Wellcome Trust Researchers Respond to Criticism of Their XMRV Virus Conclusions
London, UK (Scicasts) - Last week (on Thursday, January 6th, 2011), we published the story: Chronic Fatigue Syndrome Not Caused By XMRV Virus, reporting the Wellcome Trust's research which stated that XMRV virus – previously thought to be associated with chronic fatigue syndrome – is not the cause of the disease. We received many comments and e-mails from our readers criticizing Wellcome Trust's conclusions and we have asked their leading scientists, who published the report, to respond to our readers.
Below, is the official statement that we have received from Professors Greg Towers and Paul Kellam:
"On 20 December 2010, the peer-review journal Retrovirology published a series of papers relating to XMRV, a virus previously linked to CFS/ME. These included our paper, Disease-associated XMRV sequences are consistent with laboratory contamination by Hue et al at University College London (UCL) and the Wellcome Trust Sanger Institute, with funding from a number of organisations including the Wellcome Trust.
In our study, we showed that it is extremely unlikely that XMRV is a human pathogen or one which transmits between humans. There has been much discussion of what exactly we can and did conclude from our observations. We would like to take this opportunity to reiterate the following.
Comparison of XMRV found in patients and XMRV found in the prostate cancer cell line 22Rv1 tells us that patient-derived XMRV sequences do not contain sequence variation that invariably accompanies transmission of retroviruses between individuals. XMRV is like any other virus: it has a genome, which, when replicated during the process of infection, accumulates mutations, with the number of mutations acting as a counter for the number of replication events. XMRV is not able to replicate without variation and we showed this by determining the sequence variation of the virus in the 22Rv1 cells. Thus we can conclude that XMRV sequences from CFS samples are not from a virus that has transmitted between individuals and thus cannot be the cause of chronic fatigue syndrome or prostate cancer.
Our study did not address the issue of anti-MLV antibodies in CFS patients and we therefore cannot conclude anything about these observations.
We recognise that chronic fatigue syndrome/ME is a very real and distressing condition. It is important to recognize that we are not claiming that CFS/ME is not caused by a virus – this may well still be the case. It is still not clear what causes the condition and it is important that scientists explore all avenues of research to identify its cause or causes and enable better treatments. Read more>>
See ALSO: What cell line 22Rv1 tells us about XMRV