Early Persistent Proteinuria After Kidney Transplant as a Predictor of Long-Term Graft Outcomes: A Retrospective Cohort Study.

Abstract

Objectives: The source and clinical significance of early proteinuria following kidney transplantation are complex, as proteinuria may be transient or may derive from native kidneys. This study evaluated the effects of early persistent proteinuria on long -term kidney allograft outcomes.

Materials and methods: We conducted a retrospective analysis of 312 kidney transplant recipients who received transplants between 2009 and 2020. Persistent proteinuria was defined as a spot urine protein -to -creatinine ratio ≥500 mg /g documented in at least 2 consecutive assessments within the first 24 months posttransplant. We compared graft survival according to proteinuria status.

Results: Among 312 study patients, proteinuria was detected in 46.3 % of patients at a single visit and 16.0 % met criteria for persistent proteinuria. Nineteen patients (6.1 % ) experienced graft loss. Single -visit proteinuria was associated with a 2 -fold increased risk of graft loss, whereas persistent proteinuria demonstrated a stronger independent association (hazard ratio 4.68; 95 % CI, 1.56 -14.07; P = .006 ). Proteinuria documented at least twice at the 6 -, 12 -, and 24 -month visits was related to an approximately 9 -fold higher probability of graft loss (hazard ratio 8.63; 95 % CI, 2.06-36.22; P = .003 ). Graft survival progressively declined with increasing levels of proteinuria.

Conclusions: Early persistent proteinuria is strongly and independently associated with adverse long -term graft outcomes. Frequent assessment of proteinuria can yield important prognostic insights and can help identify recipients who require enhanced monitoring and additional diagnostic evaluation.