Unità di Dermatologia, Dipartimento di Fisiopatologia e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Via Pace 9, 20122, Milano, Italy.
Br J Dermatol. 2013 Jan;168(1):80-4. doi: 10.1111/bjd.12011. Epub 2012 Nov 21.
Epidermolysis bullosa acquisita (EBA) is a rare autoimmune mucocutaneous bullous disease caused by autoantibodies against type VII collagen, a component of anchoring fibrils that stabilizes dermoepidermal adherence. Type VII collagen is composed of a collagenous domain linked by the noncollagenous (NC)1 and NC2 domains.
To assess the repeatability, sensitivity and specificity of a recently developed enzyme-linked immunosorbent assay (ELISA) for detection of anti-type VII collagen autoantibodies, and to ascertain whether they may be a marker of disease activity in EBA.
Using this ELISA, which was able to recognize autoantibodies against the NC1 and NC2 epitopes of type VII collagen, we tested 14 EBA sera, 30 healthy control sera and 113 disease control sera.
In the EBA sera group, 12 out of the 14 samples were positive in ELISA, with autoantibody titres varying from 7·2 to 127·9UmL(-1) (cutoff value <6), the sensitivity of the method being 86%. Among the controls, only two bullous pemphigoid sera tested positive, the specificity being 98·6%. A good correlation was found between EBA disease severity, expressed as autoimmune bullous skin disorder intensity score, and the serum levels of anti-collagen VII autoantibodies, measured by ELISA (n =14; r=0·965; P=0·0001). The intra- and interassay coefficients of variation of the ELISA method ranged from 6·3% to 18·3%.
This NC1+NC2 ELISA can be a practical assay for the diagnosis of EBA. The correlation between autoantibody titres and disease severity suggests its usefulness as a marker of disease activity in EBA However, this should be confirmed by studies on larger series of patients.
获得性大疱性表皮松解症（EBA）是一种罕见的自身免疫性黏膜皮肤大疱病，由针对 VII 型胶原的自身抗体引起，VII 型胶原是锚定纤维的组成部分，可稳定表皮与真皮的连接。VII 型胶原由胶原结构域和非胶原（NC）1 和 NC2 结构域组成。
评估一种新开发的酶联免疫吸附试验（ELISA）检测抗 VII 型胶原自身抗体的重复性、敏感性和特异性，并确定其是否可作为 EBA 疾病活动的标志物。
使用该 ELISA 可识别针对 VII 型胶原 NC1 和 NC2 表位的自身抗体，我们检测了 14 份 EBA 血清、30 份健康对照血清和 113 份疾病对照血清。
在 EBA 血清组中，14 份样本中有 12 份 ELISA 阳性，抗体滴度为 7.2 至 127.9U/mL（<6 为截断值），方法的敏感性为 86%。在对照组中，只有 2 份大疱性类天疱疮血清呈阳性，特异性为 98.6%。EBA 疾病严重程度（用自身免疫性大疱性皮肤障碍严重程度评分表示）与 ELISA 检测的抗 VII 型胶原自身抗体血清水平之间存在良好相关性（n=14；r=0.965；P=0.0001）。ELISA 方法的批内和批间变异系数范围为 6.3%至 18.3%。
该 NC1+NC2 ELISA 可作为 EBA 的实用诊断方法。抗体滴度与疾病严重程度之间的相关性表明其可作为 EBA 疾病活动的标志物。但需要在更大系列的患者中进行研究来证实。
