A new human retrovirus, discovered in 2006 from tissue samples of a rare human prostate cancer, has some health officials concerned that it might be transmissible via blood transfusions.
According to the Centers for Disease Control and Prevention (CDC), the xenotropic murine leukemia virus-related virus (XMRV) is thought to infect many types of human cells, including some types of blood cells. It could possibly present a threat to blood safety. In addition, a potential link between XMRV and chronic fatigue syndrome (CFS) in humans was reported by researchers in a 2009 study. The report showed that XMRV was found in approximately two-thirds of CFS patients. However, other studies showed an absence of XMRV in individuals with CFS. In short, it is not yet known whether XMRV actually causes CFS or its exact mode of transmission. In addition, the overall prevalence of XMRV in the general population has not yet been determined. Federal agencies and others are trying to find answers.
Multiple studies are currently underway to establish how XMRV may be transmitted, including through the blood supply. The Department of Health and Human Services (HHS) is working with industry and academic institutions to determine if XMRV is transmissible via blood transfusions. It is also conducting studies to verify the prevalence of XMRV in the blood donor population in case risk-reduction measures need to be taken. The National Institutes of Health, the U.S. Food and Drug Administration and blood banks are also participating in the effort.
The National Hemophilia Foundation has issued the following statement:
The National Hemophilia Foundation is aware of reports concerning the xenotropic murine leukemia virus-related virus (XMRV) that is being investigated as a possible risk to the blood supply. There are ongoing investigations into whether this virus causes chronic fatigue syndrome. The Canadian Blood Service is deferring individuals with chronic fatigue syndrome from donating blood due to the uncertainty of whether this virus can be transmitted in the blood supply.
XMRV is an enveloped retrovirus; this type of virus has been demonstrated to be inactivated through viral inactivation processes (heat-treatment, solvent-detergent) that are employed during the production of clotting factor products. Thus, it is highly unlikely that this virus would pose a risk to users of clotting factor concentrates.
NHF is in communication with the FDA regarding its efforts to investigate this issue and will keep the community informed of any new developments.
An overview of XMRV, plus a Q&A concerning the virus, can be found on the CDC’s Web site.
Source: The Wall Street Journal (online), April 4, 2010