Amagai M, Komai A, Hashimoto T, Shirakata Y, Hashimoto K, Yamada T, Kitajima Y, Ohya K, Iwanami H, Nishikawa T
Departments of Dermatology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160, Japan.
Br J Dermatol. 1999 Feb;140(2):351-7. doi: 10.1046/j.1365-2133.1999.02752.x.
Pemphigus is an autoimmune blistering disease with two major subtypes, pemphigus vulgaris (PV) and pemphigus foliaceus (PF). Patients with pemphigus have circulating antidesmoglein (Dsg)1 and/or anti-Dsg3 IgG autoantibodies. We have previously developed enzyme-linked immunosorbent assays (ELISAs) using recombinant Dsg1 and Dsg3 expressed by baculovirus as a diagnostic tool for pemphigus. The purpose of this study was to evaluate the practical application of these ELISAs for clinical use with a large number of serum samples. We used 81 PV sera, 48 PF sera, 114 bullous pemphigoid (BP) sera, 124 collagen disease sera, nine sera of other non-pemphigus bullous diseases and 179 normal control sera. A cut-off value was determined by receiver-operating-characteristic plots. Forty-seven of 48 PF sera (97.9%) were positive in the Dsg1 ELISA and 79 of 81 PV sera (97.5%) were positive in the Dsg3 ELISA, while only two (1. 1%) and four (2.2%) of 179 normal sera were positive in Dsg1 and Dsg3 ELISAs, respectively. However, some disease control sera of BP and collagen diseases exceeded the cut-off value. Introduction of a grey zone helped to decrease the number of these false-positive sera. Furthermore, in three patients studied, the respective Dsg1 and Dsg3 ELISA scores showed parallel fluctuation with the disease activity along the time course. We conclude that Dsg1 and Dsg3 ELISAs provide a simple, sensitive and highly specific assay for the diagnosis of patients with PV and PF and that these ELISAs may be a valuable tool to monitor the disease activity. We also propose diagnostic criteria for pemphigus based on ELISA reactivity: if a serum is positive against Dsg3 it indicates a diagnosis of PV, regardless of reactivity against Dsg1; if a serum is negative for Dsg3 and positive for Dsg1, it indicates a diagnosis of PF.
天疱疮是一种自身免疫性水疱病，主要有两种亚型，即寻常型天疱疮（PV）和落叶型天疱疮（PF）。天疱疮患者体内存在循环抗桥粒芯糖蛋白（Dsg）1和/或抗Dsg3 IgG自身抗体。我们之前利用杆状病毒表达的重组Dsg1和Dsg3开发了酶联免疫吸附测定（ELISA）法，将其作为天疱疮的诊断工具。本研究的目的是通过大量血清样本评估这些ELISA法在临床应用中的实际情况。我们使用了81份PV血清、48份PF血清、114份大疱性类天疱疮（BP）血清、124份胶原病血清、9份其他非天疱疮性大疱病血清以及179份正常对照血清。通过受试者操作特征曲线确定临界值。48份PF血清中有47份（97.9%）在Dsg1 ELISA中呈阳性，81份PV血清中有79份（97.5%）在Dsg3 ELISA中呈阳性，而179份正常血清中分别只有2份（1.1%）和4份（2.2%）在Dsg1和Dsg3 ELISA中呈阳性。然而，一些BP和胶原病的疾病对照血清超过了临界值。引入灰色区域有助于减少这些假阳性血清的数量。此外，在研究的3例患者中，各自的Dsg1和Dsg3 ELISA评分在病程中随疾病活动呈现平行波动。我们得出结论，Dsg1和Dsg3 ELISA为PV和PF患者的诊断提供了一种简单、灵敏且高度特异的检测方法，并且这些ELISA法可能是监测疾病活动的有价值工具。我们还基于ELISA反应性提出了天疱疮的诊断标准：如果一份血清对Dsg3呈阳性反应，则表明诊断为PV，无论对Dsg1的反应性如何；如果一份血清对Dsg3呈阴性而对Dsg1呈阳性，则表明诊断为PF。
