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.

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.

Complement genes strongly predict recurrence and graft outcome in adult renal transplant recipients with atypical hemolytic and uremic syndrome.

Atypical hemolytic and uremic syndrome (aHUS) is a severe disease strongly associated with genetic abnormalities in the complement alternative pathway. In renal posttransplantation, few data are available on recurrence risk and graft outcome according to genetic background in aHUS patients. The aim of this study was to identify risk factors for recurrence and transplant outcome and, in particular, the role of complement gene abnormalities. We retrospectively studied 57 aHUS patients who had received 71 renal transplants. A mutation in complement gene was identified in 39 (68%), in factor H (CFH), factor I (CFI), membrane cofactor-protein (MCP), C3 and factor B (CFB). At 5 years, death-censored graft survival was 51%. Disease recurrence was associated with graft loss (p = 0.001). Mutations in complement genes were associated with higher risk of recurrence (p = 0.009). Patients with CFH or gain of function (C3, CFB) mutations had a highest risk of recurrence. M-TOR inhibitor was associated with significant risk of recurrence (p = 0.043) but not calcineurin inhibitor immunosuppressive treatment (p = 0.29). Preemptive plasmatherapy was associated with a trend to decrease recurrence (p = 0.07). Our study highlights that characterization of complement genetic abnormalities predicts the risk of recurrence-related graft loss and paves the way for future genetically based individualized prophylactic therapeutic strategies.

Epstein-Barr virus-associated hepatic leiomyosarcoma after renal transplantation: case report.

The incidence of neoplastic complications after solid organ transplantation is increasing tremendously probably as the consequence of long term immunosuppression. Beside usual risk factors, the oncogenic role of some viruses like Epstein-Barr virus is well established. We report a case of a primitive EBV-induced liver leiomyosarcoma after renal transplantation.

Long-term glomerular filtration rate in liver allograft recipients according to the type of calcineurin inhibitors.

The calcineurin inhibitors (CNI) cyclosporine micro emulsion (CyA-ME) and tacrolimus (Tac) both display renal and vascular toxicities. We undertook a single-center retrospective study among 149 surviving liver transplant recipients. The primary outcome was kidney function over 10 years posttransplant, evaluating the glomerular filtration rate (GFR) by the abbreviated Modification of Diet in Renal Disease formula with subsequent Kidney Disease Outcomes Quality Initiative staging. The secondary outcomes included correlations between CNI trough levels (C0), GFR, and items of cardiovascular toxicity. At 1 and 5 years, the mean GFRs were 74.2 and 76.9 mL/min/1.73 m(2) under Tac versus 62.8 and 66.0 mL/min/1.73 m(2) under CyA-ME (P < .001). The mean value in favor of Tac was + 10 mL/min/1.73 m(2). Distribution of GFR stages showed more Tac patients at stage 1 or 2 and more at stage 4 or 5 under CyA-ME. There was no significant correlation between CNI-C0 and GFR. Switches between CNI or to mycophenolate mofetil did not show any significant GFR improvement. Patients under CyA-ME displayed significantly higher blood pressures with 3 requiring dialysis versus none under Tac. In conclusion, we observed that liver transplant patients under Tac maintained significantly better renal function with less progression to dialysis as compared with CyA-ME, indicating a lower renal and vascular (lower BP) toxicity.

Two-year results of renal transplantation in kidney recipients from > or = 65-year-old deceased donors: a French region experience.

