Study: XMRV retrovirus is not present in chronic fatigue syndrome patients

April 17, 2016

It comprises a larger set of patients who fall under well-recognized criteria for CFS Patients and controls were from the same geographical area, which was not true for either of the previous studies that showed a correlation between XMRV and CFS They analyzed blood samples using multiple, well-defined, sensitive and specific methods, including methods used in the original study Unlike many other studies, Singh and her colleagues used blinded methods to evaluate samples Singh's study tested blood samples obtained from individuals tested in the original 2009 study

XMRV is closely related to many mouse retroviruses, and contamination of blood samples or testing reagents with mouse DNA could result in a false-positive test for XMRV. Singh and her colleagues found that some of the positives obtained in other CFS-XMRV studies could be due to the presence of mouse DNA in a reagent used in testing; other positives could be attributed to carry-over of XMRV from positive controls to other samples.

In her own study, Singh initially obtained false positives for XMRV in blood samples. But she determined those false readings were related to robotic equipment that previously had been used for extraction of DNA from XMRV-infected tissue culture cells. Several months later, this equipment led to new samples getting contaminated. When the robotic equipment was abandoned, no more false positives were detected in either CFS patients or healthy patients. "It's easy to see how sample extraction and tissue culture processes might be vulnerable to contamination," Singh said.

Although she found no evidence for XMRV or any related virus in either her study samples or those tested at the Whittemore Peterson Institute, Singh says there is much data to encourage further research into whether other infectious agents are associated with CFS.

"These research efforts must continue," she says. "Chronic fatigue syndrome is a devastating disease for which a cure needs to be found."

Source: University of Utah Health Sciences