A significant analysis from the Japan IgA Nephropathy Cohort Study reveals that the estimated glomerular filtration rate (eGFR) slope is a powerful predictor of kidney outcomes in patients with IgA nephropathy. This finding supports its use as a clinically meaningful surrogate endpoint.
The study tracked 937 adults with biopsy-confirmed IgA nephropathy for a median of six years. Researchers found that a steeper decline in eGFR slope was strongly associated with a higher risk of adverse kidney events, defined as a 40% decline in eGFR or the initiation of kidney replacement therapy. Each 1-standard deviation steeper eGFR slope decline increased the risk of these outcomes by 82%.
This association remained significant even after adjusting for baseline clinical and histopathological factors, indicating that eGFR slope provides prognostic information beyond static eGFR measurements. The results underscore the importance of monitoring eGFR trajectories in IgA nephropathy for better disease assessment and risk stratification.