The use of elderly deceased donors requires refining criteria for both the donor and the recipient. This report attempted to identify parameters susceptible to further improvement. This retrospective multicenter study analyzed the outcomes of kidney recipients from 15 consecutive elderly deceased donors in the south French region (IR9). Donors were 65 to 74 years old. Mean creatinine clearance was 80 mL/min/1.73 m(2). The donor risk factors for allograft dysfunction were stroke, hypertension, cardiovascular disease, cardiac death, smoking, arrhythmia, and diabetes. The recipients were 35 to 70 years old. The median cold ischemia time was 24 hours. Four patients (16%) suffered delayed graft function (DGF). Three recipients (12%) died within the first 2 months after transplantation. The postoperative complications (29%) were 2 renal artery thromboses, 4 renal artery stenoses, and 1 toe ischemia. Two years after transplantation, their mean serum creatinine was 157 micromol/L. The patient and graft survivals were 88% and 70%, respectively. These results seemed worse than those reported in the literature, but it was a small cohort and a new experience. DGF is probably linked to improvable management to reduce cold ischemia time. The elevated rate of surgical complications might be related to a lack of experience in donor and recipient evaluations. Kidney transplantation from elderly donors requires an efficient organization and an accurate evaluation of both donor renal function and recipient cardiovascular state.

Recurrence of hemolytic uremic syndrome after renal transplantation.

Non-Shiga toxin-associated hemolytic uremic syndrome (non-Stx-HUS) is a rare disease. The clinical outcome is often unfavorable: 50% of patients progress to end-stage renal failure. Several mutations in complement regulatory genes predispose to non-Stx-HUS. Transplantation outcomes are poor among patients with either mutation in the genes encoding complement H or I factors, with 80% graft loss due to HUS recurrence. In contrast, patients with mutation in the gene encoding MCP have no disease relapse after transplantation. There are no treatment guidelines for non-Stx-HUS recurrence. Herein we have presented 8 patients with non-Stx-HUS recurrence after transplantation during the last 10 years in the South of France. HUS recurrence, which occurred early after transplantation in all but 1 patient, was treated by plasma exchange (PE) with substitution by fresh frozen plasma (FFP). Three patients still treated with long-term plasma therapy have no recurrence at 15, 19, or 24 months. An international registry would help to define new guidelines.

Radiographic follow-up of a phalangeal brown tumor.

We report the 6-year radiographic follow-up of a phalangeal brown tumor in a patient with severe hyperparathyroidism secondary to chronic renal failure treated with hemodialysis. The phalangeal lesion increased in size during the first 3 years, until the patient finally accepted to undergo parathyroidectomy. The initial radiographic change was a small intracortical lytic area. Two years later, an expansile cystic lesion was visible in the phalanx, and computed tomography showed a cortical defect. Ossification of the lesion occurred over the 2.5 years following parathyroidectomy. The epidemiology, radiographic changes and post-treatment evolution of brown tumor in dialysed patients is reviewed. Surgical parathyroidectomy is the standard treatment for brown tumor complicating secondary hyperparathyroidism. The usefulness and limitations of treatment with vitamin D analogs, recently reported in a few case reports, are discussed.

Acute renal failure as initial presentation of visceral leishmaniasis in an HIV-1-infected patient.

We report the case of an HIV-infected patient who presented with acute renal failure due to visceral leishmaniasis (VL). Although renal failure is the leading cause of death in dogs, the natural reservoir of Leishmania infantum, renal involvement is usually absent in human VL. However, L. infantum can be considered a cause of renal failure in HIV-infected patients.

The role of SOS and flap processing in microsatellite instability in Escherichia coli.

Mutations affecting mismatch repair result in elevated frequencies of microsatellite length alteration in prokaryotes and eukaryotes. However, the finding that microsatellite instability is found often in cells with a functional mismatch repair system prompted a search for other factors of tract alteration. In the present report, we show that, in Escherichia coli, poly(AC/TG) tracts are destabilized by mutations that induce SOS. These observations may have implications for eukaryotic cells because recent results suggest the existence of a mammalian SOS response analogous to that in prokaryotes. In addition, a defect in the 5'-3' exonuclease domain of DNA polymerase I, homologous to the mammalian FEN1 and the yeast RAD27 nucleases, leads to a marked increase in repeat expansions characteristic of several genetic disorders. Finally, we found that the combination of a proofreading defect with mismatch repair deficiency results in extreme microsatellite instability.

