Philip Belitsky

A blinded, randomized clinical trial of mycophenolate mofetil for the prevention of acute rejection in cadaveric renal transplantation

Mycopehenolate mofetil (MMF) is a powerful immunosuppressant that inhibits the proliferation of T and B lymphocytes by blocking the enzyme inosine monophosphate dehydrogenase. MMF has been shown to prevent acute graft rejection in animal experiments and may have an important role in clinical renal transplantation. We conducted a prospective, double-blind, multi-center trial to compare the efficacy and safety of MMF and azathioprine within standard immunosuppressive regimen for patients receiving a first or second cadaveric renal graft. A total of 503 patients were randomized to groups receiving MMF 3 g (n=164), MMF 2 g (n=173), or azathioprine (AZA) 100-150 mg (n=166) daily. All were treated simultaneously with equivalent doses of cyclosporine and oral corticosteroids and followed for 12 months. The primary endpoint was treatment failure, defined as the occurrence of biopsy-proven graft rejection, graft loss, patient death, or discontinuation of the study drug during the first 6 months after transplantation. Treatment failure occurred in 50.% of patients in the AZA group by 6 months after transplantation, compared with 34.8% in the MMF 3g group (P=0.0045) and 38.2 % in the MMF 2g group (P=0.0287). Biopsy-proven rejection occurred in 15.9% of patients in the MMF 3 g group and 19.7% in the MMF2 g group, compared with 35.5% in the AZA group. Rejection of histologic severity grade II or more developed in 6.1 %, 10.4% and 19.9% of patients in the MMF 3 g, MMF 2 g, and AZA groups, respectively. Patients receiving MMF required less frequent and less intensive treatment for acute rejection: 24.4% of patients on MMF 3 g and 31.0% on MMF 2 g were tested for acute rejection, compared with 47.5% on AZA. Only 4.9% on MMF 3 g and 8.8% on MMF 2 g required antilymphocyte antibodies for treatment of severe or steroid-resistant rejection, compared with 15.4% of the patients on AZA. At 1 year after transplantation, graft survival in the MMF groups was marginally superior to that in the AZA group, although this difference was not statistically significant. Gastrointestinal toxicity and tissue-invasive cytomegalovirus infection were more common in the MMF 3 g group. Noncutaneous malignancies occurred in six patients on MMF 3 g, three patients on MMF 2 g, and four patients on AZA. Lymphoproliferative disorders occurred in two patients per MMF group, compared with one patient receiving AZA. MMF appears to be an important advance in prophylaxis following renal transplantation. It is associated with a significantly lower rate of treatment failure compared with AZA during the first 6 months after renal transplantation and produces a clinically important reduction in the incidence, severity, and treatment of acute graft rejection. These differences persist throughout the first year of follow-up. Clinical benefit was greatest with a dose of MMF 3 g/day, but gastrointestinal effects, invasive cytomegalovirus infection, and malignancies were slightly more common at that dose. The appropriate dose may lie between 2 g and 3 g per day and may require individualization depending on clinical course or other factors.

Neoral Monitoring By Simplified Sparse Sampling Area Under The Concentration-time Curve: Its Relationship to Acute Rejection and Cyclosporine Nephrotoxicity Early After Kidney Transplantation

