Skip to main content

Verified by Psychology Today


MLV Joins XMRV As The Latest Unproven Cause of Chronic Fatigue Syndrome

I want my MLV.

The spinmeisters are spinning, the scientific community remains unsatisfied, and the chronic fatigue syndrome patient continues on the roller coaster ride provided by research demonstrating replicating retroviruses that is not always replicated in different research labs.

In a paper published today by "The Proceedings of the National Academy of Sciences", scientists found traces (in the form of gene sequences) of murine leukemia virus- (MLV) related viruses in 32 of 37 chronic fatigue syndrome patients; but in only 3 of 44 healthy blood donors.

The researchers did not find XMRV, as had been erroneously reported last month by a variety of sources. A paper published by the CDC at that time found no XMRV or other MLV-related viruses in patients with the syndrome.

Dr. Harvey Alter of the National Institutes of Health (NIH), the senior author of the work published today, stressed that his study does not prove that any of these viruses causes harm. It may be that individuals with chronic fatigue syndrome are more vulnerable to infection, including infection due to the several MLV-related viruses found in the patients in this latest research

MLV are known to cause cancer and neurological problems in mice, but it is not known whether they cause any diseases in human beings. XMRV is among several different members of the MLV family; and its conspicuous absence from the results in this study means that there remains no resolution as to the role XMRV may play in chronic fatigue syndrome.

It remains unclear why only two research teams have found evidence of these retroviruses. It is possible that different research teams are using significantly different methods of detection; and federal health officials are attempting to standardize the process. Of concern is the fact that the head of the federal tissue safety laboratory has been unable to isolate XMRV, whereas the group in Reno, Nevada claims to have done so.

Despite all the uncertainty, certain individuals are calling for treating chronic fatigue syndrome with agents used to treat another retrovirus, HIV. The pharamaceutical companies, while always interested in a new market for their wares, are wisely demurring, citing the need to await stronger evidence that such viruses cause chronic fatigue syndrome before launching large clinical trials of anti-HIV drugs for the treatment of chronic fatigue syndrome.

So, there was no conspiracy this summer. There was no consensus this summer. There was just summer.

It would behoove us to reflect on all the vitriol and misinformation that seems to be the only thing that XMRV has been shown to cause this long, hot summer.

More from Mark Borigini M.D.
More from Psychology Today