Recombination-dependent repair of DNA double-strand breaks with purified proteins from Escherichia coli.

We have developed an in vitro system in which repair of DNA double-strand breaks is performed by purified proteins of Escherichia coli. A segment was deleted from a circular duplex DNA molecule by restriction at two sites. 3' single-stranded overhangs were introduced at both ends of the remaining linear fragment. In a first step, RecA protein catalyzed the formation of a D-loop between one single-stranded tail and a homologous undeleted supercoiled DNA molecule. In a second step, E. coli DNA polymerase II or III used the 3' end in the D-loop as a primer to copy the missing sequences of the linear substrate on one strand of the supercoiled template. Under proper conditions, the integrity of the deleted substrate was restored, as shown by analysis of the products by electrophoresis, restriction, and transformation. In this reaction, DNA synthesis is strictly dependent on recombination, and repair is achieved without formation of a Holliday junction.

Effect of length and location of heterologous sequences on RecA-mediated strand exchange.

We systematically investigated the effect of heterology on RecA-mediated strand exchange between double-stranded linear and single-stranded circular DNA. Strand exchange took place through heterologies of up to 150-200 base pairs when the insertion was at the proximal (initiating) end of the duplex DNA but was completely blocked by an insert of only 22 base pairs placed at the distal end of the duplex. In the case of medial heterology created by insertion either in the duplex or the single-stranded DNA, the ability of RecA to exchange strands decreased as the heterology was shifted toward the distal end of the duplex. These results suggest that two different strand exchange mechanisms operate in the proximal and distal portions of the duplex substrate.

[Fenestration by laparoscopic approach of a post-transplantation renal lymphocele]. / Fenestration par voie coelioscopique d'une lymphocèle post-transplantation rénale.

Symptomatic post-transplantation renal lymphoceles are usually treated with Byron's technique--medical laparotomy, internal drainage with fenestration, transperitoneal marsupialization and epiploplasty. The same procedure was performed laparoscopically in a 34 year old obese man who had a renal transplantation 18 months earlier. The procedure, together with its advantages are discussed.

Antipairing and strand transferase activities of E. coli helicase II (UvrD).

The product of the uvrD gene of Escherichia coli, UvrD (helicase II), is known to be involved in methyl-directed mismatch repair, transposon excision and uvrABC excision repair. In conjugational crosses, various uvrD mutants have been reported to result in higher, lower or unaffected recombination frequencies. In an attempt to clarify the role of UvrD in recombination, we have studied in vitro its effects on two key reactions driven by RecA, homologous pairing and strand exchange. We show here that UvrD efficiently prevents or reverses RecA-mediated homologous pairing. Unexpectedly, we also found that it can stimulate RecA-driven branch migration and even catalyze strand exchange in the absence of RecA. A possible in vivo role for these antagonistic activities is discussed.

Partial purification of an activity from human cells that promotes homologous pairing and the formation of heteroduplex DNA in the presence of ATP.

An activity that can promote homologous pairing and strand transfer between suitable DNA substrates has been partially purified from human skin fibroblasts and from HeLa cells. The strand transfer reaction was investigated with DNA substrates consisting of single-stranded circular and duplex linear phage DNA. It requires ATP, and under optimal conditions yields heteroduplex molecules containing one strand from each parental DNA substrate. The reactions appears to be of the same general nature as those mediated by RecA proteins of Escherichia coli and the Rec1 protein of Ustilago maydis.

The binding of RecA protein to duplex DNA molecules is directional and is promoted by a single stranded region.

RecA protein from E. coli binds more strongly to single stranded DNA than to duplex molecules. Using duplex DNA that contains single stranded gaps, we have studied the protection by RecA protein at various concentrations, of restriction sites as a function of their distance from the single stranded region. We show that the binding of RecA protein, initiated in the single stranded region, extends progressively along the adjoining duplex in the 5' to 3' direction with respect to the single stranded region. The strand exchange reaction is known to proceed in the same direction.