PRODIG (Prevention of new onset diabetes after transplantation by a short term treatment of Vildagliptin in the early renal post-transplant period) study: study protocol for a randomized controlled study

BACKGROUND

Post-transplant diabetes is a frequent and serious complication of kidney transplantation. There is currently no treatment to prevent or delay the disease. Nevertheless, identification of risk factors make it possible to target a population at risk of developing de novo diabetes. We hypothesized that a short-term treatment with vildagliptin may prevent new onset diabetes after transplantation (NODAT) in high-risk patients.

METHODS/DESIGN

This is a multicenter, double-blind, placebo-controlled randomized clinical trial. Patients undergoing first kidney transplantation will be included from ten French transplant centers. Included patients will be randomized (1:1) to receive either vildagliptin 100 or 50 mg/day (depending on glomerular filtration rate) during 2 months (the first dose being administered before entering the operating theatres) or placebo. Additional antidiabetic therapy could be administered according to glycemic control. The primary outcome is the proportion of diabetic patients 1 year after transplantation, defined as patients receiving a diabetic treatment, or having a fasting glucose above 7 mmol/l, and/or with an abnormal oral glucose tolerance test. Secondary outcomes include glycated hemoglobin, the occurrence of acute rejection, infection, graft loss and patient death at 3 months, 6 months, and 12 months after transplantation. Outcomes will be correlated to clinical and general characteristics of the patient, cardiovascular history, nephropathy, dialysis history, transplantation data, biological data, health-related quality of life, and the cost-effectiveness of prevention of diabetes with vildagliptin.

DISCUSSION

We have scarce data on the pharmacological prevention of post-transplant diabetes. If our hypothesis is verified, our results will have a direct application in clinical practice and could limit diabetes-associated morbidity, reduce cardiovascular complications, increase quality of life of renal transplant patients, and consequently promote graft and patient survival. Our results may possibly serve for non-transplant patients carrying a high-risk of diabetes associated with other co-morbidities.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02849899 . Registered on 8 February 2016.

Pre-transplant end-stage renal disease-related immune risk profile in kidney transplant recipients predicts post-transplant infections

BACKGROUND

End-stage renal disease (ESRD) is associated with premature aging of the T-cell system. Nevertheless, the clinical significance of pre-transplant ESRD-related immune senescence is unknown.

METHODS

We studied whether immune risk phenotype (IRP), a typical feature of immune senescence, may affect post-transplant infectious complications. A total of 486 patients were prospectively studied during the first year post transplant. IRP was defined as positive cytomegalovirus serology with at least 1 of the following criteria: CD4/CD8 ratio <1 and/or CD8 T-cell count >90th percentile.

RESULTS

We found that 47 patients (9.7%) had pre-transplant IRP. IRP+ patients did not differ from IRP- patients for any clinical characteristics, but exhibited more pronounced immune senescence. Both opportunistic infections (43% vs. 6%, P < 0.001) and severe bacterial infection (SBI) (40% vs. 25%, P = 0.028) were more frequent in IRP(+) patients. In multivariate analysis, IRP was predictive of both opportunistic infection (hazard ratio [HR] 2.97 [95% confidence interval {CI} 1.53-5.76], P = 0.001), and SBI (HR 2.33 [95% CI 1.34-3.92], P = 0.008). Acute rejection rates were numerically much lower in IRP+ patients. A total of 418 patients (86%) had biological evaluation 1 year post transplant. Among 41 IRP+ patients, 35 (85%) remained IRP+ 1 year post transplant.

CONCLUSION

Pre-transplant IRP is associated with an increased risk of post-transplant infection.

ATG-induced accelerated immune senescence: clinical implications in renal transplant recipients

Persistent ATG-induced CD4(+) T cell lymphopenia is associated with serious clinical complications. We tested the hypothesis that ATG induces accelerated immune senescence in renal transplant recipients (RTR). Immune senescence biomarkers were analyzed at transplant and one-year later in 97 incident RTR -62 patients receiving ATG and 35 receiving anti-CD25 mAb (α-CD25). This consisted in: (i) thymic output; (ii) bone marrow renewal of CD34(+) hematopoietic progenitor cells (CD34(+) HPC) and lymphoid (l-HPC) and myeloid (m-HPC) progenitor ratio; (iii) T cell phenotype; and (iv) measurement of T cell relative telomere length (RTL) and telomerase activity (RTA). Clinical correlates were analyzed with a 3 year follow-up. Thymic output significantly decreased one-year posttransplant in ATG-treated patients. ATG was associated with a significant decrease in l-HPC/m-HPC ratio. Late stage differentiated CD57(+) /CD28(-) T cells increased in ATG-treated patients. One-year posttransplant T cell RTL and RTA were consequently lower in ATG-treated patients. ATG is associated with accelerated immune senescence. Increased frequency of late differentiated CD4(+) T cell frequency at transplantation tended to be predictive of a higher risk of subsequent opportunistic infections and of acute rejection only in ATG-treated patients but this needs confirmation. Considering pretransplant immune profile may help to select those patients who may benefit from ATG to prevent severe infections and acute rejection.

Subclinical Epstein-Barr virus viremia among adult renal transplant recipients: incidence and consequences

The natural history and clinical significance of posttransplant Epstein-Barr virus (EBV) infection remain largely unknown. The aims of this study are to describe the incidence, risk factors and consequences of EBV infection after kidney transplantation. A total of 383 consecutive patients having received a kidney transplant between January 2002 and December 2010 were included. EBV polymerase chain reaction (PCR) was performed every 2 weeks for 3 months, and every 4 weeks for the next 9 months. A total of 155 of the 383 patients (40%) had at least one positive viremia during the first year posttransplant. The median time to viremia was day 31 posttransplant (14-329). A total of 73 (47%) had EBV viremia > 10(3) log and 23 (15%) had positive viremia for more than 6 months. EBV D+/R- patients (12/18 (67%) versus 143/365 (39%), p = 0.02) and those having received antithymocyte globulins (ATG) (54% vs. 35%; p<0.001) were more likely to develop EBV infection. EBV infection (hazard ratio [HR], 3.03; 95% confidence interval [CI], 1.72-8.29; p = 0.01) was associated with the occurrence of opportunistic infections. A positive EBV PCR during the first 6 months posttransplant was associated with graft loss (HR, 3.04; 95% CI, 1.36-6.79; p = 0.014). EBV reactivation is frequent after transplantation and reflects overimmunosuppression. Prospective studies should examine the association between EBV and graft loss.