Factors influencing kidney transplantation rates: a study from the ERA Registry

BACKGROUND

Large international differences exist in kidney transplantation (KT) rates. We aimed to investigate which factors may explain the total, deceased donor, and living donor KT rates over the last decade.

METHODS

KT experts from 39 European countries completed the Kidney Transplantation Rate Survey on measures and barriers and their potential effect on the KT rate in their country. In the analyses, countries were divided into low, middle, and high KT rate countries based on the KT rate at the start of study period in 2010.

RESULTS

Experts from low KT rate countries reported more frequently to have taken measures regarding staff, equipment and facilities to increase total KT rate compared with middle and high KT rate countries. For donor type specific KT, the largest international differences in measures taken were reported for deceased donor KT, with middle and high KT rate countries taking more measures, such as the use of expanded criteria donor kidneys, the presence of transplantation coordinators, and (inter)national exchange of donor kidneys. Once a measure was taken, experts' opinion on its success was similar across the low, middle and high KT rate countries. Experts from low KT rate countries more often reported potential barriers, such as patients' lack of knowledge and distrust in the health care system.

CONCLUSIONS

In particular in low KT rate countries, KT rate might be stimulated by optimizing staff, equipment, and facilities. In addition, all countries may benefit from deceased and living donor specific measures.

Daclizumab Versus Rabbit Antithymocyte Globulin in High-Risk Renal Transplants: Five-Year Follow-up of a Randomized Study

We previously reported a randomized controlled trial in which 227 de novo deceased-donor kidney transplant recipients were randomized to rabbit antithymocyte (rATG, Thymoglobulin) or daclizumab if they were considered to be at high immunological risk, defined as high panel reactive antibodies (PRA), loss of a first kidney graft through rejection within 2 years of transplantation, or third or fourth transplantation. Patients treated with rATG had lower incidences of biopsy-proven acute rejection (BPAR) and steroid-resistant rejection at 1 year. Patients were followed to 5 years posttransplant in an observational study; findings are described here. Treatment with rATG was associated with a lower rate of BPAR at 5 years (14.2% vs. 26.0% with daclizumab; p = 0.035). Only one rATG-treated patient (0.9%) and one daclizumab-treated patient (1.0%) developed BPAR after 1 year. Five-year graft and patient survival rates, and renal function, were similar between the two groups. Overall graft survival at 5 years was significantly higher in patients without BPAR (81.0% vs. 54.8%; p < 0.001). In conclusion, rATG is superior to daclizumab for the prevention of BPAR among high-immunological-risk renal transplant recipients. Overall graft survival at 5 years was approximately 70% with either induction therapy, which compares favorably to low-risk cohorts.

Pre-terminal renal insufficiency in a patient with enteric hyperoxaluria: effect of medical management on renal function

Enteric hyperoxaluria causes tubular deposition calcium oxalate crystals and severe chronic interstitial nephritis. We describe a patient with pre-terminal renal failure due to oxalate nephropathy after ileal resection. Increased oral hydration, low oxalate diet, and oral calcium carbonate and potassium citrate supplements resulted in a significant improvement of renal function. During the three-year follow-up, urinary oxalate concentration was repeatedly reduced below the crystallization threshold and serum creatinine decreased from 4.5 to 1.7 mg/dL. This case illustrates the benefit of combining and optimizing dietary and medical management in enteric hyperoxaluria, even in patients with advanced chronic kidney disease.

The ORION study: comparison of two sirolimus-based regimens versus tacrolimus and mycophenolate mofetil in renal allograft recipients

Safety and efficacy of two sirolimus (SRL)-based regimens were compared with tacrolimus (TAC) and mycophenolate mofetil (MMF). Renal transplantation recipients were randomized to Group 1 (SRL+TAC; week 13 TAC elimination [n = 152]), Group 2 (SRL + MMF [n = 152]) or Group 3 (TAC + MMF [n = 139]). Group 2, with higher-than-expected biopsy-confirmed acute rejections (BCARs), was sponsor-terminated; therefore, Group 2 two-year data were limited. At 1 and 2 years, respectively, graft (Group 1: 92.8%, 88.5%; Group 2: 90.6%, 89.9%; Group 3: 96.2%, 95.4%) and patient (Group 1: 97.3%, 94.4%; Group 2: 95.2%, 94.5%; Group 3: 97.0%, 97.0%) survival rates were similar. One- and 2-year BCAR incidence was: Group 1, 15.2%, 17.4%; Group 2, 31.3%, 32.8%; Group 3, 8.2%, 12.3% (Group 2 vs. 3, p < 0.001). Mean 1- and 2-year modified intent-to-treat glomerular filtration rates (mL/min) were similar. Primary reason for discontinuation was adverse events (Group 1, 34.2%; Group 2, 33.6%; Group 3, 22.3%; p < 0.05). In Groups 1 and 2, delayed wound healing and hyperlipidemia were more frequent. One-year post hoc analysis of new-onset diabetes posttransplantation was greater in TAC recipients (Groups 1 and 3 vs. 2, 17% vs. 6%; p = 0.004). Between-group malignancy rates were similar. The SRL-based regimens were not associated with improved outcomes for kidney transplantation patients.

