Dutch Press release : Positive ‘XMRV-study’ a matter of time Prague - May 3, 2010. Last October U.S. scientists presented a breakthrough around the research on chronic fatigue syndrome (CFS), which was published in Science. They found traces of the retrovirus XMRV in the blood of CFS patients. Thereafter, three groups of European researchers, including a Dutch group from Nijmegen, couldn’t confirm these findings. However, at the 'Centennial Retrovirus Meeting' in Prague it became clear that the first positive 'replication study' seems only a matter of time. The June issue of the Dutch magazine Ortho will focus on the multi-day conference in Prague, which ends today. Especially in the corridors this new retrovirus was the talk of the day. Insiders agree that the negative XMRV-studies which have been published so far, were not exact replication studies. The several groups of researchers used techniques that differed too much from those used by the U.S. researchers. This is also true for a yet unpublished German study, where XMRV wasn’t found in blood samples from CFS patients either. Recently the American scientist Dr. Judy Mikovits visited several European research groups to help them with the proper laboratory technique. It is now clear that these visits are starting to pay off. During the Prague Conference Mikovits explained once more in great detail the complex methodology of the Whittemore-Peterson Institute (WPI), the National Cancer Institute (NCI) and the Cleveland Clinic. This methodology of culturing the virus is imperative because XMRV is only present in extremely low concentrations in the peripheral blood. Dr. Francis Ruscetti of the renowned NCI – an U.S. government agency – told Ortho that he hopes this controversy will all die away in 2011. He is especially surprised about the fact that the investigators of the UMC St. Radboud at Nijmegen concealed in their publication that the Americans found traces of XMRV in the same blood samples from the Dutch patients. "I don’t know how they get away ethically with this," said Ruscetti. "I don’t think that is good science." Ruscetti pointed out again that the WPI, the NCI and the Cleveland Clinic applied four procedures in their research. "In those negative studies they only tried one." Ruscetti also ventilated his annoyance over what he calls the "whispering campaign" about contamination. According to the Nijmegen researchers, the Americans contaminated or polluted the Dutch blood samples. Among others Ruscetti is supported by Prof. Dr. John Coffin, who is linked both to the NCI and Tufts University in Boston. He is considered one of the most prominent retrovirologists in the world. "People have raised the issue of contamination," said Coffin. "But we don’t really know anything about that yet. We don’t have any evidence. A lot of the studies were done in fact at the NCI, in the lab of Francis and Sandra Ruscetti. They have a long experience with these viruses and are very carefull workers." Coffin emphasized once again that doing a replication study implies that it is performed in exactly the same way. "In none of the studies that have been published so far that were negative, the virus was cultured," said Coffin. "Only the Science-study did this, which is a very compelling point." Researchers from Nijmegen were not present at this leading conference.