Liu T C, Ji Z M, Skinsnes O K
Research Department of Pathology, Sun Yat-Sen University of Medical Science, Guangzhou, People's Republic of China.
Int J Lepr Other Mycobact Dis. 1989 Mar;57(1):65-72.
Lesions in peripheral nerves of armadillos experimentally infected with Mycobacterium leprae were studied by light- and electron-microscopy. Bacilli could be found clearly inside axons of unmyelinated nerve fibers. Heavily bacillated Schwann cells were seen embracing unmyelinated axons with interrupted cytoplasmic membranes. This indicated the initiation of rupture of those cells which were responsible for the liberation of bacilli into the axons. The nerve lesions were divided into three grades according to their severity: grade I showed lesions focalized in the perineurium; grade II lesions were scattered inside nerve tissue; and in grade III lesions the nerve tissues were diffusely affected. No regressive changes, such as fibrosis or scar formation, were seen in the nerve lesions. Bacillated macrophages were not as foamy as those of human lesions, indicating that these bacillated cells were younger or more easily disrupted with a higher turnover than the cells in human lesions. This would promote the spread of lesions in armadillos, and would explain the less foamy appearance of the cells. We found bacilli inside lymphatics surrounding the nerves, substantiating the opinion that lesions spread to peripheral nerves not only by a hematogenous route but also by the lymphatics.
通过光学显微镜和电子显微镜对实验感染麻风分枝杆菌的犰狳外周神经病变进行了研究。在无髓神经纤维的轴突内可清晰发现杆菌。可见大量含杆菌的施万细胞包裹着无髓轴突，其细胞膜中断。这表明那些负责将杆菌释放到轴突中的细胞开始破裂。根据神经病变的严重程度将其分为三级：I级病变局限于神经束膜；II级病变散在于神经组织内；III级病变中神经组织受到弥漫性影响。在神经病变中未见纤维化或瘢痕形成等退行性改变。含杆菌的巨噬细胞不像人类病变中的那样呈泡沫状，这表明这些含杆菌的细胞较年轻，或比人类病变中的细胞更新换代更快，更容易被破坏。这会促进犰狳病变的扩散，并解释了细胞泡沫状外观较少的原因。我们在神经周围的淋巴管内发现了杆菌，证实了病变不仅通过血行途径，还通过淋巴管扩散到外周神经的观点。
