Department of Pathology, Maulana Azad Medical College, New Delhi, Delhi, India.
Department of Dermatology, Maulana Azad Medical College, New Delhi, Delhi, India.
Indian J Pathol Microbiol. 2024 Apr 1;67(2):336-339. doi: 10.4103/ijpm.ijpm_113_23. Epub 2024 Feb 19.
Pemphigus is a group of bullous disorders of the skin characterized by the formation of autoantibodies present in the intercellular junction of the epidermis. Diagnosis is made by clinical, histopathological examination, and DIF. As DIF needs frozen sections, fluorescent tagged antibodies, UV light microscope for examination, and trained personnel, its non-availability makes a definitive diagnosis challenging.
To evaluate the utility of IHC staining of complements and Ig in cases of Pemphigus.
Twenty-six diagnosed cases of Pemphigus were stained by Peroxidase immunohistochemical method using monoclonal antibody to IgG, IgA, IgM, IgG4, C3, C4 d with DAB as chromogen. Pemphigus cases include twenty of pemphigus vulgaris (PV), four cases of pemphigus foliaceous (PF), and two of pemphigus vegetans (Pveg). Positivity was defined as the deposition of Ig and complements as distinct, continuous brown staining of keratinocytes at intercellular junctions.
On IHC total of 20 PV 17 showed positivity (85%) for IgG, 11 (55%) C4d, 19 (95%) C3d, and 16 (80%) IgG4 deposits at the intercellular junction of the epidermis. All cases of PF showed a deposit of IgG, with three (75%) cases for IgG4, C3d, and C4d. Both cases of Pveg showed positivity for IgG and C4d while one case was negative for IgG4 and C3d. The overall IgG, C3, IgG4, and C4d expression for pemphigus was seen in 88%, 88%, 76.9%, and 61.5% of cases. The relation between these markers, combination of IgG and C3, was best related to each other ( P value = 0.80). The sensitivities for IgG, IgG4, and C3 were 77.8%%, 73%, and 73% resp.
We conclude that IHC is a useful tool in the diagnosis of PV with the highest sensitivity of IgG and C3d. The combination of IgG and C3d could replace the DIF in almost all of our cases, so IHC on FFPE sections be used as an alternative method to DIF.
天疱疮是一组以表皮细胞间形成自身抗体为特征的水疱性皮肤病。诊断通过临床、组织病理学检查和 DIF 进行。由于 DIF 需要冷冻切片、荧光标记抗体、紫外线显微镜检查和经过培训的人员，因此其不可用性使得明确诊断具有挑战性。
评估免疫组织化学染色补体和 Ig 在天疱疮病例中的应用。
使用针对 IgG、IgA、IgM、IgG4、C3 和 C4d 的单克隆抗体，通过过氧化物酶免疫组织化学方法对 26 例确诊的天疱疮病例进行染色，并用 DAB 作为显色剂。天疱疮病例包括 20 例寻常型天疱疮 (PV)、4 例落叶型天疱疮 (PF) 和 2 例增殖型天疱疮 (Pveg)。阳性定义为细胞间连接的角蛋白细胞有明显、连续的棕色染色的 Ig 和补体沉积。
在免疫组化中，20 例 PV 中有 17 例 (85%) 显示 IgG 阳性，11 例 (55%) 显示 C4d 阳性，19 例 (95%) 显示 C3d 阳性，16 例 (80%) 显示 IgG4 沉积在表皮细胞间。所有 PF 病例均显示 IgG 沉积，其中 3 例 (75%) 为 IgG4、C3d 和 C4d。2 例 Pveg 均显示 IgG 和 C4d 阳性，1 例 IgG4 和 C3d 阴性。天疱疮的总 IgG、C3、IgG4 和 C4d 表达在 88%、88%、76.9%和 61.5%的病例中可见。这些标志物之间的关系，即 IgG 和 C3 的组合，彼此之间的相关性最好 (P 值=0.80)。IgG、IgG4 和 C3 的敏感性分别为 77.8%、73%和 73%。
我们得出结论，免疫组化是诊断 PV 的有用工具，其 IgG 和 C3d 的敏感性最高。IgG 和 C3d 的组合几乎可以替代我们所有病例中的 DIF，因此可以使用 FFPE 切片上的免疫组化作为 DIF 的替代方法。
