Silvio Sandrini

Performance of Different Prediction Equations for Estimating Renal Function in Kidney Transplantation

Numerous formulas have been developed to estimate renal function from biochemical, demographic and anthropometric data. Here we compared renal function derived from 12 published prediction equations with glomerular filtration rate (GFR) measurement by plasma iohexol clearance as reference method in a group of 81 renal transplant recipients enrolled in the Mycophenolate Mofetil Steroid Sparing (MY.S.S.) trial. Iohexol clearances and prediction equations were carried out in all patients at months 6, 9 and 21 after surgery. All equations showed a tendency toward GFR over‐estimation: Walser and MDRD equations gave the best performance, however not more than 45% of estimated values were within ±10% error. These formulas showed also the lowest bias and the highest precision: 0.5 and 9.2 mL/min/1.73 m2 (Walser), 2.7 and 10.4 mL/min/1.73 m2 (MDRD) in predicting GFR. A significantly higher rate of GFR decline ranging from −5.0 mL/min/1.73 m2/year (Walser) to −7.4 mL/min/1.73 m2/year (Davis–Chandler) was estimated by all the equations as compared with iohexol clearance (−3.0 mL/min/1.73 m2/year). The 12 prediction equations do not allow a rigorous assessment of renal function in kidney transplant recipients. In clinical trials of kidney transplantation, graft function should be preferably monitored using a reference method of GFR measurement, such as iohexol plasma clearance.

Mycophenolate mofetil versus azathioprine for prevention of acute rejection in renal transplantation (MYSS): a randomised trial

BACKGROUND Mycophenolate mofetil has replaced azathioprine in immunosuppression regimens worldwide to prevent graft rejection. However, evidence that its antirejection activity is better than that of azathioprine has been provided only by registration trials with an old formulation of ciclosporin and steroid. We aimed to compare the antirejection activity of these two drugs with a new formulation of ciclosporin. METHODS The mycophenolate steroids sparing multicentre, prospective, randomised, parallel-group trial compared acute rejections and adverse events in recipients of cadaver-kidney transplants over 6-month treatment with mycophenolate mofetil or azathioprine along with ciclosporin microemulsion (Neoral) and steroids (phase A), and over 15 more months without steroids (phase B). The primary endpoint was occurrence of acute rejection episodes. Analysis was by intention to treat. FINDINGS 168 patients per group entered phase A. 56 (34%) assigned mycophenolate mofetil and 58 (35%) assigned azathioprine had clinical rejections (risk reduction [RR] on mycophenolate mofetil compared with azathioprine 13.7% [95% CI -25.7% to 40.7%], p=0.44). 88 patients in the mycophenolate mofetil group and 89 in the azathioprine group entered phase B. 14 (16%) taking mycophenolate mofetil and 11 (12%) taking azathioprine had clinical rejections (RR -16.2%, [-157.5% to 47.5%], p=0.71). Average per-patient costs of mycophenolate mofetil treatment greatly exceeded those of azathioprine (phase A 2665 Euros [SD 586] vs Euros 184 [62]; phase B 5095 Euros [2658] vs 322 Euros [170], p<0.0001 for both). INTERPRETATION In recipients of cadaver kidney-transplants given ciclosporin microemulsion, mycophenolate mofetil offers no advantages over azathioprine in preventing acute rejections and is about 15 times more expensive. Standard immunosuppression regimens for transplantation should perhaps include azathioprine rather than mycophenolate mofetil, at least for kidney grafts.

Recurrence of focal segmental glomerulosclerosis after renal transplantation in patients with mutations of podocin.

