Higashihara Eiji, Nutahara Kikuo, Okegawa Takatsugu, Shishido Toshihide, Tanbo Mitsuhiro, Kobayasi Kuninori, Nitadori Toshiaki
Department of ADPKD Research, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan,
Clin Exp Nephrol. 2014 Feb;18(1):157-65. doi: 10.1007/s10157-013-0834-4. Epub 2013 Jul 18.
The 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.
Between 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.
TKV 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.
TKV 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.
在常染色体显性遗传性多囊肾病（ADPKD）中，总肾体积（TKV）作为肾功能生物标志物的意义存在争议，目前已被重新评估。
2007年至2012年期间，对64例患者进行了平均39.7个月的随访观察。每年通过磁共振成像测量TKV，并使用肾脏病饮食改良方程和24小时尿肌酐清除率估算肾小球滤过率（eGFR）来评估肾功能。
TKV及其校正参数（身高校正、体表面积校正和对数转换后的TKV [log-TKV]）与eGFR显著相关。其中，log-TKV的相关系数最为显著（r = -0.6688，p < 0.001）。eGFR斜率与TKV斜率呈负相关（p < 0.05）。随着慢性肾脏病（CKD）分期进展，TKV增长更快且体积更大。随着年龄增长，eGFR显著下降（p < 0.001），但eGFR斜率保持不变。TKV与年龄之间无显著相关性，但log-TKV斜率随着年龄增长而变小。如果基线TKV较大，则eGFR斜率更陡（p < 0.05），这表明肾体积较大的患者eGFR下降更快。
TKV被确认为ADPKD中具有临床意义的替代标志物。log-TKV与eGFR的相关性最为显著。肾脏增大率较高和肾体积较大与肾功能下降更快相关。随着CKD分期进展，肾功能下降更快，但至少在30岁以后，其下降斜率随年龄变化不显著。