BACKGROUND Cyclosporine (CsA) dosing is traditionally based on trough blood levels (C0) rather than area under the concentration-time curve (AUC), although AUC correlates better with posttransplantation clinical events. For Neoral, AUC based on limited sampling correlates closely with full 12-hr AUC. The purpose of our study was to correlate C0 with AUC based on CsA levels at 0, 1, 2, 3, and 4 hr after dose (PK0-4) and to compare this AUC with C0 in predicting acute rejection (AR) and acute cyclosporine nephrotoxicity (CsANT) in de novo first kidney transplant patients. METHODS PK0-4 was done 2-4 days after starting Neoral for 156 patients. All received CsA-based triple-drug immunosuppression without antibody induction. AUC was calculated as projected 12-hr (AUC0-12) and actual 4-hr (AUC0-4) from the PK0-4 using the parallel trapezoid rule. Neoral dosing was based on C0 not AUC. AUC was retrospectively compared with C0 as a predictor of AR and CsANT during the first 90 days. RESULTS C0 correlated poorly with AUC0-12 and AUC0-4 (r=0.61 and r=0.42). C0 (mean+/-SEM) levels were not significantly different in 34 patients with and 109 without AR (293+/-21 vs. 294+/-11 microg/L, P=0.95). AUC0-12 and AUC0-4 were significantly lower in patients with than without AR (AUC0-12 9090+/-598 vs. 10608+/-336 microg x h/L, P=0.01; AUC0-4 3934+/-306 vs. 4802+/-166 microg.h/L, P=0.006). In stepwise regression analysis only AUC0-12 or AUC0-4 (P=0.03/P=0.02) and delayed graft function (P=0.007) predicted AR. AUC0-12, AUC0-4, and C0 were all significantly higher in patients with CsANT than without CsANT (AUC0-12 11746+/-650 vs. 10023+/-301 microg x h/L, P=0.01; AUC0-4 5270+/-358 vs. 4474+/-150 microg x h/L, P=0.01; C0 343+/-18 vs. 287+/-10 microg/L, P=0.01), but in stepwise regression analysis C0 was not an independent predictor of CsANT. Patients with AUC0-12 in the range of 9500 to 11500 microg x h/L or AUC0-4 between 4400 and 5500 microg x h/L had the lowest incidence of AR (13% and 7%, respectively) without significantly higher risk for CsANT. CONCLUSION C0 correlates poorly with AUC based on PK0-4. Early AUC based on PK0-4 is more closely associated with AR and CsANT than is C0. Our data suggest that a target AUC0-12 of 9500-11500 or AUC0-4 of 4400-5500 microg x h/L may provide optimal Neoral immunosuppression.

The incidence and impact of early rejection episodes on graft outcome in recipients of first cadaver kidney transplants

The objective of this study was to define the incidence and significance of acute rejection occurring in the first year following transplantation. The influence of contemporary induction immunosuppression on rejection, as well as the effect of rejection on graft and patient loss, renal function, and maintenance immunosuppression during the first year in 110 recipients of first cadaver renal transplants were analyzed. All patients received CsA, Aza, and prednisone for 30 days with withdrawal of Aza at 30 days and then prednisone at 105 days; 57 patients were prospectively randomized to receive ALG (Merieux) until serum creatinine was less than 300 mumol/L. Short-term ALG administration did not influence the incidence, severity, nature, or outcome of rejection episodes. Fifty-five (50%) patients had at least 1 rejection in the first 90 days. All patients with delayed graft function and 7/8 (88%) sensitized patients (current PRA greater than 50%) had at least 1 rejection episode; 71% (n = 35) of all rejection episodes occurred in the first 30 days posttransplant. Patients rejection free at 90 days remained rejection free the entire first year. Graft loss was 18% for rejections in the first month, 13% for rejections occurring later (P = NS); 20% (n = 11) of patients had a second rejection and 1% (n = 2) had a third rejection. The risk of graft loss was 9% with a first rejection, 38% with a second rejection, and 50% with a third rejection. Of 12 (22%) rejections that were steroid resistant, 10 (83%) were reversed with OKT3. One-year graft survival for patients without rejection, with steroid-sensitive rejection, and with steroid-resistant rejection was 96%, 88% (P = ns), and 58% (P less than 0.001), respectively; 1 year SCr was 168 +/- 93, 196 +/- 77 (P = ns), and 268 +/- 96 microMol/L (P less than 0.05), respectively. Patients free of rejection and with stable renal function continued to do well on maintenance CsA monotherapy, and they were more likely to be on CsA monotherapy than those with rejection episodes (P less than 0.01).

Is routine ureteric stenting needed in kidney transplantation? A randomized trial.

Background. Whether routine ureteric stenting in low-urological-risk patients reduces the risk of urological complications in kidney transplantation is not established. Methods. Eligible patients were recipients of single-organ renal transplants with normal lower urinary tracts. Patients were randomized intraoperatively to receive either routine stenting or stenting only in the event of technical difficulties with the anastomosis. All patients underwent Lich-Gregoire ureteroneocystostomy. Results. Between June 1994 and December 1997, 331 kidney transplants were performed at a single center, 305 patients were eligible, and 280 patients were enrolled and randomized. Donor and recipient age, sex, donor source, whether first or subsequent grafts, ureteric length, native renal disease, and immunosuppression were similar in each group. In the no-routine-stenting group 6 of 137 patients (4.4%) received stents after randomization for intraoperative events that in the surgeon’s opinion required use of a stent. In an intention-to-treat analysis there was no difference between groups in the primary outcome cluster of obstruction or leak [routine stenting 5 of 143 (3.5%) vs. no routine stenting 9 of 137 (6.6%);P =0.23], or in either of these complications analyzed separately. All urological complications were successfully managed without major morbidity. Living donor organs and shorter ureteric length (after trimming) were univariate risk factors for leaks, although increasing donor age was associated with obstruction. Conclusions. Routine ureteric stenting is unnecessary in kidney transplantation in patients at low risk for urological complications. Careful surgical technique with selective stenting of problematic anastomoses yields similar results.

