Division of Nephrology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, 10400, Bangkok, Thailand.
Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
BMC Nephrol. 2021 May 15;22(1):178. doi: 10.1186/s12882-021-02392-0.
Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disorder that leads to end stage renal disease (ESRD). Cyst expansion in ADPKD is strongly associated with the decline in renal function. However, the correlation between total kidney volume (TKV) and glomerular filtration rate (GFR) at an early stage has not been well demonstrated. There is growing evidence that utilization of estimated GFR (eGFR) may induce misleading information in a population with near normal renal function. Therefore, a more accurate method is essential.
A prospective cohort of ADPKD patients was conducted with clinical data and laboratory collection. Measured GFR (mGFR) was assessed by iohexol plasma clearance method using ultra performance liquid chromatography. eGFR was calculated using the CKD-EPI equation. Kidney volumes were evaluated using MRI imaging protocol.
Thirty two patients completed the study. The mean age was 56 years old. The mean initial mGFR was 83.8 mL/min/1.73m. The mean change in mGFR per year was -2.99 mL/min/1.73m/year. The mean initial height-adjusted TKV (htTKV) was 681.0 mL/m. The mean percentage change in htTKV per year (%ΔhtTKV/y) was 4.77 %/year. mGFR had a better association with clinical parameters than eGFR. Initial mGFR was significantly and inversely correlated with initial htTKV and age. The percentage change in mGFR per year was significantly and inversely correlated with the %ΔhtTKV/y and 24-hr urine albumin. The %ΔhtTKV/y was significantly correlated with initial htTKV.
Our studies demonstrated that mGFR using iohexol is a more reliable and accurate method than eGFR for evaluating GFR changes in the early stages of ADPKD patients. There is a strong inverse correlation between kidney volume and mGFR in an Asian ADPKD population. The initial htTKV is a good predictor of kidney volume progression. The %ΔhtTKV/y is a good early surrogate marker for the decline in renal function. 24-hr urine albumin is also a good indicator for renal progression.
常染色体显性遗传性多囊肾病（ADPKD）是最常见的遗传性肾脏疾病，可导致终末期肾病（ESRD）。ADPKD 中的囊肿扩张与肾功能下降密切相关。然而，在早期阶段，总肾体积（TKV）与肾小球滤过率（GFR）之间的相关性尚未得到很好的证明。越来越多的证据表明，在肾功能接近正常的人群中，利用估算的肾小球滤过率（eGFR）可能会导致误导性信息。因此，需要一种更准确的方法。
对一组 ADPKD 患者进行前瞻性队列研究，收集临床和实验室数据。采用超高效液相色谱法测定 iohexol 血浆清除率来评估实测肾小球滤过率（mGFR）。使用 CKD-EPI 方程计算 eGFR。采用 MRI 成像方案评估肾脏体积。
32 例患者完成了研究。平均年龄为 56 岁。平均初始 mGFR 为 83.8 mL/min/1.73m。每年 mGFR 的平均变化为-2.99 mL/min/1.73m/year。平均初始身高校正 TKV（htTKV）为 681.0 mL/m。每年 htTKV 的平均百分比变化（%ΔhtTKV/y）为 4.77%/year。mGFR 与临床参数的相关性优于 eGFR。初始 mGFR 与初始 htTKV 和年龄呈显著负相关。每年 mGFR 的变化百分比与%ΔhtTKV/y 和 24 小时尿白蛋白呈显著负相关。%ΔhtTKV/y 与初始 htTKV 显著相关。
我们的研究表明，使用 iohexol 的 mGFR 是一种比 eGFR 更可靠和准确的方法，可用于评估 ADPKD 患者早期 GFR 变化。在亚洲 ADPKD 人群中，肾脏体积与 mGFR 呈强烈的负相关。初始 htTKV 是预测肾脏体积进展的良好指标。%ΔhtTKV/y 是肾功能下降的良好早期替代标志物。24 小时尿白蛋白也是肾脏进展的良好指标。
