I. C. van Riemsdijk

Proteinuria after renal transplantation affects not only graft survival but also patient survival

Background. Proteinuria is associated with an increased risk of renal failure. Moreover, proteinuria is associated with an increased death risk in patients with diabetes mellitus or hypertension and even in the general population. Methods. One year after renal transplantation, we studied the influence of the presence of proteinuria on the risk of either graft failure or death in all 722 recipients of a kidney graft in our center who survived at least 1 year with a functioning graft. Proteinuria was analyzed both as a categorical variable (presence versus absence) and as a continuous variable (quantification of 24 hr urine). Other variables included in this analysis were: donor/recipient age and gender, original disease, race, number of HLA-A and HLA-B mismatches, previous transplants, postmortal or living related transplantation, and transplantation year. At 1 year after transplantation, we included: proteinuria, serum cholesterol, serum creatinine, blood pressure, and the use of antihypertensive medication. Results. In the Cox proportional hazards analysis, proteinuria at 1 year after transplantation (both as a categorical and continuous variable) was an important and independent variable influencing all endpoints. The influence of proteinuria as a categorical variable on graft failure censored for death showed no interaction with any of the other variables. There was an adverse effect of the presence of proteinuria on the graft failure rate (RR=2.03). The influence of proteinuria as a continuous variable showed interaction with original disease. The presence of glomerulonephritis, hypertension, and systemic diseases as the original disease significantly increased the risk of graft failure with an increasing amount of proteinuria at 1 year. The influence of proteinuria as a categorical variable on the rate ratio for patient failure was significant, and there was no interaction with any of the other significant variables (RR=1.98). The death risk was almost twice as high for patients with proteinuria at 1 year compared with patients without proteinuria. The influence of proteinuria as a continuous variable was also significant and also without interaction with other variables. The death risk increased with increasing amounts of proteinuria at 1 year. Both the risks for cardiovascular and for noncardiovascular death were increased. Conclusion. Proteinuria after renal transplantation increases both the risk for graft failure and the risk for death.

CHOLESTEROL AS AN INDEPENDENT PREDICTOR OF OUTCOME AFTER RENAL TRANSPLANTATION

BACKGROUND The debate on the role of high serum cholesterol levels in cardiovascular disease or chronic vascular rejection in kidney-transplanted patients has not yet been settled. METHODS We studied the influence of serum cholesterol at 1 year after transplantation on the failure risk in all 676 kidney graft recipients who survived with a functioning graft. Other variables included in this analysis were donor/recipient age and gender, original disease, race, number of HLA-A and -B mismatches, previous transplants, postmortal or living-related transplantation, and transplantation year. At 1 year after transplantation, we included: serum cholesterol, serum creatinine, proteinuria, and hypertension. RESULTS In the Cox proportional hazards analysis, serum cholesterol at 1 year after transplantation turned out to be an important, independent variable influencing all end points (adjusted for all other variables in the model). The influence on graft failure censored for death was log-linear, and there was interaction with serum creatinine at 1 year. The adverse effect of elevated serum cholesterol levels on the graft failure rate decreased with increasing serum creatinine levels. The influence of serum cholesterol on the rate ratio (RR) for patient failure was linear too, and here there was interaction with recipient age. The negative influence of serum cholesterol on the RR for patient failure decreased with increasing recipient age. The risk for over-all graft failure was influenced by increasing serum cholesterol levels, and there was interaction with recipient age. Because recipient age had interaction with donor age and serum creatinine, the influence of all four variables together on the RR was estimated. It is shown that whereas the RR for over-all graft failure in young recipients of a renal transplant increases significantly with higher cholesterol levels, there is very little influence on the RR of elderly recipients. The risk increases proportionally with increasing serum creatinine levels. CONCLUSION Serum cholesterol levels have an independent influence on graft, patient, and over-all graft failure.

