Dept of Laboratory Medicine and Pathology, Mayo Clinic, 200 First St SW, Rochester, MN 55905;
Am J Clin Pathol. 2014 Feb;141(2):234-8. doi: 10.1309/AJCPTMWTCN04GSJH.
Immunoglobulin (Ig) G4-related disease (IgG4-RD), a fibroinflammatory condition that can affect multiple organs, is suggested by lymphoplasmacytic inflammation, fibrosis, phlebitis, and increased IgG4+ plasma cell (PC) tissue density. In patients with suspected IgG4-RD and skin changes, skin biopsy may serve as a diagnostic screen or to supplement nondiagnostic visceral biopsy specimens. We aimed to determine whether increased cutaneous IgG4+ PCs or IgG4/IgG ratio is specific for IgG4-RD.
We examined 50 mucocutaneous specimens representing seven PC-rich dermatoses and reactive PC-rich infiltrates with IgG and IgG4 immunohistochemical stains.
IgG4+ density exceeded 10 cells per high-power field in 22 (44%) of 50 specimens, representing six of seven diagnoses and reactive infiltrates. In five specimens (10%), the IgG4/IgG ratio exceeded 0.40.
Moderately elevated IgG4+ PC density or IgG4/IgG ratio is a nonspecific finding in the skin. In cutaneous biopsy specimens showing increased IgG4+ PCs, careful consideration should be given to clinical, serologic, and other histopathologic features before attributing clinical changes to IgG4-RD.
免疫球蛋白（Ig）G4 相关疾病（IgG4-RD）是一种淋巴浆细胞炎症、纤维化、静脉炎和 IgG4+浆细胞（PC）组织密度增加可影响多个器官的纤维炎症性疾病。在疑似 IgG4-RD 且伴有皮肤改变的患者中，皮肤活检可作为诊断筛查手段，或补充非诊断性内脏活检标本。我们旨在确定皮肤中 IgG4+PC 或 IgG4/IgG 比值增加是否对 IgG4-RD 具有特异性。
我们用 IgG 和 IgG4 免疫组化染色，检测了 50 份黏膜皮肤标本，这些标本代表了七种富含 PC 的皮肤病和反应性富含 PC 的浸润。
在 50 份标本中的 22 份（44%）中，IgG4+密度超过每高倍视野 10 个细胞，代表了七种诊断中的六种和反应性浸润。在五份标本（10%）中，IgG4/IgG 比值超过 0.40。
皮肤中中等程度升高的 IgG4+PC 密度或 IgG4/IgG 比值是非特异性发现。在显示 IgG4+PC 增加的皮肤活检标本中，在将临床变化归因于 IgG4-RD 之前，应仔细考虑临床、血清学和其他组织病理学特征。
