CFIDS analyse av det siste XMRV-studie fra England
Suzanne D. Vernon, PhD, Scientific Director hos CFIDS har kommet med en analyse av det siste XMRV-studie fra England.
«The Retrovirology study found evidence of XMRV by detecting specific antibodies in samples from study subjects, demonstrating that XMRV has infected people. But like the other study from the U.K. reported in PLoS ONE, this study did not detect XMRV at a higher rate in people with CFS. Why? The PCR technique used in the paper was identical to the Science paper and other methods they used could be considered better and more sensitive. The antibodies used by the two labs were different, though. These investigators did not test quite as many healthy control blood samples (157 in the SGUL cohort) as did the authors of the Science paper (218 healthy controls), which found XMRV in 3.7% of healthy controls. (The source of healthy control samples was not described in the Science paper.) Perhaps more important is that this Retrovirology paper tested for XMRV in healthy blood donors; blood donors are screened for many things and are likely to be a much healthier group than controls obtained from the general population. The inclusion of the BLT comparison group of individuals with other conditions was new for this study.
Why wasn’t XMRV DNA found in the CFS samples? One difference between the CFS patients selected for the SGUL cohorts and those tested in the Science paper might be severity and duration of illness. The SGUL CFS cohort blood samples were taken relatively early in course of CFS (1-4 years). The CFS patients in the Science paper were severely ill in addition to having immune dysfunction, although specific characteristics have not been released. It could simply be that the CFS patients in the SGUL cohorts were not comparable (e.g., as sick as long) to those studied in the Science paper. However, Dr. Kerr’s reputation and experience in CFS/ME research, along with his current collaborations with the Whittemore Peterson Institute, suggest that he would have taken care to use similar selection criteria in his design of the study. (It is noted in the acknowledgements that “JK” – Jonathan Kerr – was one of the three authors who conceived of and designed the study.)»
Les hele analysen HER