Very Low-Grade Proteinuria at 3 Months Posttransplantation Is an Earlier Marker of Graft Survival

Proteinuria is an early finding that appears in the first 3 months after transplantation in half of patients. Frequently, it is very low grade (VLP; <0.5 g/24 h). The aim of this study was to analyze the risk factors and prognostic significance of VLP at 3 months posttransplantation, which was maintained for the first year among our renal recipients. We compared 141 patients (39.7%) who showed VLP with 214 patients (60.3%) without proteinuria. VLP was associated with older recipients (P = .002), HLA incompatibilities (P = .001), older donors (P = .000), nontraumatic cause of brain death (P = .033) and previous hypertension (P = .030), tacrolimus (P = .000) and induction treatment with Thymoglobulin (P = .018) or anti-CD25 monoclonal antibodies (P = .000), as well as delayed graft function (DGF; P = .000). VLP patients showed worse renal function (P < .05) and greater requirement for antihypertensive drugs (P = .001). Multivariate analysis confirmed the impact of donor age, HLA incompatibilities, DGF, and tacrolimus treatment to predict the presence of VLP. Graft (P = .0019) and patient (P = .0146) survivals were lower among the VLP group. Cox analysis showed that VLP (RR: 2.047; P = .018) and DGF (RR: 2.062; P = .0017) were independently associated with reduced graft survival. The positive predictive value of VLP on graft survival was low. In conclusion, VLP was related to increasing acceptance of marginal donors, DGF, and worse renal function. Proteinuria was a noninvasive, readily determined parameter which was related to reduced graft and patient survivals, so renoprotective measures are mandatory from the early stages after transplantation.