Low incidence of malignancy among sirolimus/cyclosporine-treated renal transplant recipients.

BACKGROUND: Malignancies, a well-known complication of immunosuppressive therapy in renal transplant recipients, represent an important cause of long-term morbidity and mortality. One approach to addressing this problem is identifying agents that display antineoplastic properties concomitant with their immunosuppressive effects. METHODS: We examined the neoplasms among 1008 renal transplant recipients treated at a single center with sirolimus-cyclosporine +/- prednisone. RESULTS: Clinical and laboratory data, including 62.3+/-26.1 months follow-up (range 27.1-131), revealed 36 tumors in 35 patients (3.6%) presenting at 32.5+/-29.8 months. The 2.4% incidence of skin tumors, the most common neoplasms, was 1.58-fold greater than the general U.S. population. In addition to a 0.4% incidence of posttransplant lymphoproliferative disorders (PTLD) and a 0.2% incidence of renal cell carcinomas, we observed single cases of breast, bladder, endometrial, lung, and brain neoplasms as well as leukemia. The mean trough drug concentrations at the time of diagnosis in affected recipients were within our putative target ranges. In addition to eleven graft losses due to death with a functioning kidney, two were related to chronic rejection following reduced immunosuppression, and one, therapeutic nephrectomy for PTLD. Five of twelve deaths were caused by malignancies; four others among 1008 patients over the entire follow-up were attributed to cardiovascular events; one, to respiratory failure; and two, at distant locations to unknown causes. CONCLUSIONS: The sirolimus-cyclosporine +/- prednisone combination appears likely to be associated with a reduced incidence of tumors.

The selective use of basiliximab versus thymoglobulin in combination with sirolimus for cadaveric renal transplant recipients at low risk versus high risk for delayed graft function.

BACKGROUND: We previously reported that the use of basiliximab together with sirolimus permits a window of recovery from delayed graft function before the introduction of reduced-dose cyclosporine. The present study reviews our experience with the substitution of thymoglobulin for basiliximab as induction therapy for recipients at increased risk for early acute rejection episodes. METHODS: We retrospectively reviewed 145 cadaveric renal allograft recipients who received either basiliximab (n=115) or thymoglobulin (n=30) in combination with sirolimus and prednisone, followed by delayed introduction of reduced doses of cyclosporine. Recipients were stratified as high immune responders if they were African American, a retransplant recipient, or a recipient with a panel-reactive antibody greater than 50%. All other recipients were considered low immune responders. RESULTS: Basiliximab-treated high immune responders exhibited a higher incidence of acute rejection episodes (26%) than either basiliximab-treated low immune responders (10%, P=0.04) or thymoglobulin-treated high immune responders (3%, P=0.01). The median time to initiation of cyclosporine was 12 days; cyclosporine was initiated when the serum creatinine level was 2.5 mg/dL or less. Patients with early return of renal function displayed a lower incidence of acute rejection episodes than those with later recovery of function (P=0.003). High immune responders treated with basiliximab expressed a higher mean serum creatinine level at 3 months (P<0.01), 6 months (P=0.02) and 12 months (P=0.01) than either low immune responders treated with basiliximab or high immune responders treated with thymoglobulin. CONCLUSION: A strategy combining sirolimus with basiliximab for low-immunologic risk recipients and thymoglobulin for high-risk recipients leads to prompt recovery of renal function with a low risk of acute rejection episodes.

Risk factors for impaired wound healing in sirolimus-treated renal transplant recipients.

