IgA肾病中补体系统及肾小球肥大对足细胞的损伤

目的探讨IgA肾病中补体系统及肾小球体积改变对足细胞的损伤。方法采用免疫组化方法观察IgA肾病患者肾小球内WT1、C5b-9、CR1表达的改变,免疫荧光观察C3染色及laminin-C5b-9双染。采用肾小球体视学研究方法观察IgA肾病患者的系膜区/毛细血管襻点密度比、肾小球体积、肾小球毛细血管襻表面积。结果IgA肾病患者肾小球内WT1阳性细胞数明显减少。IgA肾病肾小球内存在C3的明显沉积,与WT1阳性细胞数呈明显负相关,CR1的表达减少并与WT1阳性细胞数呈正相关趋势。肾小球内明显伴有C5b-9的沉积,并证实确实攻击足细胞,C5b-9的沉积与WT1阳性细胞数和CR1均呈明显负相关。IgA肾病患者存在明显的系膜区扩张、小球体积肥大,系膜区的扩张和小球体积肥大呈明显正相关。结论IgA肾病中确实存在足细胞数目的减少。同时,补体系统及系膜区的扩张所导致的肾小球体积的增加可能参与了IgA肾病中足细胞的损伤。

Effect of complement system and glomerular hytropathy on podocyte injury in IgA nephropathy

Objective To investigate the effect of complement system and glomerular volume to podocyte injury in IgA nephropathy.Methods Protein levels of WT1,C5b-9,CR1 were investigated by semi-quantitative immunohistochemical assays.The WT1 positive cell number in glomerular(N(podocyte))was observed.Duplex staining for C3 and laminin-C5b-9 was performed.The ratio of mesangial area and glomerulas tuft(R(M/G)),volume of glomerulas(V(glom))and total surface area of capillaries in a glomerulas(S(cap))were evaluated respectively by stereologic techniques.Results The WT1 positive cell number in glomerular(N(podocyte))was markedly decreased in IgA nephropathy than that in controls.The deposit of C3 was observed in glomeruli,which was inversely correlated with the N(podocyte).The expression of CR1 was strikingly decreased in IgA nephropathy,which was positively correlated with N(podocyte).The expression of C5b-9 was detected in glomeruli,mainly deposited in mesangial area of glomeruli,partly at subepithel,which was comfirmed by the costainging of laminin and C5b-9.Expression of C5b-9 was negatively correlated with N(podocyte)and CR1.There was mesangial expansion,leading to glomerular hypertrophy in IgA nephropathy.N(podocyte)showed a significant negative correlation with R(M/G)and V(glom).Conclusions Loss of podocyte is observed in IgA nephropathy.The complement system and glomerular hypertrophy,caused by mesangial expansion are possibly participated in the process.