Incidence and treatment outcome of borderline rejection in kidney transplant recipients
Johanna Melander, Matilda Olsson, Carl Raihle, Oleg Slivca, Alireza BiglarniaAbstract
Introduction
The clinical significance and optimal management of borderline rejection after kidney transplantation remain uncertain, with studies reporting varying incidence and conclusions regarding the benefit of treatment versus surveillance.
Methods
We reviewed 388 kidney transplant recipients from 2020–2025, including 290 transplant biopsies. 274 biopsies were performed with suspicion of rejection and 15 as part of a protocol. Biopsy timing, histopathological findings and subsequent rejection management were collected through chart review. Serum creatinine at time of biopsy, 1 week and 3 months after biopsy was used to evaluate effect on graft function following increased immunosuppressive treatment or no additional treatment. Fisher's exact test was used to compare groups, with statistical significance defined as P < 0.05.
Results
Overall incidence of borderline rejection was 20% during the study period. Out of 75 borderline rejections, 53 were treated with SoluMedrol pulses or additional Thymoglobuline and 22 were left untreated. 1 week after borderline rejection, a lower creatinine was observed in 45% of treated cases and in 36% of untreated cases (P = 0.6). 3 months after borderline rejection, a lower creatinine was observed in 42% of treated cases and in 41% of untreated cases (P = 1.0).
Discussion
These preliminary findings highlight the uncertainty regarding the clinical significance of borderline rejection and the need for treatment. While some patients demonstrated improved graft function following treatment, improvement was also observed in untreated cases. An in-depth analysis of this cohort is needed to better define the impact of borderline rejection on graft outcomes and to identify which patients may benefit from active treatment versus surveillance.