Antibody-dependent lymphocyte cytotoxicity against basic protein of myelin in multiple sclerosis.

An antibody was demonstrated in the serum of 166 out of 200 patients with MS which enabled normal lymphocytes to develop a cytotoxic (ADLC) reaction against MBP. The ADLC correlated with the stage of the process and was positive in 94% of those with active and in 62% of those with inactive disease independent of the type--relapsing or chronic progressive--and of the severity of the disease. Control studies in 200 patients with other organic nervous complaints gave positive findings in patients with carcinoma (7.5%), in rheumatoid arthritis (10-15%) and in syphilis (30%). On the ground of its good specificity and the frequency of positive findings, the reaction may be of diagnostic significance. In 55 of 57 CSF samples investigated in MS, the ADLC was positive. The intensity of the cytotoxicity in serum and CSF is practically identical. This finding supports the pathogenetic significance of the ADLC against MBP although it has no validity as a primary aetiological factor.