IMPACT OF COLD AND WARM ISCHEMIC TIME ON THREE-MONTH ALLOGRAFT FUNCTION IN KIDNEY TRANSPLANT RECIPIENTS

Ischemic time is an important modifiable factor that affects allograft survival in kidney transplantation. Cold ischemic time (CIT) and warm ischemic time (WIT) have been reported to be independent risk factors for delayed graft function as well as worse long-term outcomes of the graft. However, their exact effect on early allograft function of recipients at three months after transplantation with regard to estimated glomerular filtration rate (eGFR), serum creatinine and proteinuria, is not well defined. We aimed to assess the relationship between ischemic time parameters and 3-month renal allograft function in kidney transplant recipients.

A retrospective cohort study was conducted among 36 kidney transplant recipients who were transplanted at tertiary refferal hospital in Yogyakarta Indonesia between January 2023 and June 2025. Retrospective data were obtained on donor and recipient characteristics, cold ischemic time (CIT), first warm ischemic time (WT1), and second warm ischemic time (WT2). Allograft function was monitored at 3 months by eGFR (as estimated from CKD-EPI equation), serum creatinine, and proteinuria. Categorical data were reported as frequencies and proportions, normally distributed continuous data as mean ± standard deviation, and non-normally distributed as median (range). Statistical analysis was conducted with SPSS, version 26 (IBM Corp., Armonk, NY, USA). Spearman’s correlation coefficient was used in order to assess the relationships between ischemic time parameters (CIT, WT1, and WT2) and 3-month graft function (eGFR, serum creatinine, proteinuria). A p-value <0.05 (two-tailed) was considered to be statistically significant.

The mean age was 39.39±12.80 years and 80.6% of the recipients were male in the study group that included 36 kidney transplant recipients. All recipients were on hemodialysis before transplantation. The donors were 72.2% men with a mean age of 39.50±10.93 years, and nonrelated donors accounted for 66.7%. Average cold ischemic time was 31.97±17.45 min, WT1 was 3.83±1.99 min, and WT2 was 44.61±19.52 minutes. The median eGFR, serum creatinine and negative proteinuria were 68.00 (range 22-129) mL/min/1.73m², 1.33 (range 0.77-2.86) mg/dL and 64.5% at three months post-transplantation, respectively. Correlation analysis demonstrated no correlation between cold ischemic time and 3-month eGFR (r=-0.043, p=0.805), serum creatinine (r=0.000, p=1.000) or proteinuria (r=-0.099, p=0.597). Similarly, no significant relationships were found between first warm ischemic time and three-month eGFR (r=-0.106, p=0.538), serum creatinine (r=0.024, p=0.896) or proteinuria (r=-0.230, p=0.213). Lastly, second warm ischemic time was not significantly correlated with 3-month eGFR (r=-0.054, p=0.756), serum creatinine (r=0.131, p=0.466), or proteinuria (r=0.006, p = 0.976).

In a cohort of kidney transplant recipients in tertiary referral center in Indonesia, there were no significant associations between cold ischemic time and warm ischemic time with three month allograft function such as eGFR, serum creatinine and proteinuria. The relatively short ischemic times obtained in this center (average CIT 31.97 minutes and average total ischemic time 84.64 minutes) could justify the lack of impact on early graft function. It is important to note that all kidney transplants at tertiary refferal hospital during this study period were from living donors, which typically have shorter ischemic times compared to deceased donor transplants. Future prospective studies with larger numbers of patients, longer durations of observation and the evaluation of recipients who have undergone prolonged ischemic times are needed to clarify the threshold at which this time period starts to negatively impact on kidney allograft function and survival.