PREventing Delayed Graft Function by Driving Immunosuppressive InduCtion Treatment (PREDICT-DGF): study protocol for a randomized controlled trial.

BACKGROUND: In kidney transplantation, the use of Anti-Thymocyte Globulins (ATG) as induction therapy has been described as a possible treatment for reducing the prevalence of Delayed Graft Function (DGF). ATG possesses pharmaceutical proprieties that could help control the lesions caused by ischemia reperfusion injury. However, other studies have questioned this potential protective effect. We hypothesized that the benefits related to ATG for reducing DGF prevalence may be higher and more consistently recognized if only patients with high DGF risk are considered. We recently proposed a scoring system entitled DGFS (Delayed Graft Function Score) for such stratification of kidney transplant recipients according to their risk of DGF. Using the DGFS calculation, we aim to determine whether a short course of ATG can decrease the incidence of DGF in comparison with Basiliximab in kidney transplant recipients with low immunological risk but high DGF risk. METHODS: We conduct a phase IV, open label, randomized, multicentric and prospective study, to compare ATG in parallel with a control group treated by Basiliximab. The 1:1 randomized allocation of patients between groups is stratified on the clinical center, and on the hypothermic machine-perfusion device. We aimed to include a total of 384 patients to achieve a statistical power at 0.80. The study was initiated at the Nantes University hospital in July 2014, with data collection continuing until April 2018, and publication of the results proposed for 2019. DISCUSSION: The main expected benefits of this study are i) the reduction of unjustified ATG over-prescriptions associated with serious adverse events, ii) the reduction of chance losses related to ATG under-prescription, iii) the decrease in the incidence of DGF which was described as a risk factor of graft failure and patient death, and iv) the reduction in hospitalization duration and number of post transplantation dialysis sessions, both being associated with reduced medical costs. In conclusion, the current study is innovative by proposing a more efficient and personalized induction therapy. TRIAL REGISTRATION: The study was registered in the Clinical Trials Registry (# NCT02056938, February 5, 2014), and in the European Clinical Trials Database (EudraCT #2014-000332-42, January 30, 2014).

A personalized follow-up of kidney transplant recipients using video conferencing based on a 1-year scoring system predictive of long term graft failure (TELEGRAFT study): protocol for a randomized controlled trial.

BACKGROUND: Numerous well-established clinical parameters are taken into consideration for the follow-up adaptation of kidney transplant recipients, but there are important disparities between countries, centres and clinicians. Therefore, novel scoring systems have been developed, for instance the Kidney Transplant Failure Score (KTFS) which aims to stratify patients according to their risk of return to dialysis. We hypothesize that the efficiency of the follow-up after one year post-transplantation can be improved by adapting it to the risk of graft failure defined by the KTFS estimation. METHODS/DESIGN: We propose a phase IV, open label, randomized, multicentric and prospective study. The study is registered with the Clinical Trials Registry NCT01615900. 250 patients will be allocated to one of two arms: the eHealth program versus the standard of care at hospital. In the standard group, patients classified at low-risk (KTFS ≤ 4.17) will be scheduled 4 visits at hospital per year, whilst high-risk patients will visit hospital 6 times. In the eHealth group, patients classified at low-risk will be interviewed 3 times by video conferencing and once at hospital, whilst 6 visits at hospital and 6 video conferencing will be scheduled for high-risk patients. DISCUSSION: The current study allows to scientifically evaluate the etiologic impact of a novel eHealth program. This is important to clarify the possible contribution of telemedicine in the improvement of medical follow-up. The proposed design based on 4 different sub-groups can be interesting to evaluate other personalized medicine programs.

A useful scoring system for the prediction and management of delayed graft function following kidney transplantation from cadaveric donors.

Delayed graft function (DGF) is a common complication in kidney transplantation and is known to be correlated with short- and long-term graft outcomes. Here we explored the possibility of developing a simple tool that could predict with good confidence the occurrence of DGF and could be helpful in current clinical practice. We built a score, tentatively called DGFS, from a French multicenter and prospective cohort of 1844 adult recipients of deceased donor kidneys collected since 2007, and computerized in the Données Informatisées et VAlidées en Transplantation databank. Only five explicative variables (cold ischemia time, donor age, donor serum creatinine, recipient body mass index, and induction therapy) contributed significantly to the DGF prediction. These were associated with a good predictive capacity (area under the ROC curve at 0.73). The DGFS calculation is facilitated by an application available on smartphones, tablets, or computers at www.divat.fr/en/online-calculators/dgfs. The DGFS should allow the simple classification of patients according to their DGF risk at the time of transplantation, and thus allow tailored-specific management or therapeutic strategies.

