We tested the hypothesis that the plasma level of endothelin-1 (ET-1) is increased in patients with multiple sclerosis (MS). The peptide ET-1 is one of the most potent known vasoconstrictors. An increased level of endothelin could explain some of the vascular symptoms of these patients.
A specific radioimmunoassay was used to determine ET-1 plasma levels. Twenty patients with MS were compared to 20 age-and sex-pair-matched healthy subjects.
The plasma ET-1 levels were, on average, 224% higher in the patients with MS than in the controls (p < 0.005). The mean ET-1 levels (mean ± standard deviation [SD]) were 3.5 ± 0.83 pg/mL (min 2.13, max 5.37 pg/mL) in patients with MS and 1.56 ± 0.3 pg/mL (min 0.9, max 2.13 pg/mL) in healthy volunteers. Neither the different forms nor stages of MS had an influence on the results. The ET-1 level was also not correlated with the duration of the disease.
The plasma ET-1 level is markedly and significantly increased in patients with MS. Neither the cause of such an increase nor the pathogenetic role is known.
From the University Eye Clinic (TH, JF), Basel, Switzerland; Department of Clinical Research (SGS), University of Berne, Berne, Switzerland; and Department of Neurorehabilitation (JK), Rehabilitation Centre, Valens, Switzerland.
Manuscript received September 23, 1999; accepted January 9, 2001.
Address correspondence and reprint requests to Prof. J. Flammer, University Eye Clinic, Mittlere Str. 91, PO Box, CH-4012 Basel, Switzerland; e-mail: Josef.Flammer@ubaclu.unibas.ch.