[Pregnancy after kidney transplantation : the Erasme Hospital experience]

Kidney transplantation can restore the fertility of women with chronic renal insufficiency, allowing them to bear children. Yet, pregnancy after renal graft is associated with high maternal and fetal morbidity. The purpose of this case-controlled retrospective study was to evaluate maternal and fetal outcomes of pregnancies in renal transplant recipients, and to compare the results to a control population. We studied 18 pregnancies in 14 renal grafted patients, between 1990 and 2003. Each pregnancy was paired for age, number of pregnancies and parity with 2 controls. The analyses concerned the presence of risk factors at the conception, the outcome of the pregnancy and the occurring of maternal-fetal complications. There were significantly more infections (50 % versus 11 %), anaemia (28 % versus 3 %), caesarean sections (72 % versus 14 %), intrauterin growth restriction (39 % versus 3 %), premature babies (44 % versus 8 %) and small weights at birth (50 % versus 8 %) in the transplanted women and a trend to an increased incidence of hypertensive complications. One baby of a transplanted mother died. No deterioration of renal function nor any maternal death occurred. In conclusion, the rates of maternal-fetal complications in pregnancies after kidney transplantation found in our hospital are similar to those of the literature and in comparison with controls, make them high-risk pregnancies. Nevertheless, by respecting certain criteria, the majority have a successful outcome.

Early prognostic factors of infants with chronic renal failure caused by renal dysplasia

Renal dysplasia (RD) is a common cause of chronic renal failure (CRF) in children. The evolution towards end-stage renal failure is unpredictable due to the paucity of early prognostic factors. In order to identify early prognostic clinical criteria, we have retrospectively analyzed renal function and growth in 11 infants with RD and CRF from birth up to 4 years of age. Children with obstructive RD were not included. Glomerular filtration rate (GFR) was estimated from Schwartz formula. In infants with a GFR below 15 ml/min per 1.73 m2 at 6 months of age (group A, n=5), kidney function did not further improve; 4 reached end-stage renal failure between 8 months and 6 years of age. In contrast, infants with a GFR above 15 ml/min per 1.73 m2 at 6 months of age (group B, n=6) experienced a significant improvement in renal function during follow-up, and none required renal replacement therapy. During the first 3 months of life all infants with RD and CRF developed severe growth retardation. Between 6 months and 4 years of age, children from group B grew significantly better than those from group A. In conclusion, our experience suggests that GFR, estimated from Schwartz formula at 6 months of age, is a useful prognostic factor in infants with RD and CRF. Infants with a GFR below 15 ml/min per 1.73 m2 are at risk of severe growth delay and the need for early renal replacement therapy, whereas those with a GFR above 15 ml/min per 1.73 m2 have a relatively favorable long-term prognosis.

Hypercholesterolemia is associated with increased kidney graft loss caused by chronic rejection in male patients with previous acute rejection

BACKGROUND

Whereas acute rejection is the main risk factor for the occurrence of chronic rejection, mechanisms in addition to the donor-specific immune response probably contribute to late allograft failure. In this study, we investigated the possible role of hypercholesterolemia in the incidence of chronic kidney graft loss.

METHODS

By using the actuarial method, we retrospectively analyzed the long-term loss of cadaveric kidney grafts in patients who had a functioning graft at 1 year and had received a transplant and undergone cyclosporin A therapy in our center between 1983 and 1997.

