BACKGROUND:Our objective was to determine the impact of thymoglobulin-sirolimus-cyclosporine immunosuppression on the alloimmune response of pancreas-kidney transplant recipients. METHODS:Thirty-six pancreas transplant recipients received an induction protocol of thymoglobulin, sirolimus, reduced-dose cyclosporine, and corticosteroids. A subset of 10 recipients were also enrolled in a study to measure immune responsiveness. Flow PRA-determined HLA antibody, donor-specific flow cytometry crossmatching (FCXM), T-cell subset, and suppressor cell assays were performed at various timepoints during the first posttransplant year. RESULTS:One-year patient, kidney, and pancreas survivals were 97%, 94%, and 92%, respectively. There was 1 death due to sepsis, and 1 kidney and 2 pancreas graft losses. There were no acute rejection episodes. Recipients in the immune-monitoring study displayed depression of CD3, CD4, and CD8 counts (<80%) until 3 months posttransplant. At transplantation, 9 of 10 patients displayed <10% class I HLA antibody. By 3 months, 7 of 10 showed a transient elevation in class I HLA antibodies, with 2 patients expressing >80% flow PRA. At transplant 1 patient was FCXM-positive, whereas, by 3 months posttransplant, 2 of 10 patients demonstrated a positive FCXM. There were no clinical consequences to either the presence of HLA antibody or the positive FCXMs. By 6 months, 7 of 9 patients expressed immunoregulatory suppressor cell activity. CONCLUSIONS:The absence of acute rejection events was likely due to inhibition of donor-specific immunity. Seventy percent of patients demonstrated an early non-donor-directed HLA antibody response that had no adverse effect on graft function and 78% of the patients displayed immunoregulatory suppressor cell function, probably contributing to the successful clinical outcome.

Aim. To evaluate the outcome of single pediatric kidneys transplanted into adult recipients.Methods. A retrospective single-center review was performed of transplants from donors less than 5 years of age. Outcomes were compared with recipients of grafts from donors 18 to 45 years transplanted during the same time period.Results. Thirty single renal transplants from pediatric donors and 117 transplants from adult donors between 18 and 45 years of age were performed during the study period. The mean age of the pediatric donors was 2.9 +/- 0.8 years versus 31.5 +/- 8.9 years for adult donors (P < .001). The mean age of the recipients of pediatric donors was 41.9 +/- 13 years versus 48 +/- 12.6 years for recipients of adult grafts (P = .020). The mean recipient weight of pediatric donors was 55.9 +/- 7.8 kg versus 78.0 +/- 17.7 kg for recipients of adult donors (P < .001). Sixty-six percent of pediatric donor recipients were of female gender compared to only 36% of adult donor recipients (P = .005). Death-censored actuarial graft survivals at 1 and 4 years for recipients of pediatric donor grafts were 90% and 85% compared to 93% and 85% for recipients of adult donor grafts (P = NS). The mean calculated creatinine clearances of adult donor graft recipients at 1 and 4 years posttransplantation were 70.8 +/- 26.5 and 73.7 +/- 27.2 mL/min, respectively, compared to 50.3 +/- 20.1 and 56.3 +/- 21.4 mL/min for pediatric donor grafts (P < .01 at 1 and 4 years).Conclusion. The use of single pediatric donor kidneys provides an excellent opportunity to safety expand the donor pool.

Background. Monitoring cyclosporine microemulsion (CsA-ME; Neoral) exposure 2 hours postdose (C2) has been reported to optimize the efficacy and safety of CsA-ME therapy. The addition of induction therapy to a maintenance regimen including CsA-ME C2 monitoring has not been evaluated. Methods. In all, 123 adult renal transplant recipients were recruited at 14 U.S. centers for this 6-month study. CsA-ME dose was to be titrated to attain C2 targets of 1700 and 1500 ng/ml during posttransplant months 1 and 2, respectively. After 2 months, patients were randomized to one of two groups with different, decreasing C2 targets. Basiliximab, mycophenolate mofetil, and corticosteroids completed the study immunosuppression. Results. Of the 119 evaluable patients, 76% were male, 22% African American, and 66% deceased donor recipients. Biopsy-proven acute rejection occurred in 10 patients (9.3%); there were two failed grafts and one death. Serum creatinine and calculated GFR values suggest good renal function, with month 6 medians of 1.5 ng/ml and 67 ml/min/1.73 m2. Safety and tolerability assessments revealed no unexpected outcomes. Observed C2 levels were generally lower than protocol targets, particularly in the first weeks posttransplantation. Conclusions. The striking efficacy and outcomes may have been achieved in this study with lower C2 levels of CsA-ME because of the addition of basiliximab induction.

