Supplementary Material for: Glomerular Density-Associated Changes in Clinicopathological Features of Minimal Change Nephrotic Syndrome in Adults

<i>Background:</i> Differences in nephron number and/or glomerular size between individuals, in relation to intrauterine growth retardation or low birth weight, have been suggested to affect the clinical course of minimal change nephrotic syndrome (MCNS) in children. However, no previous study has investigated the potential influences of these histological variables on the clinical course of adult patients with MCNS. <i>Methods:</i> The glomerular density (GD; the number of non-sclerotic glomeruli per renal cortical area) and the glomerular volume (GV) were evaluated using renal biopsy specimens from adult patients with a histological diagnosis of MCNS (n = 50). Relationships between these variables and clinicopathological features, including the initial response to corticosteroid therapy, were analyzed. <i>Results:</i> Both the GD (1.5–6.5/mm²) and the GV (1.2–4.4 × 10⁶ µm³) showed about 4-fold variations, and a close inverse correlation was observed between these two variables. Notably, the MCNS patients with a low GD showed a trend towards having similar clinicopathological characteristics as patients with a histological diagnosis of focal segmental glomerular sclerosis, as compared to the MCNS patients with a high GD. In addition, during the initial treatment with corticosteroids, the number of patients achieving complete remission was significantly lower in the MCNS patients with a low GD than that in the MCNS patients with a high GD. <i>Conclusion:</i> These results suggest that the GD in renal biopsies may be an important determinant of the glomerular size variability, and can therefore influence the clinical phenotype, such as the response to corticosteroid therapy, in adult patients with MCNS.

**背景：** 个体间肾单位数量及/或肾小球大小的差异与宫内生长受限或低出生体重相关，既往研究认为该差异可影响儿童微小病变型肾病综合征（minimal change nephrotic syndrome, MCNS）的临床病程。然而，目前尚无研究探讨此类组织学指标对成人MCNS患者临床病程的潜在影响。**方法：** 本研究纳入经组织学确诊为MCNS的成人患者共50例，采用其肾活检标本评估肾小球密度（glomerular density, GD，即每肾皮质面积内的未硬化肾小球数量）与肾小球体积（glomerular volume, GV），进而分析上述指标与临床病理特征（包括糖皮质激素治疗初始应答情况）之间的关联。**结果：** GD范围为1.5~6.5个/mm²，GV范围为1.2~4.4×10⁶ μm³，二者均存在约4倍的个体差异，且两者间呈显著负相关。值得注意的是，与GD较高的MCNS患者相比，GD较低的MCNS患者的临床病理特征呈现出与局灶节段性肾小球硬化（focal segmental glomerular sclerosis, FSGS）患者相似的趋势。此外，在糖皮质激素初始治疗期间，GD较低的MCNS患者中达到完全缓解的人数显著低于GD较高的MCNS患者。**结论：** 本研究结果表明，肾活检标本中的GD可作为肾小球大小异质性的重要决定因素，进而影响成人MCNS患者的临床表型（如糖皮质激素治疗应答情况）。