Department of Pediatrics, Jichi Medical University, 3311-1 Yakushiji Shimotsuke, Tochigi, 329-0498, Japan,
Clin Exp Nephrol. 2015 Feb;19(1):107-13. doi: 10.1007/s10157-014-0957-2. Epub 2014 Mar 15.
Various humoral factors have been proposed as causal agents of idiopathic steroid-sensitive nephrotic syndrome (ISSNS), resulting in varying data. We used mass spectrometry (MS) to analyze serum proteins in a search for proteins that might be involved in ISSNS pathophysiology.
Serial serum samples were obtained from 33 children with ISSNS. Samples were collected during Phase A1 [the acute phase prior to steroid treatment (STx)], Phase A2 (remission with STx), and Phase A3 (remission without any medication). We also included age- and sex-matched two control groups comprising children with normal urinalysis (Group B) and children with a nephrotic syndrome other than ISSNS (Group C). The urinary protein/urinary creatinine (UP/UCr) ratios were not statistically different between Phase A1 and Group C. Samples were analyzed using surface-enhanced laser desorption/ionization time of flight MS.
A total of 207 peptide ion peaks were detected in the range of m/z 2000-10000. Four peptide ions (m/z 6444, 6626, 8695, and 8915) were detected at significant elevation during Phase A1 compared with Phase A2, Phase A3, and Group C. The intensities of m/z 6444 and 8695 were higher in Phase A3 than in Group B. There were significant correlations between the intensities of m/z 6626, 8695, and 8915 and UP/UCr levels. The m/z 8695 was identified as apolipoprotein AII.
Apolipoprotein AII was detected as a protein associated with the UP/UCr levels in pediatric ISSNS. Our findings present an interesting starting point for further investigation into the pathophysiology of ISSNS.
各种体液因子被认为是特发性类固醇敏感型肾病综合征（ISSNS）的致病因素，导致数据各不相同。我们使用质谱（MS）分析血清蛋白，寻找可能参与 ISSNS 病理生理学的蛋白质。
收集 33 例 ISSNS 患儿的系列血清样本。在 A1 期（接受类固醇治疗（STx）前的急性期）、A2 期（STx 缓解期）和 A3 期（无任何药物缓解期）采集样本。我们还包括年龄和性别匹配的两个对照组，包括尿液分析正常的儿童（B 组）和非 ISSNS 的肾病综合征儿童（C 组）。A1 期和 C 组的尿蛋白/尿肌酐（UP/UCr）比值无统计学差异。使用表面增强激光解吸/电离飞行时间 MS 进行分析。
共检测到 m/z 2000-10000 范围内的 207 个肽离子峰。与 A2 期、A3 期和 C 组相比，A1 期有 4 个肽离子（m/z 6444、6626、8695 和 8915）明显升高。与 B 组相比，A3 期 m/z 6444 和 8695 的强度更高。m/z 6626、8695 和 8915 的强度与 UP/UCr 水平呈显著相关。m/z 8695 被鉴定为载脂蛋白 AII。
在儿科 ISSNS 中，载脂蛋白 AII 被检测为与 UP/UCr 水平相关的蛋白质。我们的发现为进一步研究 ISSNS 的病理生理学提供了一个有趣的起点。
