Transplant Patients With Failing Renal Allografts

Urinary vitronectin identifies patients with high levels of fibrosis in kidney grafts

BACKGROUND

In kidney transplantation, fibrosis represents the final and irreversible consequence of the pathogenic mechanisms that lead to graft failure, and in the late stages it irremediably precedes the loss of renal function. The invasiveness of kidney biopsy prevents this condition from being frequently monitored, while clinical data are rather unspecific. The objective of this study was to find noninvasive biomarkers of kidney rejection.

METHODS

We carried out proteomic analysis of the urinary Extracellular Vesicles (uEVs) from a cohort of kidney transplant recipients (n = 23) classified according to their biopsy-based diagnosis and clinical parameters as interstitial fibrosis and tubular atrophy (IFTA), acute cellular rejection (ACR), calcineurin inhibitors toxicity (CNIT) and normal kidney function (NKF).

RESULTS

Shotgun mass spectrometry of uEV-proteins identified differential expression of several proteins among these different groups. Up to 23 of these proteins were re-evaluated using targeted proteomics in a new independent cohort of patients (n = 41) classified in the same diagnostic groups. Among other results, we found a differential expression of vitronectin (VTN) in patients displaying chronic interstitial and tubular lesions (ci and ct mean > 2 according to Banff criteria). These results were further confirmed by a pilot study using enzyme-linked immunosorbent assay (ELISA).

CONCLUSION

Urinary vitronectin levels are a potential stand-alone biomarker to monitor fibrotic changes in kidney transplant recipients in a non-invasive fashion.

Transplant Radical Nephrectomy and Transplant Radical Nephroureterectomy for Renal Cancer: Postoperative and Survival Outcomes

BACKGROUND The treatment of complex tumors in non-functioning renal transplants requiring surgical extirpation is challenging. Here, we report the largest series of patients who underwent transplant radical nephrectomy for renal cell carcinoma (RCC) and transplant radical nephroureterectomy for urothelial cell carcinoma (UCC) in their transplanted kidneys. MATERIAL AND METHODS From 2004 to 2018, 10 patients underwent transplant radical nephrectomy (7 patients) and nephroureterectomy (3 patients). Retrospective analyses, in terms of complications, oncological recurrence, and survival, of peri-operative and long-term outcomes, were performed. RESULTS Out of the 10 patients, 7 had RCC and 3 had UCC. No intraoperative mortality occurred. Three patients presented with Clavien-Dindo grade IIIa or greater within 30 days of surgery. Two patients died within 60 days of surgery, both due to vascular events: one due to myocardial infarction and one due to stroke. Two other patients died: one after 2.9 years, due to myocardial infarction, and the other after 6 years, due to unknown reasons. At the 7-year follow-up, there was a 60% overall survival rate. For all patients, average survival post-nephrectomy was approximately 4.5 years, including the 6 living patients and 4 deceased patients. Importantly, there was no observed cancer recurrence. CONCLUSIONS This study reports outcomes of the largest series of transplant radical nephrectomy and nephroureterectomy for malignancies of renal allografts. In the optimized setting, extirpative surgeries appear safe, with favorable long-term oncological and survival outcomes.