XMRV and Chronic Fatigue Syndrome: Repressed, Reprieved, Or Rehashed?

And you thought herpes was the virus that never goes away!

Posted Jul 09, 2010

In the last week or so, we have heard of another set of conflicting research results regarding chronic fatigue syndrome and the virus known as xenotropic murine leukemia virus-related virus (XMRV). The conflict is simple: one group of researchers reportedly found a link between XMRV and chronic fatigue syndrome, and the other did not.

The rumor is that a hold has been placed on the publishing of the respective findings, despite being accepted for publication. This rare occurrence has created concern for many whose lives are impacted by chronic fatigue syndrome, from fellow scientists to patients, from conspiracy theorists to the more non-specifically touched. What is going on here?

Supposedly, scientists at the United States National Institutes of Health (NIH) and the Food and Drug Administration (FDA) were reported to have confirmed the link, first published in the journal "Science" last year. In contrast, the United States Centers for Disease Control and Prevention (CDC) failed to find such a link. The "Wall Street Journal" reported on June 30 that both papers were put on hold, but I was able to review the CDC group's paper, published in internet form earlier this month in the journal "Retrovirology". The FDA/NIH paper was to be published in the journal "Proceedings of the National Academy of Sciences of the United States of America"; I have not been able to access that.

Reportedly, senior public health officials wished to have an explanation as to the reasons the research groups came to different conclusions, and thus the two teams were asked to put their papers on hold. In fact, it is not unusual for scientists to generate conflicting data, particularly in the case of a new virus that has not been well-characterized. Further, it is not unreasonable to review and re-review conflicting data regarding XMRV, as there has already been so much conflict generated in the course of the research of this virus.

Recall the skepticism engendered by the publication in "Science". Not only were there rebuttals and critiques subsequently published in "Science", but shortly thereafter two groups in the United Kingdom and one in the Netherlands published papers failing to find a link between XMRV and chronic fatigue syndrome, and several other groups from the United States and Europe have also reported negative findings.

So, at this time we can all only wait for the final product of the FDA/NIH research to be made public. The CDC conclusions, as published in "Retrovirology" are out for the world to see: "In our study population of CFS and healthy persons from the US, we did not find any evidence of infection with XMRV using PCR and serologic methods performed independently in three laboratories blinded to the clinical status of the study participants. These results do not support an association of XMRV with CFS."

The world waits for the next set of conclusions, and wonders if any study on XMRV will ever be deemed conclusive.