important finding and a major advantage of the CRR2 criterion.

“Very delayed” graft function in a patient after living related kidney transplantation: a case report

We report the case of a patient who experienced anuric renal transplant failure for 44 days after living related kidney transplantation. Immunosuppressive and other therapies were carefully adapted to the findings of frequent renal transplant biopsies, which ultimately led to excellent graft function.

Basiliximab in association with tacrolimus and steroids in caucasian cadaveric renal transplanted patients: significant decrease in early acute rejection rate and hospitalization time

Safety and tolerability of basiliximab in renal transplantation have been proven in different immunosuppressive regimens. Few informations are available about the association of basiliximab with tacrolimus and steroids. We present a retrospective analysis performed in Caucasian cadaveric renal transplant recipients, comparing a basiliximab, tacrolimus and steroids induction protocol (GrA: 51 patients) with a tacrolimus and steroids protocol (GrB: 46 patients). A significant decrease in acute rejection rate in the first 3 months (2.0% vs. 17.4%; p < 0.01) was noted. Interestingly, the recipients in GrA were at major immunologic risk for the younger age of recipients, the greater number of mismatches and the higher rate of second transplants. The hospitalization times resulted reduced of 5.3 d in GrA vs. GrB (20.8 d vs. 26.1 d; p < 0.05). The adverse events patterns and profiles were similar in the two treatments groups. One patient in each group had a post-transplant lymphoprolipherative disorder. No significant difference was found in patient and graft survival. According to the results of this study, in a Caucasian adult population, basiliximab in association with tacrolimus and steroids is a safe and efficacious tool for acute rejection prevention and it is cost saving by reducing the hospitalization times.

Delayed graft function may not adversely affect short-term renal allograft outcome

INTRODUCTION

Delayed graft function (DGF) is commonly believed to adversely impact both short- and long-term renal allograft function. Because immunosuppressive therapy is commonly altered after DGF is identified, retrospective analyses are difficult to interpret. We therefore prospectively sought to examine the natural history of DGF in a controlled patient population under identical immunosuppressive protocols.

METHODS

Adult patients undergoing cadaveric renal transplantation were treated with sequential triple drug immunotherapy. High-dose steroids were administered in the operating room and rapidly tapered to 20 mg prednisone by post-operative day (POD) 6. Cyclosporine (CsA) microemulsion was begun on POD 1, and dosed asymmetrically at 12-h intervals to reach a daytime Cav of 650 ng/mL (utilizing 2-h and 6-h levels), while PM doses were adjusted to an AM trough of 300 ng/mL. Mycophenolate (1000 mg q12 h) was added on POD 3 in most patients and discontinued after 3 months. No induction agents were used. All patients were followed for at least 6 months.

RESULTS

Sixty consecutive patients received 64 allografts (four double grafts). In all, 17 patients required dialysis and were considered to have DGF. Eight of these patients received marginal organs turned down by at least one other centre. Cold ischaemia time was significantly longer in patients with DGF (24 h vs. 19 h, P < 0.01) All patients were treated as planned and there were no major protocol violations. One patient had primary non-function and was excluded from analysis. CsA trough and Cav values were similar between groups. Mean serum creatinine levels (mg/mL) fell more slowly in patients with DGF but there was no significant difference by 3 months (1.7 vs. 1.5) and the creatinine clearance was not significantly different between the groups after 1 year (71 cm3/min in DGF vs. 61 cm3/min, P = 0.13). Our data demonstrate that alterations in routine immunosuppressive strategies may not be necessary to achieve equivalent outcomes in patients with DGF.

Use of basiliximab with mycophenolate mofetil in kidney transplantation

INTRODUCTION

Randomized, placebo-controlled studies have determined that administration of basiliximab (chimeric IL-2 receptor antagonist) decreases the acute rejection rate in kidney transplantation when used in combination with cyclosporine, azathioprine, and steroids. We report our experience using basiliximab with mycophenolate mofetil, a calcineurin inhibitor, and steroids in kidney transplantation.

