The US
National Cancer Institute
Interim Guidelines for XMRV
The National Cancer Institute has responded to the recent
news of the XMRV and ME/CFS link, thanks to a request by the CFIDS Association.
The CFIDS Association was asking for guidelines for ME/CFS patients, their
families, and for the general public regarding their thoughts on XMRV.
Here is the response from the National Cancer Institute, as it is posted on
the
CFIDS Association Facebook page.
We at the National Cancer Institute (NCI) have great interest in these initial
research findings. At present, we agree that a critical issue to be addressed is
whether the exciting recent results obtained using samples from the Nevada
cohort can be reproduced in additional cohorts of CFS-afflicted individuals. The
NCI is striving to develop tools so that the general prevalence of XMRV in the
population can be ascertained, and the association of XMRV with disease can be
examined.
In the meantime, it is very important to reiterate what we do not know at this point, specifically:
1.
We do not know whether XMRV is a causative agent for CFS, prostate cancer, or
any other disease. Even if a causal association can be established, it may be
only one of many causes, and there may be other factors, genetic or
environmental, that determine the outcome of infection. At the moment, there is
no evidence of CFS transmission between family members, even though XMRV appears
to be an infectious agent.
Thus, it is unclear whether XMRV alone underlies CFS.
2.
We do not know how XMRV is transmitted from individual to individual. Recent
suggestions of sexual or salivary transmission are not based on direct evidence,
and conclusions regarding transmission are not credible at this point. Given the
frequent isolation of virus from white blood cells, blood-borne transmission is
a real possibility, and, while we are not in a position to establish firm
guidelines, prudence would dictate that potentially infected individuals refrain
from blood donation at this time.
3.
We do not know how many apparently healthy individuals are infected, and what
the distribution of infection is within the U.S. and in the worldwide
population. The National Cancer Institute is involved in coordinating a global
effort to study these issues.
It is very important to keep in mind that there is no evidence for a new
increasing or spreading XMRV infection. Further, no credible evidence exists for
direct transmission of either CFS or prostate cancer.
John E. Niederhuber,
M.D.
Director, National Cancer Institute, National Institutes of
Health
U.S. Department of Health and Human Services
October 23, 2009
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