Ischemia times and donor serum creatinine in relation to renal graft failure

Background. The results of renal transplantation are dependent on many variables. To simplify the decision process related to a kidney offer, the authors wondered which variables had the most important influence on the graft failure risk. Methods. All transplant patients (n=1,124) between January 1981 and July 2000 were included in the analysis (2.6% had missing values). The variables included were donor and recipient age and gender, recipient original disease, race, donor origin, current smoking, cardiovascular disease, body weight, peak and current panel reactive antibody (PRA), number of preceding transplants, type and duration of renal replacement therapy, and time since failure of native kidneys. Also, human leukocyte antigen (HLA) identity or not, first and second warm and cold ischemia times, left or right kidney and fossa, donor kidney anatomy, donor serum creatinine and proteinuria, and transplantation year were included. Results. In a multivariate model, cold ischemia time and its time-dependent variable significantly influenced the graft failure risk censored for death (P <0.0001) independent of any of the other risk factors. The influence primarily affected the risk in the first week after transplantation; thereafter, it gradually disappeared during the first year after transplantation. Donor serum creatinine also significantly influenced the graft failure risk in a time-dependent manner (P <0.0001). The risk of a high donor serum creatinine is already enlarged in the immediate postoperative phase and increases thereafter; the curve is closely related to the degree of the elevation. The other variables with a significant influence on the graft failure rate were, in order of decreasing significance, recipient age, donor gender, donor age, HLA identity, transplantation year, preceding transplantations, donor origin, and peak PRA. Conclusions. Donor serum creatinine and cold ischemia time are important time-dependent variables independently influencing the risk of graft failure censored for death. The best strategy for improving the results of cadaveric transplantations is to decrease the cold ischemia time and to allocate kidneys from donors with an elevated serum creatinine to low-risk recipients.

The superior results of living-donor renal transplantation are not completely caused by selection or short cold ischemia time: a single-center, multivariate analysis.

Background. The results of living-donor (LD) renal transplantations are better than those of postmortem-donor (PMD) transplantations. To investigate whether this can be explained by a more favorable patient selection procedure in the LD population, we performed a Cox proportional hazards analysis including variables with a known influence on graft survival. Methods. All patients who underwent transplantations between January 1981 and July 2000 were included in the analysis (n=1,124, 2.6% missing values). There were 243 LD transplantations (including 30 unrelated) and 881 PMD transplantations. The other variables included were the following: donor and recipient age and gender, recipient original disease, race, current smoking habit, cardiovascular disease, body weight, peak and current panel reactive antibody, number of preceding transplants and type and duration of renal replacement therapy, and time since failure of native kidneys. In addition, the number of human leukocyte antigen identical combinations, first and second warm and cold ischemia periods, left or right kidney and fossa, donor kidney anatomy, donor serum creatinine and proteinuria, and transplantation year were included. Results. In a multivariate model, donor origin (PMD vs. LD) significantly influenced the graft failure risk censored for death independently of any of the other risk factors (P =0.0303, relative risk=1.75). There was no time interaction. When the variable cold ischemia time was excluded in the same model, the significance of the influence of donor origin on the graft failure risk increased considerably, whereas the magnitude of the influence was comparable (P =0.0004, relative risk=1.92). The influence of all other variables on the graft failure risk was unaffected when the cold ischemia period was excluded. The exclusion of none of the other variables resulted in a comparable effect. Donor origin did not influence the death risk. Conclusion. The superior results of LD versus PMD transplantations can be partly explained by the dichotomy in the cold ischemia period in these populations (selection). However, after adjustment for cold ischemia periods, the influence of donor origin still remained significant, independent of any of the variables introduced. This superiority is possibly caused by factors inherent to the transplanted organ itself, for example, the absence of brain death and cardiovascular instability of the donor before nephrectomy.

No important influence of limited steroid exposure on bone mass during the first year after renal transplantation: A prospective, randomized, multicenter study

BACKGROUND Steroid-related bone loss is a recognized complication after renal transplantation. In a prospective, randomized, multicenter study we compared the influence of a steroid-free immunosuppressive regimen with a regimen with limited steroid exposure on the changes in bone mass after renal transplantation. METHODS A total of 364 recipients of a renal transplant were randomized to receive either daclizumab (1 mg/kg on days 0 and 10 after transplantation; steroid-free group n=186) or prednisone (0.3 mg/kg per day tapered to 0 mg at week 16 after transplantation; steroids group n=178). All patients received tacrolimus, mycophenolate mofetil, and, during the first 3 days, 100 mg prednisolone intravenously. Changes in bone mineral density (BMD) were evaluated in 135 and 126 patients in the steroid-free and steroids group, respectively. RESULTS The mean (+/- SD) BMD of the lumbar spine decreased slightly in both groups during the first 3 months after transplantation (steroid-free -1.3 +/- 4.0% [P<0.01]; steroids -2.3 +/-4.2% [P<0.01]). In the following months, lumbar BMD recovered in both groups (P<0.01), resulting in a lumbar BMD at 12 months after transplantation comparable with the baseline value. No difference between the groups was found at 3 months (steroid-free versus steroids +1.0%; 95% confidence interval -0.0%-+2.0%, P=0.060) and at 12 months after transplantation (steroid-free versus steroids +0.9%; 95% confidence interval -0.8%-+2.6%, NS). CONCLUSION The use of a moderate dose of steroids during 4 months after transplantation has no important influence on bone mass during the first year after renal transplantation. On average, both regimens prevented accelerated bone loss.Background. Thymoglobulin given before allo-hematopoietic stem-cell transplantation (HSCT) from unrelated donors reduces acute graft-versus-host disease (GvHD), but the optimal dose is unknown. Method. Four different doses of Thymoglobulin were given to 162 patients with hematologic malignancies undergoing unrelated donor HSCT: 4, 6, 8, and 10 mg/kg. Stem-cell source was bone marrow in 102 cases and peripheral blood stem cells in 60. Conditioning was cyclophosphamide combined with total-body irradiation or busulfan. GvHD prophylaxis was cyclosporine and methotrexate. Results. The lowest dose of Thymoglobulin significantly increased the risk for acute GvHD II or greater (odds ratio [OR] 2.67, P=0.015) and III or greater (OR 4.12, P=0.03). GvHD-associated deaths were more common in the lowest Thymoglobulin dose (6/51) compared with higher doses (2/111), P<0.01. No difference in bacteremia and cytomegalovirus reactivation was found. A trend for more infectious death (11/55 vs. 11/107, P=0.09) was found in the 10 mg/kg group compared with lower doses. Median dose of Thymoglobulin (6–8 mg/kg) was associated with lower transplant-related mortality (TRM) (hazard ratio [HR] 0.35, P=0.03) and better survival (HR 0.45, P=0.027) in multivariate analysis, whereas no effect on relapse and relapse-free survival was found. Conclusion. Low-dose (4 mg/kg) of Thymoglobulin increased the risk for severe acute GvHD, whereas 10 mg/kg increased the risk for infectious death. Median doses (6–8 mg/kg) of Thymoglobulin resulted in the lowest TRM and best survival.

