Research on Pathomechanism and a novel treatment of HTLV-I-associated myelopathy (HAM)

点击翻译按钮获取中文摘要

HTLV-I proviral load in peripheral blood mononuclear cells (PBMC) from a large number of HAM/TSP patients and asymptomatic HTLV-I carriers were measured to explored the importance of HTLV-I proviral load to the pathomechanism of HAM.The proviral load was measured by an accurate and reproducible quantitative PCR method using a dual-labeled fluorogenic probe (ABI PRISM 7700 Sequence Detection System). The mean +1- standard error of mean (s.e.m.) HTLV-I proviral copy number per 1 x 10(4) PBMC was 798 1- 51 (median 544) in 202 HAM/TSP patients ; 120 +1- 17 (median 34) in 200 non HAM-related (general) asymptomatic HTLV-I carriers (RC) ; and 496 +/- 82 (median 321) in 43 asymptomatic HTLV-I carriers genetically related to HAM/TSP patients (FA). The prevalence of HAM/TSP rises exponentially with log (proviral load) once the proviral load exceeds 1% PBMC.The HTLV-I proviral load of female patients with HAM/TSP was significantly higher than that of male patients, however there was no significan … More t difference in proviral load between sexes in RC.There was a significant correlation between the proviral load and the concentration of neopterin in CSF of HAM/TSP patients. These results indicate that the HTLV-I proviral load in PBMC may be related to the inflammatory process in the spinal cord lesion. The increased proviral load in FA suggests the existence of genetic factors contributing to the replication of HTLV-I in vivo. Furthermore in order to elucidate the localization of HTLV-I proviral DNA directly, we performed double staining using immunohistochemistry and PCR in situ hybridization (PCR-ISH). Fresh frozen sections of the spinal cord from four HAM patients taken at autopsy were first immunostained with antibodies to pan T cells (UCHL-1), macrophages (KP-1) and helper/inducer T cells (OPD4). Then PCR-ISH was carried out with specific primers and probe for the HTLV-I pX region. UCHL- 1-positive cells were noted around perivascular areas and, to some extent, in the parenchyma. Of the UCHL-1-positive cells, 9.4% (case 1), 9.6% (case 2), 1.1% (case 3) and 6.7% (case 4) became positive in HTLV-I PCR-ISH.UCHL-1-negative cells were HTLV-I PCR-ISH negative and almost all KP-l-positive cells were HTLV-I negative. HTLV-I was localized to OPD4-positive cells in examined lesions of cases 2 and 4. These data are a direct demonstration of HTLV-1 proviral DNA localizing to infiltrated T cells in HAM/TSP spinal cord lesions. Less