Urine CXCL10 Monitoring Trial in Kidney Transplant

This is a Phase II-III multi-center prospective randomized controlled clinical trial of incident adult renal transplant patients. Patients will be screened for eligibility (n≈485) and n≈420 will be enrolled and undergo post-transplant surveillance with urinary CXCL10. Two hundred and fifty patients deemed at high risk for rejection based on a confirmed elevated urine CXCL10 will undergo 1:1 randomization to the intervention and control arms, stratified by center. The total study duration is approximately 5 years; and there two main phases - screening and intervention. All eligible, enrolled patients will undergo the Screening Phase (n≈420). Routine urine CXCL10 screening will be done from 2 weeks - 9 months post-transplant. We have previously shown that urine CXCL10 is elevated in ischemia-reperfusion injury, so screening will commence at 2 weeks (+/- 4 days) to exclude this as a potential confounding factor (60). If patient develops a confirmed elevated urine CXCL10 level and is considered high risk for rejection, they will proceed to Randomization in the Intervention Phase, which can occur anytime between 2 weeks - 9 months post-transplant. Participants in the Intervention Arm will undergo renal biopsy to check for rejection. Biopsy-proven subclinical rejection will be treated per study protocol. Participants in the Control Arm will continue routine post-transplant surveillance with serum creatinine and proteinuria; serial urine samples will continue to be collected and analyzed (blinded), but not used to direct care. All randomized participants will undergo a 12-month study exit visit with protocol biopsy to determine primary, secondary and long-term outcomes. Enrolled patients with persistently low urine CXCL10 and low risk of rejection from 2 weeks - 9 months post-transplant will be considered Off-Study (not randomized). They will undergo a 12-month study exit visit (+/- 7 days) to determine secondary and long-term outcomes.