title: Multiple sources of contamination in samples from patients reported to have XMRV infection.
abstract: Xenotropic murine leukemia virus (MLV)-related retrovirus (XMRV) was reported to be associated with prostate cancer by Urisman, et al. in 2006 and chronic fatigue syndrome (CFS) by Lombardi, et al. in 2009. To investigate this association, we independently evaluated plasma samples from 4 patients with CFS reported by Lombardi, et al. to have XMRV infection and from 5 healthy controls reported to be XMRV uninfected. We also analyzed viral sequences obtained from supernatants of cell cultures found to contain XMRV after coculture with 9 clinical samples from 8 patients. A qPCR assay capable of distinguishing XMRV from endogenous MLVs showed that the viral sequences detected in the CFS patient plasma behaved like endogenous MLVs and not XMRV. Single-genome sequences (N = 89) from CFS patient plasma were indistinguishable from endogenous MLVs found in the mouse genome that are distinct from XMRV. By contrast, XMRV sequences were detected by qPCR in 2 of the 5 plasma samples from healthy controls (sequencing of the qPCR product confirmed XMRV not MLV). Single-genome sequences (N = 234) from the 9 culture supernatants reportedly positive for XMRV were indistinguishable from XMRV sequences obtained from 22Rv1 and XMRV-contaminated 293T cell-lines. These results indicate that MLV DNA detected in the plasma samples from CFS patients evaluated in this study was from contaminating mouse genomic DNA and that XMRV detected in plasma samples from healthy controls and in cultures of patient samples was due to cross-contamination with XMRV (virus or nucleic acid).
authors.affiliation: HIV Drug Resistance Program, National Cancer Institute, Frederick, Maryland, United States of America. kearneym@mail.nih.gov
authors.forename: Mary F
authors.initials: MF
authors.lastname: Kearney
authors.forename: Jonathan
authors.initials: J
authors.lastname: Spindler
authors.forename: Ann
authors.initials: A
authors.lastname: Wiegand
authors.forename: Wei
authors.initials: W
authors.lastname: Shao
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Anderson
authors.forename: Frank
authors.initials: F
authors.lastname: Maldarelli
authors.forename: Francis W
authors.initials: FW
authors.lastname: Ruscetti
authors.forename: John W
authors.initials: JW
authors.lastname: Mellors
authors.forename: Steve H
authors.initials: SH
authors.lastname: Hughes
authors.forename: Stuart F J
authors.initials: SF
authors.lastname: Le Grice
authors.forename: John M
authors.initials: JM
authors.lastname: Coffin
mesh_terms: D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D059018:DNA Contamination; D004279:DNA, Viral / Q000097:blood / Q000235:genetics; D015673:Fatigue Syndrome, Chronic / Q000097:blood / Q000235:genetics / Q000821:virology; D005260:Female; D015686:Gene Products, env / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012192:Retroviridae Infections / Q000097:blood / Q000235:genetics* / Q000821:virology*; D013347:Subcellular Fractions / Q000378:metabolism; D058008:Xenotropic murine leukemia virus-related virus / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D004279:DNA, Viral; D015686:Gene Products, env