BACKGROUND Posttransplant recurrence of focal segmental glomerulosclerosis (FSGS) occurs in a relevant proportion of FSGS patients and represents an important clinical emergency. It is taken as a proof of the existence of circulating permeability plasma factor(s) that are also putative effectors of original proteinuria in these patients. Familial forms of FSGS do not recur, but the discovery of numerous patients with sporadic FSGS and mutations of podocin (NPHS2, that is actually an inherited disease) who received a renal graft require a re-evaluation of the problem. METHODS To evaluate the incidence of posttransplant recurrence of FSGS in patients with NPHS2, the authors screened for podocin mutations in 53 patients with the clinical and pathologic stigmata of FSGS who had renal failure and who had undergone renal transplantation.Results. Twelve children were found to carry a homozygous (n9) or a heterozygous (n4) mutation of podocin and were classified, according to current criteria, as patients with inherited FSGS. In 5 patients of this group (38%), proteinuria recurred after renal graft and in 2, renal biopsy results showed recurrence of FSGS. Prerecurrence serum of 3 patients of this cohort was tested for antipodocin antibodies with indirect immuno-Western utilizing human podocyte extracts and were found negative. The rate of FSGS recurrence was comparable in non-NPHS2-FSGS children (12 of 27) and adults (3 of 13). Also clinical outcome of recurrence and response to plasmapheresis and immunosuppressors were comparable, suggesting a common mechanism. CONCLUSION These data show a high rate of FSGS recurrence in patients with NPHS2 mutations that is comparable with idiopathic FSGS and describe the successful therapeutic approach. Recurrence of an apparently inherited disease should stimulate a critical review of the mechanisms of recurrence and of original proteinuria in these cases.

Mycophenolate Mofetil versus Azathioprine for Prevention of Chronic Allograft Dysfunction in Renal Transplantation: The MYSS Follow-Up Randomized, Controlled Clinical Trial

The Mycophenolate Steroids Sparing (MYSS) study found that in renal transplant recipients who were on immunosuppressive therapy with the cyclosporine microemulsion Neoral, mycophenolate mofetil (MMF) was not better than azathioprine in preventing acute rejection at 21 mo after transplantation and was 15 times more expensive. The MYSS Follow-up Study, an extension of MYSS, was aimed at comparing long-term outcome of 248 MYSS patients according to their original randomization to MMF (1 g twice daily) or azathioprine (75 to 100 mg/d). Primary outcome was estimated GFR at 5 yr after transplantation. Mean 5-yr GFR difference between azathioprine and mycophenolate was 4.67 ml/min per 1.73 m(2) (95% confidence interval [CI] -0.43 to 9.77 ml/min per 1.73 m(2); P = 0.07). GFR from month 6 (mean +/- SEM: 54.3 +/- 1.6 versus 53.9 +/- 1.5 ml/min per 1.73 m(2); P = 0.83) to month 72 after transplantation (49.5 +/- 2.2 versus 47.3 +/- 2.4 ml/min per 1.73 m(2); P = 0.50); GFR slopes (mean +/- SEM: -1.10 +/- 0.56 versus -1.23 +/- 0.31 ml/min per 1.73 m(2) per year; P = 0.83); and 72-mo patient mortality (4.0 versus 4.0% [P = 0.95]; HR 0.96; 95% CI 0.28 to 3.31; P = 0.95), graft loss (6.8 versus 6.1% [P = 0.82]; HR 0.89; 95% CI 0.32 to 2.46; P = 0.83), incidence of persistent proteinuria (25.0 versus 27.4%; P = 0.72), late (>6 mo after transplantation) rejections (25.3 versus 21.2%; P = 0.53), and adverse events were similar on azathioprine (n = 124) and MMF (n = 124), respectively. Outcomes in the two groups were comparable also among patients with or without steroid therapy, considered separately. In kidney transplantation, the long-term risk/benefit profile of MMF and azathioprine therapy in combination with cyclosporine Neoral is similar. In view of the cost, standard immunosuppression regimens for kidney transplantation should perhaps include azathioprine rather than MMF.

