CFS and XMRV: no relations
UK research has taken issue with previous findings by US researchers that chronic fatigue syndrome might be linked to a recently-discovered virus known as XMRV.
XMRV (xenotropic murine leukaemia virus-related virus) is a gammaretrovirus first described in 2006. The US research linking it with CFS was published in Science in 2009. Since XMRV was first described, there has been much debate over whether or not it is associated with a number of other conditions, including prostate cancer, and with such infective agents as Epstein Barr Virus and Giarda parasites.
The UK research - which sought to replicate the Science findings - was carried out by teams from King's College London - which has been running an NHS service for CFS patients for almost 20 years - and Imperial College London.
King's sent blood samples from 186 CFS patients plus control samples from healthy patients to Imperial's Retrovirology Laboratory, which extracted and analysed the DNA in all the samples using the highly sensitive polymerase chain reaction (PCR) technique, without finding any molecular evidence of the XMRV virus.
This means, the researchers say, that anti-retrovirals should not be used to treat CFS because they would be unlikely to have any effect on the symptoms.
The London researchers say that they are confident that their work shows that there is no link between XMRV and CFS, "at least in the UK". (It has been reported in the US that CFS patients are receiving treatments based on the XMRV link reported in Science.)
Prof Myra McClure, from Imperial College, insisted that the research was carried out under rigorous conditions.
"We looked at samples from well-studied patients and we used very sensitive testing methods to look for the virus. If it had been there, we would have found it," she said. "The lab in which we carried out the analysis had never housed any of the murine leukaemia viruses related to XMRV, and we took great care to ensure that there was no contamination."
Published: 15 Mar 2010