An original approach was used to better evaluate the capacity of a prognostic marker using published survival curves.

OBJECTIVES: Predicting chronic disease evolution from a prognostic marker is a key field of research in clinical epidemiology. However, the prognostic capacity of a marker is not systematically evaluated using the appropriate methodology. We proposed the use of simple equations to calculate time-dependent sensitivity and specificity based on published survival curves and other time-dependent indicators as predictive values, likelihood ratios, and posttest probability ratios to reappraise prognostic marker accuracy. STUDY DESIGN AND SETTING: The methodology is illustrated by back calculating time-dependent indicators from published articles presenting a marker as highly correlated with the time to event, concluding on the high prognostic capacity of the marker, and presenting the Kaplan-Meier survival curves. The tools necessary to run these direct and simple computations are available online at http://www.divat.fr/en/online-calculators/evalbiom. RESULTS: Our examples illustrate that published conclusions about prognostic marker accuracy may be overoptimistic, thus giving potential for major mistakes in therapeutic decisions. CONCLUSION: Our approach should help readers better evaluate clinical articles reporting on prognostic markers. Time-dependent sensitivity and specificity inform on the inherent prognostic capacity of a marker for a defined prognostic time. Time-dependent predictive values, likelihood ratios, and posttest probability ratios may additionally contribute to interpret the marker's prognostic capacity.

Influence of anemia on patient and graft survival after renal transplantation: results from the French DIVAT cohort.

BACKGROUND AND OBJECTIVES: Contradictory results are reported concerning the influence of anemia on patient and graft survival after renal transplantation. Assuming that level of renal function and anemia are strongly correlated, posttransplantation anemia (PTA) may have a different impact depending on the stage of chronic kidney disease (CKD). METHODS: This study is a retrospective multicenter analysis using the DIVAT French database. The prevalence, risk factors, and influence of 12-month PTA (World Health Organization's definition) on patient and graft survival were analyzed according to CKD stage (Modification of Diet in Renal Disease equation). RESULTS: The prevalence of 12-month PTA in our cohort of 4217 patients was 41.1%. Multivariate analysis demonstrated that worse renal function, donor age, period of transplantation, induction therapy, and mTOR inhibitors were significant risk factors for PTA. Posttransplantation anemia was a significant risk factor for all-cause mortality in CKD stages 1 to 2T (hazard ratio, 2.39; 95% confidence interval, 1.99-4.40) and 3T (hazard ratio, 1.52; 95% confidence interval, 1.08-2.15) and for cardiovascular mortality only on CKD stages 1T and 2T. In renal transplant recipients with CKD stages 4 to 5T, patient and graft survival were similar in patients with versus without anemia. Graft survival was not influenced by PTA, whatever the CKD stage. CONCLUSIONS: Posttransplantation anemia is associated with decreased patient survival only in CKD stages 1T, 2T, and 3T. Posttransplantation anemia has no influence on graft survival regardless of CKD stage.

A clinical scoring system highly predictive of long-term kidney graft survival.

Determining early surrogate markers of long-term graft outcome is important for optimal medical management. In order to identify such markers, we used clinical information from a cross-validated French database (Données Informatisées et VAlidées en Transplantation) of 2169 kidney transplant recipients to construct a composite score 1 year after transplantation. This Kidney Transplant Failure Score took into account a series of eight accepted pre- and post-transplant risk factors of graft loss, and was subsequently evaluated for its ability to predict graft failure at 8 years. This algorithm outperformed the traditional surrogates of serum creatinine and the estimated graft filtration rate, with an area under the receiver-operator characteristic curve of 0.78. Validation on an independent database of 317 graft recipients had the same predictive capacity. Our algorithm was also able to stratify patients into two groups according to their risk: a high-risk group of 81 patients with 25% graft failure and a low-risk group of 236 patients with an 8% failure rate. Thus, although this clinical composite score predicts long-term graft survival, it needs validation in different patient groups throughout the world.

Kidney and recipient weight incompatibility reduces long-term graft survival.

