CFS Central emailed University of Utah's Dr. Ila Singh about her new XMRV study, which found no evidence of XMRV in ME/CFS patients. In 2009, Singh found evidence of the retrovirus in prostate-cancer tissue.
Singh: The samples from Mikovits' patients were all tested in a completely blinded fashion. We did not know which of them were positive, so could not use them as positive controls. But more accurately, there are no real patient 'positive controls' for XMRV. In order to use patient samples as controls, you'd have to first be absolutely certain that these patients have XMRV. How could you do that right now? So we used what you call a 'clone' for our PCR studies. But remember, this clone was isolated from a patient (a prostate cancer patient). And this is over 99% identical to the isolates from CFS patients described in Lombardi et al. For the viral culture studies, we used very small amounts of titrated virus that was grown in the lab as positive controls. And all of these positive controls were always positive.
Singh: The patient and their doctor did not make the decision to try antiretroviral drugs in a vacuum. It was based on reports of finding XMRV in CFS patients. We are now convinced that there is no XMRV in CFS patients--so the reason for starting those drugs does not exist. And there is no good evidence for continuing to use drugs that could lead to serious side effects of liver or bone-marrow failure.
Singh: That was our poor wording in the paper (the words in bold). All positive controls grew XMRV--as one would expect. None of the samples from the healthy controls or CFS patients grew any virus in culture. And of course the negative controls did not grow any XMRV.