Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia.
Nephrol Dial Transplant. 2012 May;27(5):1880-8. doi: 10.1093/ndt/gfr539. Epub 2011 Oct 9.
Measurement of individual glomerular volumes (IGV) has allowed the identification of drivers of glomerular hypertrophy in subjects without overt renal pathology. This study aims to highlight the relevance of IGV measurements with possible clinical implications and determine how many profiles must be measured in order to achieve stable size distribution estimates.
We re-analysed 2250 IGV estimates obtained using the disector/Cavalieri method in 41 African and 34 Caucasian Americans. Pooled IGV analysis of mean and variance was conducted. Monte-Carlo (Jackknife) simulations determined the effect of the number of sampled glomeruli on mean IGV. Lin's concordance coefficient (R(C)), coefficient of variation (CV) and coefficient of error (CE) measured reliability.
IGV mean and variance increased with overweight and hypertensive status. Superficial glomeruli were significantly smaller than juxtamedullary glomeruli in all subjects (P < 0.01), by race (P < 0.05) and in obese individuals (P < 0.01). Subjects with multiple chronic kidney disease (CKD) comorbidities showed significant increases in IGV mean and variability. Overall, mean IGV was particularly reliable with nine or more sampled glomeruli (R(C) > 0.95, <5% difference in CV and CE). These observations were not affected by a reduced sample size and did not disrupt the inverse linear correlation between mean IGV and estimated total glomerular number.
Multiple comorbidities for CKD are associated with increased IGV mean and variance within subjects, including overweight, obesity and hypertension. Zonal selection and the number of sampled glomeruli do not represent drawbacks for future longitudinal biopsy-based studies of glomerular size and distribution.
个体肾小球体积（IGV）的测量可以识别没有明显肾脏病理的受试者中肾小球肥大的驱动因素。本研究旨在强调 IGV 测量的相关性及其可能的临床意义，并确定需要测量多少个样本才能实现稳定的大小分布估计。
我们重新分析了使用分割器/卡瓦列里法在 41 名非裔美国人和 34 名白种美国人中获得的 2250 个 IGV 估计值。对均值和方差进行了 pooled IGV 分析。蒙特卡罗（Jackknife）模拟确定了采样肾小球数量对平均 IGV 的影响。Lin 的一致性系数（R(C)）、变异系数（CV）和误差系数（CE）衡量了可靠性。
IGV 均值和方差随着超重和高血压状态的增加而增加。在所有受试者中，浅层肾小球明显小于髓质肾小球（P < 0.01），按种族（P < 0.05）和肥胖者（P < 0.01）划分。患有多种慢性肾脏病（CKD）合并症的患者 IGV 均值和变异性显著增加。总体而言，平均 IGV 特别可靠，采样肾小球数量为 9 个或更多（R(C) > 0.95，CV 和 CE 的差异小于 5%）。这些观察结果不受样本量减少的影响，也不会破坏 IGV 均值与估计总肾小球数之间的线性反比关系。
CKD 的多种合并症与受试者中 IGV 均值和方差的增加相关，包括超重、肥胖和高血压。区域选择和采样肾小球的数量不会成为未来基于肾活检的肾小球大小和分布的纵向研究的障碍。
