获得性大疱性表皮松解症基底膜自身抗体靶抗原的定位研究

The localization of target antigen of basement membrane zone autoantibody in epidermolysis bullosa acquisita

目的 探讨获得性大疱性表皮松解症 (EBA)基底膜带自身抗体 (BMZ Ab)的靶抗原及其定位情况。方法 用免疫印迹 (IB)、盐裂皮肤间接免疫荧光 (IIF)、间接免疫电镜 (I IEM)等方法检测 6例EBA血清中IgG型及IgA型BMZ Ab识别的真表皮抗原以及抗原定位情况。结果 6例EBA血清中IgG型BMZ Ab均结合真皮提取物中 2 90ku蛋白 ,3例同时伴有结合 2 90ku蛋白的IgA型BMZ Ab。盐裂皮肤IIF显示BMZ真皮侧IgG线状沉积 ,IIEM示金颗粒沉积于BMZ致密下层 ,即真皮锚原纤维的Ⅶ型胶原处。结论 位于BMZ致密下层的Ⅶ型胶原是EBA中BMZ Ab的特异性靶抗原 ,Ⅶ型胶原上的抗原表位可被EBA血清中IgG及IgA型BMZ Ab识别。

Objective To investigate the target antigen and i ts localization of basement membrane zone autoantibody (BMZ-Ab) in epidermolysis bullosa acquisita (EBA) Methods Immunoblotting (IB), indirect imm unofluorescense (IIF) and indirect immunoelectron microscopy (IIEM) technique we re employed to detect the dermoepidermal antigen and its localization of IgG and IgA BMZ-Ab in EBA sera Results IgG BMZ-Ab in 6 EBA sera reacte d with 290ku dermal antigen, while 3 cases had IgA BMZ-Ab reacted with this ant igen IIF of salt-split skin showed linear IgG deposition along the dermal sid e of the skin IIEM study confirmed that gold particles were distributed within sub-lamina densa of BMZ, the region identical with type Ⅶ collagen in anchori ng fibrils Conclusion The type Ⅶ collagen within sub-lamina den sa of BMZ is the specific target antigen of BMZ-Ab in EBA sera, the epitope on which can be recognized by IgG and IgA BMZ-Ab in EBA sera