Purpose: Estimated Glomerular Filtration Rate (eGFR) is an intuitive indicator of kidney function. Accumulating clinical evidence supports that lower eGFR 1year after kidney transplantation (KT) is associated with early graft loss. This study aimed to investigate the risk factors for low eGFR at 1year after KT.
Methods: A retrospective study was performed in patients who underwent deceased donor KT at our hospital from 2009 to 2018. Only Koreans were included. Graft loss within 1 year after KT or failure to follow-up within 1 year, including death, were excluded from this study. Simultaneous transplantations of other organs were also excluded. According to the Modification of Diet in Renal Disease (MDRD) equation, if the eGFR was less than 45 at one month after KT, it was defined as the low eGFR. Logistic regression analysis was used to identified the risk factors for low eGFR.
Results: This study included 148 patients consisting of 112 with normal eGFR and 36 with low eGFR at 1 year after KT. There was no significant difference in the baseline characteristics of the recipient, and there were no significant risk factors for low eGFR. The age of donors was higher in the low eGFR group, and the proportion of female was higher in the low eGFR group. Donor age 50 years and older was a significant risk factor for low eGFR (OR 3.949, P = 0.012), and BMI above 25 of the donors was also a significant risk factor for low eGFR (OR 3.096, P = 0.028). There was no significant difference in the types of immunosuppressive agent in both groups, and there were no significant risk factors for low eGFR among immunosuppressive agents. The peak panel reactive antibody (PRA) of human leukocyte antigen (HLA) class II was low in the low eGFR group, and was a significant negative risk factor for low eGFR when PRA was above 10% (OR 0.234, P = 0.048). Acute rejection within 1 year after KT was significantly higher in the low eGFR group (20.5% vs 63.9%), which was a strong risk factor for low eGFR (OR 7.774, P < 0.001). CMV infection within 1 year after KT was significantly higher in the low eGFR group (18.8% vs 47.2%), however, it was not a significant risk factor for low eGFR (OR 2.543, P = 0.070).
Conclusions: Aged donors or higher BMI were donor factors predicting the low eGFR at 1 year after KT. High PRA and, not surprisingly, acute rejection were risk factors affecting low eGFR at the same period of time.