Related Experiment Video
Updated: Sep 6, 2025
Author Spotlight: Novel Assay for Studying B-Cell Responses in Multiple Sclerosis Research
Published on: December 1, 2023
Diagnostic reference value of antibody levels measured using enzyme immunoassay for subacute sclerosing
Yohei Kume1, Koichi Hashimoto1, Keiji Iida2
1Department of Pediatrics, Fukushima Medical University, 1 Hikarigaoka, Fukushima, Japan.
Abstract:
High measles-specific antibody titers in the cerebrospinal fluid (CSF) have important diagnostic significance for subacute sclerosing panencephalitis (SSPE), a progressive neurological disorder caused by measles virus variants. However, the diagnostic reference value of antibody levels and the usefulness of the CSF/serum ratio measured using enzyme immunoassays (EIAs) for SSPE diagnosis remain unclear. To facilitate SSPE diagnosis using EIAs, measles immunoglobulin G (IgG) titers in the CSF and serum of patients with and without SSPE were measured and their CSF/serum antibody ratios evaluated. Serum and CSF antibody levels were compared among three patients with SSPE (59 paired samples), 37 non-SSPE patients, and 2618 patients of unknown backgrounds. Of the 59 paired samples from three patients with SSPE, 56 paired samples (94.9%) showed CSF measles IgG levels ≥0.5 IU/mL and a CSF/serum ratio ≥0.05, whereas non-SSPE cases showed CSF measles IgG levels <0.1 IU/mL and a CSF/serum ratio <0.03. Of the 2618 CSF samples with unknown backgrounds, 951 showed measurable IgG levels with EIA, with a CSF/serum ratio peak of 0.005-0.02, with a 90th percentile of 0.05. Assuming the SSPE criteria as CSF measles IgG ≥0.5 IU/mL and a CSF/serum ratio ≥0.05, only 20 samples (0.8%) with unknown backgrounds were categorized as having SSPE. Conversely, assuming the non-SSPE criteria as CSF measles IgG <0.1 IU/mL and a CSF/serum ratio <0.03, 2403 samples (92%) with unknown backgrounds were categorized as not having SSPE. In conclusion, high CSF/serum ratios (≥0.05) and high measles CSF IgG levels (≥0.5 IU/mL) may be useful for diagnosing SSPE.
Insights
High measles-specific antibody titers in cerebrospinal fluid (CSF) are key for diagnosing subacute sclerosing panencephalitis (SSPE). Enzyme immunoassays (EIAs) show elevated CSF/serum ratios and IgG levels can aid SSPE diagnosis.
Area of Science:
- Neurology
- Virology
- Immunology
Background:
- Subacute sclerosing panencephalitis (SSPE) is a severe neurological disorder caused by measles virus variants.
- High measles-specific antibody titers in cerebrospinal fluid (CSF) are diagnostically significant for SSPE.
- The diagnostic utility of enzyme immunoassays (EIAs) for measuring CSF/serum antibody ratios in SSPE remains unclear.
Purpose of the Study:
- To evaluate the diagnostic reference values of measles-specific antibody levels in CSF and serum.
- To assess the usefulness of the CSF/serum ratio measured by EIAs for SSPE diagnosis.
- To facilitate SSPE diagnosis using EIAs by establishing reliable antibody level criteria.
Main Methods:
- Measured measles immunoglobulin G (IgG) titers in CSF and serum from SSPE patients and controls using EIAs.
- Calculated and evaluated CSF/serum antibody ratios.
- Compared antibody levels and ratios between SSPE and non-SSPE groups, and analyzed a large cohort of unknown backgrounds.
Main Results:
- SSPE patients (94.9%) exhibited high CSF measles IgG levels (≥0.5 IU/mL) and CSF/serum ratios (≥0.05).
- Non-SSPE cases showed significantly lower levels (CSF IgG <0.1 IU/mL, CSF/serum ratio <0.03).
- Analysis of unknown samples indicated that criteria of CSF IgG ≥0.5 IU/mL and CSF/serum ratio ≥0.05 could identify potential SSPE cases with low false positives.
Conclusions:
- High CSF measles IgG levels (≥0.5 IU/mL) are strongly indicative of SSPE.
- Elevated CSF/serum ratios (≥0.05) are a valuable marker for diagnosing SSPE.
- These EIA-based criteria can aid in the reliable diagnosis of SSPE.
