Dissociation of lymphoblastic transformation and MIF production in response to a peptide fragment of basic myelin protein

Basic myelin protein is effective in inducing (EAE) in a variety of animals. Its C terminal 54 amino acid residue (peptide T) is also capable of inducing EAE in primates, but not in rodents. Sensitization to the whole protein and peptide T has also been demonstrated during exacerbations of multiple sclerosis. The C terminal 17 amino acid fragment (peptide Y) has also been observed to produce EAE in primates. We sought to determine if cellular sensitization to this peptide was present in multiple sclerosis. Two assay techniques were used: the macrophage migration inhibition factor (MIF) assay, and lymphoblastic transformation (LBT) assay. Peptide Y was used in a 1 mcg/ml concentration, 8 normal subjects and 16 suspect MS patients were studied. 47 probable MS were assayed at differing time intervals after clinical attacks of MS. Normals gave a stimulation index (SI) of 0.8 ± 0.29 and a migration index (MI) of 114 ± 22. Suspect MS patients gave an SI of 1.51 ± 1.2 and an MI of 102 ± 1.9. MS patients within 3 weeks of an attack gave an SI = 1.38 ± 0.49 and an MI = 83 ± 16; those 4-6 weeks after SI = 1.17 ± 0.4 and MI = 110.1 ± 25; and those 7 weeks to 6 months gave an SI = 0.86 ± 0.6 and an MI = 102 ± 17. Patients 6 months or longer after an attack showed an SI = 152 ± 1.3 and an MI = 100 ± 8. Six of 12 MS patients within the first three weeks after an attack and 4 of 9 in second 3 week period gave statistically significant, but smaller increases in SI; but only 1 of 10 in the 7-24 week period, and 1 of 6, 6 months or longer after an exacerbation gave significant results. In contrast to this only 2 patients, one in each of the first 2 groups of MS patients gave a significant MIF response.