Prophylactic deoxyspergualin treatment in living-related renal-transplant recipients transfused with donor-specific blood

BACKGROUND: Deoxyspergualin (DSG) prophylaxis has improved long-term graft survival in living-related renal-transplant recipients transfused with donor-specific blood (DST). We examined the influence of acute rejection (AR) on graft survival in these patients. METHODS: The study groups consisted of either historic control recipients without DSG (group A, n=64, 1985-1989) and recipients with DSG as the initial immunosuppressive agent (group B, n=76, 1989-1995). Both groups received DST from a one-haplotype identical donor and were treated with cyclosporine-based immunosuppression. Rejection was classified into accelerated rejection (Acc, within 5 days), AR (from 6 days-3 months), and late AR (LAR, from 4 months-1 year). RESULTS: Overall 5-year graft survival rates were significantly higher in group B than group A (89.5 vs. 73.4%, P=0.0070). Each group was then subdivided on the basis of whether or not they had an episode of Acc, AR, or LAR. In group A, 5-year graft survival rate was not affected the presence or absence of Acc (75.0 vs. 73.1%), and it was influenced significantly by the presence or absence of AR (50.0 vs. 85.7%, P=0.0012) or LAR (46.7 vs. 81.6%, P<0.0001). In group B, 5-year graft survival did not change significantly by the presence or absence of Acc (100 vs. 88.7%), AR (81.8 vs. 92.6%), or LAR (81.0 vs. 92.7%). CONCLUSIONS: Prophylactic use of DSG in living-related renal-transplant recipients treated with DST improves long-term graft survival, even in patients with AR episodes.     

Predictors of graft survival in pediatric living-related kidney transplant recipients

BACKGROUND: A successful kidney transplant from a living-related donor (LRD) remains the most effective renal replacement therapy for children with end-stage renal failure. The use of LRD kidneys results in decreased time on dialysis, increased graft survival, and better function compared with kidneys transplanted from cadaver donors. We retrospectively analyzed data from the United Network of Organ Sharing (UNOS) Scientific Renal Transplant Registry to determine risk factors for graft loss in children who received an LRD kidney. METHODS: Data was obtained from the UNOS Scientific Renal Transplant Registry on 2418 children ranging in age from 0 to 18 years who underwent an LRD kidney transplantation between January 1988 and December 1994. Multivariate analysis of graft survival was performed using Kaplan-Meier and Cox regression models. RESULTS: The effects of age, pretransplantation dialysis, early rejection, and race were found to significantly affect graft survival. Gender, peak panel-reactive antibody, and ABO blood type were not found to be significant risk factors. Infants <2 years of age initially had the worst graft survival; however, over time their results stabilized, and at 7 years estimated graft survival was good (71%). Adolescents ranging in age from 13-18 years had the best initial graft survival, but as time went on graft survival worsened (55%). Patients who underwent pretransplantation dialysis had a relative risk for graft loss of 1.77 (P<0.001), whereas those who had an early rejection had a relative risk for graft loss of 1.41 (P<0.002). African-Americans had a significantly higher relative risk for graft loss than either Caucasians (1.57, P<0.0005) or Hispanics (2.01, P<0.0003). CONCLUSIONS: Predictors of graft survival for children who receive LRD kidney transplants include age at transplantation, pretransplantation dialysis, early rejection, and race. Over time, adolescents and African-Americans seem to have the lowest graft survival.     

Basiliximab improves graft survival in renal transplant recipients with delayed graft function

The aim of this study was to evaluate the use of basiliximab in first renal transplant recipients with delayed graft function, defined by the need for dialysis in the first week posttransplantation. Among 148 patients in the study, 90 received basiliximab (60.8%) with 58 comprising the control group. There were no significant differences between the 2 groups related to the evaluated variables, except that the control group received more blood transfusions pretransplantation. There was a lower incidence of steroid-resistant rejection (6% vs 20.9%; P = .017) and humoral rejections (0% vs 7%; P = .038) in the basiliximab group. Also, graft survival was significantly higher in basiliximab group compared with the control one (92.8% vs 80.4%; P = .028). There were no significant differences in the other outcomes. In conclusion, this study confirmed the beneficial effects of addition of basiliximab to the immunosuppressive schema of patients with delayed graft function.     

