Cell-mediated immunity in multiple sclerosis as determined by sensitivity of different lymphocyte populations to...

Peripheral blood lymphocytes from patients with multiple sclerosis (MS) or other neurological diseases and from healthy individuals were separated by density gradient sedimentation into several subfractions. Individual cell populations were cultured in the presence of several human brain tissue antigens. In comparison to controls, mononuclear cells with a density of less than 1.077 gm/cm3 from MS patients displayed a significantly increased sensitivity after incubation with purified human myelin basic protein (MBP) but not with other brain tissue antigens. In particular, the lymphocytes of patients suffering from MS for more than four years reacted positively with MBP, suggesting that the reaction dependent. No difference between MS patients and controls in sensitivity to any brain tissue antigen could be detected with cells of lower density (i.e., 1.073 to 1.069 gm/cm3 or less than 1.069 gm/cm3). Comparable lymphocyte activity was found to antigens isolated from both MS and control brain tissue. These results suggest that patients with chromic progressive MS have a secondary immune activity to MBP.