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.

O424* Aims: The presence of Flow PRA identified IgG HLA antibodies (Abs) in the pretransplant (Tx) sera of renal allograft recipients (recips) is significantly correlated with the occurrence of acute rejections (AR). Little is known, however, about the clinical significance of post-Tx detected HLA Abs. The aim of this study is to understand the impact of specific immunosuppressants on the presence of post-Tx HLA Abs. Methods: We, therefore, studied the pre and post-Tx sera of 133 Sirolimus treated primary recips of a deceased-donor renal allograft for the presence of HLA Ab. Results were correlated with the occurrence of AR and chronic rejection (CR) episodes. Results: The follow-up time was 12 to 55 months (mos) post-Tx. Pre-Tx, 58% (77/133) of the recips presented with no (0%) HLA Ab and experienced 8% (6/77) ARs within 12 months post-Tx. Post-Tx, 15.6% (12/71) of these recips presented with de novo HLA Abs. In contrast, 18% (24/133) of recips presented with class I HLA Ab only and experienced significantly more ARs (29% vs 8%, p<0.02) than the 0% HLA Ab recips. Post-Tx, 50% (12/24) of these recips continued presenting class I HLA Ab, 8% (2/24) now presented with class II HLA Ab, however, 42% (10/24) converted to a 0% HLA Ab presentation. Only 8% (11/133) of the recips presented with class II HLA Abs only and experienced 18% (2/11) ARs (18% vs 8%, p<0.05). Post-Tx 45% (5/11) remained the same, 1 was now positive for class 1 HLA Ab, and 5 recips converted to 0% HLA Ab. Finally, 16% (21/133) of the recips presented with both class I and II HLA Abs and experienced significantly more ARs (43% vs 8%, p<0.01) than 0% HLA Ab recips. Post-Tx, 67% (14/21) of the recips remained positive for both class I and II HLA Abs, 3 were class II only and 3 lost class I and 4 lost both class I and II HLA Abs. The mean time to CR for recips with pre-Tx 0% HLA Ab was 32 ±14 mos, for recips with class I, II or both pre-Tx, but who lost HLA Ab post-Tx, the time was a similar 30 ± 11 mos. In contrast, recips with class I, II or both HLA Abs pre and/or post-Tx experienced the occurrence of chronic rejection within 11± 8 mos (32 ± 14 vs 11± 8, p<0.02). Conclusions: Therefore, the presence of HLA Ab pre and/or post-Tx was a significant risk factor for both acute and chronic rejections.

A79 Aims: To determine long-term outcomes of prednisone withdrawal after renal transplantation, using sirolimus-cyclosporine immunosuppression. Methods: A retrospective single center review of 126 renal transplant recipients, at low-immune risk, selected for prednisone withdrawal. Maintenance immunosuppression utilized sirolimus (target C0 10±2 ng/ml) in combination with reduced-dose cyclosporine (CsA, target C0 25-75 ng/ml). Results: Ninety percent of the kidney transplants were first grafts, 51% from living and 49% from deceased donors. Mean recipient age was 45±13years, 60% male, 53% Caucasian, 26% Hispanic, 13% African-American and 8% Asian. Only 7 patients expressed a current PRA>20%. Median time to cessation of steroids was 12 months (range 1-41 months), 20% of recipients were discontinued from prednisone by 3 months, 44% by 12 months and 70% by 24 months post-transplantation. After a median follow-up of 50 months (range 3-118 months) 75% of recipients remained prednisone-free. Five-year graft survival from the time of prednisone withdrawal was 70%. Prednisone withdrawal at early (1-3 months), intermediate (4-12 months) or late (>12 months) time points after transplantation resulted in equivalent 5 year graft survivals of 81%, 73%, and 67% respectively (p: ns). Quality of renal function, expressed as mean (±SD) serum creatinine at 1, 3, and 5 years of the entire cohort was 1.7±0.6, 1.8±0.9, and 1.7±0.5 mg/dl respectively. Conclusions: Prednisone withdrawal, utilizing sirolimus-cyclosporine immunosuppression in renal transplant recipients at low risk of rejection, resulted in excellent long-term graft survival with no significant deterioration in quality of function.

