#2843 Urinary extracellular vesicles in after deceased donor kidney transplantation

Abstract

Abstract Background and Aims Urinary extracellular vesicles (uEV) are membrane-bound organelles which contain several molecules from their host tissue, including proteins, membrane receptors, nucleic acids, and lipids. Currently it is unknown whether uEV can be used as a liquid biopsy tool to determine injuries of the allograft after kidney transplantation. The objective of the present study was to compare uEV early posttransplant in kidney transplant recipients with allografts from deceased male and deceased female donors. Method We measured the principal cell specific aquaporine 2 (AQP2) abundance in uEV with an Enzyme-linked immunosorbent assay (ELISA) using novel generated specific antibodies, 19-64-1. The AQP2 abundance in uEV was detected in urine samples from incident deceased donor kidney transplant recipients during two periods posttransplant, i.e., the first period was from 6 to 11 hours and the second period was from 12 to 23 hours posttransplant, respectively. The AQP2 abundance in uEV was normalized to urinary creatinine, i.e., abundance/mmol creatinine. Results Complete data were obtained from 71 kidney transplant recipients with median age, 50 years (IQR, 42 to 57 years), median weight 73 kg (IQR, 64 to 86 kg), median systolic blood pressure, 144 mmHg (IQR, 130 to 160 mmHg), median diastolic blood pressure, 87 mmHg (IQR, 78 to 98 mmHg), median time on dialysis 25 months (IQR, 10 to 44 months). In 43 kidney transplant recipients with deceased male donors the AQP2 abundance in uEV significantly decreased from median 0.12 (IQR, 0.06 to 0.29) at the first postoperative period to median 0.05 (IQR, 0.03 to 0.12; P = 0.0004 by Wilcoxon matched-pairs signed rank test). On the other hand, in 31 kidney transplant recipients with deceased female donors the AQP2 abundance in uEV did no change from median 0.09 (IQR, 0.05 to 0.24) at the first postoperative period to median 0.05 (IQR, 0.03 to 0.13; P = 0.09 by Wilcoxon matched-pairs signed rank test). Conclusion The larger postoperative decline of the AQP2 abundance in uEV from deceased male donors compared to deceased female donors in early periods posttransplant may point to a larger principal cell mass in males.