Long-term function of kidney allografts depends on multiple variables, one of which may be the compatibility in size between the graft and the recipient. Here, we assessed the long-term consequences of the ratio of the weight of the kidney to the weight of the recipient (KwRw ratio) in a multicenter cohort of 1189 patients who received a transplant between 1995 and 2006. The graft filtration rate increased by a mean of 5.74 ml/min between the third and sixth posttransplantation months among patients with a low KwRw ratio (<2.3 g/kg; P<0.0001). In this low KwRw ratio group, the graft filtration rate remained stable between 6 months and 7 years but then decreased at a mean rate of 3.17 ml/min per yr (P<0.0001). In addition, low KwRw ratios conferred greater risk for proteinuria, more antihypertensive drugs, and segmental or global glomerulosclerosis. Moreover, a KwRw ratio<2.3 g/kg associated with a 55% increased risk for transplant failure by 2 years of follow-up. In conclusion, incompatibility between graft and recipient weight is an independent predictor of long-term graft survival, suggesting that avoiding kidney and recipient weight incompatibility may improve late clinical outcome after kidney transplantation.

How well do pre- and peritransplant variables predict the long-term results of kidney transplantation?

In organ transplantation, several clinical risk factors that are available before or immediately following the time of surgery have been shown to affect long-term transplant outcomes. We examined their ability to predict long-term survival accurately using a novel statistical method and data from the Données Informatisees et Validées en Transplantation on 3,227 kidney transplant recipients between 1996-2006 at 5 French transplant centers. The results clearly illustrate that the correlation of these parameters with survival is not sufficient to constitute a prognostic marker. In kidney transplantation, classical pre- and peritransplant clinical risk factors of graft loss are poor predictive markers for medical decision-making.

Effect of brain-dead donor resuscitation on delayed graft function: results of a monocentric analysis.

BACKGROUND: We have previously shown that a delayed graft function (DGF) longer than 6 days was a crucial threshold for long-term graft outcome. The aim of this study was to analyze the correlation of DGF >or=6 days with brain-dead donor variables, including those related to resuscitation, in a population of 262 consecutive brain-dead donors from 1990 to 2003. METHODS: We used a marginal logistic model in which DGF was considered as a binary variable with a cutoff of 6 days. RESULTS: Monovariate analysis of donor parameters showed that male, age above 35 years, primary history of hypertension, hydroxyethyl starch (HES) fluid greater than 1500 mL or epinephrine infusion during resuscitation were risk factors for prolonged DGF. The multivariate logistic regression model showed that epinephrine use during donor resuscitation (P<0.001, odds ratio [OR]=4.35), cold ischemia time (CIT) >or=16 hr (P=0.01, OR=2.16), and recipient age >55 years (P=0.003, OR=2.75), were associated with a risk of prolonged DGF. A long stay (>40 hr) in intensive care and a large volume of colloids (>1250 mL, except HES) correlated with a lower risk of DGF. CONCLUSION: Our study shows an impact for only a limited number of brain dead donor resuscitation parameters on DGF duration. We also show that CIT has a much lower threshold (<16 hr) for DGF risk than previously described. Importantly, we show that recipient age is clearly a major independent risk factor for prolonged DGF, whereas donor age seems to act mostly as a dependent risk factor.

Impact of graft mass on the clinical outcome of kidney transplants.

The effect of nephronic mass reduction of kidney transplants has not been analyzed specifically in a large cohort. Transplant injuries in cadaver kidney graft may have led to an underestimation of the magnitude of this factor. The aim of this study was to analyze the consequences of kidney mass reduction on transplantation outcome. The weights of 1142 kidney grafts were collected prospectively immediately before grafting. Donors and recipients <15 yr of age, simultaneous kidney/pancreas grafts, and technical failures before day 7 were excluded from the analysis. The analysis was performed on Cockroft-calculated creatinine clearance and proteinuria in 964 patients for whom all of the necessary information was available. This study reports that the smallest kidneys transplanted into the largest recipients (donor kidney weight/recipient body weight [DKW/RBW] <2 g/kg, n = 88) increased their clearance by 2.38 ml/min every month for 6 mo (P < 0.0001) and by 0.27 ml/min thereafter (P < 0.0001). Conversely, creatinine clearance did not change for the largest kidneys transplanted into the smallest recipients (DKW/RBW ratios >/=4 g/kg). Next, using a Cox model analysis, it was shown that the risk of having a proteinuria >0.5 g/kg was significantly increased for the low DKW/RBW ratios <2 g/kg with 50% of patients having a proteinuria, compared with DKW/RBW ratios >/=4 g/kg (P < 0.001). In cadaver transplant recipients, graft mass has a rapid impact on graft filtration rate and proteinuria. Avoiding major kidney/recipient inadequacy should have a significant influence on long-term transplant function.

Ten-year survival of second kidney transplants: impact of immunologic factors and renal function at 12 months.

