Dot Microfiltration Sandwich Eia for the Measurement of Igm Concentrations in Cerebrospinal Fluid

Abstract

A sensitive and simple sandwich enzyme immunoassay (EIA) using a dot microfiltration apparatus has been developed for the measurement of immunoglobulin M (IgM) concentrations in cerebrospinal fluid (CSF). The lower detection limit was 0.5 μg/dl. We applied this method to the testing of 200 CSF samples with normal concentrations of albumin, IgG and total protein, and normal cell counting. The non-parametric 2.5 and 97.5 percentile limits of IgM and the IgM index were 6.1-64.3 μg/dl and 0.012-0.063, respectively. We also applied this method to the testing of samples from 11 cases of multiple sclerosis (MS) and 15 cases of Guillain-Barré syndrome (GBS). High values for IgM and the IgM index were observed in 18.2% and 9.1% of MS, respectively and in 66.6% and 20.0% of GBS, respectively.

Key Words:

• cerebrospinal fluid
• dot assay
• Guillain-Barré syndrome
• immunoglobulin M (IgM)
• IgM index
• multiple sclerosis
• sandwich immunoassay