In 2009 a controversial study published in Science made an extraordinary claim: Chronic fatigue syndrome, whose cause had long been unknown, could be linked to a retrovirus that first arose in mice. According to retroviral immunologist Judy Mikovits of the Whittemore Peterson Institute (WPI) in Reno, Nevada, xenotropic murine leukemia virus–related virus, or XMRV, was present in 68 out of 101 people with chronic fatigue syndrome, compared with only 8 of 218 healthy controls.
Extraordinary finds like these must be replicated at other labs, however, and subsequent studies could not corroborate the results. Then, last September, a crushing blow came when Science published a study by nine independent labs, including Mikovits’s own, that failed to confirm the presence of XMRV in patients with chronic fatigue. In fact, researchers at WPI could identify only 6 out of 10 positive samples that they themselves had supplied. The theory came under additional fire when one of the authors of the original Science study, Robert Silverman, announced that further research on his part showed the positive specimens from chronic fatigue patients had actually been contaminated with XMRV DNA. All the authors, including Mikovits, offered a partial retraction of the paper.
Nevertheless, Mikovits is not giving up on her search for a retroviral cause for the illness. At an October presentation on her work at the International Association for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis in Ottawa, she suggested that a related retrovirus in the same family as XMRV (gammaretroviruses) was actually behind chronic fatigue syndrome. Other scientists have grown increasingly skeptical, however. In the fall WPI announced that Mikovits had been terminated.
The final word may have to wait until completion of a multicenter study coordinated by Ian Lipkin, a molecular biologist at Columbia University. “Even if we cannot implicate gammaretroviruses like XMRV in chronic fatigue syndrome,” says Lipkin, “their discovery must be credited with focusing new researchers and resources on this complex and crippling disorder.”
