#1641 Assessing Long-Term Prognosis in Patients with Glomerular Disease: Nephrotic Syndrome Versus Nephrotic Range Proteinuria Comparison

Abstract Background and Aims Although there is considerable research on the role of proteinuria in the progression of chronic kidney disease, a direct comparison between biopsy-diagnosed glomerular disease (GD) patients presenting with nephrotic syndrome (NS) and those with nephrotic range proteinuria (NRP) is lacking. Our study aims to bridge this gap by comparing the long-term outcomes of patients with NS and NRP. Method We conducted a unicentric retrospective study on 240 kidney biopsy-proven GD patients (median age 50 years, 65% men, median eGFR 58 mL/min, median proteinuria 6.0 g/24 h), tracked from 2010-2015 until end-stage kidney disease (ESKD), death, or study end in January 2022. Results The median follow-up was 8.8 years. Diagnoses were predominantly nonproliferative (53%), proliferative (25%) nephropathies, diabetic nephropathy (12%), and paraprotein diseases (10%). NS was observed in 141 (59%) patients, presenting more frequently with arterial hypertension (61 vs 43%, p 0.001), higher eGFR (64.9 vs 51.5 mL/min, p 0.001), increased proteinuria (6.4 vs 5.4g/24 h, p 0.01), and dyslipidemia (serum cholesterol 316 vs 251 mg/dL, p 0.001; serum triglycerides 226 vs 184 mg/dL, p 0.001) than NRP patients. NRP patients more often had proliferative (30 vs 22%) GD and diabetic nephropathy (22 vs 5%) ; their renal chronicity score was higher (2 vs 0, p 0.001). ESKD endpoint occurred in 35% NS and 39% NRP patients (p 0.4). The cohort's mean kidney survival time was 8.2 years. In multivariate analysis, NS (HR 1.79, 95% CI: 1.09, 2.94), lower eGFR (HR 0.97, 95% CI: 0.96, 0.98), higher renal chronicity score (HR 1.12, 95% CI: 1.02, 1.23), and diabetic nephropathy (Ref, p 0.001) were associated with ESKD. 64 patients (27%) died, 73% post-kidney replacement therapy initiation, mostly from cardiovascular disease (63%). Mortality between proteinuria forms showed no difference. Multivariate analysis found lower eGFR (HR 0.98, 95% CI: 0.97, 0.99), higher Charlson comorbidity score (HR 1.38, 95% CI: 1.17, 1.64), and diabetic nephropathy (Ref, p 0.01) associated with mortality. Conclusion Our study found no difference in all-cause mortality between NS and NRP in glomerular diseases. However, adjusted analysis revealed poorer kidney survival for NS patients, emphasizing the need for personalized management to improve renal prognosis.