Kidney volume and function in autosomal dominant polycystic kidney disease

Abstract

BackgroundThe significance of total kidney volume (TKV) as a biomarker of kidney function in autosomal dominant polycystic kidney disease (ADPKD) is controversial and has been reappraised.MethodsBetween 2007 and 2012, 64 patients were followed with a mean 39.7-month observation period. TKV measurements by magnetic resonance imaging and estimation of renal function with estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease equation and 24-h urine creatinine clearance were repeated annually.ResultsTKV and its adjusted parameters (height-adjusted, body surface area-adjusted and log-converted TKV [log-TKV]) correlated with eGFR significantly. Among them, the correlation coefficient of log-TKV was most significant (r = −0.6688, p < 0.001). The eGFR slope correlated negatively with TKV slope (p < 0.05). TKV increased faster and became larger as chronic kidney disease (CKD) stage advanced. As age advanced, eGFR declined significantly (p < 0.001), but the eGFR slope remained constant. There was no significant correlation between TKV and age, but the log-TKV slope became smaller as age advanced. If baseline TKV was large, the eGFR slope was steeper (p < 0.05), which suggests that eGFR declines faster in patients with larger kidney volume.ConclusionsTKV is confirmed as a clinically meaningful surrogate marker in ADPKD. Log-TKV correlates with eGFR most significantly. Higher rates of kidney enlargement and larger kidney volume are associated with a more rapid decrease in kidney function. Kidney function decreased faster as CKD stage advanced, but its declining slope did not change significantly by age, at least after ~30 years of age.

Kidney Volume Estimations with Ellipsoid Equations by Magnetic Resonance Imaging in Autosomal Dominant Polycystic Kidney Disease

“…Standard-KV measurements in ADPKD patients have been performed since 2007 with the same methods of MRI acquisition and volumetric measurement [3]. All patients fulfilled Pei's diagnostic criteria for ADPKD [10].…”

“…All coronal images were transferred to a 3D workstation [3]. Using the signal intensity threshold difference of the renal parenchyma and the background, the kidney border was delineated on each slice and a 3D kidney image was extracted with an automated algorithm [14].…”

“…Kidney function deteriorates and kidney volume (KV) increases progressively. KV has been recognized as a surrogate biomarker of kidney function [1,2,3]. Recent reports suggest that KV has a prognostic value to predict kidney function deterioration [4,5].…”

Autosomal Recessive Polycystic Kidney Disease: A Hepatorenal Fibrocystic Disorder With Pleiotropic Effects

“…Unlike in ADPKD, in which decline in renal function clearly correlates with increasing total kidney and cyst volume, 86,87 there is no clear relationship between kidney size and function in ARPKD. There was no correlation between kidney length and serum creatinine in one large cohort.…”

Two autosomal dominant polycystic kidney (ADPKD) cases with advanced renal dysfunction, effectively treated with tolvaptan

“…The disease changes the kidney structure and function through massive growth of numerous fluid-filled cysts and cell proliferation [1,5]. Higher rates of kidney enlargement and larger kidney volume in Japanese ADPKD patients are associated with a more rapid decrease in kidney function [6]. In the Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and Outcome (TEMPO) 3:4 trial, treatment with tolvaptan for 36 months slowed the increase in total kidney volume (TKV) (the primary endpoint) and the decline in kidney function, and reduced associated symptoms (the composite secondary endpoint) in patients with ADPKD [7].…”