Proteinuria treatment delays kidney failure and prolongs survival in patients with IgA nephropathy (IgAN), investigators reported at the 60th annual European Renal Association Congress in Milan, Italy.
Treatments that reduce proteinuria by 40% and 50% within 9 months significantly predict a 59% and 67% lower risk, respectively, of a composite of kidney failure or death compared with treatments that do not reduce proteinuria, Jonathan Barratt, MD, of the University of Leicester and Leicester General Hospital in Leicester, UK, and colleagues reported. According to a model, a 59% reduction in the risk for the composite outcome extended the median time to kidney failure or death from 8.6 years to 14.9 years. A 67% reduction in the risk for the composite outcome extended the median time to kidney failure or death from 8.6 years to 17.1 years.
The 5-year rate of freedom from kidney failure or death was 75% without proteinuria-reducing treatment compared with 89% and 91% for a treatment-related 59% and 67% reduced risk in the composite outcome, respectively.
“Therapeutic interventions that reduce proteinuria and the risk of [kidney failure] can confer important and clinically meaningful extensions in the time patients are alive and free from [kidney failure],” Dr Barratt’s team wrote.
The study involved 535 patients from the UK National Registry of Rare Kidney Disease (RaDaR) IgAN cohort. The baseline period was defined as the time point when patients had a urinary protein to creatinine ratio of 0.88 g/g or more at 6 months from diagnosis or later and had an estimated glomerular filtration rate (eGFR) of 30 mL/min/1.73 m2 or more. Kidney failure was defined as an eGFR less than 15 mL/min/1.73 m2, initiation of dialysis, or transplantation. The composite outcome also included doubling of serum creatinine and death.
Mercer A, Carroll K, Conley L, et al. Estimating delay in time to kidney failure or death for treatment effects on proteinuria in IgA nephropathy. Nephrol Dial Transplant. 38(1). Published online June 14, 2023. Abstract 4503. doi:10.1093/ndt/gfad063a_4503