Diffusion Tensor Imaging and Neuropsychological Outcomes in HIV/HCV Co-infection

据估计，几乎三分之一的艾滋病毒阳性患者同时感染丙型肝炎病毒。检查合并感染群体认知功能的研究发现，与仅感染艾滋病毒或丙型肝炎病毒的群体相比，许多认知领域的神经心理学检查表现较差（Cherner等人，2008; Clifford等人，2005; Hilsabeck等人，2005; Letendre等人，2002; Martin等人，2004; Parsons等人，2006; Ryan等人，2004; von Giesen等人，2004年）。此外，据报道，共感染者明显更有可能发展为AIDS痴呆综合征（Ryan等人，2004年）。尽管在合并感染中认知功能下降的结果一致，但迄今为止，尚未发表使用旨在研究合并感染对CNS影响的神经影像学的报告。有几项已发表的研究使用MRI技术来确定HCV单一感染对大脑的影响;在HCV中实施磁共振光谱（MRS）的研究已经发现了与白色物质完整性破坏相关的标志物（Weissenborn et.所有列表中的其他人）类似于MRS在HIV中的发现。在HIV中使用扩散张量成像（DTI）的研究数量有限，发现表明白色物质受损，即使在看起来正常的白色物质中也是如此（Stebbins等人，2007年）。在合并感染中发现的神经心理学缺陷和使用MRS在HCV中发现的类似结果，尽管有限，但提示了专门设计用于检查合并感染对大脑影响的额外研究。需要采用对白色物质变化敏感的新型成像技术来确定合并感染中发生的损伤程度，并可能导致早期诊断和改善神经系统症状的治疗。我们认为，由于DTI对检测白色物质结构完整性变化的特异性敏感性，DTI是检查CNS合并感染的最佳工具。此外，由于并非所有研究都确定了HCV合并感染状态对脑功能的显著影响，因此需要采用多学科方法，包括神经心理学评估，神经影像学指标和实验室数据。这项研究将比较一个样本的艾滋病毒阳性的个人艾滋病毒/丙型肝炎病毒共感染的个人的DTI措施，以及神经心理学测试，以确定在大脑中的共同感染的签名。这项拟议的研究将是第一个将这些地区具体纳入合并感染人群的研究。

It is estimated that almost a third of HIV-positive patients are co-infected with hepatitis C virus. Studies examining cognitive function in co-infected groups have found worse performance on neuropsychological examinations in a number of cognitive domains compared to groups with HIV or HCV alone (Cherner et al., 2008; Clifford et al., 2005; Hilsabeck,et al., 2005; Letendre et al., 2002; Martin et al., 2004; Parsons et al., 2006; Ryan et al., 2004; von Giesen et al., 2004). Additionally, it has been reported that co-infected persons are significantly more likely to develop AIDS dementia complex (Ryan et al., 2004). Despite the consistent findings of decreased cognitive functioning in co-infection, to date, there are no published reports using neuroimaging designed to study the impact of co-infection in the CNS. There are a few published studies using MRI techniques to determine the impact of HCV mono-infection on the brain; studies implementing Magnetic Resonance Spectroscopy (MRS) in HCV have found markers associated with the breakdown of white matter integrity (Weissenborn et. al list others) similar to MRS findings in HIV. There are a limited number of studies using diffusion tensor imaging (DTI) in HIV, with findings indicating white matter compromise, even in white matter that appears normal (Stebbins et al., 2007). The neuropsychological deficits found in co-infection and the similar findings in HCV using MRS, though limited, prompt additional research specifically designed to examine the effects co-infection on the brain. Novel imaging techniques that are sensitive to white matter changes need to be employed to determine the extent of injury that occurs in co-infection, and perhaps lead to earlier diagnosis and improved treatment of neurological symptoms. We believe DTI is the best tool to examine co-infection in the CNS, due to its specific sensitivity to detect changes in white matter structural integrity. Further, as not all studies have identified a significant effect of HCV co-infection status on brain function, a multidisciplinary approach is needed inclusive of neuropsychological assessment, neuroimaging indices and laboratory data. This study will compare a sample of HIV-positive individuals to HIV/HCV co-infected individuals on DTI measures, as well as neuropsychological tests, to determine the signatures of co-infection in the brain. The proposed study will be the first to integrate these areas specifically in a co-infected population.