Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou China.
PLoS One. 2013 Aug 5;8(8):e70983. doi: 10.1371/journal.pone.0070983. Print 2013.
Detection of immunoreactants including IgG, IgM, IgA, and C3 by direct immunofluorescence (DIF) from skin is useful for distinguishing lupus lesions from other skin disorders. Despite their diagnostic value, the type and number of cutaneous immunoreactants as they relate to serological disorders and disease severity has been poorly studied. We examined 36 patients with systemic lupus erythematosis (SLE) with positive DIF (DIF+) and 28 patients with negative DIF (DIF-) tests performed on lesional skin. Among DIF+ patients, the most frequent patterns of immunoreactants were IgM alone (36%) and the coexistence of IgM with C3 (28%). IgM was the highest detected individual immunoreactant (86%). As classified by number, 17 of 36 DIF+ patients had one immunoreactant (= 1), while the remaining patients had two to four immunoreactants (>1). Compared with DIF- patients, DIF+ patients were more likely to have severe disease as indicated by lower serum C3 levels and a higher SLE disease activity index (SLEDAI). The coexistence of IgM with any other immunoreactants indicated a more severe disease than that present in the DIF- group, whereas the IgM-alone group was comparable with the DIF- group in both serum C3 levels and SLEDAI. These findings were also applicable in the comparison of patients with more than one (>1) immunoreactant and patients with no (DIF-) and one ( = 1) immunoreactant. Collectively, the presence of multiple immunoreactants in lesional skin implies a more severe disease activity of SLE, while a single immunoreactant may be equal to the absence of immunoreactants (DIF-) in terms of predicting disease activity.
通过直接免疫荧光法（DIF）从皮肤中检测包括 IgG、IgM、IgA 和 C3 在内的免疫反应物，有助于将狼疮病变与其他皮肤疾病区分开来。尽管它们具有诊断价值，但与血清学异常和疾病严重程度相关的皮肤免疫反应物的类型和数量尚未得到充分研究。我们检查了 36 例皮肤直接免疫荧光检测阳性（DIF+）的系统性红斑狼疮（SLE）患者和 28 例皮肤直接免疫荧光检测阴性（DIF-）的患者。在 DIF+患者中，最常见的免疫反应物模式是单独的 IgM（36%）和 IgM 与 C3 共存（28%）。IgM 是检测到的最高的单个免疫反应物（86%）。按数量分类，36 例 DIF+患者中有 17 例（=1）存在一种免疫反应物，其余患者有两种或四种免疫反应物（>1）。与 DIF-患者相比，DIF+患者的血清 C3 水平较低，SLE 疾病活动指数（SLEDAI）较高，表明疾病更严重。与 DIF-组相比，IgM 与任何其他免疫反应物共存表明疾病更严重，而 IgM 单独组在血清 C3 水平和 SLEDAI 方面与 DIF-组相似。这些发现也适用于比较存在多种（>1）免疫反应物的患者和无（DIF-）和一种（=1）免疫反应物的患者。总之，皮肤病变中存在多种免疫反应物提示 SLE 的疾病活动更为严重，而单一免疫反应物与无免疫反应物（DIF-）在预测疾病活动方面可能相当。
