The T-lymphocyte response against myelin-associated glycoprotein and myelin basic protein in patients with multiple sclerosis.

In addition to myelin basic protein (MBP), other minor components of myelin, such as myelin-associated glycoprotein (MAG), may be important autoantigens in MS. To determine whether MAG might be involved in an autoimmune reaction in MS, we screened peripheral blood lymphocytes from MS patients and normal subjects for their sensitization to human MBP and MAG antigen using a [3H]thymidine incorporation assay. We recorded three patterns in MS patients: (1) patients who responded neither to MAG nor to MBP (4/11); (2) patients who responded to both MBP and MAG (5/11); and (3) patients who gave an exclusive response to MAG (2/11). The 10 healthy controls did not respond to either MAG or MBP. That some individuals with MS expressed a specific response against MAG and that more than 50% of MS patients expressed a sensitization to MAG suggest that MAG may have a role in the pathogenesis of MS.