As we have shown with the cytokine gene expression studies, patient with severe fibromyalia actually did not have quite as bad Th2/Th1 imbalance, as comparing to patients with debilitating fatigue without as much myalgia. Conversely, the viral proteins seen in the stomach biopsy are much more abundant in CFS patients than that in fibromyalgia patients (unpublished data). CFS and fibromyalgia are probably the two ends of the same spectrum: one end has much more viruses but little immune response, the other end has few viruses in the tissues but very severe and yet ineffective inflammatory response. I have often seen patients progress from severe CFS to fibromyalgia over several years.
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Interestingly, the use of antibiotics for Mycoplasma has no clear benefit in most patients with CFS/fibromyalgia and GWS. This may mean that Mycoplasma is not important in these diseases. The benefit seen in some patients may be due to the way the antibiotics (doxycycline, zithromax) modulate the immune system rather than the antimicrobial effect, as we have seen in patients with rheumatoid arthritis.