HHV-6 & Chronic Fatigue Syndrome

 

Efforts to establish an association between HHV-6 infection and CFS have been complicated by the fact that several studies have been published using tests that don’t differentiate between active and latent HHV-6 infection. Studies that utilized such assays showed no association between HHV-6 and CFS, contradicting the positive studies and creating confusion. However, when assays able to distinguish active and latent infection have been employed (by surveying for specific agents such as IgG “early antigen” antibodies, which are present only during active viral infection), strong disease associations have been observed, suggesting an important role for HHV-6 in CFS.

For example, Ablashi et al found that 57% of CFS patients were positive for IgM early antigen antibodies, compared to only 8% of controls; this group also found that CFS patients had a greater lymphocyte response (Ablashi 2000). Buchwald et al found that 70% of 114 CFS patients were positive for HHV-6 by primary cell culture, as compared to 20% of controls (Buchwald 1992). However, when assays such as qualitative PCR testing on whole blood were used, there was often no significant difference found between patients and controls (Reeves 2000, Wallace 1999). This is because most healthy adults have a small amount of latent HHV-6 DNA in the whole blood.

Key Papers: HHV-6 & Chronic Fatigue Syndrome