Analysis of antibodies to surface epitopes of contactin-2 in multiple sclerosis

Contactin-2 was recently identified as an autoantigen targeted by T-cells and autoantibodies in multiple sclerosis (MS). Here we analyzed the frequency of antibodies to contactin-2 (contactin-2-ab) by a cell-based assay in the serum from 105 MS patients and at least 5 years of follow-up (19 clinically isolated syndromes, 51 relapsing-remitting, 20 secondary-progressive, and 15 primary-progressive). Contactin-2-ab were detected in 4 (7.8%) relapsing-remitting patients. Clinical and magnetic resonance imaging characteristics were not significantly different from the rest of relapsing-remitting patients. In conclusion, contactin-2-ab are identified in a minority of MS patients but their presence is not associated with a particular clinical-radiological profile.