Lin W R, Casas I, Wilcock G K, Itzhaki R F
Department of Optometry and Vision Sciences, UMIST, Manchester, UK.
J Neurol Neurosurg Psychiatry. 1997 Jun;62(6):586-9. doi: 10.1136/jnnp.62.6.586.
In studies on the possible role of viruses in the aetiopathogenesis of Alzheimer's disease, herpes simplex virus type 1 (HSV1) DNA was detected by the polymerase chain reaction (PCR) in a high proportion of normal elderly people and of patients with Alzheimer's disease. The combination of HSV1 and a host factor, the type 4 allele of the gene for apolipoprotein E, is a strong risk factor for the disease.
Brain specimens were examined for another herpes virus, varicella zoster (VZV), which, like HSV1, is neurotropic, has a predilection for residing latently in the peripheral nervous system, and can reactivate.
Using primers for sequences in the VZV origin of replication gene or thymidine kinase gene, VZV DNA was not found in any of 24 samples (18 HSV1 positive), from 17 patients with Alzheimer's disease, nor in 20 samples (12 HSV1 positive from 12 aged normal people. Hybridisation of the PCR products with a radiolabelled oligonucleotide probe capable of detecting less than 10 copies of the target sequence, confirmed the absence of VZV DNA.
The presence of one neurotropic virus--HSV1--and the absence of another--VZV--in aged human brains is consistent with a role for HSV1 in the aetiology of Alzheimer's disease.
在关于病毒在阿尔茨海默病病因发病机制中可能作用的研究中，通过聚合酶链反应（PCR）在高比例的正常老年人和阿尔茨海默病患者中检测到了1型单纯疱疹病毒（HSV1）DNA。HSV1与一种宿主因子——载脂蛋白E基因的4型等位基因相结合，是该疾病的一个强风险因素。
对脑标本进行另一种疱疹病毒——水痘带状疱疹病毒（VZV）的检测，该病毒与HSV1一样具有嗜神经性，倾向于潜伏在外周神经系统中，并且能够重新激活。
使用针对VZV复制起点基因或胸苷激酶基因序列的引物，在17例阿尔茨海默病患者的24个样本（18个HSV1阳性）中均未发现VZV DNA，在12名老年正常人的20个样本（12个HSV1阳性）中也未发现。PCR产物与能够检测少于10个靶序列拷贝的放射性标记寡核苷酸探针杂交，证实不存在VZV DNA。
在老年人大脑中存在一种嗜神经性病毒——HSV1，而另一种——VZV不存在，这与HSV1在阿尔茨海默病病因学中的作用是一致的。
