伴有奥尔波特综合征女性患者的表皮基底膜α5(IV)表达与肾脏疾病严重程度

Epidermal basement membrane alpha 5(IV) expression in females with Alport syndrome and severity of renal disease.

作者信息

Massella Laura, Onetti Muda Andrea, Faraggiana Tullio, Bette Cristiano, Renieri Alessandra, Rizzoni Gianfranco

机构信息

Division of Nephrology and Dialysis, Bambino Gesù Children's Hospital and Research Institute, Rome, Italy.

出版信息

Kidney Int. 2003 Nov;64(5):1787-91. doi: 10.1046/j.1523-1755.2003.00251.x.

DOI:10.1046/j.1523-1755.2003.00251.x

PMID:14531812

Abstract

BACKGROUND

X-linked Alport syndrome is a progressive nephritis caused by mutations of the COL4A5 gene. This gene encodes the collagen alpha 5(IV) chain, which is abnormally distributed in the glomerular basement membrane (GBM) and epidermal basement membrane (EBM). It has been reported a negative correlation between alpha 5(IV) chain distribution in EBM and the degree of proteinuria in heterozygous females with Alport syndrome.

METHODS

In the present study, we evaluated the distribution of the alpha 5(IV) chain in the EBM and the degree of proteinuria in 22 females with X-linked Alport syndrome. The distribution of the cutaneous alpha 5(IV) chain was measured by a confocal laser microscope using an anti-alpha 5(IV) monoclonal antibody. The expression ratio of alpha 5(IV) distribution was quantified dividing the extension of the positive signal and the maximal extension of the specimen. Urinary protein excretion was expressed as urinary protein over urinary creatinine ratio.

RESULTS

Proteinuria was present in five of the 22 patients. In two patients with proteinuria, alpha 5(IV)chain was normally distributed; in the remaining three, the expression ratio of alpha 5(IV)chain was 35%, 47%, and 48%. Of the 17 patients without proteinuria, two displayed a complete absence of the alpha 5(IV) chain in EBM, five displayed a normal staining, and the remaining 10 had an expression ratio between 18% and 65%.

CONCLUSION

Our data suggest that there is no correlation between the severity of the glomerular involvement (expressed by proteinuria) and the staining of the alpha 5 chain in the EBM in females with X-linked Alport syndrome.

摘要

背景

X连锁遗传性Alport综合征是一种由COL4A5基因突变引起的进行性肾炎。该基因编码胶原蛋白α5（IV）链，其在肾小球基底膜（GBM）和表皮基底膜（EBM）中分布异常。据报道，在患有Alport综合征的杂合子女性中，EBM中α5（IV）链的分布与蛋白尿程度呈负相关。

方法

在本研究中，我们评估了22例X连锁遗传性Alport综合征女性患者EBM中α5（IV）链的分布及蛋白尿程度。使用抗α5（IV）单克隆抗体，通过共聚焦激光显微镜测量皮肤α5（IV）链的分布。α5（IV）分布的表达率通过将阳性信号的延伸长度除以标本的最大延伸长度来量化。尿蛋白排泄量以尿蛋白与尿肌酐比值表示。