Noah Patricia W, Handorf Charles R, Skinner Robert B, Mandrell Timothy D, Rosenberg E William
Department of Medicine (Dermatology) and Preventive Medicine, University of Tennessee, Memphis, TN 38104-7514, USA.
Skinmed. 2006 Mar-Apr;5(2):72-9; quiz 80-1. doi: 10.1111/j.1540-9740.2006.04277.x.
Elevated levels of antibody to streptococcal exoenzymes have been found in patients with psoriasis or psoriatic arthritis. Research on the role of streptococcal antigen in psoriasis has been hampered by a potential molecular mimicry between streptococcal epitopes and human epidermal keratin.
Evidence of microbial product was sought in skin biopsies of psoriasis patients thought clinically to have either streptococcal carrier state or gastrointestinal candidal colonization. A polyclonal antibody to streptococcal-derived exoenzymes unlikely to share antigenic structures with normal human skin, and an anticandidal antibody, were used with linked streptavidin biotin amplification stain.
The predicted microbial product appeared heavily in lesional epidermis, but unexpectedly also as a thin deposit along the skin basement membrane zone (SBMZ) of apparently unaffected skin. Staining was negative for nonpsoriatic subjects.
The findings support a direct effect of microbial antigen in psoriasis. They also suggest an important role for SBMZ as a very large adhesive surface in the first step of a process of percutaneous epidermal elimination of foreign antigens and microbial toxins. The many autoimmune phenomena seen so often at the SBMZ are probably a physiologic part of this important immune function. Efforts to enhance the adhesive properties of SBMZ should be exploitable for both diagnostic and therapeutic benefit.
在银屑病或银屑病关节炎患者中发现抗链球菌外酶抗体水平升高。链球菌抗原在银屑病中的作用研究受到链球菌表位与人类表皮角蛋白之间潜在分子模拟的阻碍。
在临床诊断为链球菌携带状态或胃肠道念珠菌定植的银屑病患者的皮肤活检中寻找微生物产物的证据。使用一种与正常人皮肤不太可能共享抗原结构的抗链球菌衍生外酶的多克隆抗体和一种抗念珠菌抗体，采用链霉亲和素生物素连接放大染色法。
预测的微生物产物在皮损表皮中大量出现，但出乎意料的是，在明显未受影响皮肤的皮肤基底膜带（SBMZ）也有薄层沉积。非银屑病受试者的染色为阴性。
这些发现支持微生物抗原在银屑病中具有直接作用。它们还表明SBMZ作为一个非常大的黏附表面，在经皮表皮清除外来抗原和微生物毒素过程的第一步中具有重要作用。在SBMZ经常出现的许多自身免疫现象可能是这种重要免疫功能的生理组成部分。增强SBMZ黏附特性的努力在诊断和治疗方面都应具有可利用价值。
