Renal Blood Flow as Marker for Disease Progression in ADPKD

Disease progression in autosomal dominant polycystic kidney disease (ADPKD) is variable. Renal blood flow (RBF) and filtration fraction (FF), reflecting hemodynamic alterations and hyperfiltration, may improve risk stratification.

This prospective study included 238 adults with ADPKD from the Developing Intervention Strategies to Halt Progression of ADPKD observational cohort study and 1421 healthy controls. Multivariable regression analyses assessed associations of RBF and FF with disease severity and progression. Kaplan-Meier analysis and classification performance metrics were used to evaluate clinical use beyond established risk stratification tools.

Cross-sectionally, patients with ADPKD had significantly lower RBF compared with controls across all age groups, even in young patients with similar estimated glomerular filtration rate (eGFR) to controls. Within patients with ADPKD, lower RBF was associated with reduced kidney function and larger kidney volume. During follow-up of 5.6 ± 3.5 years, higher RBF (per SD) was associated with slower annual eGFR decline (standardized β = 0.34; 95% confidence interval [CI], 0.09-0.58; P = 0.01), lower odds of rapid disease progression (eGFR decline ≥ 3.0 ml/min per 1.73 m²/year) (odds ratio [OR] = 0.34; 95% CI, 0.17-0.70; P = 0.003) and lower composite-end point risk (kidney failure or ≥ 30% eGFR decline) (hazard ratio [HR] = 0.35; 95% CI, 0.20-0.60; P < 0.001). FF was significantly higher in patients aged 30-40 years, consistent with early hyperfiltration, but was not associated with disease progression. For the association with rapid progression, adding RBF to the Mayo Imaging Classification (MIC) increased the area under the curve (AUC) from 0.69 (95% CI, 0.60-0.76) to 0.79 (95% CI, 0.72-0.85).

Reduced RBF is an early hallmark of ADPKD, associated with disease severity and kidney function decline, and improves risk stratification beyond MIC.