Patton T, Plunkett R W, Beutner E H, Deng J S, Jukic D M
Department of Dermatology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
J Cutan Pathol. 2006 Apr;33(4):299-302. doi: 10.1111/j.0303-6987.2006.00458.x.
Pemphigoides gestationis (PG) is a blistering disorder of pregnancy caused by antibodies against basement membrane proteins. They are directed against the 180 kD bullous pemphigoid antigen (BPAg2), towards the epitopes within the NC 16A domain. There are many similarities between pemphigoid gestationis and bullous pemphigoid (BP), but the literature so far indicated different immunofluorescence results in regards with C3 and IgG, and IgG subclasses (IgG4 vs. IgG1).
We evaluated staining patterns and IgG subclasses, as well as C5b-9 membrane attack complex (MAC) in 10 pregnant patients with PG, using sandwich double antibody immunofluorescence (SDAI) and direct immunofluorescence (DIF).
All ten specimens stained with C3 by DIF, but only five had trace amount of IgG reactants by this method. By SDAI, 100% were positive for the IgG4 and C5b-9 MAC, 70% for IgG2, 50% for IgG1, and 40% for IgG3.
IgG4 was the predominant IgG subtype identified. This finding has not been reported for PG, but it mimics results reported for BP. One explanation is prolonged disease course, as well as blocking of antigenic domains by IgG4. Understanding this completely will help develop therapies and prevention strategies for immunobullous and other autoimmune diseases, and perhaps aid in an exact classification.
妊娠类天疱疮（PG）是一种由针对基底膜蛋白的抗体引起的妊娠水疱性疾病。这些抗体针对180kD大疱性类天疱疮抗原（BPAg2），作用于NC 16A结构域内的表位。妊娠类天疱疮和大疱性类天疱疮（BP）之间有许多相似之处，但迄今为止的文献表明，在C3和IgG以及IgG亚类（IgG4与IgG1）方面，两者的免疫荧光结果有所不同。
我们使用夹心双抗体免疫荧光法（SDAI）和直接免疫荧光法（DIF），评估了10例妊娠类天疱疮患者的染色模式、IgG亚类以及C5b-9膜攻击复合物（MAC）。
通过DIF，所有10个标本均被C3染色，但通过该方法只有5个标本有微量IgG反应物。通过SDAI，100%的标本IgG4和C5b-9 MAC呈阳性，70%的标本IgG2呈阳性，50%的标本IgG1呈阳性，40%的标本IgG3呈阳性。
IgG4是鉴定出的主要IgG亚型。这一发现尚未见妊娠类天疱疮的报道，但与大疱性类天疱疮报道的结果相似。一种解释是病程延长以及IgG4对抗原结构域的封闭作用。完全理解这一点将有助于开发免疫性水疱病和其他自身免疫性疾病的治疗及预防策略，或许有助于进行准确分类。
