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Updated: Dec 21, 2025
Quantitative Measurement of Intrathecally Synthesized Proteins in Mice
Published on: November 29, 2019
Cerebrospinal fluid oligoclonal IgM test in routine practice: Comparison with quantitative assessment of intrathecal
David Zeman1, Pavlína Kušnierová2, František Všianský3
1Institute of Laboratory Diagnostics, University Hospital Ostrava, 17. listopadu 1790, 708 52 Ostrava, Czech Republic; Clinic of Neurology, University Hospital Ostrava, 17. listopadu 1790, 708 52 Ostrava, Czech Republic; Dept. of Biomedical Sciences, Faculty of Medicine, University of Ostrava, Syllabova 19, 703 00 Ostrava, Czech Republic.
Background:
Intrathecal IgM synthesis demonstrated either as cerebrospinal fluid (CSF)-restricted oligoclonal (o-) IgM bands or calculated using various formulas has been linked to more aggressive multiple sclerosis (MS) course. However, the proportion of MS patients showing intrathecal IgM synthesis varies largely between studies. We aimed to explore the relation between different formulas and results of o-IgM, and to assess the frequency of o-IgM bands in an unselected series of samples.
Methods:
432 samples were analyzed for o-IgM, o-IgG and quantitative measures of IgM and IgG synthesis. IgM index and formulas of Reiber, Auer and Öhman were compared to the result of the o-IgM test.
Results:
At the cut-off commonly used, the non-linear formulas for intrathecal synthesis were specific (>94%) but rather insensitive (<40% even at a cut-off of 4 CSF-restricted bands) compared to o-IgM. No significant difference was noted in the performance of different formulas. At a cut-off of 4 bands, 61% of MS patients, but none of the controls were positive for o-IgM.
Conclusions:
Formulas for intrathecal IgM synthesis are insensitive compared to o-IgM. We propose to evaluate samples with 2 or 3 extra-CSF IgM bands as borderline and only samples with 4 or more as definitely positive.
