Survival and specific outcome of sickle cell disease patients after renal transplantation

The prognosis of sickle cell disease (SCD) patients who need dialysis is poor, but experience with kidney transplantation is limited. This study assessed the characteristics of 36 SCD patients undergoing renal transplantation. Immediate post-surgical complications occurred in 25% of cases. Cytomegalovirus and bacterial infections were frequently observed. Twelve patients died after a median follow-up period of 17·4 months. Overall patient survival was significantly lower in SCD than in the control group without significant difference for overall death-censored graft survival. Our data suggest that renal transplantation should be systematically considered in SCD patients with end-stage renal disease.

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.

Lack of impact of pre-emptive deceased-donor kidney transplantation on graft outcomes: a propensity score-based study

BACKGROUND

A significant number of studies have compared graft outcomes between patients with Pre-emptive Kidney Transplantation (PreKT) and patients on Dialysis before their Kidney Transplantation (DiaKT). These studies have suffered from the limitation that the DiaKT group is composed of all the dialysed patients, including those placed on a waiting list at the time of their first dialysis session. This seriously questions the comparability of these patients with those placed on the waiting list a long time before the need for renal replacement therapy. The aim of this study was to precisely evaluate the causal effect of PreKT from deceased donors.

METHODS

Data were extracted from the multicentric French DIVAT (Données Informatisées et VAlidées en Transplantation) cohort. The DiaKT group was composed of patients placed on the waiting list with an initial intention of pre-emptive transplantation. Cause-specific Cox models with propensity scores (inverse probability weighting) were used to study the patient and graft outcomes.

RESULTS

Among the 1138 included patients, 554 patients were in the PreKT group. The outcomes of the PreKT group were similar compared with the DiaKT group. In particular, the life expectancy with a functioning graft was 8.51 years [95% confidence interval (CI) 8.20-8.81] for the PreKT recipients versus 8.49 years (95% CI 8.15-8.84) for the DiaKT recipients.

CONCLUSIONS

Our results challenge the utility of PreKTs from deceased donors, especially with regard to the consequential increase in the waiting list.

Endovascular Treatment of Transplant Renal Artery Stenosis: Evaluation of Postoperative Outcomes and Risk Factors for Recurrence

Angioplasty with or without stenting has become a well-established procedure to treat transplant renal artery stenosis (TRAS). We evaluated our experience on postoperative outcomes following the intervention and identified potential predictive factors of TRAS recurrence. Consecutive patients who underwent endovascular treatment of TRAS were retrospectively reviewed. The study end points were the technical success, 30-day postoperative complications, and the estimated glomerular filtration rate (eGFR). Thirty-two patients underwent endovascular treatment for TRAS. The technical success rate was 96.6%. Complications were observed for 7 (21.9%) patients: 4 had a dissection, 2 a pseudoaneurysm, and 1 (3.1%) patient developed an acute pulmonary edema. The mean eGFR significantly increased at 7 days, 3 months, and 6 months postintervention (43.1, 44.9, and 44.3 vs 33.9 mL/min/1.73 m2 preoperatively, P < .05). The TRAS recurrence was observed in 7 (21.9%) patients. These patients had significantly higher preoperative peak systolic velocity and systolic rise time (5 vs 4 m/s, P = .0383 and 103 vs 80 milliseconds, P = .0148, respectively). Endovascular treatment of TRAS is associated with high technical success and significant improvement in renal function. Further studies are required to confirm predictive factors of TRAS recurrence following endovascular treatment.

High-resolution melting analysis (HRM) for mutational screening of Dnajc17 gene in patients affected by thyroid dysgenesis

BACKGROUND

Congenital hypothyroidism is a frequent disease occurring with an incidence of about 1/1500 newborns/year. In about 75% of the cases, CH is caused by alterations in thyroid morphogenesis, defined "thyroid dysgenesis" (TD). TD is generally a sporadic disease but in about 5% of the cases a genetic origin has been demonstrated. Previous studies indicate that Dnajc17 as a candidate modifier gene for hypothyroidism, since it is expressed in the thyroid bud, interacts with NKX2.1 and PAX8 and it has been associated to the hypothyroid phenotype in mice carrying a single Nkx2.1 and Pax8 genes (double heterozygous knock-out).

PURPOSE

The work evaluates the possible involvement of DNAJC17 in the pathogenesis of TD.

METHODS

High-resolution DNA melting analysis (HRM) and direct sequencing have been used to screen for mutations in the DNAJC17 coding sequence in 89 patients with TD.