Anti-CD25 monoclonal antibody therapy affects the death signals of graft-infiltrating cells after clinical heart transplantation.

Background. To define whether immunosuppressive agents that block the interleukin (IL)-2 pathway could prevent activation-induced cell death of activated T cells in the graft, we measured expression of IL-2, IL-2 receptor &agr; chain (CD25), IL-15, Fas, and Fas ligand by real time reverse transcription-polymerase chain reaction in cardiac allografts. Methods. We characterized the phenotype of the infiltrating cells (CD3, CD68, CD25) by immunohistochemistry. The proportion of apoptotic graft-infiltrating cells was determined by TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labeling) staining. We analyzed endomyocardial biopsy specimens from cardiac allograft recipients who were treated with anti-CD25 monoclonal antibody (mAb) induction therapy (daclizumab) or with matching placebo in combination with cyclosporine, steroids, and mycophenolate mofetil. Results. Treatment with anti-CD25 mAb affected the number of infiltrating CD3 and CD68 cells and the IL-2–regulated apoptotic pathway. During anti-CD25 mAb treatment, significantly lower intragraft IL-2 and CD25 mRNA transcription levels and decreased numbers of CD25+ T cells were found compared with the levels measured in endomyocardial biopsy specimens from placebo-treated patients (5- to 10-fold, P =0.002 and P <0.0001, respectively). In these samples the intragraft mRNA expression levels of IL-15 were also lower (P =0.02). Inhibition of the IL-2 pathway by anti-CD25 mAb therapy was accompanied by reduced mRNA and protein of Fas ligand and not by reduced Fas expression (P =0.001 and P =0.03). TUNEL staining revealed that the proportion of graft-infiltrating cells was lower in the anti-CD25 mAb patient group than the proportion of apoptotic cells in patients receiving placebo (P =0.06). Conclusion. Our data suggest that immunosuppressive agents that affect the IL-2 pathway hinder the mechanism of activation-induced cell death by which the immune system eliminates alloreactive cells.

Patients on Chronic Hemodialysis Have No Intrinsic Lymphocyte Defect upon Stimulation with Interleukin-2, Interleukin-15 or Tumor Necrosis Factor-Alpha

Background: Patients on chronic hemodialysis (HD) suffer from general immune incompetence, resulting in a high incidence of infectious complications, impaired response to vaccinations and a high incidence of malignancy. Although various abnormalities in T cell function of HD patients have been described, it remains unclear whether this is due to an intrinsic T cell defect. Aim: In the present study we tested the capacity of T cells to proliferate upon stimulation with antigen-presenting cell and T-cell-derived cytokines. Methods: The proliferation capacity of lymphocytes obtained from patients on HD and healthy controls was determined by measuring the proliferation of peripheral blood mononuclear cells (PBMC) after stimulation with rhIL-2, rhIL-15, rhTNF-α, or combination of those cytokines. In all samples the percentage of α/β TCR-positive T cells was measured. Results: After isolation of PBMC the percentage of T cells varied from 70% (before stimulation) to 80% (after stimulation). IL-2, IL-15 and TNF-α all induced PBMC proliferation, while the combination TNF-α plus IL-2 or TNF-α plus IL-15 appeared to be additive. No difference between PBMC from HD patients and controls was found. Conclusion: We conclude that lymphocytes from HD patients have no intrinsic defects in their proliferation capacity after stimulation with IL-2, IL-15 or TNF-α, in vitro, as the increase in counts per minute is predominant.

