Are we still making progress in patient survival after kidney transplantation? Results of a regional registry.

Many studies have shown a trend to improved long-term survival of renal transplant recipients. We analyzed the survival of recipients in Andalusia, Spain, from 1984-2007. The study included all the deceased donor, non-multiorgan grafts (n = 5599), grouped over successive 6-year periods, compared for corrected recipient survival. Changes were noted in the recipient characteristics: increased age, diabetes, vascular nephropathy, retransplantation, duration of prior replacement therapy, and reduction in positive hepatitis C virus (HCV+) serology. The univariate analysis showed a significantly worse survival associated with increased age (P < .001), diabetes (P < .001), HCV+ serology (P < .01; 1996-2007), and longer times on replacement therapy, but not with sex or retransplantation. The respective survivals at 1, 5, and 10 years in 1984-1989 were 93%, 86%, and 75%; in 1990-1995, 97%, 92%, and 84%; in 1996-2001, 96%, 91%, and 84%; and in 2002-2007, 96% and 92%, respectively. There was a significant improvement between the first and second periods (P < .001), but no change thereafter. The multivariate analysis (Cox) showed, a significant influence of age >40 years, female gender (relative risk [RR] 0.8; 95% confidence interval [CI] 0.7-0.9), diabetes (RR 2.5; 95% CI 1.8-3.4), and duration of prior replacement therapy (RR 1.08; 95% CI 1.05-1.1). The risk varied significantly depending on the period: using 2002-2007 as the reference period, the RR in 1984-1989 was 3.4 (95% CI 2.6-4.5); in 1990-1995, 1.8 (95% CI 1.3-2.3); and in 1996-2001, 1.4 (95% CI 1.1-1.8; all P < .02). The model remained for 1996-2007, though HCV+ serology was not significant. In conclusion, we showed a significant improvement in recipient survival in Andalusia over time. Correction for worse recipient characteristics suggests continued advances.

Regional survey of patient survival after cadaver renal transplant failure.

Graft failure with return to dialysis is associated with higher mortality, but the determining factors have not been completely studied. We determined predictive factors for survival after renal transplant failure by analyzing demographic and clinical data on kidney recipients in a Spanish regional registry (Andalusia). Among 5547 single-organ cadaveric grafts in Andalusia between 1984 and 2007, 1534 patients returned to dialysis and were followed to death (n = 450), retransplantation (n = 574), or the end of the study period. The most frequent cause of death was cardiovascular disease (36.9%). Actuarial survival rates were 89%, 72%, and 51% at 1, 5, and 10 years, respectively. Upon univariate (Kaplan-Meier) analysis, survival was significantly related only to age at return to dialysis and diabetes. Cox forward step wise multivariate regression analysis showed that predictive factors for lower survival (relative risk -95% confidence interval) were: age (per year), 1.05 (1.05-1.06); male sex, 1.33 (1.1-1.6); and duration of pre-graft renal replacement therapy (per year), 1.02 (1.00-1.05). According to Cox backward stepwise regression analysis, a more saturated model, the predictive factors were: age; male sex; duration of pre-graft renal replacement therapy (per year), 1.03 (1.01-1.06); later study period (1996-2007), 0.81 (0.6-1.0); and primary etiology of chronic kidney disease (CKD). Survival after renal transplant failure was lower among male recipients of advanced age or with a long period of prior renal replacement therapy. Time of transplantation and primary etiology of CKD may also play roles.

Increase in malignancies as cause of death in renal transplant patients.

The Andalusian Kidney Transplant Registry is a Public Health Service Regional Registry of Andalusia, Spain. We have analyzed the causes of death among 5599 kidney transplantations performed between January 1, 1984 and December 31, 2007. The total number of patients who died after renal transplantation was 1106. Of these, 656 patients died with functioning renal grafts, which constituted the group analyzed in this study. No significant differences in the causes of death were observed as a function of age, sex, retransplant status, cause of end-stage renal disease, diabetes, and duration of the previous renal replacement therapy. Infections were the most frequent cause of death in the first year posttransplantation (early deaths). A significant difference was observed when these early deaths were compared with those that occurred after the first year posttransplantation (late deaths); there were fewer deaths due to infections (40.4% vs 15.9%, early vs late) and more deaths from cancer (4.9% vs 23.7%). The causes of death in the period 1984-1995 were compared with those in 1996-2007, excluding the deaths that occurred more than 12 years posttransplantation (not possible in the 1996-2007 periods n = 583). The causes of early death did not change. A significant difference was observed among late deaths with an increase in infections (14% vs 17%) and cancers (20% vs 29.7%). Thus, malignancies became the most frequent cause of late death in the 1996-2007 period. In conclusion, in our region, a long-term change in renal transplant patient mortality is taking place, with a significant increase in deaths due to cancer.

Trends in kidney transplantation outcome: the Andalusian Kidney Transplant Registry, 1984-2007.

Herein we have presented the first report from the Andalusian Kidney Transplant Registry, a Public Health Service Regional Registry in Andalusia, Spain (general population, 8 million). The current analysis was limited to 5599 kidney-alone transplants from deceased donors, grouped into 4 time periods: 1984-1989 (n = 846); 1990-1995 (n = 1172); 1996-2001 (n = 1801); and 2002-2007 (n = 2060). The age of the transplant patients rose over time to 21.7% of recipients of ages >or=60 years in 2002-2007. In the later years we observed an increased incidence of vascular and diabetic causes of end-stage renal disease (ESRD). Patients who underwent retransplantation increased from 2.7% in 1984-1989 to 8.1% in 2002-2007. Time on previous renal replacement therapy (RRT) increased from 33.1 +/- 29 to 48 +/- 53 months. Patient survivals at 1, 5, 10, and 20 years were 96%, 91%, 83%, and 63%, respectively. Censoring for death, graft survivals were 90%, 80%, 67%, and 45%, respectively. Compared with the 1984-1989 period, patient survival improved by about 10% (P < .001) since 1990, remaining stable to 2007. Censored 5-year graft survivals progressively improved from 72% to 77%, 82%, and 85% (P < .001). Upon multivariate analysis, gender, age >39 years, diabetes, and RRT duration were independent predictors of patient survival. Age <18 years, retransplantation, and positive hepatitis C virus serology were independent predictors of lower graft survival. Considering 1984-1989 as the reference time period, both patient and graft mortality risks continuously decreased over the following 3 periods (relative risk [RR] = 0.5-0.4-0.3 for patient mortality; RR = 0.8-0.6-0.5 for graft mortality). In summary, despite an increased number of adverse risk factors, both patient and graft survivals have improved from 1984 to date.