RESULTS

Two mutations have been identified in the coding sequence of DNAJC17 gene, one in exon 5 (c.350A>C; rs79709714) and one in exon 9 (c.610G>C; rs117485355). The last one is a rare variant, while the rs79709714 is a polymorphism. Both are present in databases and the frequency of the alleles is not different between TD patients and controls.

CONCLUSIONS

DNAJC17 mutations are not frequently present in patients with TD.

Comparative clinical trial of the variability factors of the exposure indices used for the drug monitoring of two tacrolimus formulations in kidney transplant recipients

BACKGROUND

Several studies found differences in tacrolimus whole blood trough levels (C0) or area-under-the curve (AUC) between the twice-daily (Tac-BID) and once-daily (Tac-OD) formulations given to kidney transplant recipients at equal doses. As C0 is widely used as a surrogate of the AUC for individual dose adjustment, this study investigated the correlation and proportionality between C0 and the 24h-AUC, depending on the formulation, time post-transplantation, pharmacogenetics traits and other individual characteristics.

METHODS

45 adult kidney transplant recipients were randomized to receive either Tac OD or Tac BID. On days 8±1 (D8) and 90±3 (month 3, M3), blood samples were collected over 24h in both groups. Tacrolimus concentrations were determined using HPLC-MS/MS and common CYP3A5, CYP3A4 and ABCB1 genotypes characterized using allelic discrimination assays. Tacrolimus population pharmacokinetics was studied in the two patient groups using the Iterative Two Stage (ITS) technique, considering a one-compartment model with two gamma laws to describe the absorption phase. Bayesian estimation based on the C0, C1h and C3h concentrations was employed to estimate individual Tac AUC_0-12h and AUC_12-24h (for Tac BID), or AUC_0-24h (for Tac OD). Multiple linear regression was used to evaluate the influence of Tac formulation, post-transplantation period, recipient gender, existing glucose metabolism disorders, and CYP3A5, CYP3A4 and ABCB1 genotypes on C0, AUC_0-24h and the AUC-to-trough concentration ratios.

RESULTS

The Full Analysis Set comprised 22 patients on Tac OD and 20 on Tac BID. Tac exposure indices as well as their time evolution were similar in the two groups. Multi-linear modeling analysis showed that the Tac dose was higher with Tac-OD than Tac-BID, on D8 than at M3 and in CYP3A5 expressors (p<0.0001 for all). No such influence was found on C0 or C24h, while the AUC_0-24h was significantly higher on D8 than at M3. The AUC_0-24h/C0 ratio was not affected by the drug formulation and the polymorphisms studied, but it was significantly lower on D8 than at M3 (p=7.8×10^-5). In contrast, both the post-transplantation period (p=1.53×10^-4), and CYP3A5 expression (p=0.003) had a significant influence on the AUC_0-24h/C24h ratio, explaining 19% and 12% of its variability, respectively. Consistently, for both Tac formulations, the AUC_0-24h was better correlated with C24h than C0, and for Tac-BID the AUC_0-12h was better correlated with C12h than C0.

CONCLUSIONS

This study confirms that the precisely timed 12h- or 24h-post-dose blood concentration (as opposed to the vaguely defined 'trough level') is a convenient surrogate of the 24h-AUC of tacrolimus for the two TAC formulations over the first 3 months post-transplantation. Still, for a given C24h value, AUC_0-24h was higher on D8 and in CYP3A5 expressors. Bayesian estimation of AUC_0-12h for TAC BID and AUC_0-24h for TAC OD is feasible using only 3 time points within the first 3h, thus giving access to the actual overall exposure.

Reduction of Extended-Release Tacrolimus Dose in Low-Immunological-Risk Kidney Transplant Recipients Increases Risk of Rejection and Appearance of Donor-Specific Antibodies: A Randomized Study