Incidence of cancer after kidney transplant: Results from the north italy transplant program

Background. Patients undergoing kidney transplantation demonstrate a higher risk of developing cancer as the result of immunosuppressive treatment and concurrent infections. Methods. The incidence of cancer in a cohort of patients who underwent kidney transplantation between 1990 and 2000, and who survived the acute phase (10 days), was analyzed as part of the North Italy Transplant program. Results. A total of 3,521 patients underwent transplantation during a 10-year period in 10 of 13 participating centers; the length of follow-up after kidney transplant was 67.7±36.0 months. During the follow-up, 172 patients developed cancer (39 with Kaposi sarcoma, 38 with lymphoproliferative diseases, and 95 with carcinomas [17 kidney, 11 non-basal cell carcinoma of the skin, 10 colorectal, 8 breast, 7 gastric, 7 lung, 6 bladder, and 3 mesothelioma]). The average time to cancer development after transplant was 40.1±33.4 months (range 0–134 months). Twenty-four patients developed cancer within 6 months from the transplant (10 with carcinomas, 7 with Kaposi sarcoma, and 7 with lymphoproliferative diseases). Three patients demonstrated a second primary cancer. The average cancer incidence was 4.9%. The incidence of cancer was 0.01 per year. Independent determinants of cancer development were age, gender, and immunosuppressive protocol including induction. Ten-year mortality was significantly higher in patients with cancer (33.1%) than among patients without cancer (5.3%). The relative risk of death in subjects with cancer was 5.5 (confidence interval 4.1–7.4). Conclusions. These preliminary data underline the importance of long-term surveillance of transplant recipients, choice of immunosuppressive treatment, and careful donor selection.

ABCB1 Genotypes Predict Cyclosporine-Related Adverse Events and Kidney Allograft Outcome

Cyclosporine A (CsA) is a substrate of P-glycoprotein, an efflux transporter encoded by the ABCB1 gene. Compared with carriers of the wild-type gene, carriers of T allelic variants in exons 21 or 26 have reduced P-glycoprotein activity and, secondarily, increased intracellular concentration of CsA; therefore, carriers of T variants might be at increased risk for CsA-related adverse events. We evaluated the associations between ABCB1 genotypes (in exons 12, 21, and 26) and CsA-related outcomes in 147 renal transplant recipients who were receiving CsA-based immunosuppression and were included in the Mycophenolate Steroids Sparing study. During a median of 65.5 mo follow-up, carriers of T allelic variants in exons 21 or 26 had a three-fold risk for delayed graft function (DGF), a trend to slower recovery of renal function and lower GFR at study end, and significantly higher incidences of new-onset diabetes and cytomegalovirus reactivation compared with carriers of the wild-type genotype. T variants in both exons 21 and 26 were independently associated with 3.8- and 3.5-fold higher risk for DGF, respectively (P = 0.022 and P = 0.034). The incidence of acute rejection and the mean CsA dose and blood levels were comparable in genotype groups. In conclusion, renal transplant recipients with T allelic variants in ABCB1 exons 21 or 26 are at increased risk for CsA-related adverse events. Genetic evaluation may help to identify patients at risk and to modulate CsA therapy to optimize graft and patient outcomes.

A comparative prospective study of two available solutions for kidney and liver preservation

