Abstract: TH-PO0509
Persistent Hematuria at Nine Months Predicts Subsequent Proteinuria at 18 Months and Both Urinary Abnormalities Relate to Poor Prognosis in IgAN
Session Information
- Glomerular Diseases: Clinical, Outcomes, and Therapeutics Research - IgAN
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Moriyama, Takahito, Tokyo Ika Daigaku, Shinjuku, Tokyo, Japan
- Saito, Suguru, Tokyo Ika Daigaku, Shinjuku, Tokyo, Japan
- Kanno, Yoshihiko, Tokyo Ika Daigaku, Shinjuku, Tokyo, Japan
Background
Hematuria is increasingly recognized as a marker of ongoing glomerular inflammation in IgA nephropathy (IgAN). While baseline hematuria was reported to associate to subsequent hypertension and proteinuria, the clinical significance of hematuria persistence after initial treatment remains unclear. We investigated whether the amount of hematuria at 9 months after diagnosis was associated with subsequent proteinuria and long-term renal outcomes in IgAN patients.
Methods
This retrospective cohort study included 170 IgAN patients diagnosed at our institution between January 2010 and April 2023. Patients were stratified according to urinary red blood cell counts (U-RBC) at 9 months using thresholds of 5, 20, and 50 per high power field (HPF). Associations between U-RBC at 9 months and proteinuria at 18 months were evaluated. Renal outcomes were assessed using Kaplan–Meier analysis, with the composite endpoint defined as 30% decline in estimated glomerular filtration rate (eGFR) or progression to end-stage kidney disease. Risk factors for composite endpoint were analyzed using univariate and multivariate Cox regression analyses.
Results
Thresholds of 5 or 50 U-RBC/HPF at 9 months were not associated with proteinuria, whereas 20/HPF was identified as the optimal threshold. Patients with U-RBC >20/HPF at 9 months had significantly higher proteinuria at 18 months compared with those with ≤20/HPF (mean 0.32 vs. 0.16 g/gCr, p=0.028), despite similar baseline U-RBC counts and proteinuria. Among patients with U-RBC >20/HPF, a proteinuria threshold of >1.0 g/gCr at 18 months was most strongly associated with poor renal prognosis. The 10-year renal survival rate was significantly lower in patients with both high U-RBC >20/HPF and proteinuria >1.0 g/gCr (62.2 vs. 84.2%, p=0.028). This combination was an independent risk factor for progression to composite endpoint in univariate [hazard ratio (HR) 3.73, p=0.044] and multivariate analysis adjusted for clinical and histological backgrounds and treatments (HR 29.3, p=0.012).
Conclusion
Persistent hematuria (>20/HPF) at 9 months after IgAN diagnosis is associated with subsequent severe proteinuria at 18 months, and both urinary abnormalities are related with adverse long-term renal outcomes. Hematuria reduction after initial treatment may represent an important therapeutic target in IgAN.