Early Adequate Mycophenolic Acid Exposure is Associated with Less Rejection in Kidney Transplantation

This study examines the importance of early mycophenolic acid (MPA) exposure in the cyclosporine‐ and mycophenolate mofetil (MMF)‐treated kidney transplant population.

Impact of Absorption Profiling on Efficacy and Safety of Cyclosporin Therapy in Transplant Recipients

The optimisation of cyclosporin therapy remains a challenge because of the very narrow therapeutic window and the highly variable pharmacokinetics of the drug. Therefore, there has been a concerted effort in the clinical transplant community to explore and test cyclosporin monitoring tools and techniques that will allow blood concentrations of cyclosporin to be maintained within the narrow therapeutic window in order to maximise efficacy and minimise toxicity.Absorption profiling is a simple and accurate technique for adjusting dosages of cyclosporin microemulsion that utilises an estimation of the rate and extent of cyclosporin absorption in order to optimise immunosuppression in the individual patient. Two estimation tools in particular are an abbreviated area under the concentration-time curve (AUC) for the first 4 hours postdose and a single sampling point at 2 hours postdose. These 2 monitoring strategies have not only been validated as an accurate estimation of cyclosporin bioavailability but have been demonstrated to significantly improve clinical outcomes in patients compared with traditional trough concentration monitoring.The evidence presented in this review demonstrates that absorption profiling results in the following clinical benefits compared with trough concentration monitoring: (i) reduced incidence of acute rejection; (ii) reduced severity of rejection episodes; (iii) reduced nephrotoxicity; and (iv) a rational basis for dosage adjustments.The optimisation of immunosuppressive therapy continues to be a major priority in the management of the organ transplant recipient. Absorption profiling is a sensitive and practical approach for optimising the dosage of cyclosporin microemulsion, and can further extend the benefits of cyclosporin immunosuppression in the individual patient.

KIDNEY TRANSPLANTATION IN CHILDREN WITH URINARY DIVERSION OR BLADDER AUGMENTATION

PURPOSE Urinary tract anomalies or dysfunction leaves the bladder unsuitable for urine drainage in a significant proportion of children presenting for kidney transplantation. We reviewed a multi-institutional experience to determine the ramifications of kidney transplantation in children with bladder augmentation or urinary diversion. MATERIALS AND METHODS During a 28-year period 18 boys and 12 girls 1.7 to 18 years old (mean age 12.1) received 31 kidney transplants. Cause of end stage renal disease was renal dysplasia in 8 cases, posterior urethral valves in 5, obstructive uropathy in 5, neurogenic bladder/chronic pyelonephritis in 4, spina bifida/chronic pyelonephritis in 3, prune belly syndrome in 3 and reflux in 2. RESULTS Of the patients 17 had augmented bladder (ileum 9, ureter 5, sigmoid 2 and stomach 1), 12 had incontinent urinary conduits (8 ileum, 6 colon) and 1 had a continent urinary reservoir. Surgical complications included 1 case each of stomal stenosis, stomal prolapse, renal artery stenosis, urine leak, enterovesical fistula and wound dehiscence. Medical complications included urinary tract infection in 21 cases and metabolic acidosis in 5. A bladder stone developed in 1 patient. There was no correlation between the incidence of symptomatic urinary tract infections and type of urinary drainage. Acidosis was more common in patients with augmented bladder (4 of 17 versus 1 of 14) but there was no correlation between the bowel segment used and the occurrence of acidosis. Graft survival was 90% at 1 year, 78% at 5 years and 60% at 10 years. Etiology of graft loss included chronic rejection in 6 cases, noncompliance in 4 and acute rejection in 1. There were no deaths. CONCLUSIONS Drainage of transplanted kidneys into an augmented bladder or urinary conduit is an appropriate management strategy when the native bladder is unsuitable or absent. Patients with kidney transplants drained into augmented bladder or urinary conduit are at increased risk for urine infection. Graft survival is not adversely affected compared to historical controls when a kidney transplant is drained into a urinary conduit or augmented bladder.

