Factors associated with patient and graft survival using kidneys from cadaveric donors in transplanted patients over 18 years of age in Argentina.

BACKGROUND

With improvements in short-term kidney graft and patient survival, focus has shifted to understand patient and graft features that affect long-term survival.

MATERIALS AND METHODS

This retrospective analysis from January 1998 to December 2009 employed Kaplan-Meier analysis to evaluate survival ratios at 30 days as well as 1, 5, and 10 years. A multivariable Cox regression model considered variables of donor and recipient, gender and age, cold ischemia time (CIT), chronic renal failure etiology, time on dialysis (TD) and cause of donor death. The mismatch (MM) value was coded according to the number of antigens shared by both the donor and the recipient for HLA-A, B, and DR. The MM values ranged between 0 and 6. Two groups were analyzed according the number of shared antigens: 0 to 3 versus 4 to 6.

RESULTS

Among 3030 (55.85%) males and 2395 (44.15%) females, the overall mean age was 46.9 ± 13.9 years. Median follow-up was 4 years (max 13 years). Patient survival rate (SR) was 97.5% at 30 days, 87.5% at 1 year, 74.5% at 5 years, and 59.2% at 10 years. Using Cox analysis, patient SR was affected by: diabetic nephropathy (DN) hazard ratio (HR) 1.55 (95% confidence interval [CI 95%] 1.21-1.97) P = .0005; head trauma (HT) cause of donor death HR 0.83 (0.73-0.95) P = .0005 and donor age (DA) compared by 18 to 44 years: 45 to 59 years HR 1.44 (CI95% 1.00-1.30) P = .043, >60 years HR 1.41 (CI95% 1.17-1.70) P = .0004. In addition relevant factors were recipient age (RA) compared by 18 to 44 years: 45 to 59 HR 1.99 (CI95% 1.74-2.27) P < .0001, >60 years HR 3.24 (CI95% 2.79-3.75) P < .0001 and DT >7 years HR 1.33 (CI95% 1.19-1.48) P = .0001. MM HLA 0 to 3 level HR 0.78 (CI95% 0.69-0.88) P < .0001. Graft SR was 95% at 30 days, 81.6% at 1 year, 64.7% at 5 years, and 47.3% at 10 years. The relevant factors were: DN HR 1.26 (CI95% 1.01-1.57) P = .04; HT HR 0.82 (0.74-0.91) P = .0004; DA compared by 18 to 44 years: 45-59 years HR 1.19 (CI95% 1.07-1.32) P = .002, >60 years HR 1.53 (CI95% 1.30-1.80) P < .0001; RA compared by 18 to 44 years: 45-59 HR 1.33 (CI95% 1.19-1.47) P < .0001, >60 years HR 1.84 (CI95% 1.63-2.09) P < .0001; DT > 7 years HR 1.22 (CI95% 1.11-1.35) P = .0001; CIT >24 hours HR 1.13 (CI95% 1.03-1.23) P = .009 and MM HLA 0 to 3 HR 0.82 (CI95% 0.74-0.91) P = .0002.

CONCLUSION

HT as the cause of donor death and MM between 0 and 3 were associated with better patient and graft SR, DN, TD over 7 years, DA and RA over 45 were associated with lower patient SR. CIT > 24 hours, DN, TD over 7 years, as well as donor and recipient ages over 45 yr were associated with a lower graft SR.