Suppressor cell induction in donor-specific transfused mouse heart recipients

Administration of donor-specific blood presenting major or minor foreign histocompatibility antigens to the mouse recipient improved heart allograft survival when a single transfusion of 0.25 ml was given to the recipient prior to transplantation. Multiple transfusions did not prolong allograft survival, which suggested a presensitization effect. In addition, when the single transfusion volume was reduced to 0.025 ml, no significant effect in prolongation of graft survival was observed. Thus the amount of blood transfused seemed to be a critical factor in achieving the transfusion effect. Splenic suppressor cells after transfusion and transplantation (as determined by adoptive transfer) were present during the stable maintenance phase of graft survival in transfused recipients with long-term surviving heart allografts. Also, an intact spleen was required to achieve improved allograft survival in mice transfused with donor-specific blood. Thus a mechanism for the favorable effect of blood transfusion may be the generation of splenic suppressor cells in response to transfusion followed by transplantation.     

Atorvastatin improves endothelial function in renal-transplant recipients.

BACKGROUND: Hyperlipidaemia and endothelial dysfunction are common features in cyclosporin A (CsA)-treated renal transplant recipients. Endothelial dysfunction may contribute to the risk of premature atherosclerosis and cardiovascular death in these patients. A beneficial effect of statin therapy beyond cholesterol lowering may be an improvement of endothelial function. The present study was designed to assess the effect of atorvastatin on serum lipids and endothelial function in CsA treated renal transplant recipients. METHODS: This pilot study was an open trial of 4 weeks atorvastatin (10 mg per day) treatment in renal transplant recipients (n=22). All patients received a CsA- and prednisolone-based immunosuppressive regimen. Endothelial function was assessed in the forearm skin microvasculature by acetylcholine stimulation and laser Doppler flowmetry, before and after atorvastatin treatment. Serum lipids, plasma endothelin-1 (ET-1), nitric oxide (NO), and von Willebrand factor (vWF) were also measured. RESULTS: Both total and LDL cholesterol were significantly reduced by 26.8 +/- 8.4 and 41.5 +/- 11.0% respectively, after 4 weeks of treatment. Endothelial function was significantly improved during atorvastatin treatment, area under the flux versus time curve (AUC)(ACh) was 538 +/- 362 AU x min before and 682 +/- 276 AU x min after treatment (P=0.042). Plasma NO levels also showed a borderline significant increase from 49 +/- 30 to 57 +/- 37 micromol/l during the treatment period (P=0.051), though plasma ET-1 (0.37+/-0.08 vs 0.37+/-0.12 fmol/ml) and vW (196+/-57 vs 197+/-37%) were unchanged. CONCLUSION: Atorvastatin lowered serum cholesterol significantly and improved endothelial function in renal transplant recipients after 4 weeks of treatment. Plasma NO levels were increased during atorvastatin treatment, indicating a possible endothelial protective effect through an "endothelial-NO pathway".     

Significance of anti-HLA and donor-specific antibodies in long-term renal graft survival

Numerous studies have demonstrated an association of posttransplant HLA antibodies with decreased long-term graft survival. The presence of C4d deposition in these cases supports the hypothesis that antibody and complement deposition are involved in the pathogenesis of graft failure. Development of HLA antibodies may predate the clinical manifestation of chronic rejection (CR). However, frequency of donor-specific antibody is low when all patients are screened regardless of their graft function, and it may be more valuable to look for antibody only in patients with mild dysfunction. Effective treatment for CR has not been identified, although increased immunosuppression has been shown to decrease antibody levels and stabilize graft function. Many patients have been identified with good graft function despite the presence of circulating donor-specific HLA antibody. Additional studies focusing on the mechanism behind the apparent protection from the detrimental effects of antibody in such patients are needed.     

