XMRV Is…..Is……Is…..There!

May 21, 2010

Posted by Cort Johnson

XMRV is…is…..is….There! – Yes, someone actually found XMRV. (gasp!). They weren’t looking for it in the blood or in the prostate tissue or in CFS patients and no, it wasn’t a US Lab that found it, it was a German lab remarkably enough but after months of no positive results it was remarkable finding…XMRV appears to be alive and well in Europe, and, of course, if it’s there it’s probably everywhere.

This German team lead by Dr. Fisher looked for XMRV in respiratory secretions – a highly targeted bodily fluid by researchers, no doubt, because of worries about XMRV’s infectious nature. Since many viruses are spread by coughing, kissing (eg EBV – we know all about that one) or sneezing, one of the first areas (after the blood) researchers will want to about is the respiratory system.

These researchers used PCR to search for XMRV (and other viruses) in respiratory samples from about 260 people with respiratory infections who were healthy, had chronic obstructive pulmonary disorder or who were immunocompromised because they had undergone an organ transplant.

They found XMRV in about 3.2% of the healthy controls and COPD patients and in about 10% in the immunocompromised patients. The increased prevalence in the immunocompromised patients, of course, suggested that the immune system plays an important role in keeping this virus in check, and that if it is compromised then the virus can either be reactivated or perhaps gain entry into the body.

Just An Opportunistic Virus?- What does this say about CFS? It’s hard to tell. We’ve always known that XMRV could be an ‘opportunistic virus’; ie, one that does not cause ME/CFS but exploits the damage that has already occurred. Is that what this study is saying? That XMRV is probably going to be a ‘hanger on’ virus that maybe adds to the burden of the illness but does not cause it? That’s what appears to be happening in these immunocompromised patients. Indeed, if you were going to find an infectious retrovirus anywhere you’d probably find it in these transplant patients because the drugs they take turn down the immune response causing them sometimes to collect pathogens.

Some would say the same type of process occurs in ME/CFS; that the immune abnormalities in CFS allow pathogens to flourish. Not everybody, though, thinks the amount of immune dysfunction found in CFS is particularly significant. Some researchers certainly do but others characterize it as ‘mild immune dysfunction’. Since XMRV appears to be 6-7 or more times more prevalent in ME/CFS than in these post-transplant patients one would think their degree of immune suppression would need to be 6-7 times higher for the ‘opportunistic paradigm’ to hold true.

On the face of it one wouldn’t think it is. If its not, then we have to ask why XMRV would show up in such a large percentage of CFS patients and in such smaller percentages in patients the medical profession in general really does consider immunocompromised?

Or a Special Virus For ME/CFS? - This could happen if this virus that somehow targeted CFS patients. My guess is that XMRV is still a special problem for CFS patients and that it just happens to be in immune compromised patients (along with whatever other pathogens they have) – as well; ie the theory that XMRV could cause ME/CFS is still alive and well.

The study illustrates how little we know about XMRV and is hopefully a portrend of things to come with XMRV being assessed in all sorts of body fluids and in all sorts of diseases. Will it show up in other diseases in similar portions as in ME/CFS (thus diluting its impact on ME/CFS) or will it continue to be a ‘special virus’ for CFS? Only time will tell.

A Big Win - My takeaway from this study is that, unless this lab made a big error somewhere, the WPI’s finding of XMRV is considerably strengthened and this study is a big and much needed win for them. It shows that XMRV is present, puts into question the findings of the three negative studies, and puts the onus on other researchers to find it. The similar prevalence of XMRV in health controls (3.2% – 4.0%) despite the different tissues examined (respiratory secretions vs blood) was encouraging. The fact that these researchers did not use the WPI’s techniques to find the virus further strengthens the overall XMRV finding.

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