MYELIN BASIC-PROTEIN IN CEREBROSPINAL-FLUID AND OTHER BODY-FLUIDS

Myelin basic protein (MBP) or a fragment thereof may enter cerebrospin al fluid (CSF) and other body fluids in on etiologically nonspecific f ashion to provide information about the status of central nervous syst em (CNS) myelin damage. MBP immunochemically detected is referred to a s MBP-like material (MBPLM). The clinical utility of the essay for MBP LM in CSF is to document the presence, continuation, or resolution of CNS myelin injury. The analysis of CSF for MBPLM is subject to many va riables, among which ore the antisera and the form of the assay utiliz ed. The dominant epitope of CSF MBPLM is in the decapeptide of 80-89 f rom the intact MBP molecule of 170 residues. Normally, CSF has no dete cted MBPLM. Following on acute relapse of MS, MBPLM rises quickly in t he range of ng/ml and rapidly declines and disappears. The presence of MBPLM in CSF in chronic and progressive phases of the disease is unus ual, but it may sometimes be detected in low levels, depending on the assay used for detection. The level of CSF MBPLM is related to both th e mass of CNS myelin damage and how recently it occurred. The level of CSF MBPLM rarely is elevated in optic neuritis. The level of CSF MBPL M is unrelated to CSF protein level, level of IgG, presence of oligocl onal bonds or pleocytosis. CSF MBPLM has the potential of serving as a marker of therapeutic effectiveness in MS and does have predictive va lue for response to glucocorticoids given for worsening of disease. Th e detection of MBPLM in body fluids other than CSF would be of great v alue because of the resulting improved feasibility for objectively mon itoring the natural history of MS and response to therapy Studies on b lood have yet to produce a valid assay of MBPLM. Urinary MBPLM, though different in its features from that in CSF, may Provide a correlate, not with acute demyelination in MS as is the case for CSF, but with pr ogression of disease.