Importance of Early Adequate Exposure to Cyclosporine in Renal Transplant Outcome: Study of 1-Year Creatinine

Incidence and factors associated with delayed graft function in renal transplantation at Carlos Van Buren Hospital, January 2000 to June 2008

Delayed graft function (DGF) is defined as the need for dialysis within the first week after renal transplantation, and slow graft function as persistence of serum creatinine concentration of at least 3 mg/dL on day 5 after the procedure. In the present study, we analyzed the incidence and risk factors for DGF at our center. This retrospective study included 106 patients who underwent renal transplantation between January 2000 and June 2008. Of these, 11 patients were excluded. Two of the remaining 95 patients received organs from living donors, and 93 received cadaver organs. Variables analyzed included donor age, cause of death, cause of chronic renal failure, recipient age, method and time of long-term renal replacement therapy, residual diuresis, panel of reactive antibodies (PRA), HLA mismatch, sex compatibility, cold and warm ischemia times, biopsy-confirmed episodes of acute rejection, urine output in the operating room and in the first 24 hours after the procedure, and intraoperative induction therapy. Data were analyzed using the chi(2) and Fisher exact tests and analysis of variance, and are given as mean (SD) and frequency. Variables associated with DGF at univariate analysis (P < .05) were divided between risk factors and predictors of DGF for inclusion in logistic regression models. The incidence of DGF was 32.6%; slow graft function, 16.8%; and immediate graft function, 50.5%. Cold ischemia time longer than 20 hours (P = .02) and donor age (P = .008) were directly associated with DGF. Twenty-four-hour urine output was a strong predictor of DGF. Patients with DGF demonstrated a 25% incidence of an episode of acute rejection before discharge from the hospital. No difference in DGF was observed for use of intraoperative induction therapy.

Duration of delayed graft function is an important predictor of 1-year serum creatinine

OBJECTIVE

The purpose of this study was to evaluate the importance of various factors on 1-year serum creatinine (SCr) as a surrogate endpoint for allograft survival among a series of kidney transplantations performed at 2 centers.

PATIENTS AND METHODS

Two hundred sixty consecutive renal transplantations were included with overall mean age of 40 +/- 13 years, including 55% men and 19% living donor grafts. Factors considered for analysis were donor and recipient ages, and sexes, number of transplantations, panel-reactive antibodies, total number of HLA mismatches, cold ischemia time (CIT), acute rejection (AR) rate, and presence/duration of delayed graft function (DGF). Multiple regression analyses were performed for 1-year SCr, AR rate, and DGF duration.

RESULTS

One-year SCr was 1.46 +/- 0.5 mg/dL, 6-month AR rate was 22%, and DGF rate was 29% of mean duration 3 +/- 8 days. Multiple regression analysis for lower 1-year SCr value identified as significant female recipient sex, lower donor age, absence of AR within 6 months, and decreased DGF duration (P < .05). The only significant factor affecting AR rate was DGF duration. Finally, prolonged CIT was associated with a longer DGF duration.

CONCLUSIONS

We confirmed that 1-year SCr was primarily affected by well-known factors, such as AR incidence, donor age, and female recipient sex. However, we identified DGF duration as a significant factor affecting 1-year SCr. AR rate was also associated with DGF duration, which in turn depended upon longer CIT.

Markers of cellular senescence in zero hour biopsies predict outcome in renal transplantation

Although chronological donor age is the most potent predictor of long-term outcome after renal transplantation, it does not incorporate individual differences of the aging-process itself. We therefore hypothesized that an estimate of biological organ age as derived from markers of cellular senescence in zero hour biopsies would be of higher predictive value. Telomere length and mRNA expression levels of the cell cycle inhibitors CDKN2A (p16INK4a) and CDKN1A (p21WAF1) were assessed in pre-implantation biopsies of 54 patients and the association of these and various other clinical parameters with serum creatinine after 1 year was determined. In a linear regression analysis, CDKN2A turned out to be the best single predictor followed by donor age and telomere length. A multiple linear regression analysis revealed that the combination of CDKN2A values and donor age yielded even higher predictive values for serum creatinine 1 year after transplantation. We conclude that the molecular aging marker CDKN2A in combination with chronological donor age predict renal allograft function after 1 year significantly better than chronological donor age alone.

Combination therapy with tacrolimus and mycophenolate mofetil: effects of early and late minimization of mycophenolate mofetil after renal transplant

The objectives of the study were: (i) to compare the efficacy and safety of minimizing mycophenolate mofetil (MMF) early (30 d) or late (90 d) after renal transplantation, when used in combination with tacrolimus; (ii) to retrospectively investigate factors associated with early, acute rejections and (iii) to investigate the pharmacokinetic interaction between tacrolimus and diltiazem. A prospective, randomized, multicenter, open-label study was conducted in 124 de novo kidney transplant recipients. Efficacy and safety outcomes were assessed for 180 d after transplantation and subjects were followed-up for a mean duration of 5.1 yr. The efficacy and safety outcomes were comparable whether the dose of MMF was minimized early or late. The incidence of early, acute rejection episodes was higher for recipients who were younger, received a graft from an unrelated donor or failed to achieve adequate tacrolimus concentrations (trough > 10 ng/mL) in the first seven d after transplant. Concomitant use of diltiazem had a tacrolimus-sparing effect in some subjects. Based on these results, we support the achievement of a high target tacrolimus concentration within the first week after renal transplant and suggest that early minimization of MMF can be achieved when used in combination with tacrolimus.