IgA肾病与肾小球微小病变患者合并基底膜变薄的体视学分析

Stereological analysis of thinning of glomerular basement membrane in patients with IgA nephropathy and glomerular minimal change disease

目的了解IgA肾病和肾小球微小病变(MCD)患者合并肾小球基底膜(GBM)变薄的比例。方法选择年龄为21～40岁,经临床、免疫荧光染色、光镜及透射电镜诊断确诊,并且无其它合并症或并发症的MCD患者(29例)和原发IgA肾病患者(33例)的肾穿刺标本,常规固定、包埋、半薄切片定位及超薄切片,在透射电镜下进行观察,根据等距离曲线移动原则对每个样本的一个肾小球拍照15张,覆盖体视学测试系统,从测试线与GBM足细胞侧相交的点作GBM的垂直线,到与内皮细胞相交处的距离为该点GBM截面宽度,计算每个病例GBM平均截面宽度及调和平均厚度。根据GBM变薄的界点值,对MCD和IgA肾病患者合并GBM变薄的情况进行分析。结果 MCD组和IgA肾病组中男性GBM平均截面宽度分别为443.17±78.75(309.82～679.61)nm和408.61±74.49(272.43～543.60)nm;调和平均厚度为341.93±62.48(234.47～445.50)nm和318.93±58.81(215.00～423.55)nm。女性GBM平均截面宽度分别为359.74±73.49(280.40～525.94)nm和371.08±60.15(280.89～451.19)nm;调和平均厚度为281.14±60.18(216.43～419.15)nm和293.17±49.12(214.72～366.93)nm。MCD组不同性别GBM平均截面宽度和GBM平均厚度的统计学检验均有差异。GBM节段性变薄在MCD组和IgA肾病组分别为13.8%和21.2%,弥漫性变薄比例为3.4%和12.1%,均无统计学意义。结论 MCD组与IgA肾病组合并GBM变薄比例的差别无统计学意义,按性别制定GBM变薄的标准是必要的。

Objective To assess the difference of thinning of glomerular between IgA nephropathy and minimal change disease （MCD）. Methods basement membrane （GBM） Renal biopsy specimens of pa- tients who were diagnosed as MCD （n = 29）or IgA nephropathy （n = 33 ） by clinical manifestations, immunofluorescenee, light microscopy and electron microscopy, aging from 21 to 40 years old and without any other complicated nephropathy, were selected. Ultrasections were observed by electron microscopy at magnification of 12 000. Fifteen photos were taken from one section of each sample according to the rule of equidistant zigzag movement. Test grids were set by Scandium system and the cross-sectional wideness of GBM was obtained. The value of thin GBM calculated from normal thickness of GBM was applied to e- valuate the status of thin GBM in MCD and IgA nephropathy. Results The mean arithmetic cross- sec- tional thickness of GBM was 443.17 ± 78.75 （309.82 - 679.61 ） nm and 408.61 ± 74. 49 （272.43 - 543.60） nm in the male group of MCD and IgA nephropathy respectively, and the corresponding value in the female group was 359.74 ± 73.49 （280. 40 - 525.94） nm and 371.08 ± 60. 15 （280. 89 - 451.19） nm, respectively. The mean harmonic thickness of GBM was 341.93 ± 62.48 （234. 47 - 445.50） nm and 318.93 ±58.81 （215.00 -423.55） nm in the male groups of MCD and IgA nephropathy, respec- tively, and the corresponding value of the female group was 281.14± 60. 18 （216.43 - 419. 15） nmand 293.17 ±49. 12 （214.72 - 366.93） nm, respectively. Both arithmetic and harmonic thickness of GBM in the male and female groups showed a statistical significance in the MCD group （P = 0. 006 and 0. 013, respectively）. The proportion of segmental attenuation of GBM in the MCD and IgA nephropathy groups was 13.8% and 21.2% , and diffuse attenuation was 3.4% in the MCD and 12. 1% in the IgA nephropathy groups, with a non - significant difference. Conclusions There is no significant difference between the proportion of GBM thinning in MCD and IgA nephropathy. It is necessary to define standards of thin GBM according to sex.