Neuroimmunology Unit, Department of Genetics, Evolution and Bioagents, University of Campinas, Campinas, Brazil.
PLoS One. 2012;7(7):e39372. doi: 10.1371/journal.pone.0039372. Epub 2012 Jul 10.
The seroprevalence of human T-cell leukemia virus type 1 (HTLV-1) is very high among Brazilians (1:200). HTLV-1 associated myelopathy or tropical spastic paraparesis (HAM/TSP) is the most common neurological complication of HTLV-1 infection. HAM/TSP can present with an acute/subacute form of longitudinally extensive myelitis, which can be confused with lesions seen in aquaporin-4 antibody (AQP4-Ab) positive neuromyelitis optica spectrum disorders (NMOSD) on MRI. Moreover, clinical attacks in patients with NMOSD have been shown to be preceded by viral infections in around 30% of cases.
To evaluate the frequency of AQP4-Ab in patients with HAM/TSP. To evaluate the frequency of HTLV-1 infection in patients with NMOSD.
23 Brazilian patients with HAM/TSP, 20 asymptomatic HTLV-1+ serostatus patients, and 34 with NMOSD were tested for AQP4-Ab using a standardized recombinant cell based assay. In addition, all patients were tested for HTLV-1 by ELISA and Western blotting.
20/34 NMOSD patients were positive for AQP4-Ab but none of the HAM/TSP patients and none of the asymptomatic HTLV-1 infected individuals. Conversely, all AQP4-Ab-positive NMOSD patients were negative for HTLV-1 antibodies. One patient with HAM/TSP developed optic neuritis in addition to subacute LETM; this patient was AQP4-Ab negative as well. Patients were found to be predominantly female and of African descent both in the NMOSD and in the HAM/TSP group; Osame scale and expanded disability status scale scores did not differ significantly between the two groups.
Our results argue both against a role of antibodies to AQP4 in the pathogenesis of HAM/TSP and against an association between HTLV-1 infection and the development of AQP4-Ab. Moreover, the absence of HTLV-1 in all patients with NMOSD suggests that HTLV-1 is not a common trigger of acute attacks in patients with AQP4-Ab positive NMOSD in populations with high HTLV-1 seroprevalence.
人类 T 细胞白血病病毒 1 型（HTLV-1）在巴西人中的血清流行率非常高（1:200）。HTLV-1 相关脊髓病或热带痉挛性截瘫（HAM/TSP）是 HTLV-1 感染最常见的神经并发症。HAM/TSP 可表现为长节段性横贯性脊髓炎的急性/亚急性形式，这可能与 MRI 上水通道蛋白 4 抗体（AQP4-Ab）阳性视神经脊髓炎谱系疾病（NMOSD）的病变混淆。此外，NMOSD 患者的临床发作已被证明在大约 30%的病例中，先前有病毒感染。
评估 HAM/TSP 患者中 AQP4-Ab 的频率。评估 NMOSD 患者中 HTLV-1 感染的频率。
对 23 例巴西 HAM/TSP 患者、20 例无症状 HTLV-1+血清状态患者和 34 例 NMOSD 患者进行 AQP4-Ab 检测，采用标准化的重组细胞基础检测。此外，所有患者均通过 ELISA 和 Western blot 检测 HTLV-1。
34 例 NMOSD 患者中有 20 例 AQP4-Ab 阳性，但 HAM/TSP 患者和无症状 HTLV-1 感染者均无阳性。相反，所有 AQP4-Ab 阳性 NMOSD 患者均为 HTLV-1 抗体阴性。1 例 HAM/TSP 患者除亚急性 LETM 外还发生视神经炎；该患者也为 AQP4-Ab 阴性。NMOSD 和 HAM/TSP 组患者主要为女性和非洲裔；两个组的 Osame 量表和扩展残疾状况量表评分无显著差异。
我们的结果既不支持 AQP4 抗体在 HAM/TSP 发病机制中的作用，也不支持 HTLV-1 感染与 AQP4-Ab 发展之间的关联。此外，所有 NMOSD 患者均无 HTLV-1 感染提示 HTLV-1 不是高 HTLV-1 血清流行率人群中 AQP4-Ab 阳性 NMOSD 患者急性发作的常见触发因素。