Ten year follow-up of recipients of a kidney or heart transplant who received induction therapy with a monoclonal antibody against the interleukin-2 receptor

OBJECTIVES Twelve years ago, we performed two randomized clinical trials to investigate safety and efficacy of induction therapy with BT563, a highly potent murine monoclonal antibody against the interleukin-2 receptor after kidney and heart transplantation. We analyzed the long-term safety and efficacy data from all 120 patients who participated in the two randomized trials after kidney and heart transplantation 10 years ago. MATERIALS AND METHODS One of these two trials was a randomized, double-blind, placebo-controlled trial, with 60 primary and secondary kidney allograft recipients (cadaveric and living-related donors). The control group was treated with the standard regimen at that time, consisting of cyclosporin and prednisone. In the study group, BT563 was added for 10 days. The second trial was a randomized, double-blind trial, with 60 recipients of a primary heart transplant. In that study, we compared induction therapy with BT563 with the standard regimen at that time, consisting of cyclosporin, prednisone, and OKT3 (both induction agents were given for 7 days). RESULTS Patient survival in the kidney trial was excellent: in the BT563 group, 24 patients were alive (80%), and in the placebo, group 21 (70%) 10 years after transplantation. Also, graft survival was good: in the BT563 group, 63.3% of the kidneys (19/30) were functioning, in the placebo group, 72.4% (21/29) were functioning (P = 0.455). Also, in the heart study, patient (and graft) survival was excellent: 18 patients were alive in the BT563 group (58%), and in the OKT3 group, 21 (72%) patients were alive (P = ns). No increase in the incidence of malignancies was observed between patients treated with BT563 compared with the control groups. Patients following heart transplantation more often suffered from a malignancy than did patients after kidney transplantation (20/60 vs 10/59). CONCLUSIONS We report follow-up data on all patients participating in the two randomized trials, and our data reflect a total of 932 years of patient follow-up. Patient and graft survival appear to be excellent in both the BT563-treated patients and the control groups. BT563 treatment was not associated with an increased likelihood of developing infections or malignancies.

Tacrolimus Dose Requirement Is Significantly Higher When Used in Combination With Cortico‐Steroids

Clinical Pharmacology & Therapeutics (2003) 73, P81–P81; doi:

Anti-CD25 therapy affects the death signals of activated T-cells after clinical heart transplantation.

IL-2 was initially defined as the T-cell growth factor mediating allograft rejection. However, recent experimental studies have shown that IL-2 also regulates the mechanism by which the immune system eliminates activated T-cells. IL-2 is required for the apoptosis of antigen specific T-cells by upregulating FAS receptors. To define whether inhibition of the IL-2 pathway by immunosuppressive agents prevents activation induced cell death (AICD) of activated T-cells, we measured intragraft mRNA expression of IL-2, IL-15, CD25, FAS, FASL, and characterized the phenotype of graft infiltrating T-cells (CD3, CD25) by real time RT-PCR and immunohistochemistry, respectively. Analysis was performed in EMB (n536) from cardiac allograft recipients who were treated with anti-CD25 mAb induction therapy (Daclizumab, n58) or with placebo (n56), in combination with CsA, steroids, and mycophenolate mofetil. Treatment with anti-CD25 mAb significantly affected the IL-2 pathway. In the presence of circulating anti-CD25 mAb, the first 4 months post-transplant, extremely low intragraft IL-2, and CD25 mRNA transcription levels and low numbers of activated CD25 positive T-cells were found compared to the levels measured in EMB from placebo treated patients (5-10 fold, p, 0.0001). The inhibition of the IL-2 pathway during anti-CD25 mAb therapy was associated with reduced FASL mRNA expression and low numbers of CD3 positive T-cells in the graft. Significantly lower FASL mRNA expression levels and CD3 positive T-cells were measured in EMB of anti-CD25 mAb treated patients than in EMB from patients who received placebo (p50.01 and p50.02, respectively). No effect of anti-CD25 therapy was found on intragraft IL-15 and FAS mRNA expression levels. In conclusion, our data suggest that immune activation in the absence of IL-2 is associated with impaired apoptosis of activated T-cells in the graft. Manipulation of the immune system by immunosuppressive agents such as anti-CD25 mAb might prevent the induction of activation induced cell death (AICD) of alloreactive T-cells by hindering the IL-2 dependent FASL expression.