ACUTE OPTIC NEURITIS - MYELIN BASIC-PROTEIN AND PROTEOLIPID PROTEIN ANTIBODIES, AFFINITY, AND THE HLA SYSTEM

Anti-myelin basic protein, anti-proteolipid protein, and anti-myelin b asic protein peptide (amino acid residues 1-20, 63-88, and 89-101) ant ibody-secreting cells were studied in 20 patients with idiopathic opti c neuritis, 20 with optic neuritis as part of multiple sclerosis, and 20 neurological control subjects. Antibody-secreting cells were enumer ated with an immunospot assay; the relative binding affinity of the an tibodies was estimated by elution with thiocyanate. Patients with opti c neuritis had more anti-myelin basic protein and anti-proteolipid pro tein antibodies than did control subjects (both p < 0.05); there was n o difference between idiopathic optic neuritis and optic neuritis as a symptom of multiple sclerosis. Presence of the multiple sclerosis-ass ociated DRB11501 gene was not associated with preferential synthesis of high-affinity antibodies reactive with a single myelin basic protei n peptide or with preferential synthesis of either anti-myelin basic p rotein or anti-proteolipid protein antibodies. The results demonstrate a potential for intrathecal synthesis of both anti-myelin basic and a nti-proteolipid protein antibodies of high apparent affinity in patien ts with optic neuritis.