Predicting long-term graft survival in adult kidney transplant recipients

The ability to accurately predict a population's long-term survival has important implications for quantifying the benefits of transplantation. To identify a model that can accurately predict a kidney transplant population's long-term graft survival, we retrospectively studied the United Network of Organ Sharing data from 13,111 kidney-only transplants completed in 1988- 1989. Nineteen-year death-censored graft survival (DCGS) projections were calculated and compared with the population's actual graft survival. The projection curves were created using a two-part estimation model that (1) fits a Kaplan-Meier survival curve immediately after transplant (Part A) and (2) uses truncated observational data to model a survival function for long-term projection (Part B). Projection curves were examined using varying amounts of time to fit both parts of the model. The accuracy of the projection curve was determined by examining whether predicted survival fell within the 95% confidence interval for the 19-year Kaplan-Meier survival, and the sample size needed to detect the difference in projected versus observed survival in a clinical trial. The 19-year DCGS was 40.7% (39.8-41.6%). Excellent predictability (41.3%) can be achieved when Part A is fit for three years and Part B is projected using two additional years of data. Using less than five total years of data tended to overestimate the population's long-term survival, accurate prediction of long-term DCGS is possible, but requires attention to the quantity data used in the projection method.     

Three-year posttransplant graft survival in renal-transplant patients with graft function at 6 months receiving tacrolimus or cyclosporine microemulsion within a triple-drug regimen

BACKGROUND: Registry data can provide valuable information about possible treatment effects; however, pretreatment differences in patient characteristics may influence treatment assignment. Careful analysis must therefore be undertaken when evaluating treatment differences in the context of nonrandomized studies so that the impact of treatment selection bias is minimized. METHODS: A multivariable risk factor analysis of adult patients registered in the US Renal Data System who received a primary renal allograft during 1995 to 1998 was undertaken to compare 3-year graft survival using tacrolimus or Neoral with mycophenolate mofetil (MMF) and steroids. RESULTS: In total, 9,449 patients were included (cadaveric donor n=6,011; living donor n=3,438). Patients (2,130) received tacrolimus, and 7,319 received Neoral. At 3 years posttransplant, the proportion of cadaveric donor recipients experiencing all causes of graft loss was 10.0% for tacrolimus and 10.6% for Neoral; for living donor recipients these figures were 6.5% and 6.7%, respectively (unadjusted Kaplan-Meier analysis). The incidence of graft failure excluding death was also similar between the two groups. With Cox proportional hazards modeling, the adjusted relative hazard of 3-year graft failure for cadaveric donor patients taking tacrolimus versus Neoral was 1.02 (95% confidence interval [CI] 0.8-1.3), and for living-donor recipients it was 1.15 (95% CI 0.8-1.8). CONCLUSIONS: These results indicate excellent 3-year graft survival for both cadaveric and living-donor renal-transplant patients receiving either Neoral or tacrolimus with MMF and steroids, with no significant differences between treatment groups. On the basis of these results, relative cost-effectiveness may become increasingly important in selection of tacrolimus or Neoral as primary immunosuppressant for renal-transplant patients.     

A prospective randomized multicenter study of tacrolimus in combination with sirolimus in renal-transplant recipients

