Proteinuria Affecting Kidney Allograft and Recipient Survival: Single Centre Experience.

Abstract

Proteinuria frequently affects renal transplant recipients. It is linked to cardiovascular events, a premature death and graft loss. Herein we assessed the association between proteinuria and graft and recipient survival. The cohort included 285 kidney allograft recipients who had proteinuria (measured) at 1-year posttransplant. Post-transplant proteinuria at 1 year was detected in 79 (27.7 %) patients. Moderate proteinuria (< 1 g/l) was found in 65 (22.8 %) and overt proteinuria ( ≥ 1 g/l) in 14 (4.9 %) cases. Proteinuria, both moderate and overt, was more common in patients with delayed graft function (DGF). The prevalence of DGF was 26.7 %, 51.6 % and 42.9 %, p = 0.001) in the groups with no proteinuria, moderate proteinuria and overt proteinuria respectively. Overt proteinuria was found more frequently in patients, who had peritoneal dialysis before transplantation (1.0%, 3.1 %, and 14.3 %, p = 0.003) and in patients on sirolimus based immunosuppression (6.4 %, 16.9 % and 23.1 %, p = 0.01). Recipients with overt proteinuria had significantly higher systolic blood pressure (137.50 ± 18.239 mmHg, 142.34 ± 22.572 mmHg and 153.64 ± 26.181 mmHg, p = 0.042) and serum creatinine concentration (118.53 ± 41.004 μmol/l, 148.40 ± 52.924 μmol/l and 192.43 ± 111.923 μmol/l, p < 0.001). The multivariate analysis of graft survival showed, that both as a continuous and as a categorical variable, proteinuria was associated with reduced graft survival had an independent influence on the graft failure rate censored for death (HR 17.6 (95 % CI 3.167 - 97.969, p = 0.001 for overt proteinuria and HR 3.86 (95 % CI 1.144 - 13.027, p = 0.030 for moderate proteinuria). Multivariate analysis of recipient survival also showed that proteinuria was a significant and independent predictor of recipient death (HR 2.848; 95 % CI 1.803 - 4.497; p < 0.001 for continuous measurement and HR 13.75; 95 % CI 2.587 - 73.121; p = 0.002 for overt proteinuria group compared to no proteinuria group). Thus, residual proteinuria is a significant complication and an independent risk factor for graft and recipient survival.