To investigate the risk factors of kidney re-transplantation recipients and graft survival during the long-term follow-up.

The clinical data of kidney transplant donors and recipients performed at the Kidney Disease Center of the First Affiliated Hospital of Zhejiang University from January 1, 1991 to December 31, 2017 were retrospectively analyzed. A total of 5 374 cases of first kidney transplantation and 37 cases of re-transplantation were included. In addition, the recipients of re-transplantation were divided into long-term survival group (19 cases, >5 years) and short-term survival group (18 cases, ≤5 years). The age of donor and recipient, the interval between first and second kidney transplantation, HLA mismatch and cold/warm ischemia time of donor and recipient in long-term and short-term survival groups were compared by group t test. Chi-square test was used to compare the gender of recipients, type of donor kidney, rate of positive panel reactive antibodies before and after re-transplantation, initial graft nephrectomy, immune induction before re-transplantation, delayed graft function (DGF) and acute rejection in two groups. The 1, 5 and 10-year patient/graft survival rates were calculated by Kaplan-Meier method. The Cox proportional hazard model was used to analyze the possible risk factors on long-term survival of transplanted kidney. P<0.05 was statistically significant.

As of March 1, 2018, the median follow-up time of re-transplantation group was 152 months (11-323 months), 2 recipients died, 18 reipients suffered from renal allograft dysfunction and 17 patients had stable renal transplant function. The median follow-up time of the first transplantation group was 108.9 months (0.1-350.0 months). 459 cases died and 1 343 cases suffered from renal transplant failure. The 1, 5 and 10-year recipient/graft survival rates in the re-transplantation group were 86%/81%, 86%/62% and 82%/36%, and the 1, 5 and 10-year recipient/graft survival rates in the first transplantation group were 99%/98%, 93%/89% and 88%/80%. The 1, 5 and 10-year recipients survival rates of re-transplantation group were lower than those in the first transplantation group (χ²= 60.816, 25.110 and 43.900, P<0.05), and the 1-year recipients survival rate in the re-transplantation group was lower than the first transplantation group (χ²= 40.409, P<0.05). Univariate analysis showed that there were significant differences in DGF and acute rejection rates between long-term and short-term survival groups (χ²=4.039 and 4.748, P<0.05). Cox regression analysis showed that DGF and acute rejection were independent risk factors for long-term survival of transplanted kidneys in re-transplanted recipients (RR=4.317 and 4.571, P<0.05).

The survival rate of re-transplant recipients is lower than that of the first renal transplant recipients. DGF and acute rejection are independent risk factors affecting the survival of re-transplant recipients.