Consequences of Nephrotic Proteinuria and Nephrotic Syndrome after Kidney Transplant

María José Ortega; Miguel Martínez-Belotto; Cristina García-Majado; Lara Belmar; Covadonga López Del Moral; Jose María Gómez-Ortega; Rosalía Valero; Juan Carlos Ruiz; Emilio Rodrigo

doi:10.3390/biomedicines12040767

Consequences of Nephrotic Proteinuria and Nephrotic Syndrome after Kidney Transplant

Biomedicines. 2024 Mar 30;12(4):767. doi: 10.3390/biomedicines12040767.

Authors

María José Ortega¹, Miguel Martínez-Belotto¹, Cristina García-Majado¹, Lara Belmar¹, Covadonga López Del Moral¹, Jose María Gómez-Ortega², Rosalía Valero¹, Juan Carlos Ruiz¹, Emilio Rodrigo¹

Affiliations

¹ Immunopathology Group, Nephrology Department, Marqués de Valdecilla University Hospital-IDIVAL, University of Cantabria, 39012 Santander, Spain.
² Pathological Anatomy Department, Marqués de Valdecilla University Hospital-IDIVAL, University of Cantabria, 39012 Santander, Spain.

Abstract

Proteinuria is the main predictor of kidney graft loss. However, there is little information regarding the consequences of nephrotic proteinuria (NP) and nephrotic syndrome (NS) after a kidney transplant. We aimed to describe the clinical and histopathological characteristics of kidney recipients with nephrotic-range proteinuria and compare the graft surveillance between those who developed NS and those who did not. A total of 204 patients (18.6% of kidney transplants in the study period) developed NP, and 68.1% of them had NS. Of the 110 patients who underwent a graft biopsy, 47.3% exhibited ABMR, 21.8% the recurrence of glomerulonephritis, 9.1% IFTA, and 7.3% de novo glomerulonephritis. After a median follow-up of 97.5 months, 64.1% experienced graft loss. The graft survival after the onset of NP declined from 75.8% at 12 months to 38% at 5 years, without significant differences between those with and those without NS. Patients who developed NS fewer than 3 months after the onset of NP exhibited a significantly higher risk of death-censored graft loss (HR: 1.711, 95% CI: 1.147-2.553) than those without NS or those with late NS. In conclusion, NP and NS are frequent conditions after a kidney transplant, and they imply extremely poor graft outcomes. The time from the onset of NP to the development of NS is related to graft survival.

Keywords: kidney transplantation; nephrotic proteinuria; nephrotic syndrome.

Grants and funding

This work was sponsored by the Spanish Ministry of Science and Innovation, the Carlos III Health Institute and The Networks for Cooperative Research Health Results (“RICORS2040” RD21/0005/0010).