Urinary presepsin can efficiently detect T-cell-mediated rejection in patients who have undergone kidney transplantation

Urinary presepsin (uPSEP) is a marker of tubular interstitial injury. For patients who have undergone kidney transplantation, the early diagnosis of rejection is important to early treatment and preservation of the transplanted kidney function. We investigated whether uPSEP is useful for predicting T-cell-mediated rejection (TCMR). Patients who underwent graft biopsy in 2020 and 2023 after kidney transplantation at our hospital were included. We excluded protocol biopsy samples obtained at 1 h. We measured uPSEP and divided the patients into groups based on the presence or absence of TCMR; then, group comparisons were performed. A total of 39 patients (17 female and 22 male patients) with a median age of 57 years (interquartile range [IQR], 46.5-63 years) at the time of biopsy were included. Thirty-one patients underwent protocol biopsies and eight underwent episode biopsies. TCMR occurred in three patients. The uPSEP value of the TCMR group was 6788.63 ng/gCr (IQR, 5374.57-9931.87 ng/gCr), and that of the non-TCMR group was 777.61 ng/gCr (IQR, 321.57-1299.63 ng/gCr) (P < 0.01). The receiver-operating characteristic curve for predicting TCMR had a cutoff value of 3961 ng/gCr and an area under the curve of 0.982 (95% confidence interval [CI], 0.942-1). The odds ratio of TCMR based on uPSEP (per 1000-ng/gCr increase in uPSEP) was 1.90 (95% CI, 1.10-3.28; P = 0.02). uPSEP levels may predict TCMR with high accuracy.