Neuropathological Study of HTLV-I Related Diseases- Adult T-cell Leukemia (ATL) and HTLV-I Associated Myelopathy (HAM)

为了阐明ATL中观察到的神经系统疾病和HAM的发病机制，进行了以下研究。(1)在ATL中经常观察到神经系统体征。对41例ATL患者尸检的系统神经病理学研究显示，白血病细胞直接浸润脑和脊髓，与嗜睡和痴呆密切相关。部分病例表现为巨细胞或艾滋病样空泡性脊髓病，但ATL病例的脊髓中未检测到与HAM相容的炎性病变。(2)基于HTLV-Ⅰ感染的活化T细胞通过血脑屏障向脊髓内迁移在HAM发病中起重要作用的假设，对HTLV-Ⅰ携带者（n=4）、非携带者（n=7）和非流行区病例（n=17）脊髓内UCHL-Ⅰ阳性T细胞群进行了半定量检测。然而，它们之间没有显著差异。相反，常规神经病理学阴性临床HAM病例显示T细胞增加超过3倍。(3)应用聚合酶链反应（PCR）技术，以Tax编码区SK 45为模板，对一例HAM患者的HTLV-Ⅰ基因在各器官中的分布进行了研究。Tax在脊髓、坐骨神经、腰大肌、肺、肝中表达阳性，在大脑、小脑、中脑、脑桥、肾中表达阴性。HTLV-I似乎与多器官炎症性疾病有关。

Following studies were performed in order to elucidate the neurological disorders observed in ATL and pathogenesis of HAM. (1) Neurological signs are frequently observed in ATL. Systemic neuropathological study of 41 ATL patient autopsied revealed direct infiltration of leukemic cells in the brain and spinal cord, which were closely related to drowsiness and dementia. Some cases showed giant cells or AIDS-like vacuolar myelopathy, but inflammatory lesions compatible with HAM was not detected in the spinal cord of ATL cases. (2) Based on the hypothesis that migration of HTLV-I infected activated T-cell into the spinal cord through blood-brain barrier is important for the pathogenesis of HAM, population of UCHL-I positive T-cells in the spinal cords of HTLV-I carrier (n=4), non-carrier (n=7), non-endemic area cases (n=17) was semiquantitatively examined. However, there was no significant difference among them. On the contrary, a conventional neuropathology negative clinical HAM case showed more than 3 times increase of T-cells. (3) Distribution of HTLV-I gene in various organs of a HAM case was studied by Polymerase Chain Reaction (PCR) using Tax coding SK45. The spinal cord, sciatic nerve, psoas muscle, lung and liver were Tax positive, while cerebrum, cerebellum, midbrain, pons and kidney were negative. HTLV-I seems to be related to multi-organ inflammatory disorders.