Reference values for CSF-IgM, CSF-IgM/S-IgM ratio and IgM index, and its application to patients with multiple sclerosis and aseptic meningoencephalitis

Abstract

Immunoglobulin M (IgM) concentrations were determined in cerebrospinal fluid (CSF) and serum (S) by enzyme-linked immunosorbent assay (ELISA). In 52 reference subjects, the upper reference limit was 0.46 mg/l for CSF-IgM, 0.32 X 10(-3) for CSF-IgM/S-IgM ratio, and 0.061 for IgM index equal to CSF-IgM X S-albumin/S-IgM X CSF-albumin ratio. No correlation to age over 15-85 years was found for any of these variables. Among 22 patients with aseptic meningoencephalitis (AM) elevated values of CSF-IgM were found in 68%, CSF-IgM/S-IgM ratio in 73%, and IgM index in 73%. The corresponding values among 35 patients with multiple sclerosis (MS) were 66%, 60% and 63%. The differences in diagnostic sensitivities for the three IgM variables were not significant. Eleven of 16 AM patients and two of 22 with MS had elevated IgM index in the presence of normal IgG and IgA indices. Determination of IgM index should therefore be performed in suspected inflammatory nervous system disorders.

Cerebrospinal fluid immunoglobulin abnormalities in systemic lupus erythematosus.

“…28 For structural brain antigens, our ELISA technique has successfully demonstrated autoantibodies against various antigens in r-EAE. 3 It has also been applied to CSF and serum samples from multiple sclerosis patients, where about one third of the patients showed low levels of antibodies against myelin basic protein.…”

Detecting immunoglobulin abnormalities in the cerebrospinal fluid (CSF): Which methods are best for clinical purposes?

“…The IgM concentration in the CSF is too low to be calculated using the previous techniques: enzyme-linked immuno-adsorbent assay or solid phase radioimmunoassay should be used [36,37,38]. Reference values for CSF/serum albumin ratio related to age and for IgG, IgA and IgM index have been calculated [12,23] but each laboratory should have its own normal values.…”

Improved Formulae for the Judgement of Intrathecal Produced IgA and IgM in the Presence of Blood CSF Barrier Damage

“…This in turn depends on how to consider outliers in the reference group. Earlier studies have reported such outliers to occur, 10,20 but the reference ranges were calculated parametrically after exclusion of them. Recently, a non-parametric design was recommended;" consequently yielding higher reference limits in the present study.…”

“…10 In the previous study all sampling was performed by a few experienced persons. In the present study, data were taken retrospectively from analytical records of the clinical routine.…”