RESULTS

As observed previously, patients with acute rejection during the 1st posttransplant year (n=198) had significantly higher actuarial graft loss at 10 years compared with those free of acute rejection (n=244). In patients free of acute rejection at 1 year, hypercholesterolemia (> or =250 mg/dl) had no impact on graft loss at 10 years. On the contrary, in patients with previous acute rejection, those with hypercholesterolemia (n=59) had a higher immunological (36.0% vs. 19.2%; P<0.01) and overall (50.0% vs. 25.3%; P<0.01) graft loss at 10 years compared with patients with serum cholesterol <250 mg/dl (n=139). Among patients with 1st year acute rejection, hypercholesterolemia was associated with a significant increase in graft loss in male but not in female recipients. Multivariate analysis confirmed that hypercholesterolemia was an independent risk factor for chronic graft loss in male patients (P<0.05).

CONCLUSION

Hypercholesterolemia is an independent risk factor for kidney graft loss from chronic rejection in male patients with previous acute rejection. Correction of hypercholesterolemia could help to reduce kidney graft loss caused by chronic rejection in this category of patients.

Downregulation of antigen-presenting cell functions after administration of mitogenic anti-CD3 monoclonal antibodies in mice

Antibodies against CD3epsilon are widely used as immunosuppressive agents. Although it is generally assumed that these reagents exert their immunomodulatory properties by inducing T-cell deletion and/or inactivation, their precise mechanism of action remains to be elucidated. Using a murine model, we demonstrate in this report that administration of anti-CD3epsilon antibodies causes the migration and maturation of dendritic cells (DC) in vivo, as determined by immunohistochemical analysis. This maturation/migration process was followed by selective loss of splenic DC, which resulted in a selective inhibition of antigen-presenting cell (APC) functions in vitro. Spleen cells from anti-CD3epsilon-treated animals were unable to productively stimulate naive alloreactive T cells and Th1-like clones in response to antigen, while retaining the ability to present antigen to a T-cell hybridoma and Th2 clones. Anti-CD3epsilon treatment was found to induce a selective deficiency in the ability of spleen cells to produce bioactive interleukin-12 in response to CD40 stimulation. APC dysfunction was not observed when nonmitogenic forms of anti-CD3epsilon antibodies were used, suggesting that splenic DC loss was a consequence of in vivo T-cell activation. Nonmitogenic anti-CD3epsilon monoclonal antibodies were found to be less immunosuppressive in vivo, raising the possibility that APC dysfunction contributes to anti-CD3epsilon-induced immunomodulation. Collectively, these data suggest a novel mechanism by which mitogenic anti-CD3epsilon antibodies downregulate immune responses.

Down-regulation of interleukin-2 and interferon-gamma and maintenance of interleukin-4 and interleukin-10 production after administration of an anti-CD3 monoclonal antibody in mice

BACKGROUND

Activating anti-CD3 monoclonal antibodies (mAbs), such as OKT3, are potent immunosuppressive agents that are widely used in clinical transplantation. We investigated whether the in vivo induction of T cell unresponsiveness contributes to the immunosuppressive properties of the anti-mouse-CD3 mAb 145-2C11.

METHODS

After a single in vivo administration of 145-2C11 residual T cells were restimulated in vivo and in vitro to assess cytokine production. Mice were also transplanted with allogeneic skin 9 days after 145-2C11 administration to investigate whether the immunosuppressive properties of the antibody persist after the reexpression of the T cell receptor.

RESULTS

Pretreatment with anti-CD3 mAbs caused a profound deficit in both interleukin- (IL) 2 and interferon- (IFN) y secretion upon restimulation in vivo, whereas IL-4 was only partially inhibited and IL-10 production was significantly increased. Purified T cells obtained from mice injected with anti-CD3 mAb also displayed deficient IL-2 and IFN-gamma production together with persisting IL-4 and IL-10 secretion. 145-2C11 had immunosuppressive properties that per sisted after the reexpression of the T cell receptor because mice transplanted with allogeneic skin 9 days after a single anti-CD3 mAb injection still had significantly prolonged graft survival (14.1+/-0.6 days vs. 10.7+/-0.4 days in controls, P<0.02). Blocking IL-4 and IL-10 by neutralizing mAbs further prolonged skin graft survival in mice injected with 145-2C11 (18.3+/-0.7 vs. 14.8+/-0.6 days, P<0.02).

CONCLUSION

The in vivo administration of the 145-2C11 anti-CD3 mAb results in the selective inhibition of Thl-type cytokine secretion upon restimulation, which correlates with a state of immunosuppression. The persistent production of Th2-type cytokines does not contribute to the anti-CD3 mAb-mediated prolonged survival of skin allografts in our experimental model.

