Department of Dermatology and Allergology, Philipps-University, Marburg, D-35043, Germany.
Istituto Dermopatico dell'Immacolata, Rome, Italy.
Br J Dermatol. 2017 Dec;177(6):1683-1692. doi: 10.1111/bjd.15800. Epub 2017 Dec 1.
Epidermolysis bullosa acquisita (EBA) is a rare, potentially devastating autoimmune disease of the skin. IgG autoantibodies directed against type VII collagen (Col7), the major component of anchoring fibrils, induce skin fragility leading to cutaneous and mucocutaneous blister formation, which is mostly of a scarring phenotype. Thus, powerful and reproducible diagnostic assays are critical to establish the diagnosis of EBA early to avoid irreversible sequelae.
The present international, retrospective multicentre study included a large cohort of patients with EBA and evaluated the diagnostic power of four different diagnostic assays for the detection of anti-Col7 IgG autoantibodies.
Overall, 95 EBA sera and 200 control sera consisting of 100 bullous pemphigoid sera, 50 pemphigus vulgaris sera and 50 sera of healthy controls were tested for anti-Col7 IgG autoantibodies using indirect immunofluorescence (IIF), two commercial enzyme-linked immunosorbent assay (ELISA) systems and Western blot (WB) analysis. EBA sera were taken from patients with positive direct immunofluorescence and IgG reactivity in at least one of the immunoserological assays (IIF, ELISA, WB).
A Col7-NC1/NC2 ELISA (MBL, Nagoya, Japan) showed the highest sensitivity (97·9%), followed by a Col7-NC1 ELISA (Euroimmun, Lübeck, Germany) (89·5%), WB with Col7-NC1 (85·3%), and IIF on saline-split human skin (74·7%). The specificities of both ELISA systems were comparable (NC1 98·7%, NC1/NC2 99·3%). Furthermore, WB was more sensitive than IIF, which was more specific.
The two commercially available ELISA systems allow for a highly sensitive and specific diagnosis of EBA. The sensitivity of the Col7-NC1/NC2 ELISA is significantly higher compared with the ELISA based on the Col7-NC1 domain only.
获得性大疱性表皮松解症（EBA）是一种罕见的、潜在破坏性的皮肤自身免疫性疾病。针对 VII 型胶原（Col7）的 IgG 自身抗体，即锚定纤维的主要成分，导致皮肤脆弱，引起皮肤和黏膜水疱形成，主要表现为瘢痕样表型。因此，强有力且可重复的诊断检测对于早期诊断 EBA 以避免不可逆转的后遗症至关重要。
本国际回顾性多中心研究纳入了大量 EBA 患者，并评估了四种不同的 Col7 IgG 自身抗体检测诊断试验的诊断效能。
总共检测了 95 份 EBA 血清和 200 份对照血清，包括 100 份大疱性类天疱疮血清、50 份寻常型天疱疮血清和 50 份健康对照血清，使用间接免疫荧光（IIF）、两种商业酶联免疫吸附试验（ELISA）系统和免疫印迹（WB）分析检测 Col7 IgG 自身抗体。EBA 血清取自至少一种免疫血清学检测（IIF、ELISA、WB）中直接免疫荧光和 IgG 反应均为阳性的患者。
Col7-NC1/NC2 ELISA（日本名古屋 MBL）的敏感性最高（97.9%），其次是 Col7-NC1 ELISA（德国吕贝克 Euroimmun）（89.5%）、Col7-NC1 WB（85.3%）和盐裂人皮肤 IIF（74.7%）。两种 ELISA 系统的特异性相当（NC1 为 98.7%，NC1/NC2 为 99.3%）。此外，WB 比 IIF 更敏感，而 IIF 比 WB 更特异。
两种商业 ELISA 系统可高度敏感和特异诊断 EBA。Col7-NC1/NC2 ELISA 的敏感性明显高于仅基于 Col7-NC1 结构域的 ELISA。
