肾小球滤过屏障超微结构改变与Alport综合征蛋白尿的关系

Relationship between ultrastructural lesions of glomerular filtration barrier and proteinuria in Alport syndrome

目的:探讨肾小球滤过屏障超微结构改变与Alport综合征(AS)蛋白尿发生的关系。方法:AS患者35例,男24例,女11例,肾活检的年龄为1.17～24岁。根据尿蛋白结果将患者分为2组:无/间歇性蛋白尿组(13例)和持续性蛋白尿组(22例)。测量AS肾小球基底膜(GBM)变薄、增厚和致密层撕裂分层的长度,计算其各占GBM总长度的百分比;根据平均足突宽度(FPW)=π/4×(∑基底膜长度/∑足突个数)计算患者足突宽度。分析比较2组患者GBM变薄、增厚、致密层撕裂分层比例和平均FPW及其与AS蛋白尿的关系。结果:持续性蛋白尿组GBM增厚、致密层撕裂分层比例和平均FPW较无/间歇蛋白尿组高(均P<0.05)。平均FPW与GBM增厚、致密层撕裂分层及肾活检年龄均呈正相关(均P<0.01)。结论:AS患者GBM病变程度越重,足突融合越严重,蛋白尿越严重,提示AS基底膜异常有可能通过影响足突及裂孔膜的结构和功能导致蛋白尿发生。

AIM： To explore the relationship between the ultrastructural lesions of glomerular filtration barrier （GFB） and proteinuria in Alport syndrome （AS）. METHODS： Thirty-five AS patients （24 males and 11 females）, who were admitted to our hospital from 2008 to 2012, were enrolled in this study. The median age was 6 years （ 1.17 ~ 24 years） according to the time of renal biopsy. The data of clinical and electron microscopic examination were collected for retrospective analysis. The patients were divided into 2 groups according to the degree of urinary protein ： non-/interval pro- teinuria group （13 cases） and persistent proteinuria group （22 cases）. The length of glomerular basement membrane （GBM） attenuation, thickening, and dense layer splitting and layering was measured, and the percentages of these lesions were calculated. The foot process width （FPW） was measured according to the formula average FPW = 7r/4 x （ Y~ GBM length/~ foot process number）. The differences of the ultrastructural lesions in GFB between the 2 groups were compared, and the association between GFB ultrastructural lesions and proteinuria were analyzed. RESULTS： The percentages of GBM thickening, splitting and layering were higher, and the foot processes were wider in persistent proteinuria group than those in non-/interval proteinuria group. The median age at renal biopsy in persistent proteinuria group was older than that in non-/interval proteinuria group. The average FPW of the 35 patients was positively correlated with the percentage of GBM thickening, splitting and layering, and the age at biopsy, respectively. CONCLUSION： The severity of GBM le- sions is associated with the severity of foot process damage and the severity of proteinuria, suggesting that foot process dam- age associated with proteinuria in AS may be secondary to GBM lesions.