CHRONIC FATIGUE SYNDROME: GAMMARETROVIRUS LINK

[dreamweaver]

CHRONIC FATIGUE SYNDROME: GAMMARETROVIRUS LINK ********************************************** A ProMED-mail post <http://www.promedmail.org> ProMED-mail is a program of the International Society for Infectious Diseases <http://www.isid.org>  Date: Thu 8 Oct 2009 Source: US News & World Report, Associated Press (AP) report [edited] <http://www.usnews.com/science/articles/2009/10/08/study-links-virus-to-chronic-fatigue-syndrome.html>   Study links virus to chronic fatigue syndrome --------------------------------------------- A virus recently linked to prostate cancer is a new suspect in  chronic fatigue syndrome. US scientists tested blood from 101  patients and found two-thirds carried it. That does not mean the  virus causes chronic fatigue, stressed the research published  Thursday [8 Oct 2009] in the journal Science [the abstract of this  paper is reproduced below].  The team of scientists from the National Cancer Institute and  Nevada's Whittemore Peterson Institute said it was possible the  virus, named XMRV [xenotropic murine leukemia virus-related virus]  was just "a passenger virus" that catches a ride in patients whose  immune systems are weakened by chronic fatigue.  Moreover, the researchers found nearly 4 percent of healthy people  carried the virus, too. That raises bigger questions about just what  role this recently discovered virus -- a relative of viruses that  cause cancer in mice -- may be playing in overall health. "This  suggests that several million Americans may be infected with a  retrovirus of as-yet-unknown pathogenic potential," the researchers concluded.  Various viruses have been linked to chronic fatigue over the years,  only to fall by the wayside as potential culprits in the mysterious  illness thought to afflict millions. It is characterized by at least  6 months of severe fatigue, impaired memory, and other symptoms, but  there's no test for it -- doctors rule out other possible causes --  and no specific treatment.  XMRV is related to mouse leukemia viruses. No one knows how it arose  or how people become infected. But another research team recently  found the virus lurking in about a quarter of 200 prostate tumors --  and in about 6 percent of non-cancerous prostate samples they used  for comparison. [See below and: Retrovirus XMRV is found in prostate  cancer cells <http://www.pnas.org/content/104/5/1449.full>]. "There  is still much that we do not understand," including whether people  with either disease just are more prone to infection, cautioned Tufts  University microbiologist John Coffin in an accompanying editorial.  Still, "further study may reveal XMRV as a cause of more than one  well-known 'old' disease."  XMRV was discovered just a few years ago. Researchers reported in  2007 that they had found it in prostate cancer tissue, but no one  knew what that meant because no one knew anything about the virus.  Researchers are now looking for the XMRV in other types of human  tumors, including breast cancer; and they are trying to find out  whether the virus causes the tumors to develop, or is just there incidentally.  -- Communicated by: Powell Gammill Phoenix, AZ, USA <pgammill@cox.net>  [The following are the details of the Science Express paper discussed  in the report above  (<http://www.sciencemag.org/cgi/content/abstract/sci;1179052v1>):  Detection of an Infectious Retrovirus, XMRV, in Blood Cells of  Patients with Chronic Fatigue Syndrome. Science Express, 8 Oct 2009 ---------------------------------------------------------------------- [Authors: Vincent C Lombardi1, Francis W Ruscetti2, Jaydip Das  Gupta3, Max A Pfost1, Kathryn S Hagen1, Daniel L Peterson1, Sandra K  Ruscetti4, Rachel K Bagni5, Cari Petrow-Sadowski6, Bert Gold2,  Michael Dean2, Robert H Silverman3, Judy A Mikovits1 1. Whittemore Peterson Institute, Reno, NV 89557, USA. 2. Laboratory of Experimental Immunology, National Cancer  Institute-Frederick, Frederick, MD 21701, USA. 3. Department of Cancer Biology, The Lerner Research Institute, The  Cleveland Clinic Foundation, Cleveland, OH 44106, USA. 4. Laboratory of Cancer Prevention, National Cancer  Institute-Frederick, Frederick, MD 21701, USA. 5. Advanced Technology Program, National Cancer Institute-Frederick,  Frederick, MD 21701, USA. 6. Basic Research Program, Scientific Applications International  Corporation, National Cancer Institute-Frederick, Frederick, MD 21701, USA.]  Abstract -------- "Chronic fatigue syndrome (CFS) is a debilitating disease of unknown  etiology that is estimated to affect 17 million people worldwide.  Studying peripheral blood mononuclear cells (PBMCs) from CFS  patients, we identified DNA from a human gammaretrovirus, xenotropic  murine leukemia virus-related virus (XMRV), in 68 of 101 patients (67  percent) compared to 8 of 218 (3.7 percent) healthy controls. Cell  culture experiments revealed that patient-derived XMRV is infectious  and that both cell-associated and cell-free transmission of the virus  are possible. Secondary viral infections were established in  uninfected primary lymphocytes and indicator cell lines following  exposure to activated PBMCs, B cells, T cells, or plasma derived from  CFS patients. These findings raise the possibility that XMRV may be a  contributing factor in the pathogenesis of CFS."  The earlier paper in Proceedings of the National Academy of Sciences  reported that a retrovirus known as "xenotropic murine leukemia  virus-related virus" (XMRV) has been found in tumor tissue from men  with prostate cancer. Of 233 prostate tumors tested, 23 percent had  evidence of the virus, while only 4 percent of samples from 101 men  with benign prostatic enlargement contained the virus. The tumors  that scored the highest on a 10-point scale of severity were more  likely to contain the virus than tumors that were less severe. (Of  the tumors scoring 9 or higher on the 10-point scale, 44 percent had  the virus in the tumor cells.) XMRV was discovered just a few years  ago. Researchers reported in 2007 that they had found it in prostate  cancer tissue, but no one knew what that meant because no one knew  anything about the virus (<http://www.pnas.org/content/104/5/1449.full>).  In neither of these situations is there an exact correlation between  the presence of XMRV and the diseases/conditions concerned. Further  research will be required to establish the precise role of XMRV in  human prostate cancer and chronic fatigue syndrome.