Peripheral blood mononuclear cell beta-endorphin concentration is decreased in chronic fatigue syndrome and fibromyalgia but not in depression: preliminary report.
OBJECTIVE
The aim of this study was to examine the possible role of the immune system in the pathophysiology of chronic fatigue syndrome and fibromyalgia syndrome and in the differential diagnosis of depression by investigating changes in peripheral blood mononuclear cell levels of beta-endorphin, an endogenous opioid known to be involved in regulation of the immune system function.


METHODS
Beta-endorphin concentrations were measured by radioimmunoassay in peripheral blood mononuclear cells from healthy controls (n = 8) and patients with chronic fatigue syndrome (n = 17), fibromyalgia syndrome (n = 5), or depression (n = 10).


RESULTS
Beta-endorphin concentrations were significantly lower in patients with chronic fatigue syndrome or fibromyalgia syndrome than in normal subjects and depressed patients (p <0.001 and p <0.01, respectively). They were significantly higher in depressed patients than in controls (p <0.01).


CONCLUSIONS
Evaluation of peripheral blood mononuclear cell beta-endorphin concentrations could represent a diagnostic tool for chronic fatigue syndrome and fibromyalgia and help with differential diagnosis of these syndromes versus depression. The results obtained are also consistent with the hypothesis that the immune system is activated in both chronic fatigue syndrome and fibromyalgia syndrome.
Department of Pharmacology, Istituto di Ricerca e Cura a Carattere Scientifico, University of Milan, Italy.
Alberto E
AE
Panerai
Jacopo
J
Vecchiet
Paolo
P
Panzeri
PierLuigi
P
Meroni
Silvio
S
Scarone
Eligio
E
Pizzigallo
Maria A
MA
Giamberardino
Paola
P
Sacerdote
D000328:Adult; D003863:Depression / Q000097:blood* / Q000175:diagnosis; D003937:Diagnosis, Differential; D015673:Fatigue Syndrome, Chronic / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D005260:Female; D005356:Fibromyalgia / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D001615:beta-Endorphin / Q000097:blood* / Q000276:immunology / Q000378:metabolism
D001615:beta-Endorphin