Sasaki Takaya, Tsuboi Nobuo, Kanzaki Go, Haruhara Kotaro, Okabayashi Yusuke, Koike Kentaro, Kobayashi Akimitsu, Yamamoto Izumi, Ogura Makoto, Hoy Wendy E, Bertram John F, Shimizu Akira, Yokoo Takashi
Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan.
Centre for Chronic Disease, The University of Queensland, Brisbane, Australia.
Clin Exp Nephrol. 2019 May;23(5):629-637. doi: 10.1007/s10157-018-01686-2. Epub 2019 Jan 12.
Increasing evidence suggests that individuals with low nephron number have an increased lifetime risk of renal insufficiency, thereby emphasizing the importance of evaluating total nephron number in each individual. In recent years, new methods have been described for estimating human total nephron number using a combination of image analysis and renal biopsy, though the reproducibility and accuracy of these methods remain uncertain. This study estimated total nephron number in healthy Japanese subjects using such a method.
Implantation biopsies from 44 living kidney donors were analyzed. Using pre-donation contrast CT angiograms, transplantation donor kidneys were three-dimensionally reconstructed, and total renal cortical volume was estimated. Total nephron number was estimated based on glomerular density in biopsy specimens and total renal cortical volume. The obtained results were analyzed in relation to clinical variables and compared with those of a previously reported Japanese autopsy study.
The estimated non-sclerotic and total numbers of glomeruli in this cohort were 650,000 ± 220,000 and 710,000 ± 220,000 (mean ± SD) per kidney. Non-sclerotic glomerular number ranged from 280,000 to 1,220,000 per kidney (4.4-fold) and correlated directly with eGFR (r = 0.328, p = 0.030) and inversely with age (r = - 0.355, p = 0.018).
The estimated total nephron number obtained in the present study was 25% less than that reported in American living kidney donors obtained using the same procedure and similar to that obtained in a previous Japanese autopsy study using the disector/fractionator method. These results confirm the feasibility of a combined CT angiography and biopsy-based method to estimate total nephron number in humans.
越来越多的证据表明，肾单位数量低的个体肾功能不全的终生风险增加，从而强调了评估每个个体总肾单位数量的重要性。近年来，已经描述了使用图像分析和肾活检相结合的方法来估计人类总肾单位数量，尽管这些方法的可重复性和准确性仍不确定。本研究使用这种方法估计了健康日本受试者的总肾单位数量。
分析了44名活体肾供体的植入活检。利用捐赠前的对比CT血管造影，对移植供体肾脏进行三维重建，并估计总肾皮质体积。根据活检标本中的肾小球密度和总肾皮质体积估计总肾单位数量。将获得的结果与临床变量相关联进行分析，并与先前报道的日本尸检研究结果进行比较。
该队列中估计的非硬化性肾小球总数和每个肾脏的总肾小球数分别为650,000±220,000和710,000±220,000（平均值±标准差）。每个肾脏的非硬化性肾小球数量范围为280,000至1,220,000（4.4倍），与估算肾小球滤过率（eGFR）直接相关（r = 0.328，p = 0.030），与年龄呈负相关（r = -0.355，p = 0.018）。
本研究中获得的估计总肾单位数量比使用相同程序在美国活体肾供体中报告的数量少25%，与先前使用分割器/分馏器方法的日本尸检研究中获得的数量相似。这些结果证实了联合CT血管造影和基于活检的方法来估计人类总肾单位数量的可行性。
