Wednesday, February 23, 2011
New US study finds no XMRV in ME/CFS but again FAILS to culture
Brent C. Satterfield , Rebecca A. Garcia , Hongwei Jia , Shaohua Tang , HaoQiang Zheng and William M. Switzer:
Retrovirology 2011, 8:12doi:10.1186/1742-4690-8-12
Published: 22 February 2011
In 2009, a newly discovered human retrovirus, xenotropic murine leukemia virus (MuLV)-related virus (XMRV), was reported by Lombardi et al. in 67% of persons from the US with chronic fatigue syndrome (CFS) by PCR detection of gag sequences. Although six subsequent studies have been negative for XMRV, CFS was defined more broadly using only the CDC or Oxford criteria and samples from the US were limited in geographic diversity, both potentially reducing the chances of identifying XMRV positive CFS cases.
A seventh study recently found polytropic MuLV sequences, but not XMRV, in a high proportion of persons with CFS. Here we tested blood specimens from 45 CFS cases and 42 persons without CFS from over 20 states in the United States for both XMRV and MuLV. The majority of CFS patients (31/45, 69%) had a minimum of 6 months of post-exertional malaise and a high degree of disability, the same key symptoms described in the Lombardi et al. study.
Using highly sensitive and generic DNA and RNA PCR tests, and a new Western blot assay employing purified whole XMRV as antigen, we found no evidence of XMRV or MuLV in all 45 CFS cases and in the 42 persons without CFS. Our findings, together with previous negative reports, do not suggest an association of XMRV or MuLV in the majority of CFS cases.
My PS: we know that XMRV is hard to find, and that you need to CULTURE for 45 days, yet again a negative study DID NOT do any cultures.