Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA.
Semin Respir Crit Care Med. 2010 Aug;31(4):375-9. doi: 10.1055/s-0030-1262205. Epub 2010 Jul 27.
Sarcoidosis is a disease of unknown etiology, characterized pathologically by noncaseating granulomas that most commonly involve the lung, skin, lymph nodes, and eyes. Syndromes with similar pathological and immunologic features to sarcoidosis such as chronic beryllium disease, hypersensitivity pneumonitis, and tuberculosis illustrate that granulomatous diseases may or may not have an infectious etiology. Although the etiology of sarcoidosis remains unknown, recent molecular, genetic, and immunologic studies strengthen the association of sarcoidosis with infectious antigens. Currently, the strongest agents considered include PROPIONIBACTERIUM and MYCOBACTERIUM species. Independent studies report the presence of microbial nucleic acids and proteins within sarcoidosis specimens. Th-1 immune responses to mycobacterial proteins have been detected within sarcoidosis diagnostic bronchoalveolar lavage (BAL). These proteins are actively secreted by the mycobacterial SecA 2 secretion system and are important to evade the host immune system. Recent discoveries regarding MHC class II alleles provide additional insight regarding the role of microbial antigens in sarcoidosis pathogenesis. Although further investigation is warranted, the recent progress of independent laboratories, using complementary techniques, strengthens the role of microbial antigens in sarcoidosis pathogenesis. These studies lay a strong foundation toward identifying therapeutic targets.
结节病是一种病因不明的疾病，其病理特征为非干酪样肉芽肿，最常累及肺、皮肤、淋巴结和眼睛。类似于结节病的具有相似病理和免疫特征的综合征，如慢性铍病、过敏性肺炎和结核病，表明肉芽肿性疾病可能具有也可能不具有感染病因。尽管结节病的病因仍然未知，但最近的分子、遗传和免疫学研究加强了结节病与感染抗原的关联。目前，被认为最强的病原体包括丙酸杆菌和分枝杆菌属。独立的研究报告在结节病标本中存在微生物核酸和蛋白质。在结节病诊断性支气管肺泡灌洗液 (BAL) 中检测到针对分枝杆菌蛋白的 Th-1 免疫反应。这些蛋白质被分枝杆菌 SecA2 分泌系统主动分泌，对逃避宿主免疫系统很重要。最近关于 MHC Ⅱ类等位基因的发现为微生物抗原在结节病发病机制中的作用提供了更多的认识。尽管还需要进一步的研究，但独立实验室使用互补技术的最新进展，加强了微生物抗原在结节病发病机制中的作用。这些研究为确定治疗靶点奠定了坚实的基础。
