Department of Environmental and Radiological Health Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
J Neurovirol. 2011 Aug;17(4):341-52. doi: 10.1007/s13365-011-0040-7. Epub 2011 Jul 23.
HIV infection results in a highly prevalent syndrome of cognitive and motor disorders designated as HIV-associated dementia (HAD). Neurologic dysfunction resembling HAD has been documented in cats infected with strain PPR of the feline immunodeficiency virus (FIV), whereas another highly pathogenic strain (C36) has not been known to cause neurologic signs. Animals experimentally infected with equivalent doses of FIV-C36 or FIV-PPR, and uninfected controls were evaluated by magnetic resonance diffusion-weighted imaging (DW-MRI) and spectroscopy (MRS) at 17.5-18 weeks post-infection, as part of a study of viral clade pathogenesis in FIV-infected cats. The goals of the MR imaging portion of the project were to determine whether this methodology was capable of detecting early neuropathophysiology in the absence of outward manifestation of neurological signs and to compare the MR imaging results for the two viral strains expected to have differing degrees of neurologic effects. We hypothesized that there would be increased diffusion, evidenced by the apparent diffusion coefficient as measured by DW-MRI, and altered metabolite ratios measured by MRS, in the brains of FIV-PPR-infected cats relative to C36-infected cats and uninfected controls. Increased apparent diffusion coefficients were seen in the white matter, gray matter, and basal ganglia of both the PPR and C36-infected (asymptomatic) cats. Thalamic MRS metabolite ratios did not differ between groups. The equivalently increased diffusion by DW-MRI suggests similar indirect neurotoxicity mechanisms for the two viral genotypes. DW-MRI is a sensitive tool to detect neuropathophysiological changes in vivo that could be useful during longitudinal studies of FIV.
HIV 感染导致广泛存在的认知和运动障碍综合征，称为 HIV 相关痴呆（HAD）。已在感染猫免疫缺陷病毒（FIV）PPR 株的猫中记录到类似于 HAD 的神经功能障碍，而另一种高致病性株（C36）则没有引起神经症状。用 FIV-C36 或 FIV-PPR 的等效剂量感染的动物以及未感染的对照动物在感染后 17.5-18 周通过磁共振扩散加权成像（DW-MRI）和光谱（MRS）进行评估，作为研究 FIV 感染猫中病毒群发病机制的一部分。该项目磁共振成像部分的目的是确定该方法是否能够在没有神经症状表现的情况下检测早期神经病理生理学，并比较两种病毒株的磁共振成像结果，这两种病毒株预计会有不同程度的神经影响。我们假设 FIV-PPR 感染猫的大脑中会出现扩散增加，这表现为 DW-MRI 测量的表观扩散系数增加，以及 MRS 测量的代谢物比值改变，与 C36 感染猫和未感染对照猫相比。在 PPR 和 C36 感染（无症状）猫的白质、灰质和基底节中都可以看到明显的扩散系数增加。各组间丘脑 MRS 代谢物比值无差异。DW-MRI 显示出相同的扩散增加，表明这两种病毒基因型具有相似的间接神经毒性机制。DW-MRI 是一种敏感的工具，可用于检测体内的神经病理生理学变化，在 FIV 的纵向研究中可能很有用。