Mycophenolate mofetil, together with cyclosporin A, prevents anti-OKT3 antibody response in kidney transplant recipients

OKT3 monoclonal antibody, a murine IgG2a monoclonal antibody targeting the T cell CD3 antigen, elicits a neutralizing humoral response in 20 to 50% of kidney transplant recipients when the concomitant immunosuppression consists of CsA-Sandimmun (SAND) and azathioprine (AZA). In the present study, we investigated the impact of the newer agents, CsA-Neoral (NEO) and mycophenolate mofetil (MMF) on OKT3 sensitization. Sixty-two consecutive kidney transplant recipients received prophylactic OKT3 (5 mg/d) from days 0 to 13, together with steroids. Concomitant immunosuppression consisted of either AZA + SAND (n=20), AZA + NEO (n=31), or MMF + NEO (n=11). The following doses were used: AZA, 2 mg/kg per d from days 0 to 13, then 1 mg/kg per d; MMF, 2 g/d starting on day 1; and CsA, either SAND or NEO, 6 mg/kg per d from day 6. At least two serum samples per month were available during the initial 3 mo for each patient. IgG anti-OKT3 antibodies were first evaluated by enzyme-linked immunosorbent assay. Patients were considered sensitized if their serum scored positive at a dilution > or = 1/1000. Peak titers of IgG anti-OKT3 antibodies and the incidence of patients harboring neutralizing anti-idiotypic antibodies were also determined. A first reduction in OKT3 sensitization was seen in patients receiving Neoral instead of Sandimmun (AZA + SAND: 10 of 20 [50%] patients sensitized versus 6 of 31 [19%] in the AZA + NEO group; P=0.03). This was probably related to the achievement of higher mean CsA trough blood levels in the NEO group during the first month (253+/-44 versus 186+/-49 ng/ml in SAND patients). Peak antibody titers and the proportion of patients with anti-idiotypic antibodies were similar in the AZA + SAND and AZA + NEO groups. A further reduction in the sensitization rate was observed with the replacement of AZA by MMF (MMF + NEO: 0% sensitized patients; P=0.0013). It is concluded that the combination of CsA-Neoral and MMF efficiently prevents sensitization against OKT3.

A pilot trial of recombinant human interleukin-10 in kidney transplant recipients receiving OKT3 induction therapy

BACKGROUND

We conducted a randomized, double-blind, placebo-controlled, rising single-dose study to investigate the effects of recombinant human (rh) interleukin (IL) 10 in renal transplant patients who received OKT3 as induction therapy.

METHODS

Patients received 0.1 (n=6), 1 (n=6), or 10 microg/kg (n=3) rhIL-10 or placebo (n=6) intravenously 30 min before the first injection of 5 mg of OKT3. We monitored IL-10 serum levels, the effect of rhIL-10 on OKT3-induced cytokine production, clinical toxicity, and the incidence of immunization against OKT3.

RESULTS

Serum IL-10 levels in the three experimental groups reached 0.8+/-0.2, 7.9+/-1.3, and 118.6+/-7.3 ng/ml (mean+/-SEM), respectively, 30 min after rhIL-10 injection. Peak plasma levels of tumor necrosis factor-alpha (TNF-alpha) were reduced from 2953+/-1599 pg/ml in patients injected with OKT3 and placebo to 447+/-155, 703+/-246, and 459+/-246 pg/ml in patients injected with 0.1, 1, and 10 microg/kg rhIL-10, respectively. Values for 24-hr TNF-alpha area under the curve decreased from 8988+/-3551 pg x hr/ml in control patients to 2284+/-494, 3950+/-955, and 2420+/-931 pg x hr/ml for the 0.1, 1, and 10 microg/kg rhIL-10 dose groups, respectively (P=0.045). There was also a trend toward reduced plasma levels of IL-2, IL-8, and interferon-gamma in rhIL-10-pretreated patients. Although none of the patients who received placebo or 0.1 or 1 microg/kg rhIL-10 developed an IgM antibody response directed against OKT3 during the first 10 days, this occurred in all three patients who received the highest rhIL-10 dose. In two of these patients, neutralization of OKT3 was associated with a reversible acute rejection episode.

CONCLUSIONS

Pretreatment with doses of up to 1 microg/kg rhIL-10 is safe and reduces the release of TNF-alpha induced by OKT3. However, higher doses might promote early sensitization to OKT3.