#1644 Prognostic significance of hematuria on kidney survival in podocytopathies

Abstract

Abstract Background and Aims Hematuria is common in podocytopathies, but its prognostic impact on kidney survival in these proteinuric diseases is not well-established. Our study examines the prevalence of hematuria at podocytopathy diagnosis and its association with renal survival. Method In our retrospective study, we analyzed 236 patients (median age 50 years, 60% male, median eGFR 65.5 mL/min/1.73 m2, median proteinuria 3.9g/g) with biopsy proven podocytopathies—48% membranous nephropathy (MN), 32% minimal change disease (MCD), 20% focal and segmental glomerulosclerosis (FSGS)—diagnosed at a tertiary center from 2010 to 2015. Hematuria was defined as the presence of 5 or more red blood cells (RBCs) per high-power field in 3 of 3 consecutive centrifuged urine specimens obtained at least 1 week apart. The follow-up period extended until the onset of end-stage kidney disease (ESKD: start of kidney replacement therapy or renal transplantation), death, or January 2022, with a median duration of 8.5 (95% CI: 8.1, 8.8) years. Results In our patient cohort, 31% (n = 73) presented with hematuria, having a median of 120 (IQR: 40-220) red blood cells (RBCs). Those with hematuria more frequently exhibited arterial hypertension (55% vs 36%, p 0.007) and had higher levels of proteinuria (5.3 vs 3.2g/g, p 0.01). However, no significant differences were noted in terms of age (53 vs 48 years, p 0.08), Charlson comorbidity score (2 vs 2, p 0.9), type of podocytopathy (MN 52 vs 47%, MCD 27 vs 34%, FSGS 21 vs 19%, p 0.5), eGFR (62.1 vs 68.8 mL/min, p 0.08), serum albumin levels (3.3 vs 3.4g/dL, p 0.6), total renal chronicity score on histology (0 vs 0, p 0.6), and treatment with ACE inhibitors/angiotensin receptor blockers (43% vs 50%, p 0.4) or immunosuppression (81% vs 74%, p 0.4). Thirty-two percent of the patients with hematuria reached ESKD versus 9% in the group without hematuria (p 0.001); there were no differences regarding mortality between the two groups. Mean kidney survival time for the entire cohort was 10.3 (95% CI: 9.9, 10.8) years; renal survival at 1, 3, 5 and 10 years were 97%, 92%, 88% and 82%, respectively. Patients with hematuria at diagnosis had a significant shorter kidney survival time (9.0 (95% CI: 8.0, 10.0) vs 11.0 (95% CI: 10.6, 11.4) years, p 0.001). In a multivariate Cox proportional hazard model (backward Wald), presence of hematuria at diagnosis (HR 3.64, 95% CI: 1.87, 7.07), lower eGFR (HR 0.96, 95% CI: 0.94, 0.97) and higher total renal chronicity score on histology (HR 1.10, 95% CI: 1.00, 1.22) were independent predictors of reduced kidney survival. Conclusion Hematuria is prevalent in the three podocytopathies and independently correlates with poorer kidney survival outcomes. This underscores the possible need for personalized treatment strategies in patients with podocytopathies presenting with hematuria.