Background. Viaspan (University of Wisconsin [UW]) solution is the gold standard for abdominal organ preservation. Celsior (CEL) is an extracellular-type, low-potassium, low-viscosity solution, initially used for heart and lung preservation. We have performed a prospective multicenter study to compare the role of these cold-storage solutions on kidney and liver recovery after transplantation. Patients and Methods. From March 15, 2000 to December 31, 2001, 441 (172 CEL and 269 UW) renal transplants (RT) and 175 (79 CEL and 96 UW) liver transplants (LT) were included in the study. Results. Perfusate volume used was significantly lower in the UW group, being 4,732±796 mL versus 5,826±834 mL in the CEL group (P <0.001). In LT, median total bilirubin serum levels were significantly higher at 5 and 7 posttransplant days in the UW group (90.6 and 92.3 μmol/L, respectively) as compared with CEL (51.3 and 63.4 μmol/L, respectively). After LT, primary nonfunction (PNF) rates in the CEL and UW groups were 3.8% and 4.2% (P =NS) respectively, with 1-year graft and patient survival being 83.3% versus 85.4% (P =NS) and 89.9% versus 90.6% (P =NS). After RT, delayed graft function (DGF) rates were 23.2% and 22.7% (P =NS), respectively; PNF rates were 1.9% and 1.7% (P =NS) respectively, with 1-year graft and patient survival being 92.3% versus 94.2% (P =NS) and 99.4% versus 97.7% (P =NS). Conclusions. CEL solution was shown to be as effective as UW in both liver and kidney preservation. In LT patients, biliary function recovery is significantly better in the CEL group. CEL solution represents an efficacious option in multiorgan harvesting.

A prospective randomized trial on azathioprine addition to cyclosporine versus cyclosporine monotherapy at steroid withdrawal, 6 months after renal transplantation

BACKGROUND Many attempts have been made to withdraw steroid therapy in renal transplant patients in order to avoid its many side effects. Results have been, so far, controversial. In this randomized prospective study, we compare the efficacy of azathioprine adjuncts to cyclosporine at the time of steroid withdrawal, 6 months after transplantation, versus Cyclosporine monotherapy, in preventing acute rejection. METHODS One hundred and sixteen kidney transplant patients with good and stable renal function (creatininemia <2 mg/dl) received, in the first 6 months, cyclosporine + steroid. They were then randomized into two groups (A and B), and steroid therapy was withdrawn over 2 months. Group A (58 patients) continued on cyclosporine monotherapy, whereas group B (58 patients) added azathioprine (1 mg/kg/day) at the beginning of randomization and continued on cyclosporine + azathioprine. In both groups, patients resumed steroid therapy at the first episode of acute rejection. Follow-up after randomization was 5.3+/-1.6 years. RESULTS After 5 years, the incidence of steroid resumption was 57% in group A and 29% in group B (P<0.02); of those, 68% and 88% of them were within 6 months from randomization. Anti-rejection therapy was always successful. Five-year patient and graft survival rates were 90% and 88% in group A and 100% and 91% in group B. Creatininemia did not differ, at follow-up. Side effects differed only for mild and reversible leukopenia caused by azathioprine in group B. CONCLUSION Cyclosporine plus azathioprine is more effective than cyclosporine monotherapy in reducing the incidence of acute rejection after steroid withdrawal. Graft loss as a result of chronic rejection, mild in both groups, did not differ. Steroid withdrawal is feasible and advantageous, and the addition of azathioprine allowed 71% of our selected patients to remain steroid-free.

Epidemiologic study on the origin of cancer after kidney transplantation.

Background. Subjects who underwent solid organ transplantation are at higher risk for a wide variety of cancers. Methods. The authors investigated the origin of cancer in a cohort of 2,526 patients followed up for 60.7±35.6 months after kidney transplantation between 1990 and 2000 in seven transplant centers. Results. One hundred four of them developed cancer. All subjects who developed solid cancer within 6 months after transplantation (n=10) and a group of subjects who developed solid cancer after 6 months posttransplant (n=10) were selected. Short tandem repeat analysis was performed on paraffin-embedded biopsy specimens of tumors and on both donor and recipient pretransplant peripheral blood. Biologic material was obtained in 17 of the 20 selected patients (85.0%). The analysis showed that 16 of 17 tumors were genetically identical to the recipient. Conclusions. The authors’ results suggest that donor transmission of solid cancer is an unlikely event in their population.

Steroid withdrawal five days after renal transplantation allows for the prevention of wound-healing complications associated with sirolimus therapy

Abstract:  Background:  Sirolimus (SRL) can increase the risk of wound complications. In this study, we investigated the impact of steroids when added to SRL, in this side effect.