The aim of this study (ClinicalTrials.gov, NCT01744470) was to determine the efficacy and safety of two different doses of extended-release tacrolimus (TacER) in kidney transplant recipients (KTRs) between 4 and 12 mo after transplantation. Stable steroid-free KTRs were randomized (1:1) after 4 mo: Group A had a 50% reduction in TacER dose with a targeted TacER trough level (C₀ ) >3 μg/L; group B had no change in TacER dose (TacER C₀ 7-12 μg/L). The primary outcome was estimated GFR at 1 year. Of 300 patients, the intent-to-treat analysis included 186 patients (group A, n = 87; group B, n = 99). TacER C₀ was lower in group A than in group B at 6 mo (4.1 ± 2.7 vs. 6.7 ± 3.9 μg/L, p < 0.0001) and 12 mo (5.6 ± 2.0 vs. 7.4 ± 2.1 μg/L, p < 0.0001). Estimated GFR was similar in both groups at 12 mo (group A, 56.0 ± 17.5 mL/min per 1.73 m²; group B, 56.0 ± 22.1 mL/min per 1.73 m²). More rejection episodes occurred in group A than group B (11 vs. 3; p = 0.016). At 1 year, subclinical inflammation occurred more frequently in group A than group B (inflammation score [i] >0: 21.4% vs. 8.8%, p = 0.047; tubulitis score [t] >0: 19.6% vs. 8.7%, p = 0.076; i + t: 1.14 ± 1.21 vs. 0.72 ± 1.01, p = 0.038). Anti-HLA donor-specific antibodies appeared only in group A (6 vs. 0 patients, p = 0.008). TacER C₀ should be maintained >7 μg/L during the first year after transplantation in low-immunological-risk, steroid-free KTRs receiving a moderate dose of mycophenolic acid.

Endoureteral Management of Renal Graft Ureteral Stenosis by the Use of Long-Term Metal Stent: An Appealing Treatment Option

Background: Ureteral stenosis is part of the common complications of renal graft reported in 3% to 7% of cases. Multiple treatments have been introduced regarding length and position of the stenosis. Metal stents for urologic purpose were created in 1998. Double percutaneous antegrade and transurethral retrograde access to a ureteral stenosis to a long-term metal stent procedure has been rarely described. Case Presentation: Here, we present a case of a ureteral stricture in a double ipsilateral kidney graft with a common ureter. A 67-year-old patient presented with obstructive nephritis associated with acute renal failure 6 years after a double renal graft with a uretero-ureteral end-to-side anastomosis. Abdominal CT scan showed double pelvic dilation. The patient underwent double percutaneous nephrostomies and antegrade pyelogram showed both renal pelvic and ureter dilations caused by a severe chronic ureteral stenosis at junction into the bladder. A Double-J ureteric stent was then inserted retrogradely over a guidewire as first-line treatment. Due to recurrent urinary tract infections (UTIs), removal and replacement of Double-J stents were carried out by placing a thermoexpandable metal stent Memokath^® 051 (Bard, Pnn Medical) through the common ureter by a double antegrade and retrograde approach. Treatment was effective with a good renal function maintained after a 3-year follow-up without UTIs. Conclusion: Double antegrade and retrograde access to a long-term metal stent treatment can be seen as an alternative treatment to either endoscopy or open surgery. Further studies should be continued using larger series.

Dosing of Enteric-Coated Mycophenolate Sodium Under Routine Conditions: An Observational, Multicenter Study in Kidney Transplantation

BACKGROUND Dosing of enteric-coated mycophenolate sodium (EC-MPS) should be adjusted to reflect concomitant immunosuppression, but it is largely undocumented whether such modifications are carried out during routine clinical practice. MATERIAL AND METHODS MyLIFE was an observational study of adult kidney-only or kidney-pancreas transplant patients starting -EC-MPS at 33 French transplant centers. Data were collected at first EC-MPS dose and 6 months later. The primary objective was to describe initial EC-MPS dosing according to concomitant immunosuppression. RESULTS There were 461 patients analyzed (174 started EC-MPS by month 1 post-transplant ['de novo'] and 287 started EC-MPS >1 month post-transplant ['maintenance']), receiving cyclosporine (CsA) (n=76), tacrolimus (n=363), or a mammalian target of rapamycin (mTOR) inhibitor (n=22). Mean (SD) starting dose was 1130 (511) mg/day, 1006 (441) mg/day, and 769 (300) mg/day in the CsA, tacrolimus, and mTOR inhibitor groups, respectively (p=0.003). In the de novo subpopulation, the starting dose was 1440 mg/day in 66.7% (14/21) of CsA-treated patients and 71.9% (110/153) of tacrolimus-treated patients, with an intensified dose of 2160 mg/day in 28.6% (6/21) and 8.5% (13/153), respectively. There was a non-significant trend to a higher rate of biopsy-proven acute rejection in patients receiving CsA versus tacrolimus or an mTOR inhibitor (p=0.082). Adverse events with a suspected relation to EC-MPS occurred in 21.0%, 23.1%, and 9.1% of the CsA, tacrolimus, and mTOR inhibitor subpopulations, respectively. CONCLUSIONS EC-MPS is usually initiated at the dose recommended for de novo CsA-treated kidney transplant patients, then titrated downwards as required. An early intensified regimen is not used frequently. The EC-MPS dose is modified in <20% of de novo patients to account for concomitant tacrolimus therapy instead of CsA administration.

