de Boer A W, Schröder C H, Reddingius R E, Willems H L, Monnens L A
Department of Paediatrics, University Hospital Nijmegen, The Netherlands.
Nephrol Dial Transplant. 1998 Sep;13(9):2348-50. doi: 10.1093/ndt/13.9.2348.
The passage of proteins across the glomerular filtration barrier is mainly determined by the size of the protein. In nephrotic syndrome (NS) the glomerular permselectivity is affected, causing proteinuria. Some authors suggest the existence of a generalized basement membrane defect. The permeability characteristics of the peritoneal basement membrane in children with NS are not known.
The transperitoneal transport of proteins with a different molecular weight (beta2-microglobulin MW 11800 D, albumin MW 69000 D, IgG MW 160000 D, and alpha2-macroglobulin MW 820000 D) was studied in a study group (group A) consisting of six stable nephrotic children (three with glomerulosclerosis and three with congenital nephrotic syndrome, one of them with mesangial sclerosis) and compared to a control group (group B) consisting of eight stable children on peritoneal dialysis. After a dwell of 6 h with Dianeal 1.36% dialysate and serum samples were collected. For each patient the dialysate to plasma (D/P) ratios of the four proteins were calculated. The D/P ratios of the nephrotic patients in group A were compared to the D/P ratios of the patients in the control group B. Data were expressed as mean +/- SD.
The values for the D/P ratios (in percentage) of beta2-microglobulin, albumin, IgG and alpha2-macroglobulin in group A were 19.6+/-9.9, 2.7+/-1.7, 1.6+/-0.9, and 0.5+/-0.4, compared to 24.9+/-10.2, 4.0+/-2.3, 2.2 +/- 1.2, and 0.7 +/- 0.3 in the control group B. The ratios were plotted against MW on a double logarithmic scale. In all patients a linear relationship between molecular weight and D/P ratio of the proteins was obtained. The D/P ratios of the study group did not differ significantly from the control group.
We conclude that the size selectivity of the capillary permeability is not affected in the peritoneal membrane in children with NS due to glomerulosclerosis and congenital nephrotic syndrome.
蛋白质通过肾小球滤过屏障主要取决于蛋白质的大小。在肾病综合征（NS）中，肾小球的选择通透性受到影响，导致蛋白尿。一些作者认为存在全身性基底膜缺陷。NS患儿腹膜基底膜的通透性特征尚不清楚。
在一个研究组（A组）中研究了不同分子量蛋白质（β2-微球蛋白分子量11800D、白蛋白分子量69000D、IgG分子量160000D和α2-巨球蛋白分子量820000D）的经腹膜转运，该研究组由6名稳定的肾病患儿组成（3名患有肾小球硬化症，3名患有先天性肾病综合征，其中1名患有系膜硬化症），并与一个对照组（B组）进行比较，对照组由8名进行腹膜透析的稳定患儿组成。用1.36%的腹透液留置6小时后收集透析液和血清样本。计算每位患者四种蛋白质的透析液与血浆（D/P）比值。将A组肾病患者的D/P比值与B组对照组患者的D/P比值进行比较。数据以平均值±标准差表示。
A组中β2-微球蛋白、白蛋白、IgG和α2-巨球蛋白的D/P比值（以百分比表示）分别为19.6±9.9、2.7±1.7、1.6±0.9和0.5±0.4，而B组对照组分别为24.9±10.2、4.0±2.3、2.2±1.2和0.7±0.3。将这些比值在双对数尺度上与分子量作图。在所有患者中，蛋白质的分子量与D/P比值之间呈线性关系。研究组的D/P比值与对照组无显著差异。
我们得出结论，由于肾小球硬化症和先天性肾病综合征，NS患儿腹膜的毛细血管通透性的大小选择性未受影响。