BACKGROUND:ISIS 2302, an antisense oligonucleotide that inhibits the expression of human intercellular adhesion molecule (ICAM)-1, was evaluated in combination with a cyclosporine (CsA)-prednisone (Pred) regimen first in a phase I safety and pharmacokinetic study and then in a phase II assessment of prophylaxis of acute rejection episodes in deceased donor renal allografts.METHODS:Both phase I and phase II trials were double-blinded and placebo-controlled, including 17 stable and 39 de novo patients, respectively, in time-lagged, ascending-dose regimens. Each study compared the outcomes of 8 alternate-day intravenous infusions of four ISIS 2302 dose levels (0.05, 0.5, 1.0, or 2.0 mg/kg) versus placebo (3:1 ratio). Patients were followed for 34 days (phase I) or 6 months (phase II). All transplant patients were followed for 3 years.RESULTS:ISIS 2302 produced no evident toxicity; a significant, dose-related increase in activated partial thromboplastin time was accompanied by a trend toward a decreased platelet count. ISIS 2302 did not alter the pharmacokinetic behavior of CsA. At 6 months, the rates of acute rejection episodes were 38.1% in the ISIS 2302 group versus 20.0% in the placebo group. Three-year graft survivals were similar. The mean creatinine values at 1, 2, and 3 years for all ISIS dose groups combined versus placebo over 3 years showed no significant differences.CONCLUSIONS:ISIS 2302 did not evoke side-effects and produced slightly improved renal function. However, in this pilot study, it did not further reduce the rate of acute rejection episodes or increase graft survival compared to a concentration-controlled CsA-Pred regimen.

O90* Aim: Previous multicenter studies of neoplasms among renal transplant recipients treated with a sirolimus (SRL)-cyclosporine (CsA)-prednisone regimen were limited to 24-mo follow-up. In contrast, we have examined the courses of 1008 patients treated at a single center for up to 10 yr. Methods: The single-center experience includes patients in the Phases I–IV development of sirolimus, using doses ranging from 1–7mg/m2 and CsA at C2 exposures of 200–1200ng/mL with limited steroid courses in about 35% of patients. The follow-up (mean±SD) of 60.3±27.5 mo was exclusively at the medical center throughout their course. Routine queries and examinations specifically probed the occurrence of skin neoplasms. The Paradox database was compared with literature sources and with the percentages in the US population as described in the Surveillance, Epidemiology, and End Results (SEER) database using chi-square analysis for the incidences of various neoplasms. Results: The overall incidence of malignancy throughout follow-up was 34/1008 (3%) with presentation at 34.8±30.1 mo (range: 1–135). The demographics of the 33 affected patients (1 with 2 malignancies) were men:women=28:5 with a mean age at presentation of 53.0±12.5 years. The incidence of various types of malignancies common to transplant patients was lymphoproliferative disorder (PTLD) 0.4%, renal cell carcinoma (RCC) 0.2%, and skin tumors 1.9%, including squamous cell (0.9%), basal cell (0.5%), melanoma (0.2%), Merkel cell (0.2%), and basosquamous (0.1%). The distribution of tumor types among malignancy-positive patients was similar to transplant registry figures for skin tumors (63.3% vs 43.1%), PTLD (13.3 vs 12.2%), and RCC (6.7 vs 4.3%). The other malignancies included single cases of breast, bladder, endometrial, and brain neoplasms, as well as two cases of lung neoplasms. Furthermore, when our data were compared to SEER over a 5-yr period, the SRL-CsA cohort showed a similar incidence of skin tumors (1.9 vs 1.5%), which is significantly less than the 7% reported among other renal transplant patient cohorts. Compared to the general US population, our patients showed a 4-fold increase in PTLD (0.4 vs 0.1%) and RCC (0.2 vs 0.05%), figures that were far less than the previously reported 27.2-and 8-fold increases, respectively, using tacrolimus plus mycophenolate. At the time of diagnosis, the trough concentrations (mean±SD) of SRL (11.4±8.9ng/mL) and CsA (138.75±84.1) in affected patients were similar to those of other recipients and not excessive. The treatment outcomes were satisfactory save for 5 deaths: PTLD in a renal allograft incidentally discovered at the time of demise, endometrial carcinoma in a 52-year-old woman, lung cancer in a 72-year-old smoker, brain tumor in a 73-year-old man, and leukemia in a 24-year-old man. Four other graft losses included 2 lethal cardiovascular events and 2 chronic rejections due to reduced immunosuppression. Conclusion: In renal allograft recipients, SRL seems to reduce the incidence of tumors, particularly of the skin, suggesting an antineoplastic effect.

