Absence of XMRV Retrovirus and Other Murine Leukemia Virus-Related Viruses in Patients with Chronic Fatigue Syndrome

Abstract

Chronic fatigue syndrome (CFS) is a multisystem disorder characterized by prolonged and severe fatigue that is not relieved by rest. Attempts to treat CFS have been largely ineffective primarily because the etiology of the disorder is unknown. Recently, CFS has been associated with xenotropic murine leukemia virus-related virus (XMRV) as well as other murine leukemia virus (MLV)-related viruses, though not all studies have found these associations. We collected blood samples from 100 CFS patients and 200 self-reported healthy volunteers from the same geographical area. We analyzed these in a blind manner using molecular, serological, and viral replication assays. We also analyzed samples from patients in the original study that reported XMRV in CFS patients. We did not find XMRV or related MLVs either as viral sequences or infectious viruses, nor did we find antibodies to these viruses in any of the patient samples, including those from the original study. We show that at least some of the discrepancy with previous studies is due to the presence of trace amounts of mouse DNA in the Taq polymerase enzymes used in these previous studies. Our findings do not support an association between CFS and MLV-related viruses, including XMRV, and the off-label use of antiretrovirals for the treatment of CFS does not seem justified at present.

No Detection of Xenotropic Murine Leukemia Virus-Related Viruses in Prostate Cancer in Sanandaj, West of Iran

“…XMRV was also reported to be presence in patients with chronic fatigue syndrome (CFS) (Lombardi et al, 2009). However, the link between XMRV and CFS is unclear, because in other studies it has failed to detect XMRV infection in CFS patients Groom et al, 2010;Switzer et al, 2010;van Kuppeveld et al, 2010;Knox et al, 2011;Satterfield et al, 2011;Shin et al, 2011). However, gammaretroviruses are known to induce cancer in animals, understanding XMRV or related MLV infections in human prostate cancer tissues will shed light on their potential contribution to human disease.…”

Chronic Fatigue Syndrome and Viral Infections

“…This finding has raised speculation that it may cause the syndrome. However, four other laboratories could not replicate this finding, whilst four new studies found it only as a laboratory contaminant (Calaway, 2011;Cohen, 2011;Kaiser, 2011;Schutzer et al, 2011;Shin et al, 2011;Kean, 2010;Mayor, 2010;Sato et al, 2010;Stoye et al,2010;Coffin & Stoye, 2009). In 2011, at a retrovirology meeting in Boston, Massachusetts, researchers presented evidence that this retrovirus is, in effect, a laboratory artefact and not a human pathogen.…”

XMRV ist nicht human-pathogen und hat keine Bedeutung für die Sicherheit von Blut und Blutprodukten

“…In der Mehrzahl der später veröffentlich-ten Studien wurde XMRV jedoch in keiner einzigen Probe nachgewiesen [8,9,10,11,12,13]. Bei Wiederholungsuntersuchungen von zuvor am WPI im Rahmen der initialen Studie [3] positiv getesteten CFS-Patienten konnten in unabhängigen Laboren in keinem einzigen Fall XMRV oder spezifische Antikörper gegen XMRV-Proteine nachgewiesen werden, obwohl nahezu identische, hochsensitive Verfahren verwendet wurden [14,15]. Hiermit stellt sich die Frage, was die Ursache für den beschriebenen Nachweis von XMRV am WPI und an einem kommerziellen Labor sowie in den anderen Studien sein könnte.…”

“…Mehrere Arbeitsgruppen, die positive XMRV-Befunde erhalten hatten, konnten zeigen, dass ihre positiven Ergebnisse auf Kontaminationen mit muriner genomischer DNA zurückzuführen sind [16,17]. Die Quelle der Verunreinigung konnte in einigen Fällen identifiziert werden [15]. In DNA-Extraktionssäulen und in kommerziellen Polymerasepräparationen wurden Spuren muriner DNA nachgewiesen, die möglicherweise durch monoklonale Antikörper bei Reinigung der Polymerase eingebracht wurden [18,19].…”