BACKGROUND: Recently, sirolimus (SRL) was introduced as an immunosuppressant in solid-organ transplantation. This study evaluated combinations of SRL and tacrolimus (Tac). METHODS: This 6-month study investigated the safety and efficacy of Tac and steroids in combination with three different doses of SRL in renal-transplant recipients. A total of 104 patients were randomized in four groups: one group received Tac and steroids (control n=28), and three groups also received the following daily SRL doses: 0.5 mg (TacSRL0.5, n=25), 1 mg (TacSRL1, n=25), or 2 mg (TacSRL2, n=26). Tac doses were adjusted to whole-blood trough levels. Steroids were tapered from 20 mg per day to 5 mg per day. The SRL groups underwent a second randomization to discontinue SRL at either month 3 or 5. RESULTS: At month 6, patient survival rates were 100%, 100%, 96.0%, and 100%, and graft survival rates were 96.4%, 84.0%, 88.0%, and 84.6%, respectively. The overall safety profile was similar in all groups. The incidences of infections during months 1 to 3 were similar in all groups (control 46.4%, TacSRL0.5 32.0%, TacSRL1 56.0%, TacSRL2 46.2%). The 3-month incidences of hypercholesteremia (cholesterol >240 mg/dL or low-density lipoprotein cholesterol >160 mg/dL) were 21.4%, 36.0%, 48.0%, and 50.0% (P=0.019). Lipid levels improved after withdrawal of SRL. The 3-month incidences of biopsy-proven acute rejection were 28.6% (control), 8.0% (TacSRL0.5), 8.0% (TacSRL1), and 3.8% (TacSRL2) (P=0.014). CONCLUSION: Tac in combination with low doses of SRL provides a very effective and safe regimen.     

Outcome of low-dose ganciclovir for cytomegalovirus disease prophylaxis in renal-transplant recipients

To assess the outcome of low-dose-ganciclovir prophylaxis (500 mg twice a day for 3 months) in renal-transplant recipients, a retrospective analysis of 185 patients transplanted between 1998 and 2001 was performed. There were 29 (15.6%) patients who belonged to the highest risk group, donor cytomegalovirus (CMV) positive, recipient negative (D + R-), and 37 (20%) patients in the lowest risk group, D-R-. Induction immunosuppression consisted of polyclonal antibody or OKT3 (n = 62, 33.5%), interleukin-2 receptor antibody (n = 61, 33%), and no induction (n = 62, 33.5%). CMV disease occurred in 13 (7%) patients. Highest incidence was in D + R- group (17.2%), with no cases in D-R- group (P = 0.03). Tissue-invasive CMV occurred in 4 of these 13 patients. In patients developing CMV disease, there was no evidence of ganciclovir resistance and no mortality over a mean follow-up of 42 months. Low-dose ganciclovir was found to be as effective in decreasing the incidence of clinical CMV disease as high-dose ganciclovir (1 gm three times a day for 3-6 months) in previous studies.     

Low dose aspirin as prophylaxis against renal-vein thrombosis in renal-transplant recipients.

BACKGROUND: Renal-vein thrombosis (RVT) is an infrequent event that accounts for a high proportion of early renal allograft losses, since graft failure secondary to acute irreversible rejection is now relatively rare. The cause of RVT may be related to technical problems, clotting disorders, diabetes, or cyclosporin, but is often difficult to define. METHODS: This retrospective study was performed to examine the influence of aspirin on the incidence of RVT in cadaveric and living-related renal transplant recipients receiving cyclosporin-based triple immunosuppression. The Oxford Transplant Centre database was used to identify all early (<30 day) non-immunological graft failures and case histories were examined for clinical and pathological evidence of RVT. In July 1991, aspirin (75 mg o.d. starting immediately before and continuing for 1 month post-transplant) was introduced as routine prophylaxis against RVT. Prior to this, aspirin prophylaxis was not used. RESULTS: In the 6-year period from July 1985 to June 1991, there were 27 cases of RVT in 475 transplants (5.6%). In the subsequent 6-year period, there were six cases of RVT in 480 transplants (1.2%) (P:<0.01). CONCLUSION: Although not abolished, this indicates a significant reduction in the incidence of RVT with the addition of low-dose aspirin.     

Improvement in long-term graft survival in cadaveric renal transplant recipients treated with mycophenolate mofetil

Though mycophenolate mofetil has markedly reduced the incidence of acute rejection in renal transplantation, a significant improvement in graft survival has been more difficult to demonstrate. This retrospective study compares an historical control group of 210 consecutive renal transplant patients, who had received ATG induction associated with cyclosporin, prednisolone and azathioprine, with 187 patients receiving mycophenolate instead of azathioprine. The incidence of acute rejection was decreased with mycophenolate. In rejection-free patients, the 3-year graft survival rates were equivalent. In contrast, graft survival at 3 years improved significantly for patients who experienced a rejection crisis and remained under the initial triple drug regimen with mycophenolate compared to the patients of the historical group who were kept on azathioprine after a rejection episode. In conclusion, mycophenolate mofetil is not only able to reduce the incidence of acute rejection but could also improve the prognostic significance of acute rejection crises.     

