Elevation of bioactive transforming growth factor-β in serum from patients with chronic fatigue syndrome

The level of bioactive transforming growth factor-β (TGF-β) was measured in serum from patients with chronic fatigue syndrome (CFS), healthy control subjects, and patients with major depression, systemic lupus erythematosis (SLE), and multiple sclerosis (MS) of both the relapsing/remitting (R/R) and the chronic progressive (CP) types. Patients with CFS had significantly higher levels of bioactive TGF-β levels compared to the healthy control, major depression, SLE, R/R MS, and CP MS groups (P < 0.01). Additionally, no significant differences were found between the healthy control subjects and any of the disease comparison groups. The current finding that TGF-β is significantly elevated among patients with CFS supports the findings of two previous studies examining smaller numbers of CFS patients. In conclusion, TGF-β levels were significantly higher in CFS patients compared to patients with various diseases known to be associated with immunologic abnormalities and/or pathologic fatigue. These findings raise interesting questions about the possible role of TGF-β in the pathogenesis of CFS.