Specific T-cell proliferation to myelin peptides in relapsing-remitting multiple sclerosis

The identification of major immunogenic peptides in multiple sclerosis (MS) is of great importance for the development of antigen-specific therapies. Cellular reactivity against a selected mix of seven myelin peptides was evaluated in vitro. The evolution of this reactivity over time and its correlation with clinical variables was also analysed.

Forty-two patients with MS, 15 with other demyelinating diseases and 40 healthy donors (HD) were studied. Cell proliferation was measured by 3[H] thymidine incorporation into samples obtained at 0, 3, 6 and 12months of MS patient follow-up.

A positive reaction to the peptide mix was detected in 31 of the 42 patients (74%), 12 of the 40 HD (30%) and 6 of the 15 (40%) patients with other demyelinating diseases. Patients with positive proliferation had greater disability (EDSS score, 3 [1-5.5] vs. 1.0[1-2], P=0.021), higher number of relapses (7±4.1 vs. 3±1.2, P<0.001) and shorter time since the last relapse (9±7.5 vs. 32±12.3months, P=0.036). After 12months of follow-up, cell reactivity was maintained in 33 patients (78%).

A high percentage of patients exhibit a significant and maintained reactivity to myelin peptides over time. Therefore, this mix may be useful as a source of antigen in the development of protocols aimed at inducing specific tolerance in MS.