Yamada H, Hashimoto T, Nishikawa T
Department of Dermatology, Keio University School of Medicine, Tokyo, Japan.
J Invest Dermatol. 1989 Apr;92(4):585-7. doi: 10.1111/1523-1747.ep12709613.
There are four main subclasses of human IgG: IgG1, IgG2, IgG3, and IgG4, among which IgG1-IgG3 activate complement, but IgG4 does not. We studied the IgG subclasses of anti-intercellular (IC) antibodies in pemphigus patients and anti-basement membrane zone (BMZ) antibodies in bullous pemphigoid (BP) patients by immunofluorescent staining using mouse monoclonal antibodies against human IgG1-IgG4. At the same time, the capability of complement fixation of each serum was determined by means of complement immunofluorescence. In both pemphigus and BP autoantibodies, various distributions of IgG subclass were shown, but specific patterns were not observed. In BP, all of the complement fixing antibodies had at least one of IgG1-IgG3 subclasses, while noncomplement fixing antibodies only possessed IgG4. This result agreed well with the biologic characteristics of IgG subclasses in respect of complement fixing capability. On the contrary, in pemphigus, the circulating antibodies showed a distribution of IgG subclass which did not correlate with the biologic characteristics in terms of complement activation. This discrepancy may further dispute the roles of the complement system on the bulla formation in pemphigus.
人IgG有四个主要亚类：IgG1、IgG2、IgG3和IgG4，其中IgG1 - IgG3可激活补体，而IgG4不能。我们通过使用抗人IgG1 - IgG4的小鼠单克隆抗体进行免疫荧光染色，研究了天疱疮患者抗细胞间（IC）抗体和大疱性类天疱疮（BP）患者抗基底膜带（BMZ）抗体的IgG亚类。同时通过补体免疫荧光法测定各血清的补体固定能力。在天疱疮和BP自身抗体中，均显示出IgG亚类的各种分布，但未观察到特定模式。在BP中，所有补体结合抗体至少具有IgG1 - IgG3亚类之一，而非补体结合抗体仅含有IgG4。这一结果与IgG亚类在补体结合能力方面的生物学特性非常吻合。相反，在天疱疮中，循环抗体显示出的IgG亚类分布与补体激活方面的生物学特性不相关。这种差异可能会进一步引发关于补体系统在天疱疮水疱形成中作用的争议。