Analysis of imaging modalities, staging systems, and prognostic indicators for renal cell carcinoma

A retrospective analysis of 314 patients with renal cell carcinoma was done focusing mainly on imaging modalities and prognostic significance of tumor stage using both the Robson and TNM systems. Computerized tomography (CT) scan proved to be the most effective modality for staging. Overall staging accuracy was 62 and 68 percent for TNM and Robson staging, respectively, and understaging was more frequent than overstaging. The actuarial five-year survival using the Robson system was 73 percent for Stage A, 68 percent Stage B, 51 percent Stage C, and 20 percent Stage D. The main limitation of the Robson system is the heterogeneity of the Stage C group which includes patients with renal vein and those with nodal involvement with a significant difference in survival. The survival by the TNM system showed no difference in those with T1, T2, T3a and T3b disease but a significant difference in those with T3c or T4a. One hundred sixteen patients (37%) presented with metastatic disease with a median survival of seventeen months (range 2-204) for those with solitary metastasis and six months (range 1-132) for those with multiple metastases (the difference was not statistically significant). Except for anecdotal cases, nephrectomy with or without treatment of the metastases did not seem to affect survival significantly. The presence of spindle cell, alone or in association with clear or granular cell, affected the prognosis adversely. Thirty-one patients had their tumors identified incidentally. Their stage at diagnosis was earlier than the symptomatic group (Stage T1-T2: 77% vs 34%), and there was a significant difference in the disease-free survival at fifty-four months between the two groups (79% vs 57%, respectively).

Fate of renal allografts transplanted in patients with urinary diversion

Fifty-five kidneys were transplanted into 50 patients with supravesical urinary diversion at 16 transplant centers between 1970 and 1991. Of the 32 males and 18 females, 40 were adults (≥18 years) and 10 were less than 18 years old at the time of first transplant. Mean follow-up was 7.8 years. At last follow-up, 94% of recipients were alive and 73% of the kidneys were functioning. Fifteen kidneys were lost: 9 to rejection, 3 to noncompliance, and 3 patients died with a functioning kidney. Ten (18%) transplants were followed by surgical complications. Twenty-four (44%) were followed by medical complications of which urinary tract infection was most common. Recipients age 18 or younger had more urinary tract infections than older patients. No patient had urinary stones and no patient required medical treatment for metabolic abnormalities. We conclude that drainage of kidney transplants into a supravesical urinary diversion is an effective treatment for end-stage renal disease patients without adequate urinary bladders.

Effect of recipient sensitization (peak PRA) on graft outcome in haploidentical living related kidney transplants.

Objective. To evaluate the influence of pre‐transplant recipient sensitization on the outcome of 1‐haploidentical live related donor (LRD) kidney transplants. 
Method. We reviewed 141 consecutive cyclosporine‐treated adult haploidentical first transplants for which panel reactive antibody (PRA) levels were available. Patients were divided into three groups according to their peak PRA levels: group I, PRA=0 (n=97); group II, PRA =1–50% (n=24); and group III, PRA=51–100% (n=20). 
Results. Differences in PRA were associated with significant differences in short‐ and longer‐term graft survival, unrelated to patient survival. Graft survival at 1, 3, and 5 yr was only 74, 40, and 27% in group III, compared to 92, 87, and 52% in group II, and 96, 91, and 85% in group I (p<0.001). Increasing PRA was associated with shorter time‐to‐graft failure. In group III, 20% lost their transplant from acute rejection in the first 6 months, versus 4% in group II and 3% in group I (p<0.01). Graft survival in group II diverged from that of group I only after 3 yr, due to an increase in loss from chronic rejection. Hospitalization was longer in group III, in association with a significantly higher incidence of acute rejection during the first 3 months after transplantation (p<0.02). Serum creatinine was higher in sensitized than nonsensitized patients at all time points. 
Conclusions. Sensitization has a significant negative impact on the outcome of haploidentical LRD kidney transplants. Sensitized potential recipients and their potential donors should be aware of this in arriving at informed decision‐making for transplantation. These patients may benefit from more sensitive cross‐match testing, more intense or more novel immunosuppression, or immunomodulation to modify their immune responsiveness.