Fibrosis progression according to epithelial-mesenchymal transition profile: a randomized trial of everolimus versus CsA

Markers of epithelial-mesenchymal transition (EMT) may identify patients at high risk of graft fibrogenesis who could benefit from early calcineurin inhibitor (CNI) withdrawal. In a randomized, open-label, 12-month trial, de novo kidney transplant patients received cyclosporine, enteric-coated mycophenolate sodium (EC-MPS) and steroids to month 3. Patients were stratified as EMT+ or EMT- based on month 3 biopsy, then randomized to start everolimus with half-dose EC-MPS (720 mg/day) and cyclosporine withdrawal (CNI-free) or continue cyclosporine with standard EC-MPS (CNI). The primary endpoint was progression of graft fibrosis (interstitial fibrosis/tubular atrophy [IF/TA] grade increase ≥1 between months 3-12) in EMT+ patients. 194 patients were randomized (96 CNI-free, 98 CNI); 153 (69 CNI-free, 84 CNI) were included in histological analyses. Fibrosis progression occurred in 46.2% (12/26) CNI-free EMT+ patients versus 51.6% (16/31) CNI EMT+ patients (p = 0.68). Biopsy-proven acute rejection (BPAR, including subclinical events) occurred in 25.0% and 5.1% of CNI-free and CNI patients, respectively (p < 0.001). In conclusion, early CNI withdrawal with everolimus initiation does not prevent interstitial fibrosis. Using this CNI-free protocol, in which everolimus exposure was relatively low and administered with half-dose EC-MPS, CNI-free patients were overwhelmingly under-immunosuppressed and experienced an increased risk of BPAR.

Early corticosteroid avoidance in kidney transplant recipients receiving ATG-F induction: 5-year actual results of a prospective and randomized study

One hundred ninety-seven patients received anti-T-lymphocyte globulins Fresenius, mycophenolate mofetil and delayed cyclosporine, and were randomized to ≥6-month corticosteroids (+CS; n=99) or no CS (-CS; n=98). One- and five-year actual graft survival (censored for death) was 93.2% and 86.4% in the +CS group versus 94.9% and 89.8% in the -CS group (5-year follow-up, p=0.487). Freedom from clinical rejection was 86.9% and 81.8% versus 74.5% and 74.5% (p=0.144), respectively, at 1 and 5 years; 5-year freedom from biopsy-proven rejection was 88.9% versus 83.7% (p=0.227). More late first rejections occurred in the +CS group. Significantly lower 5-year graft survival in patients experiencing rejection was observed for +CS (55.6% vs. 92.0%; p=0.005) with 8/18 versus 2/25 graft losses. Renal function at 5 years was stable and comparable (median serum creatinine, 159 vs. 145 µmol/L; creatinine clearance, 53.5 vs. 56.6 mL/min). More +CS patients developed diabetes, dyslipidemia and malignancies. Rejections in -CS patients occurred early after transplantation and did not impair long-term renal function. In patients receiving CS, rejections occurred later and with a higher risk for subsequent graft failure. A similar and not inferior 5-year efficacy profile and a reduced morbidity were observed in CS-free patients compared to patients who received CS for at least 6 months.

Prediction of membranous nephropathy recurrence after transplantation by monitoring of anti-PLA2R1 (M-type phospholipase A2 receptor) autoantibodies: a case series of 15 patients

BACKGROUND

The predictive value of anti-M-type phospholipase A2 receptor (PLA2R1) autoantibodies for membranous nephropathy (MN) recurrence after renal transplantation remains controversial.

METHODS

Our aim was to monitor anti-PLA2R1 IgG4 activity using a sensitive enzyme-linked immunosorbent assay in 15 kidney transplant recipients with MN, and to test the correlation between antibody titres and MN recurrence.