Sharing cross-reactive groups of MHC class I improves long-term graft survival

BACKGROUND: Renal transplant loss from chronic rejection remains substantial. To increase our understanding of this syndrome, we identified risk factors predicting late graft loss, with a special emphasis on the impact of human lymphocyte antigen (HLA) matching. METHODS: We studied all 654 cadaveric kidney transplants performed in our center between 1983 and 1996 that had survived for more than six months. Eighty-two transplants, lost because of chronic rejection, were used as the outcome variable. The influence of HLA mismatches and shares on long-term graft survival was evaluated at the level of private antigens and cross-reactive groups (CREG) of multiple histocompatibility complex (MHC) class I. HLA and other recipient, donors and transplant parameters were studied using univariate and multivariate Cox regression analysis. RESULTS: The cohort had a mean number of 1.9 HLA mismatches. Because of the homozygosity of HLA antigens, HLA mismatches were not reciprocal to shares. CREG and HLA-A-B mismatches had a relative risk for graft loss of 1.19 (95% CI, 0.97 to 1.45) and 1.05 (0.84 to 1.32) per mismatch. In contrast, the relative risk per shared CREG and broad HLA-A-B antigen was 0.76 (0.63 to 0.92) and 0.79 (0.61 to 1.03). Multivariate analysis revealed that individuals sharing less than four CREGs had a relative risk of 2.13 (1.29 to 3.75) for late graft loss. Other independent predictors were a recipient age of less than 50 years, relative risk 1.95 (1.02 to 3.71); a donor age of more than 50 years, relative risk 1.68 (1.01 to 2.80); acute rejection (vascular vs. no rejection), relative risk 3.52 (1.72 to 7.18); proteinuria (dipstick > 1+ vs. negative), relative risk 2.86 (1.29 to 6.35); and a serum creatinine concentration of more than 150 micromol/liter at six months, relative risk 3.41 (1.96 to 5.94). CONCLUSION: We identified several coexisting recipient-, donor-, and transplant-related risk factors for graft loss from chronic rejection. In this well-matched group of renal transplants, HLA mismatches and shares had a nonreciprocal relationship. Sharing of HLA antigens, especially CREG of MHC class I, was associated with improved long-term survival.     

Pretreatment of renal allograft recipients with immunosuppression and donor-specific blood

The induction of immunologic unresponsiveness to improve renal allograft survival was attempted in 64 patients by the pretransplant administration of donor-specific whole blood or buffy coat in conjunction with continuous azathioprine immunosuppression. All donor/recipient combinations were at least one-haplotype-disparate. Presensitization, defined as a positive Amos or antiglobulin crossmatch or a high-titer (greater than 1:8) B-cell-positive crossmatch, was present in 6 patients and not present in 58 patients. Attempts at desensitization of the already sensitized group were uniformly unsuccessful. Treatment of the 58 nonpresensitized patients resulted in transient sensitization in 2 patients, permanent sensitization in 1 patient, and no evidence of sensitization in 55 patients. Fifty-three patients underwent renal transplantation from the specific blood donor, and only two have experienced renal allograft rejection loss during a mean follow-up period of 22 months (5-45 months); 57% have never experienced a rejection episode. The two-year renal allograft survival rate was 85%. This is significantly (P less than 0.01) better than our historical experience of 64% with one-haplotype living-related transplants. The low rate of sensitization (5%) has permitted almost all patients to undergo eventual renal transplantation from the specific blood donor. This and the low rate of rejection (4%) argues for a modification of the immunologic response, rather than a selecting-out process as the mechanism for improved allograft survival.