AIM: As sirolimus has been implicated in impaired wound healing, the aim of this study was to evaluate risk factors for wound complications after renal transplantation in patients treated with this drug de novo. METHODS: This single center retrospective review of wound complications included 194 renal transplant recipients, all of whom received sirolimus immunosuppression in combination with reduced doses of cyclosporine (CsA) and corticosteroids de novo. A wound complication was defined as an infection, incisional hernia, or lymphocele. RESULTS: The overall incidence of wound complications within the first year post-transplantation was 36% (n = 70) including infection in 12% (n = 23), lymphocele formation in 18% (n = 34), and incisional hernia in 18% (n = 34) of patients. Seventeen patients suffered more than one wound complication. A multivariate analysis showed that independent risk factors for the development of wound complications were recipients over the age of 40 yr (odds ratio 2.536, p = 0.011), subjects with body mass index (BMI) >26 (odds ratio 2.498, p = 0.027) and especially BMI >30 (odds ratio 3.738, p = 0.007), the use of thymoglobulin for induction immunosuppression (odds ratio 3.627, p = 0.002), and a cumulative dose of sirolimus of at least 35 mg by post-transplant day 4 (odds ratio 2.694, p = 0.023). African-American (odds ratio 0.139, p < 0.001) or Hispanic recipients (odds ratio 0.337, p = 0.014) were less likely to experience a wound problem than Caucasian recipients. CONCLUSION: A number of potentially modifiable risk factors independently increase the incidence of wound complications among renal transplant recipients receiving sirolimus-based immunosuppression de novo.

Long-term outcomes of single paediatric vs. ideal adult renal allograft transplants in adult recipients.

AIM: To compare the outcomes of single paediatric vs. adult kidneys transplanted into adult recipients. METHODS: A retrospective single-centre review of 38 single cadaver kidney transplants from donors less than five yr of age to wait-listed patients of low body mass index (BMI). Survival of grafts and quality of renal function were compared with 121 similarly low BMI recipients of grafts from donors 18-45 yr of age that were transplanted during the same period. Immunosuppression consisted of sirolimus, minimal-dose cyclosporine and prednisone. The mean age of the paediatric vs. adult donors was 2.8+/-1.0 and 31.1+/-9.2 yr, respectively (p<0.01) and of the recipients, 42.0+/-12.4 and 45.7+/-14.8 yr, respectively (p=NS). The mean BMI of paediatric vs. adult donor kidney recipients was 21.8+/-2.9 and 22.4+/-2.0 kg/m2 (p=NS). Sixty-six per cent of paediatric donor recipients were women compared with 44% of adult donor recipients (p=0.03). RESULTS: Death censored actuarial graft survivals at one and five yr for recipients of paediatric vs. adult donor grafts were 93 and 84% compared with 93 and 85% (p=NS). There were no graft losses because of technical complications in the paediatric kidney donor group. At one and five yr post-transplantation, the mean estimated creatinine clearances of the paediatric donor graft recipients were 52.9+/-19.6 and 54.0+/-17.8 mL/min, respectively, compared with 56.4+/-19.8 and 49.1+/-21.7 mL/min for recipients of adult donor grafts at the same times (p=NS). CONCLUSION: Transplantation of single paediatric donor kidneys into low BMI adult recipients provided equivalent outcomes to those of grafts from adult donors between the ages of 18 and 45 yr.

Low intraindividual variability of cyclosporin A exposure reduces chronic rejection incidence and health care costs.

The present study applied a receiver operating characteristic (ROC) analysis to assess the role of intraindividual variability of cyclosporin A (CsA) drug exposure in predisposing renal transplant recipients to the occurrence of chronic rejection, as well as to increased health care costs using a resource-based economic analysis. Two hundred and four adult renal transplant recipients were treated with tapering doses of prednisone (Pred) and with a concentration-controlled strategy that selected doses of the olive oil-based formulations of CsA (Sandimmune(R)) that achieved target concentrations based on serial pharmacokinetic profiles. The ROC analysis revealed an inflection point of plots of the coefficient of variation (%CV) of CsA exposure versus the risk of chronic rejection at >/=28.4% for the average concentration (C(av)), i.e., the dosing interval-corrected area under the concentration-time curves, and >/=36% for the trough concentration (C(0)). The incidence of chronic rejection over a period of 5 yr was 24% among the less variable (LV) versus 40% among the variable (V) cohort. The economic analysis revealed that the total mean facility and physician costs per patient were $48,789 versus $60,998, respectively (P < 0.01). The degree of variability displayed by any individual could only be predicted by serial measurements of CsA concentrations, and not by demographic features, laboratory determinations, clinical characteristics, individual or mean values of any observed CsA concentration, or other pharmacokinetic parameters calculated following a single drug exposure. Thus, strategies that reduce intrapatient variability of CsA exposure over time may lead to reductions in chronic allograft loss and in treatment costs.