含抗内耳抗原特异性抗体的体液转移免疫致豚鼠先天性感音神经性聋的实验研究

Research of congenital sensorineural hearing loss induced by humoral transfer immunity of the antibodies against inner ear antigens in guinea pigs

目的:证实针对内耳组织抗原特异性抗体通过胎盘可造成子鼠先天性自身免疫性感音神经性聋。方法:同种粗制内耳抗原(CIEAgs)免疫豚鼠,造成自身免疫性感音神经性聋(ASNHL)动物模型。ELISA法测定示其血清抗体水平升高,耳蜗电图(ECochG)示其听神经复合动作电位和(或)耳蜗微音器电位阈值或伪阈升高。取其血清(含特异性抗内耳组织抗原抗体)持续转移免疫妊娠豚鼠,采用ECochG测试被动免疫妊娠母鼠和子鼠的听觉功能,再采用颞骨火棉胶切片和苏木精-伊红染色,光镜观察内耳组织形态学改变。结果:各组出现听觉损伤的动物是:采用ASNHL模型动物血清被动免疫的8只妊娠母鼠中有5只(7耳)和其所产子鼠8只中有6只(10耳),采用非ASNHL模型动物血清免疫的妊娠豚鼠所产子鼠5只中有1只(2耳)。出现听力损失的被动免疫母鼠和子鼠内耳病理形态学改变主要为螺旋神经节细胞变性和Rosenthal管中炎性细胞(以单个核细胞为主)浸润,部分动物出现膜迷路积水。结论:同种体液转移免疫可造成自身免疫性内耳病变,子鼠产生听觉功能障碍主要是由于母鼠所产生的特异性抗内耳组织抗原抗体经胎盘到达子鼠体内所致。

Objective：To demonstrate that the congenital sensorineural hearing loss of offspring guinea pigs is mainly caused by special antibodies against inner ear tissue antigens through placenta. Method：The crude conspecific inner ear antigens （CIEAgs） were prepared and used to immunize guinea pigs which generated in an animal model of autoimmune sensorineural hearing loss （ASNHL）. The contents of the antibodies against CIEAgs were measured by using ELISA technique and the hearing function was tested by electrocochleography （ECochG） measurement. Then the serum of the ASNHL animal models were taken out and transferred to other normal gravid geuiea pigs in series as passive immunity. The ECochG （including acoustic nerve compound active potential, summation potential and cochlear microphonic potentital） were recorded and analyzed within the passive immunity pregnant female guinea pigs and all of the offspring guinea pigs. After hearing examination, animals were decapitated and temporal bone of which were isolated. Celloidin embedded and sections 25-30μm in thickness were stained with hematoxylin and eosin and observed with a light microscope. Result： Different level of hearing loss happened in 5 cases of 8 （7 ears） pregnant guinea pigs with transfer immunization using serum of ASNHL animal and 6 cases of 8 （10 ears） offsprings of which. Except for that, hearing loss also occurred in 1 case of 5 （2 ears） offsprings produced by the control pregnant guinea pig with transfer immunization using serum of non-ASNHL animal （ the hearing function of which had no change following CIEAgs immunity in these guinea pigs） . The dominating histological manifestations included various degrees of spiral ganglion cells edema, perivascular mononuclear cell infiltrates in the spiral modiolar vein, and the floating substance in scala tympani. The endolymphatic hydrops appeared in 3 ear in the offspring produced by the female guinea pigs with ASNHL animal＇s serum transfer immunization. Conclusion：The conspecific humoral transfer immunity with ASNHL animal＇s serum could induce sensorineural hearing loss and inner ear pathologic morphologic changes in the passive immunized female animals. These disorders also could be shown in their offsprings. These hearing dysfunction and inner ear disorders could mainly be caused by the specific antibodies rooting in female guinea pigs through placenta.