OBJECTIVE: To investigate beta-endorphin concentrations in the
peripheral blood mononuclear cells (PBMC) of patients with
chronic fatigue syndrome (CFS).
METHODS: Sixteen patients with
CFS were enrolled in this study. Ten healthy subjects were
studied as controls. Beta-endorphin concentrations were
measured in PBMC by radioimmunoassay performed with antibodies
specific for the C-terminal portion of human beta-endorphin.
RESULTS: Beta-endorphin concentrations in the PBMC of chronic
fatigue patients were significantly lower (p < 0.001) than in
healthy subjects (mean +/- SD: 8.5 +/- 7.0 vs. 42.6 +/- 22.6).
CONCLUSION: Patients with CFS were found to have low levels of
PBMC beta-endorphin. This finding may reflect the condition of
chronic immune activation in CFS that has been reported in
previous investigations. Beta-endorphin concentrations in PBMC
seem to mirror the central nervous system homeostasis of the
opioid. Therefore, we would postulate that the fatigue and
weakness typical of CFS could be related to low beta-endorphin
concentrations at the central nervous system level.