β Endorphin concentrations in PBMC of patients with different clinical phenotypes of multiple sclerosis

The possible link between the opioid peptide β endorphin and the heterogeneity of the clinical course of multiple sclerosis (MS) was investigated. Peripheral blood mononuclear cells (PBMC) concentrations of β endorphin were measured in 50 patients in different phases of MS. Thirty nine patients also underwent post-contrast magnetic resonance imaging of the brain. Among MS forms, the highest β endorphin concentrations were found in PBMC from patients with relapsing remitting MS and the lowest n patients with the progressive forms. Average β endorphin concentrations were lower, although not significantly, in patients with than in those without magnetic resonance imaging enhanced lesions. These data suggest that β endorphin may have a role in the downregulation of the inflammatory process.