Neurotoxicity is a well-recognized side effect of calcineurin inhibitors. Rapamycin is considered to be significantly less neurotoxic than calcineurin inhibitors (CNIs). The aim of this study was to retrospectively analyze a group of post-liver transplant patients who had been converted to rapamycin because of CNI-related neurotoxicity.Orthotopic liver transplantation (OLT) was performed in 56 consecutive patients between April 1, 2003, and August 15, 2004. Immunosuppression was administered with tacrolimus, mycophenolic acid, and corticosteroids.Seven patients were converted to rapamycin due to new-onset neurotoxicity or exacerbation of previous neurological symptoms secondary to CNI. None of the patients had toxic levels tacrolimus (>15 ng/mL) at the time of symptoms, which persisted despite reduction of CNI dose. The indications for conversion were: (1) peripheral neuropathy; (2) seizure; (3) metabolic encephalopathy; and (4) central pontine myelinolysis. All patients showed improvement or resolution of their neurological symptoms after conversion to rapamycin. Two patients died, the first due to a hypoxic event and the second due to central pontine myelinolysis with limited improvement and a family decision to withdraw care. There were no complications directly attributed to rapamycin. Specifically, there were no thrombotic events, wound complications, or biliary leaks. Three patients had a rejection episode that was successfully treated with pulse corticosteroids and low-dose tacrolimus (levels < 5 ng/mL).Rapamycin can be safely used in OLT recipients with severe neurological symptoms ascribed to or exacerbated by CNIs. Rapamycin monotherapy may be inadequate to control rejection early after transplantation. Rapamycin can be combined with low doses of CNI to prevent rejection.

Sirolimus (RAPA) and corticosteroids (CS) both inhibit wound healing. To evaluate the possibility that RAPA and CS have additive effects on wound healing, we evaluated the effects of corticosteroid avoidance (CSAV) on wound healing complications in patients treated with RAPA.One hundred nine patients treated with a CSAV regimen (no pretransplantation or posttransplantation CS) were compared with a historical control group (n = 72) that received cyclosporine (CsA), mycophenolate mofetil (MMF), and CS. The CSAV group received low-dose CsA, MMF, RAPA, and thymoglobulin induction. Complications were classified as follows: wound healing complications (WHC) or infectious wound complications (IWC). WHC included lymphocele, hernia, dehiscence, diastasis, and skin edge separation. IWC included wound abscess and empiric antibiotic therapy for wound erythema.The CSAV group was largely CS-free: 11% of patients received CS for rejection, 12% of patients received CS for recurrent disease, and 85% of patients are currently off CS. The CSAV group had a significantly lower incidence of WHC (13.7% vs 28%; P = .03) and lymphoceles (5.5% vs 16%; P = .02) than the control group. There was no difference in the incidence of IWC between the 2 groups. Patients who received CSAV were 18% less likely (P = .57) to develop any type of complication, 41% less likely (P = .20) to develop a WHC, and 71% less likely (P = .018) to develop a lymphocele.CSAV in a RAPA-based regimen results in a marked reduction in WHC and lymphoceles. Therefore, CSAV provides a promising approach for addressing WHC associated with RAPA therapy.

Kerman, Ronald H.1; Katz, Stephen M.1; Buren, Charles T. Van1; Ruth, Jim A.1; McKissick, Eva1; Rassmussen, Stephanie1; Kahan, Barry D.1 Author Information