BACKGROUND: The aim of the present study was to assess long-term survival of cadaveric second kidney allografts performed in our center and to determine risk factors predictive of long-term graft outcome. METHODS: Of 1704 kidney transplantations performed between January 1985 and March 1998, 233 were second grafts. The majority of the recipients were sensitized. All patients were treated with the same quadruple immunosuppressive regimen. RESULTS: Kaplan-Meier analysis documented graft survival of 89% at 1 year, 76% at 5 years, and 53% at 10 years. Graft survival was similar for second and primary kidney transplants performed during the same period of time. When long-term second graft survival was examined, only two risk factors were found to be significant: (1) the degree of human leukocyte antigen (HLA) DR mismatch (MM) and (2) the number of acute rejection episodes. Multivariate analysis of several pre- and posttransplant variables also confirmed the importance of HLA MM (DR> A), but also, identified serum creatinine at 12 months as the most significant predictor of graft survival. In addition, the Cox proportional hazards model revealed that only the year of transplantation had an independent significant effect on acute rejection occurrence (RR = 0.591, 95%CI 0.437 to 0.801, P < 0.0007). Indeed, the incidence of acute rejection was found to decrease over time (44% of patients experienced at least one episode of acute rejection before 1990 vs. 17% after 1990). CONCLUSION: Finally, second graft long-term outcome shows an improved evolution according to the time period resulting from a strong decrease in acute rejection incidence and the impact of creatinine at 12 months.

Acute graft pyelonephritis and long-term kidney allograft outcome.

BACKGROUND: Long-term graft function is the result of multiple parameters, including both immune and non-immune components, which have a beneficial or detrimental potential. Among these, despite its frequency and theoretical interest (expression of "danger signals" in the graft itself), the effects of acute graft pyelonephritis (AGPN) on immediate and long-term outcome have not been studied in a large series. This article reviews a cohort of 1387 consecutive primary renal transplant recipients. METHODS: The objective of the study was to define the risk factor for AGPN, the risk profile for recurrence, and the impact of AGPN on long-term graft survival. According to a higher risk for AGPN in females during their follow-up, statistical analyses (Cox model, and multiple regression analysis) were performed by recipient sex strata. RESULTS: Multivariate analysis showed that CMV infection was the only risk factor for AGPN occurrence. AGPN occurred in 13% of the graft recipients during their follow-up. Taken as a whole, AGPN was not associated with a significantly poor long-term outcome. However, when assessed in more detail, the outcome of this population was found to be more complex and to depend on several factors. Early AGPN (during the first 3 months) was significantly detrimental for graft outcome, independently of acute rejection episodes. Moreover, E. coli involvement in a first episode was linked to an increased AGPN recurrence. CONCLUSION: This analysis did not support the concept that with current immunosuppression, strong "danger signals" such as those derived from bacteria within an allograft, are instrumental in initiating acute or chronic rejection.

Mycophenolate mofetil does not modify the incidence of cytomegalovirus (CMV) disease after kidney transplantation but prevents CMV-induced chronic graft dysfunction.

Ganciclovir, which is used to treat cytomegalovirus (CMV) infection, has been shown in rodent models to abolish CMV-mediated chronic cellular damage and endothelial cell proliferation; when associated with mycophenolate mofetil (MMF), it has been shown to increase its anti-herpes virus activity. This study tested the hypothesis that kidney graft recipients who received antirejection prophylaxis with MMF and who were treated with ganciclovir for a declared CMV disease could be protected from chronic graft dysfunction. Investigated was the impact of ganciclovir-treated CMV diseases in consecutive first kidney recipients according to their immunosuppressive therapy. The azathioprine (Aza)-treated group (Aza group) included 319 patients. The MMF-treated group (MMF group) included 126 patients. CMV disease was clinically defined and confirmed by virological proof of CMV infection and was treated for at least 14 d with ganciclovir. Despite having the same incidence (21.6% in the Aza group versus 24.6% in the MMF group) and severity, CMV disease was significantly associated with graft loss independent of acute rejection episodes or other factors when tested in a Cox proportional model in the Aza group only (P < 10(-4)). It was shown for the first time that patients whose CMV disease is treated with ganciclovir while they are on MMF therapy are protected from the long-term deleterious consequences of CMV disease on graft survival, independent of acute rejection. It is suggested that the enhanced anti-herpes virus activity of ganciclovir by MMF could contribute to this reported effect, which may represent a significant contribution of MMF efficacy to graft survival.