Lightner V A, Sakai L Y, Hall R P
Department of Medicine, Duke University Medical Center, Durham, NC 27710.
J Invest Dermatol. 1991 Jan;96(1):88-92. doi: 10.1111/1523-1747.ep12515903.
Dermatitis herpetiformis (DH) is characterized in part by the presence of granular deposits of IgA in the papillary dermis just beneath the dermal-epidermal junction. The nature of the structures to which IgA binds in DH skin, however, has not been clearly demonstrated. Previous immunoelectron-microscopy studies using the peroxidase-antiperoxidase technique have concluded that the IgA may bind to abnormal elastic microfibrillar bundles. Recently, antibodies have been developed against a major component of the elastic microfibril bundles, fibrillin. In addition, another dermal matrix protein, hexabrachion, has been characterized and found in normal human skin in a distribution similar to the IgA deposits of DH. Utilizing antibodies against fibrillin, hexabrachion, and human IgA and immunoelectronmicroscopy with immunogold staining techniques, we have examined the skin from patients with DH in order to localize the IgA deposits. Normal-appearing skin from five patients with DH exhibited electron-dense patches within the dermis, which were not seen in skin from normal subjects. These structures were sometimes adjacent to the basement membrane zone, but appeared amorphous and without a well-defined fibrillar structure. The electron-dense patches were labeled with anti-human IgA, but not with antibodies to fibrillin or hexabrachion. The anti-IgA antibody did not label the normal basement membrane. These studies confirm the presence of abnormal electron-dense, amorphous structures in the skin of patients with DH. Due to this lack of association with the elastic microfibril bundles and the lack of labeling with antibodies against fibrillin, we suggest that these deposits are distinct from the microfibrillar bundles of elastic tissue and may represent IgA bound to degraded basement membrane or isolated dermal deposits of IgA.
疱疹样皮炎（DH）的部分特征是在真皮乳头层紧邻真皮 - 表皮交界处存在IgA颗粒沉积。然而，在DH皮肤中IgA结合的结构性质尚未得到明确证实。以往使用过氧化物酶 - 抗过氧化物酶技术的免疫电子显微镜研究得出结论，IgA可能与异常的弹性微原纤维束结合。最近，已开发出针对弹性微原纤维束主要成分原纤蛋白的抗体。此外，另一种真皮基质蛋白六臂蛋白已被鉴定，并在正常人类皮肤中发现其分布与DH的IgA沉积相似。利用针对原纤蛋白、六臂蛋白和人IgA的抗体以及免疫金染色技术的免疫电子显微镜，我们检查了DH患者的皮肤以定位IgA沉积物。五名DH患者外观正常的皮肤在真皮内显示出电子致密斑，正常受试者的皮肤中未见此类斑。这些结构有时毗邻基底膜带，但呈无定形且无明确的纤维状结构。电子致密斑用抗人IgA标记，但不用抗原纤蛋白或六臂蛋白的抗体标记。抗IgA抗体未标记正常基底膜。这些研究证实了DH患者皮肤中存在异常的电子致密无定形结构。由于这些结构与弹性微原纤维束缺乏关联且用抗原纤蛋白抗体未标记，我们认为这些沉积物与弹性组织的微原纤维束不同，可能代表与降解的基底膜结合的IgA或孤立的真皮IgA沉积物。
