A predominant IgG4 subclass may be responsible for false-negative direct immunofluorescence in bullous pemphigoid
A predominant IgG4 subclass may be responsible for false-negative direct immunofluorescence in bullous pemphigoid
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DOI：
10.1034/j.1600-0560.2002.290504.x
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发表时间：
2002-05-01
影响因子：
1.7
通讯作者：
Abernethy, JL
中科院分区：
文献类型：
--
作者：
Buschman, KE;Seraly, M;Abernethy, JL
工作背景：大疱性类天疱疮（BP）是一种免疫介导的水疱性疾病，通常以IgG和C3沿着皮肤基底膜区（BMZ）线性沉积为免疫病理特征。然而，C3的阳性沉积，但直接免疫荧光（DIF）的研究IgG阴性染色已注意到在一些patients.Methods：12例已知有BP，但没有IgG染色被列入本研究。对来自12名患者的皮肤标本的冷冻切片进行IgG DIF，以及IgG、IgG亚类和轻链的夹心双抗体染色法。结果：在12例C3阳性、IgG阴性的皮肤标本中，双抗体夹心法检测IgG阳性9例。此外，所有12例标本的IgG（4）亚类均呈阳性线性染色沿着BMZ。不存在IgG轻链限制。通过ELISA分析了两种市售抗人IgG偶联物（均在我们实验室中常用于DIF检测）的单独IgG亚类特异性。结论：部分BP患者DIF抗体IgG染色假阴性的原因可能是：（1）皮肤标本中IgG亚类的存在，（2）抗人IgG偶联物对IgG（4）亚类的反应性有限，（3）抗人IgG偶联物对IgG（1）亚类的反应性有限，（4）抗人IgG偶联物对IgG（2）亚类的反应性有限，（5）抗人IgG偶联物对IgG（4）亚类的反应性有限，（6）抗人IgG偶联物对IgG（4）亚类的反应性有限，（7）抗人IgG偶联物对IgG（4）亚类的反应性有限，（8）抗人IgG偶联物对IgG（4）亚类的反应性有限，（9）抗人IgG偶联物对IgG（4）亚类的反应性有限，（10）抗人IgG偶联物对IgG（4）亚类的反应性有限，（10）抗人IgG偶联物对IgG（4）亚类的反应性有限。与双抗体法相比，DIF法检测IgG的灵敏度降低。对于IgG阴性、C3染色阳性的BP患者，应用双抗体夹心免疫荧光法检测IgG和/或IgG亚类可能有助于明确诊断。
Background: Bullous pemphigoid (BP) is an immune-mediated blistering disease, usually characterized immunopathologically by the linear deposition of IgG and C3 along the basement membrane zone (BMZ) of skin. However, positive deposition of C3 but negative staining for IgG on direct immunofluorescence (DIF) studies has been noted in some patients.Methods: Twelve patients known to have BP but with absence of staining for IgG were included in this study. Frozen sections of skin specimens from the 12 patients were subjected to IgG DIF, as well as a sandwich double antibody method of staining for IgG, IgG subclasses, and light chains. Enzyme-linked immunosorbent assay (ELISA) using commercially available human IgG subclasses was used to analyze the subclass restriction of FITC-labeled antihuman IgG conjugates.Results: Of the 12 skin specimens with positive C3 and negative IgG on DIF, nine were positive for IgG with the double antibody sandwich method. In addition, all 12 specimens had positive linear staining for the subclass IgG(4) along the BMZ with this method. There was no IgG light chain restriction. Two commercially obtained antihuman IgG conjugates, both commonly used in our laboratory for DIF testing, were analyzed for separate IgG subclass specificity by ELISA. Both conjugates showed high reactivity to IgG(1) and IgG(3) with less reactivity to IgG(2) and IgG(4) .Conclusion: These results suggest that the following factors contribute to false-negative staining for IgG on DIF in some BP patients: (i): subthreshold IgG in skin specimens; (ii) limited reactivity of commercial antihuman IgG conjugates to the IgG(4) subclass; and (iii) decreased sensitivity of DIF compared with double antibody methods for the detection of IgG. The use of sandwich double antibody immunofluorescence methods to test for IgG and/or IgG subclasses may be helpful in definitively diagnosing BP in patients with negative IgG and positive C3 staining on DIF.