Reactivity to myelin peptides in a selected group of patients with relapsing-remitting multiple sclerosis

• Published in: Multiple sclerosis 2008-09, Vol.14, p.S229-S229
• Main Authors: Grau, L, Naranjo, M, Raich, D, Ramo, C, Martin, R, Pujol-Borrell, R, Borras, F E, Martinez-Caceres, E
• Format: Article
• Language: English
• ISSN: 1352-4585

Background: Previous studies using low doses of antigen have allowed highly discriminatory selection of a group of immunodominant epitopes of myelin between patients and controls Objective: To evaluate, in vitro, cellular reactivity to a mix of 7 immunodominant myelin peptides and its evolution with time in patients with relapsing-remitting MS as previous step for a protocol of antigenspecific immunological tolerance. Methods: We studied 18 controls and 40 patients without immunomodulatory or corticosteroid therapy in 3 months previous to blood extraction. We performed proliferation assays with peripheral blood mononuclear cells to a definite mix of myelin peptides: MBP13-32, MBP111-129, MBP 146-170, MBP83-99, MOG1-20, MOG35-55, PLP139-154 at concentrations of 2 and 10 mu M of every peptide. Lymphocyte proliferation was measured by incorporation of 3H thymidine. Individual wells were considered positive if their cpm was greater than or equal to 3SD above the negative control wells. Those individuals with more than 50% positive wells were considered positive. In 20 patients, a second proliferation was performed after 3 months. Results: A positive reaction to mix of peptides was detected in 29 of 40 patients (73%) and 3 out of 18 controls (16%). The cellular reactivity was dose-dependent (39 % to 2 mu M and 73% to 10 mu M). Those patients with positive reactivity (n=29) had higher disability (EDSS, 2.5[2-4] vs 1.0[1-2], p=0.02), more relapses (8.23 plus or minus 3.4 vs 4.75 plus or minus 1.9, p