New Study: CFS Yields Distinct Immune Signature
(May 14th, 2011) -- According to researchers at the University of Reno and the Whittemore Peterson Institute, chronic fatigue syndrome (CFS) patients demonstrate an atypical immune response. In a blinded and controlled study published in the May 2011 issue of In vivo, 118 patients who met a well-defined diagnosis for CFS were tested for levels of a variety of cytokines using Xmap technology. The researchers found that CFS patients exhibited different cytokine expression than healthy controls.
The researchers found that they were able to accurately identify 96 percent of CFS patients by identifying differences in cytokine levels. Of 26 cytokines examined, 11 were upregulated, and 8 were downregulated in CFS patients. The cytokine with the most difference was IL-8, a cytokine typical of inflammatory response. The authors state that "CFS patients display an inflammatory cytokine and chemokine signature that distinguishes them from healthy control subjects".
The researchers incorporated testing for murine leukemia viruses (MLV's) into the design, using patients who tested positive for XMRV. Because recent studies have failed to find murine leukemia viruses in CFS or healthy controls, some researchers have urged the scientific community to abandon CFS and retroviral research. The issue will be resolved later this year. Despite the controversy over the link between CFS and retroviruses, this study's authors allow for possible theories for the CFS that do not involve retroviruses: "If future studies establish that disease status is not determined by XMRV variation, it is possible that other conditions, such as a compromised immune system, predisposing genetics, or co-infections with other pathogens, may be necessary to manifest disease."