RESUMEN
Two radioimmunoassay (RIA) procedures were used to measure human myelin basic protein (HBP) in cerebrospinal fluid (CSF): (1) an inhibition RIA, with the use of TNP-conjugated anti-BP IgG, 125I-labelled HBP, and anti-TNP-coated polystyrene beads, and (2) a non-competitive two-site RIA, with the use of Sepharose-coupled anti-BP antibodies and 125I-labeled anti-BP IgG. The two-site RIA detects less HBP in CSF than the inhibition RIA, partly due to the presence of HBP fragments in CSF that are detected by the inhibition assay, but less by the two-site RIA. The correlation was improved when in the two-site RIA Sepharose-coupled anti-BP antibodies were changed. Because certain substances (such as autoantibodies to HBP) may give false-positive results in the competitive RIA but not in the two-site RIA, we conclude that a combination of the (more sensitive) inhibition RIA with the (more specific) two-site assay provides a more reliable HBP assay than either assay alone.
Asunto(s)
Esclerosis Múltiple/inmunología , Proteína Básica de Mielina/líquido cefalorraquídeo , Animales , Sitios de Unión de Anticuerpos , Unión Competitiva , Cromatografía en Gel , Relación Dosis-Respuesta Inmunológica , Humanos , Esclerosis Múltiple/líquido cefalorraquídeo , Proteína Básica de Mielina/inmunología , Péptido Hidrolasas/farmacología , Conejos , Radioinmunoensayo/métodosRESUMEN
Twelve antisera were prepared, each specific for idiotype(s) of IgG from the cerebrospinal fluid (CSF) of an individual patient with multiple sclerosis (MS). Idiotype-positive (Id(+)) IgG represented 24 to 33% of the CSF-IgG. Radioautographic analysis showed that Id(+)IgG in CSF and in serum had a restricted electrophoretic mobility. From serum of three patients, at least two different noncross-reacting Id(+)IgG fractions were isolated. The anti-Id antisera, which detect IgG considered to be of importance in MS, were used to measure Id(+)IgG in CSF and in serum. Relative to the total IgG, Id(+)IgG was always enriched in CSF, which suggests intrathecal synthesis of such IgG. However, in all patients the absolute concentration of Id(+)IgG was higher in serum than in CSF. Studies attempting to demonstrate cross-reactivity between the IgG of different patients were negative.