Helm K F, Peters M S
Immunodermatology Laboratory, Mayo Clinic, Rochester, MN 55905.
J Am Acad Dermatol. 1993 May;28(5 Pt 1):687-91. doi: 10.1016/0190-9622(93)70093-9.
The membrane attack complex (MAC; C5b-9) localizes in the basement membrane zone (BMZ) of cutaneous lesions from patients with lupus erythematosus (LE) and has been implicated in the pathogenesis of this disease.
Our purpose was to compare the frequency of MAC deposition with that of immunoglobulin and C3 deposition (lupus band).
We studied 56 skin biopsy specimens from 42 patients with LE by direct immunofluorescence.
MAC was deposited in a granular pattern at the BMZ in 29 of 38 biopsy specimens (76%) from lesional skin; 5 of 38 specimens (13%) had focal or weak segmental deposition and 4 of 38 (11%) were negative. In contrast, IgG, IgM, IgA, and C3 were detected in 16 of 38 specimens (42%), 30 of 38 (79%), 4 of 38 (11%), and 22 of 38 (58%), respectively. None of the uninvolved skin biopsy specimens was MAC positive, although 4 of 18 (22%), 5 of 18 (28%), 1 of 18 (6%), and 2 of 18 (11%) were positive for IgG, IgM, IgA, and C3, respectively.
MAC deposition in lesional skin appears to be a relatively sensitive and specific marker for cutaneous LE and may be useful as an adjunct to the "lupus band" test.
膜攻击复合物（MAC；C5b - 9）定位于红斑狼疮（LE）患者皮肤病变的基底膜带（BMZ），并被认为与该疾病的发病机制有关。
我们的目的是比较MAC沉积频率与免疫球蛋白和C3沉积（狼疮带）的频率。
我们通过直接免疫荧光研究了42例LE患者的56份皮肤活检标本。
在38份来自病变皮肤的活检标本中，有29份（76%）的BMZ处MAC呈颗粒状沉积；38份标本中有5份（13%）有局灶性或微弱节段性沉积，38份中有4份（11%）为阴性。相比之下，IgG、IgM、IgA和C3分别在38份标本中的16份（42%）、30份（79%）、4份（11%）和22份（58%）中被检测到。18份未受累皮肤活检标本中没有一份MAC呈阳性，尽管IgG、IgM、IgA和C3分别在18份中的4份（22%）、5份（28%）、1份（6%）和2份（11%）中呈阳性。
病变皮肤中的MAC沉积似乎是皮肤型LE相对敏感和特异的标志物，可能作为“狼疮带”试验的辅助手段。
