Antigenic features of myelin basic protein-like material in cerebrospinal fluid.

Abstract

Abstract The present study was undertaken to delineate more clearly the antigenic regions of myelin basic protein (BP), which briefly appear in cerebrospinal fluid (CSF) in association with acute injury to central nervous system (CNS) myelin. Three different radioimmunoassays were developed to detect material cross-reactive with human BP peptide 1-42, human BP peptide 43-88, and human BP peptide 89-169, and were used to analyze CSF specimens from 93 persons with a variety of neurologic diseases. Although all three assays had a similar sensitivity to approximately 100 pg per assay tube, only material cross-reactive with peptide 43-88 could be detected. Further studies were performed by using four antisera that reacted well with BP peptide 43-88 but yielded CSF values of BP-like material that differed up to 100-fold. Immunochemical studies of these four anti-sera demonstrated that the ability of an antiserum to detect BP-like material in CSF was directly correlated with the ability of that antiserum to react well with intact BP, BP peptide 68-88, and BP peptide 79-88. These findings provide a basis for selecting antisera to employ in studies of CSF and other body fluids for BP-like material, and indicate that either small BP peptides from the carboxyl end of the molecular region encompassing residues 43-88 or a conformationally restrictive form of BP constitute a major component of BP-like material entering the CSF at the time of myelin damage.