Expression of intercellular adhesion molecule-1 (ICAM-1) and its ligand, leukocyte function antigen-1 (LFA-1), after pancreatic islet transplantation may affect both nonspecific and alloantigen-specific phases of graft destruction. We examined the effects of ICAM-1/LFA-1 blockade on the survival of islet allografts. Fresh C57BL/10 (H2b) pancreatic islets were transplanted under the renal subcapsular space (KC) or embolized into the liver after portal vein (PV) injection to C3H (H2k) mice. Recipients remained untreated or were treated for 7 days by IP administration of: ICAM-1 antisense phosphorothioate oligodeoxynucleotide (oligo) alone; anti-ICAM-1 (αICAM-1) monoclonal antibody (mAb) alone; αLFA-1 mAb alone; ICAM-1 oligo/αLFA mAb combination; αICAM-1 mAb/αLFA-1 mAb combination; or control oligo IP-8997 or IP-1082. In some experiments, donors were pretreated with ICAM-1 oligo. Inhibition of single ligand with 5.0 mg/kg ICAM-1 oligo (25.1 ± 10.3), 100 μg/daily αICAM-1 mAb (24.2 ± 8.0 days), or 50 μg/daily αLFA-1 mAb (42.8 ± 25.9 days) prolonged the survivals of KC islet allografts in comparison with untreated controls (11.9 ± 1.0 days; all p < 0.01). However, dual ICAM-1/LFA-1 blockade with either ICAM-1 oligo/αLFA-1 mAb (78.3 ± 16.5 days) or αICAM-1 mAb/αLFA-1 mAb (65.2 ±31.3 days) was the most effective therapy. Although pretreatment of donors with ICAM-1 oligo alone was ineffective (12.2 ± 0.8 days; NS), a combination of donor pretreatment and recipient treatment started 1 day prior to grafting with ICAM-1 oligo (39.2 ± 14.0 days) was more effective than the recipient treatment alone (24.6 ± 8.8 days). Furthermore, ICAM-1/LFA-1 blockade improved islet function as evaluated by glucose tolerance test, and decreased inflammation in comparison with untreated controls. Similar in vivo results were obtained following PV administration of islet allografts. Thus, ICAM-1/LFA-1 blockade prolongs the survival of pancreatic islet allografts and improves their early function.

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.

Background. Sirolimus, a novel immunosuppressant that inhibits cytokine-driven cell proliferation and maturation, prolongs allograft survival in animal models. After a phase I trial in stable renal transplant recipients documented that cyclosporine and sirolimus have few overlapping toxicities, we conducted an open-label, single-center, phase I/II dose-escalation trial to examine the safety and efficacy of this drug combination. Methods. Forty mismatched living-donor renal transplant recipients were sequentially assigned to receive escalating initial doses of sirolimus (0.5-7.0 mg/m2/day), in addition to courses of prednisone and a concentration-controlled regimen of cyclosporine. We conducted surveillance for drug-induced side effects among sirolimus-treated patients and compared their incidence of acute rejection episodes as well as mean laboratory values with those of a historical cohort of 65 consecutive, immediately precedent, demographically similar recipients treated with the same concentration-controlled regimen of cyclosporine and tapering doses of prednisone. Results. The addition of sirolimus reduced the overall incidence of acute allograft rejection episodes to 7.5% from 32% in the immediately precedent cyclosporine/prednisone-treated patients. At 18- to 47-month follow-up periods, both treatment groups displayed similar rates of patient and graft survival, as well as morbid complications. Although sirolimus-treated patients displayed comparatively lower platelet and white blood cell counts and higher levels of serum cholesterol and triglycerides, sirolimus did not augment the nephrotoxic or hypertensive proclivities of cyclosporine. The degree of change in the laboratory values was more directly associated with whole blood trough drug concentrations than with doses of sirolimus. Conclusions. Sirolimus potentiates the immunosuppressive effects of a cyclosporine-based regimen by reducing the rate of acute rejection episodes.

BACKGROUNDMycophenolate mofetil (MMF) is rapidly hydrolyzed to its active metabolite mycophenolic acid (MPA), which is excreted by the kidney after undergoing glucuronidation to MPAG. MPAG has been shown to accumulate in patients with renal failure. MPA is extensively and avidly bound to human serum albumin. In vitro inhibition of the pharmacologic target, inosine monophosphate dehydrogenase, is dependent on free MPA. It has been demonstrated that high MPAG concentrations decrease MPA protein binding in vitro. In addition, the uremic state is associated with altered protein binding of many drugs.METHODSWe assessed free MPA, total MPA, and MPAG kinetics in a patient with renal failure receiving MMF for a pancreas transplant, who presented with signs of MMF toxicity. MPA, MPAG, and free MPA were measured by high performance liquid chromatography and a validated 14C-MPA ultrafiltration methodology.RESULTSThe MPAG area under the concentration curve (AUC) in this patient was extremely high (5899 microg x hr/ml). The total MPA AUC of 36.8 microg x hr/ml was within the range usually obtained in stable renal patients. The free fraction of MPA and the free MPA AUC were markedly elevated (13.8% and 5.07 microg x hr/ml, respectively).CONCLUSIONSPatients with severe renal insufficiency may have markedly increased free MPA levels that may not be reflected in total MPA concentrations. These patients may be at increased risk for MMF-related toxicity.