Center for Biologics Evaluation and Research, Bethesda, MD 20892, USA.
Proc Natl Acad Sci U S A. 2010 Sep 7;107(36):15874-9. doi: 10.1073/pnas.1006901107. Epub 2010 Aug 23.
Chronic fatigue syndrome (CFS) is a serious systemic illness of unknown cause. A recent study identified DNA from a xenotropic murine leukemia virus-related virus (XMRV) in peripheral blood mononuclear cells (PBMCs) from 68 of 101 patients (67%) by nested PCR, as compared with 8 of 218 (3.7%) healthy controls. However, four subsequent reports failed to detect any murine leukemia virus (MLV)-related virus gene sequences in blood of CFS patients. We examined 41 PBMC-derived DNA samples from 37 patients meeting accepted diagnostic criteria for CFS and found MLV-like virus gag gene sequences in 32 of 37 (86.5%) compared with only 3 of 44 (6.8%) healthy volunteer blood donors. No evidence of mouse DNA contamination was detected in the PCR assay system or the clinical samples. Seven of 8 gag-positive patients tested again positive in a sample obtained nearly 15 y later. In contrast to the reported findings of near-genetic identity of all XMRVs, we identified a genetically diverse group of MLV-related viruses. The gag and env sequences from CFS patients were more closely related to those of polytropic mouse endogenous retroviruses than to those of XMRVs and were even less closely related to those of ecotropic MLVs. Further studies are needed to determine whether the same strong association with MLV-related viruses is found in other groups of patients with CFS, whether these viruses play a causative role in the development of CFS, and whether they represent a threat to the blood supply.
慢性疲劳综合征（CFS）是一种病因不明的严重全身性疾病。最近的一项研究通过巢式 PCR 从 101 名患者中的 68 名（67%）的外周血单个核细胞（PBMC）中鉴定出了源自异嗜性鼠白血病病毒相关病毒（XMRV）的 DNA，而在 218 名健康对照者中仅发现 8 名（3.7%）。然而，随后的四项研究均未能在 CFS 患者的血液中检测到任何鼠白血病病毒（MLV）相关病毒基因序列。我们检查了符合 CFS 公认诊断标准的 37 名患者的 41 份 PBMC 衍生 DNA 样本，发现 37 名患者中有 32 名（86.5%）存在 MLV 样病毒 gag 基因序列，而 44 名健康志愿者血液供体中仅有 3 名（6.8%）存在。在 PCR 检测系统或临床样本中均未检测到鼠 DNA 污染的证据。在近 15 年后获得的样本中，8 名 gag 阳性患者中有 7 名再次检测为阳性。与报告的所有 XMRV 具有近乎遗传同一性的发现相反，我们鉴定出了一组遗传多样性的 MLV 相关病毒。与 XMRV 相比，CFS 患者的 gag 和 env 序列与多嗜性鼠内源性逆转录病毒更为密切相关，与嗜性 MLV 则更为不相关。需要进一步的研究来确定在其他 CFS 患者群体中是否也发现了与 MLV 相关病毒的相同强关联，这些病毒是否在 CFS 的发展中起因果作用，以及它们是否对血液供应构成威胁。
