Itzhaki Ruth
Molecular Neurobiology Laboratory, Department of Optometry and Neuroscience, University of Manchester Institute of Science and Technology, Manchester, UK.
Herpes. 2004 Jun;11 Suppl 2:77A-82A.
Various infectious agents, and viruses in particular, have been proposed as potential causes of Alzheimer's disease. Herpes simplex virus type 1 (HSV-1) is one of the stronger candidates because it is neurotropic, ubiquitous in the general population and able to establish lifelong latency in the host. The body of evidence for the role of HSV-1 in Alzheimer's disease is contentious but centres around its presence in the regions of the brain affected by Alzheimer's disease. The fact that HSV-1 is also present in elderly patients without the disease suggests that the virus is not an independent cause of the condition. The incidence of Alzheimer's disease is highest in carriers of the apolipoprotein (APO) E-e4 allele who harbour HSV-1 DNA in the CNS, so it is possible that these agents are co-factors for the disease. However, studies investigating this have been small and limited by the need to access brain tissue from non-diseased APOE-e4 carriers. Human herpesvirus type 6 (HHV-6) is another virus investigated as a potential contributor to Alzheimer's disease. However, it is uncertain whether its presence is a cause or a consequence of the disease and it may be that HHV-6 merely exacerbates the potentially harmful effects of HSV-1 in APOE-e4 carriers. It is difficult to ascertain the role of an infectious agent in Alzheimer's disease due to the difficulty of establishing the timepoint at which the agent becomes involved. Further research into the possible link between herpesviruses and Alzheimer's disease is therefore required.
多种传染因子，尤其是病毒，被认为是阿尔茨海默病的潜在病因。单纯疱疹病毒1型（HSV-1）是较为有力的候选因素之一，因为它具有嗜神经性，在普通人群中普遍存在，并且能够在宿主体内建立终身潜伏感染。关于HSV-1在阿尔茨海默病中作用的证据存在争议，但主要集中在其在受阿尔茨海默病影响的脑区中的存在情况。HSV-1在未患该病的老年患者中也存在这一事实表明，该病毒并非该病的独立病因。阿尔茨海默病的发病率在载脂蛋白（APO）E-e4等位基因携带者中最高，这些携带者的中枢神经系统中存在HSV-1 DNA，所以这些因素有可能是该病的共同致病因素。然而，对此进行研究的规模较小，且因需要获取未患病的APOE-e4携带者的脑组织而受到限制。人类疱疹病毒6型（HHV-6）是另一种被研究作为阿尔茨海默病潜在致病因素的病毒。然而，尚不确定其存在是该病的病因还是结果，可能HHV-6仅仅加剧了APOE-ei4携带者中HSV-1的潜在有害影响。由于难以确定传染因子介入的时间点，所以很难确定其在阿尔茨海默病中的作用。因此，需要进一步研究疱疹病毒与阿尔茨海默病之间可能存在的联系。