METHODS

We retrospectively analyzed 127 patients who received their first kidney transplant between September 1, 1998, and December 30, 2000, including 59 who received basiliximab (22 living and 37 cadaveric donor recipients) and the 68 that did not receive this antibody (31 living and 37 cadaveric donor recipients). The groups were demographically comparable for risk factors such as race, peak of panel-reactive antibody, delayed graft function, donor age, and cold ischemia time. The analysis assessed serum creatinine levels, acute rejection, cytomegalovirus infection, and posttransplant lymphoproliferative disease incidence as well as patient and graft survival at 6 months.

RESULTS

Serum creatinine levels were 3 +/- 3.1 and 2.6 +/- 2.5 mg/dL (P =.346) at discharge, 1.5 +/- 0.6 and 1.7 +/- 1.1 mg/dL (P =.098) at 1 month, and 1.5 +/- 0.7 and 1.6 +/- 0.7 mg/dL (P =.454) at 6 months posttransplantation for patients treated with versus without basiliximab, respectively. Only one episode of acute rejection was seen among patients treated with basiliximab within 1 month posttransplantation versus three episodes among patients treated without basiliximab (P =.382). Three patients (5.1%) treated with basiliximab and two patients (2.9%) treated without basiliximab developed acute rejection within 6 months posttransplantation (P =.536). Patient and graft survivals at 6 months posttransplantation were not significantly different between patients treated with versus without basiliximab (100% and 100% versus 100% and 98.3%, respectively). There was no increased incidence of cytomegalovirus infection with the use of basiliximab (5.1% vs 5.9%, P =.844). There was only one case of posttransplant lymphoproliferative disease within 6 months posttransplantation in a patient treated without basiliximab.

CONCLUSION

These data suggest that the routine addition of basiliximab to a mycophenolate mofetil-based regimens does not appear to be warranted. A larger prospective randomized study with longer follow-up is needed to confirm these results.

Calcineurin-free protocols with basiliximab induction allow patients included in "old to old" programs achieve standard kidney transplant function

INTRODUCTION

The EuroTransplant "old to old" program establishes that patients older than 60 years can receive offers of organs from donors older than 60 years. The compromised function of these organs makes it a priority to preserve their initial kidney function.

HYPOTHESIS

Calcineurin-sparing protocols using anti-IL-2 receptor (IL-2R) antibody induction (Simulect) may benefit initial kidney function in these patients, as assessed by the rates of delayed graft function and of rejection during the first month after transplant.

PATIENTS AND METHODS

A cohort of 15 consecutive elderly patients were prospectively compared with 30 cadaveric kidney transplants in younger recipients. Study patients were induced with Simulect (20 mg, 30 minutes before reperfusion and 4 days after transplantation) and steroids, delaying the introduction of CsA until the serum creatinine was below 3 mg/dL. The other cohort of patients were immunosuppressed with tacrolimus (trough 8 to 12), mycophenolats mofetil (MMF, 1 g/d), and an identical taper of steroids. The analysis compared donor and recipient ages, mean cold ischemic time, incidence of initial kidney function (diuresis in the first 24 h) serum creatinine levels, glomerular filtration rate (GFR), number of dialysis sessions, and rejection rate in the two groups.

RESULTS

Except for the donor and recipient ages (72 vs 54 in donors, and 67 versus 52 years in recipients), no significant differences were observed between the groups among the rates of acute rejection (6.6% vs 13.2%), delayed graft function (13.2% required dialysis), or infection (6.6%). Within 1 month all 45 grafts showed primary function with equal creatinine levels (mean 1.65).

CONCLUSIONS

Calcineurin-free protocols using IL-2 therapy as the initial suppression allow patients in the "old to old" ET program to display equal results to cadaveric kidney transplants with initial treatment with calcineurin antagonists.