Bogner U, Kotulla P, Peters H, Schleusener H
Department of Internal Medicine, Klinikum Steglitz, Berlin, FRG.
Acta Endocrinol (Copenh). 1990 Oct;123(4):431-7. doi: 10.1530/acta.0.1230431.
Cytotoxic activity in sera of patients with Hashimoto's thyroiditis was measured with an antibody-dependent cell-mediated cytotoxicity assay. Cytotoxicity was determined in a 51chromium release assay using human thyroid cell targets incubated with heat-inactivated serum or IgG from patients with Hashimoto's thyroiditis. Effector cells were obtained from peripheral mononuclear cells of normal subjects. Cytotoxicity was significantly increased in patients with Hashimoto's thyroiditis (median specific lysis 20.2%, range 2.1-58.8) compared with normals (median specific lysis 8.1%, range 0-19.5; p less than 0.00001). The amount of percent specific lysis did not correlate with the titres of microsomal antibodies determined by different methods: passive hemagglutination technique (r = 0.2), enzyme immunoassay with microsomal antigen (r = 0.16), and radioimmunoassay for thyroid peroxidase antibody (r = 0.02). The cytotoxic activity was located in the IgG fraction, both in microsomal antibody positive and negative sera. After pre-incubation of microsomal antibody/thyroid peroxidase antibody positive or negative sera with purified thyroid peroxidase followed by analysis in the antibody-dependent cell-mediated cytotoxicity assay, cytotoxicity decreased in only 2 cases but was unchanged in the remaining sera. Western blot experiments with solubilized thyroid membranes and immunoblotting with cytotoxic-positive/microsomal antibody negative sera showed no binding to thyroid peroxidase. Our data suggest that cytotoxicity in sera from patients with Hashimoto's thyroiditis is not mediated by antibodies against thyroid peroxidase, but by antibodies not yet identified.
采用抗体依赖细胞介导的细胞毒性试验检测桥本甲状腺炎患者血清中的细胞毒性活性。细胞毒性通过51铬释放试验来测定，该试验使用来自桥本甲状腺炎患者的热灭活血清或IgG与人类甲状腺细胞靶点共同孵育。效应细胞取自正常受试者的外周单核细胞。与正常人相比，桥本甲状腺炎患者的细胞毒性显著增加（中位特异性溶解率为20.2%，范围为2.1%-58.8%），而正常人的中位特异性溶解率为8.1%，范围为0%-19.5%；p<0.00001）。特异性溶解百分比与通过不同方法测定的微粒体抗体滴度无关：被动血凝技术（r=0.2）、微粒体抗原酶免疫测定（r=0.16）以及甲状腺过氧化物酶抗体放射免疫测定（r=0.02）。细胞毒性活性存在于IgG组分中，无论是微粒体抗体阳性还是阴性血清。在将微粒体抗体/甲状腺过氧化物酶抗体阳性或阴性血清与纯化的甲状腺过氧化物酶预孵育后，再通过抗体依赖细胞介导的细胞毒性试验进行分析，仅2例细胞毒性降低，其余血清中的细胞毒性未改变。用溶解的甲状腺膜进行蛋白质印迹实验以及用细胞毒性阳性/微粒体抗体阴性血清进行免疫印迹实验，结果显示未与甲状腺过氧化物酶结合。我们的数据表明，桥本甲状腺炎患者血清中的细胞毒性不是由抗甲状腺过氧化物酶抗体介导的，而是由尚未确定的抗体介导的。
