Preliminary results from a randomized clinical trial led by Stanford physician Jose Montoya to evaluate the use of valganciclovir in a subset of patients with chronic fatigue syndrome (CFS) have been published in the Journal of Medical Virology this month. In the study, thirty CFS patients with elevated IgG antibody titers against HHV-6 and EBV were randomized 2:1 to receive valganciclovir (VGCV) or placebo for 6 months in a double-blind, placebo-controlled trial. Clinical endpoints of the study were aimed at measuring physical and mental fatigue, while biological endpoints included monocyte and neutrophil counts as well as cytokine levels.
Statistically significant differences in trajectories between groups were observed in the MFI-20 mental fatigue subscore (P = 0.039), FSS score (P = 0.006), and overall cognitive function (P = 0.025). Furthermore, VGCV patients experienced these improvements within the first 3 months and maintained that benefit over the remaining 9 months. Patients receiving VGCV were found to be 7.4 times more likely to be classified as responders (P = 0.029). VGCV patients’ monocyte counts decreased (P < 0.001), neutrophil counts increased (P = 0.037) and cytokines were more likely to evolve towards a Th1-profile (P < 0.001). Interestingly, viral IgG antibody titers did not differ between patient and control groups.
This study indicates that VGCV may have a clinical benefit among a subset of CFS patients with HHV-6 and EBV infection, independent of placebo effect, and possibly mediated by immunomodulation and/or antiviral effect. The authors of the study state that further investigation with longer treatment duration and a larger sample size is warranted.
Dr. Jose Montoya, a top infectious disease physician at Stanford known internationally for his work in the field of Chronic Fatigue Syndrome, is a longtime member of the HHV-6 Foundation Scientific Advisory Board. Dr. Montoya has previously published two additional papers on this subject, including a preliminary study in 2006 (Kogelnik 2006) and a retrospective graphical analysis of 61 CFS patients who received long term treatment with valgnaciclovir. In this study, 52% of patients responded to treatment, and 81% of responders showed improvement in cognitive functioning (Watt 2012).
The HHV-6 Foundation funded Dr. Montoya’s pilot study, and helped persuade Roche to fund the placebo controlled trial.