Urinary Mitochondrial DNA Is Related to Allograft Function in Living Donor Kidney Transplantation, a Post-Hoc Analysis of the VAPOR-1 Study

Ischemia reperfusion injury (IRI) is the primary cause of early complications in kidney transplantation and contributes to impaired graft function. Mitochondrial DNA (mtDNA), which is implicated in IRI-induced organ damage, has shown promise as a biomarker for assessing and predicting organ function, though studies have focused primarily on deceased donor transplantation. This post-hoc analysis of the VAPOR-1 study aimed to explore the presence, dynamics, and prognostic value of urinary mtDNA in a cohort of 57 living donor kidney transplantation (LDKT) recipients. Surprisingly, higher mtDNA gene levels in the first urine after transplantation were associated with higher estimated glomerular filtration rate (eGFR) at 12 as well as with an increase in eGFR between month 1 and month 24 after transplantation. These findings suggest that, contrary to prior assumptions of mtDNA as a damage marker, early urinary mtDNA levels may reflect graft function rather than injury. This study underscores the potential of urinary mtDNA as a prognostic tool for renal allograft function and advocates for a re-evaluation of the way early posttransplantation renal damage markers are interpreted in LDKT.