Multicenter, Prospective Study for Urinary Exosomal Biomarkers of Kidney Allograft Tubulointerstitial Fibrosis

Multicenter, Prospective Observational Study to Identify and Validate a Composite of Urinary Exosomal Biomarkers for Kidney Allograft Tubulointerstitial Fibrosis

The investigators aim to identify urinary exosomal biomarkers that represent the extent of graft fibrosis from deceased donor kidney transplantation. Urinary samples will be collected from deceased kidney donors at the time of procurement and zero-day kidney graft biopsy will be performed at the time of transplant. The association between urinary exosomes and the degree of graft fibrosis will be analyzed to identify biomarkers that represent fibrosis. The correlation between these biomarkers and graft long term outcomes will be investigated.

Interstitial fibrosis and tubular atrophy (IFTA), previously known as chronic allograft nephropathy (CAN), is diagnosed by pathologic changes involving all parts of the renal parenchyma and is one of the factors impacting graft survival and outcome. Currently, there is no standard to predict allograft fibrosis status at the time of procurement. Noninvasive biomarkers are necessary to monitor allograft status and to predict long-term outcomes.

The investigators aim to conduct a multicenter prospective study to identify urinary exosomal biomarkers that represent the extent of graft fibrosis from deceased donor kidney transplantation. Urinary samples will be collected from deceased kidney donors at the time of procurement and zero-day kidney graft biopsy will be performed at the time of transplant. The zero-day biopsy tissue will be stained with Masson's Trichrome staining, Collagen I, III, IV immunostaining to evaluate the degree of fibrosis. Also, by ultracentrifuge, we will extract urinary exosomes and perform proteomics analysis and RNA-sequencing. The association between urinary exosomes and the degree of graft fibrosis will be analyzed to identify biomarkers that represent fibrosis. The correlation between these biomarkers and graft long term outcomes will be investigated.

Inclusion Criteria:

• end-stage renal disease patients receiving kidney transplantation from deceased donors who have the ability to provide content for this study

Exclusion Criteria:

• multi-organ transplantation candidate or history of previous transplant, history of extra-renal solid organ or bone marrow or stem cell transplant, active infection, history of recent intoxication of alcohol or substance abuse within 24 weeks