RESULTS

Five patients never exhibited anti-PLA2R1 antibodies, and one of them relapsed. Ten patients (67%) had IgG4 anti-PLA2R1 antibodies at the time of transplantation and during follow-up. The presence of IgG4 anti-PLA2R1 antibodies at the time of kidney transplantation does not imply MN recurrence (P = 0.600, n = 15). However, a positive IgG4 anti-PLA2R1 activity during follow-up (>Month 6) was a significant risk factor for MN relapse (P = 0.0048, n = 10). Indeed, four patients had persistent IgG4 anti-PLA2R1 activity after transplantation and relapsed. Among them, one was successfully treated with rituximab. Another had persistently high IgG4 anti-PLA2R1 activity and exhibited a histological relapse but no proteinuria while on treatment with renin-angiotensin system inhibitors. In contrast, the six other patients who did not relapse exhibited a decrease of their IgG4 anti-PLA2R1 activity following transplant immunosuppression, including two with proteinuria due to biopsy-proven differential diagnoses. A weak transplant immunosuppressive regimen was also a risk factor of MN recurrence (P = 0.0048, n = 10). Indeed, the six patients who received both an induction therapy and a combined treatment with calcineurin inhibitors/mycophenolate exhibited a decrease of IgG4 anti-PLA2R1 activity and did not relapse, while the four patients who did not receive this strong immunosuppressive treatment association had persistently high IgG4 anti-PLA2R1 activity and relapsed.

CONCLUSION

The monitoring of IgG4 anti-PLA2R1 titres during follow-up helps to predict MN recurrence, and a strong immunosuppressive treatment of anti-PLA2R1 positive patients may prevent recurrence.

Post-transplantation lymphoproliferative disorder after kidney transplantation: report of a nationwide French registry and the development of a new prognostic score

PURPOSE

Post-transplantation lymphoproliferative disorder (PTLD) is associated with significant mortality in kidney transplant recipients. We conducted a prospective survey of the occurrence of PTLD in a French nationwide population of adult kidney recipients over 10 years.

PATIENTS AND METHODS

A French registry was established to cover a nationwide population of transplant recipients and prospectively enroll all adult kidney recipients who developed PTLD between January 1, 1998, and December 31, 2007. Five hundred patient cases of PTLD were referred to the French registry. The prognostic factors for PTLD were investigated using Kaplan-Meier and Cox analyses.

RESULTS

Patients with PTLD had a 5-year survival rate of 53% and 10-year survival rate of 45%. Multivariable analyses revealed that age > 55 years, serum creatinine level > 133 μmol/L, elevated lactate dehydrogenase levels, disseminated lymphoma, brain localization, invasion of serous membranes, monomorphic PTLD, and T-cell PTLD were independent prognostic indicators of poor survival. Considering five variables at diagnosis (age, serum creatinine, lactate dehydrogenase, PTLD localization, and histology), we constructed a prognostic score that classified patients with PTLD as being at low, moderate, high, or very high risk for death. The 10-year survival rate was 85% for low-, 80% for moderate-, 56% for high-, and 0% for very high-risk recipients.

CONCLUSION

This nationwide study highlights the prognostic factors for PTLD and enables the development of a new prognostic score. After validation in an independent cohort, the use of this score should allow treatment strategies to be better tailored to individual patients in the future.

Patients' preferences regarding choice of end-stage renal disease treatment options

BACKGROUND

Dialysis registries have reported a low take-up of home treatment. The aim of our study was to report patients' preferred treatment options for end-stage renal disease (ESRD) after information delivery, patients' characteristics by treatment preference, and the reasons for differences between treatment preference and the treatment delivered.

METHODS

A prospective cohort study on patients seen in our nephrology department between January 2009 and June 2011 included all patients with chronic kidney disease (GFR <20 ml/min/1.73 m(2)) and incident dialysis patients who received an information program about ESRD treatment options.

RESULTS

228 patients received information delivery and either expressed a preference for a given renal replacement therapy (peritoneal dialysis, PD: 42%; hemodialysis, HD: 33%), remained undecided (20%) or expressed reluctance to undergo renal replacement therapy (5%). Multivariate analysis revealed that compared to HD preference, patients preferring PD were older (OR 1.02, 95% CI 1.0-1.04), had a lower BMI (OR 0.9, 95% CI 0.87-0.98) and were more likely to have been informed before rather than after starting dialysis (OR 3.4, 95% CI 1.5-7.4); home treatment was the main reason given for preferring PD. Undecided patients were mainly women and the majority were eventually treated by HD. Reluctant patients were the oldest (OR 1.12, 95% CI 1.02-1.22) and were rarely treated by dialysis. Only 24% of patients informed before and 8% of patients informed after starting dialysis were ultimately treated with PD. Reasons for a mismatch between dialysis modality preference and treatment delivered were equally distributed between medical and nonmedical.

CONCLUSION

Patients should be systematically informed before starting dialysis, patients' preferences should be taken into account before organizing dialysis and all treatment modalities should be available in all centers.