免疫组化检测Alport患者基底膜Ⅳ型胶原α链分布

为了观察Ⅳ型胶原各链在Ａｌｐｏｒｔ综合征（ＡＳ）患者基底膜上分布，初步探讨ＡＳ的发病机制，评估间接免疫荧光法检测Ⅳ型胶原对ＡＳ的诊断价值，采用针对Ⅳ型胶原α１、３、４、５链ＮＣ１片段的特异性单克隆抗体，利用间接免疫荧光技术对Ⅳ型胶原在８例Ａｌｐｏｒｔ患者的肾（６例）及皮肤（５例）基底膜上的分布进行了检测。结果显示：４例Ｘ伴性显性（ＸＤ）遗传男性Ａｌｐｏｒｔ患者肾小球基底膜上有α３、４、５（Ⅳ）链共同缺失，表皮基底膜上α５（Ⅳ）链间接免疫荧光亦为阴性，而３例常染色体显性及１例常染色体隐性遗传的Ａｌｐｏｒｔ患者间接免疫荧光均为阳性，与正常结果相同。提示ＡＳ存在Ⅳ型胶原生化组成异常，ＸＤ－ＡＳ的发病与Ⅳ型胶原α５链的生成异常有关；皮肤及肾组织Ⅳ型胶原α链间接免疫荧光检测对ＸＤ－ＡＳ具重要诊断意义。

Immunohistochemical study of type IV collagen chain distribution within basement membrane in patients with Alport syndrome]

To observe the distribution of type IV collagen chains within basement membrane in patients with Alport syndrome (AS), discuss the pathogenesis of AS and assess the diagnostic value of indirect immunofluorescent study of type IV collagen chains. By using indirect immunofluorescence technique, the distribution of different chains of type IV collagen in specimen of renal (6 specimens) and skin (5 specimens) basement membrane of 8 AS patients belonging to 7 kindreds were investigated. In 4 male patients with X-linked dominant (XD) AS, the specific monoclonal antibodies against NC1 domains of the alpha 3, alpha 4 and alpha 5 chains of type IV collagen failed to localize on glomerular basement membrane (GBM) and the alpha 5 chain of type IV collagen were also absent in the epidermal basement membrane (EBM). The results of immunofluorescent study were positive in 3 autosomal dominant and 1 autosomal recessive AS patients as same as that in control. AS presents a biochemical abnormality of type IV collagen. The pathogenesis of XD-AS may associate with the abnormal products of alpha 5 chain. The immunofluorescent study of type IV collagen chains distribution within GBM and EBM by using monoclonal antibodies is useful in confirming the diagnosis of AS, especially XD-AS.