Propionibacterium aenesas a causative agent of sarcoidosis

病因不明的结节病可能是由于遗传易感对象暴露于特定的环境病原体(S)，可能是传染性病原体，尽管尚未发现任何病原体。痤疮丙酸杆菌是迄今为止从结节病损中分离到的唯一细菌。用定量聚合酶链式反应在结节状淋巴结中检测到大量痤疮螺旋体的基因组。通过原位杂交，在肉芽肿内及周围的结节状淋巴结内发现了痤疮病毒基因组。这些结果指出痤疮和一些结节病之间的病因学联系。重组痤疮触发因子蛋白(RP35)在一些结节病患者中引起细胞免疫反应，但在非结节病患者中不能。RP35在一些用该蛋白和佐剂致敏的小鼠中会导致肺颗粒细胞增多。痤疮P是周围肺组织和纵隔淋巴结最常见的固有细菌，这可能是这些器官经常发生结节病的原因。结节样肉芽肿可能是由免疫系统遗传性或获得性异常的个体对一种或多种痤疮假单胞菌抗原的Th1免疫反应而形成的，这些抗原在受影响的器官中原发或增殖。

Sarcoidosis, of unknown etiology, may result from exposure of a genetically susceptible subject to a specific enviromnental agent(s), possibly an infectious one, although none has been identified. Propionibacterium acnes is so far the only bacterium to be isolated from sarcoid lesions. Many genomes of P acnes have been detected in sarcoid lymph nodes by the quantitative polymerase chain reaction. By in situ hybridization, P acnes genomes were found in sarcoid lymph nodes in and around sarcoid granulomas. These results point to an etiological link between P acnes and some cases of sarcoidosis. A recombinant triggerfactor protein (RP35) from P acnes causes a cellular immune response in some patients with sarcoidosis, but not in subjects without sarcoidosis. RP35 causes pulmonary granuloinas in some of the mice sensitized with the protein and adjuvant. P acnes is the most common bacterium indigenous to the peripheral lung tissues and mediastinal lymph nodes, which may be the reason why these organs are so frequently involved in sarcoidosis. Sarcoid granulomas may be formed by a Th1 immune response to one or more antigens of P. acnes indigenous to or proliferating in the affected organs in an individual with a hereditary or acquired abnormality of the immune system.