Kotani T, Kato E, Hirai K, Kuma K, Ohtaki S
Endocrinol Jpn. 1986 Aug;33(4):505-10. doi: 10.1507/endocrj1954.33.505.
A distribution of immunoglobulin G (IgG) subclass of anti-thyroid peroxidase (TPO) autoantibodies was studied to know whether anti-TPO autoantibodies are closely implicated in the pathogenesis of human autoimmune thyroid diseases. As a result of analyzing 14 patients' sera, 7 with Graves' disease and 7 with Hashimoto's thyroiditis, anti-TPO autoantibodies were found to consist of mainly IgG1 subclass. Percentages of both IgG1 and IgG2 subclasses in IgG class of autoantibodies corresponded to those in the normal serum composition, whereas IgG3 subclass was scarcely contained in anti-TPO autoantibodies and IgG4 subclass markedly increased. It was thought that anti-TPO autoantibodies had a capability to lyse thyroid follicular cells by the mechanism of antibody-dependent complement-mediated cytolysis, because IgG1 and IgG2 subclasses of antibodies can fix complement and TPO locates in apical membrane surface of thyroid follicular cells. Comparing Graves' disease with Hashimoto's thyroiditis, mean percentages of both IgG1 and IgG2 subclasses of 2 groups were statistically different. Namely, sera of patients with Graves' disease had higher and lower mean percentages of IgG1 and IgG2 subclasses of autoantibodies, respectively, than those with Hashimoto's thyroiditis, though no plausible explanation for these differences can be offered at the present time.
为了了解抗甲状腺过氧化物酶（TPO）自身抗体是否与人类自身免疫性甲状腺疾病的发病机制密切相关，研究了抗TPO自身抗体的免疫球蛋白G（IgG）亚类分布。通过分析14例患者的血清，其中7例患有格雷夫斯病，7例患有桥本甲状腺炎，发现抗TPO自身抗体主要由IgG1亚类组成。自身抗体IgG类中IgG1和IgG2亚类的百分比与正常血清组成中的百分比相对应，而抗TPO自身抗体中几乎不含IgG3亚类，IgG4亚类明显增加。由于抗体的IgG1和IgG2亚类可以固定补体，且TPO位于甲状腺滤泡细胞的顶膜表面，因此认为抗TPO自身抗体具有通过抗体依赖性补体介导的细胞溶解机制裂解甲状腺滤泡细胞的能力。比较格雷夫斯病和桥本甲状腺炎，两组IgG1和IgG2亚类的平均百分比在统计学上存在差异。也就是说，格雷夫斯病患者血清中自身抗体IgG1和IgG2亚类的平均百分比分别高于和低于桥本甲状腺炎患者，尽管目前对于这些差异尚无合理的解释。
