Histopathologic Correlates and Treatment Outcomes in Elderly Patients with Glomerulonephritis: A Competing Risk Analysis

Background: With the growing elderly population, kidney biopsy plays an increasingly important role in guiding treatment decisions in glomerular diseases. This study evaluated the association between treatment decisions, histopathologic findings, and clinical outcomes in older adults with glomerulonephritis (GN). Methods: We retrospectively analyzed elderly patients (≥60 years) diagnosed with GN to assess the relationship between histopathologic findings, treatment decisions, and renal outcomes. Histopathologic lesions were grouped into four major categories—glomerular injury, tubulointerstitial injury, vascular injury, and inflammation. Each category included multiple subcomponents, which were scored based on presence or severity. Primary outcomes included a 50% decline in estimated glomerular filtration rate (eGFR) and initiation of kidney replacement therapy (KRT), analyzed using Fine-Gray competing risks regression with mortality as a competing event. Results: A total of 310 patients were followed up for a median of 20 months. Membranous nephropathy and IgA nephropathy (28.7%) were the most common diagnoses. In the competing risk analysis for 50% eGFR decline, there was no significant difference in the cumulative incidence between non-treatment and treatment groups (Gray’s test, p=0.828), while mortality was significantly higher in the treatment group (p=0.045). For KRT, no significant group difference was observed (p=0.277), although mortality showed a trend toward being higher with treatment (p=0.077). In multivariable Fine-Gray regression, age and tubular atrophy were significant predictors for 50% eGFR decline. For KRT, significant predictors included use of angiotensin-converting enzymes or angiotensin receptor blockers, baseline serum creatinine, and global glomerular sclerosis. Conclusion: In elderly patients with GN, immunosuppressive treatment did not improve renal outcomes. Careful selection of candidates for IST is essential, considering both histopathologic risk factors and competing risks such as death.