Oligoclonal immunoglobulin M in cerebrospinal fluid from multiple sclerosis patients

Frequency and relevance of IgM intrathecal synthesis in multiple sclerosis

Using a new ELISA method we have measured the IgM concentration in the serum and the cerebrospinal fluid CSF from 110 neurological patients. Among there, 41 had multiple sclerosis (MS), 48 other inflammatory diseases (OID), including 30 AIDS, and 21 non-inflammatory neurological diseases (NID). A highly significant correlation was established between results with native IgM and the dithiothreitol reduced IgM. An intrathecal synthesis (ITS) of IgM was detected using the CSF IgM/CSF albumin ratio, the IgM index and a quantitative formula in 33 patients: nine MS, 23 OID (including 18 AIDS) and one NID. The frequency of IgM ITS was 22% in MS patients, 48% in the OID (60% in AIDS) and 5% in the NID groups. This ITS was not impaired by an increase in serum IgM concentration or by a blood-CSF barrier damage. These facts confirm that intrathecal immunity is not a "steady-state" related to the general immunity but a specific response restricted to the central nervous system. Conversely, CSF IgM increase and IgM ITS were closely related (p < 10(-6) ). In addition, IgM ITS and IgG ITS were found to be highly correlated in OID, especially in AIDS patients: such correlation was not observed in the MS group. No significant correlations were observed between IgM ITS and any of the clinical parameters in MS patients. These results suggest the probable specificity of IgM ITS in MS patients.

Intrathecal synthesis of IgM and IgA in neurological diseases: comparison of two formulae with isoelectric focusing

The intrathecal IgM and IgA immune response was studied by detecting oligoclonal IgM and IgA bands in CSF and by determining both the IgM/IgA indices as well as the intrathecal production of IgM and IgA by the Reiber formula. A good correlation was found between the demonstration of oligoclonal IgM (r = 0.890) and IgA bands (r = 0.927) and the Reiber formula. Compared with the finding of oligoclonal IgM/IgA bands calculation of an intrathecal IgM/IgA synthesis by the Reiber formula was less sensitive (86%). In two out of 22 controls and in 12 of 19 patients with polyradiculitis IgM and IgA indices were elevated while the other evaluation methods were negative. Even though oligoclonal IgM and IgA bands are considered to be a useful diagnostic tool in detecting intrathecal synthesis of IgM and IgA, i.e. in meningoencephalitis or neuroborreliosis for clinical practice, the Reiber formula provides reliable results. Detection sensitivity of assays for CSF-IgM and -IgA should be at least 1.0 mg/l.

Distribution of cerebrospinal fluid oligoclonal IgM bands in neurological diseases: a comparison between agarose electrophoresis and isoelectric focusing

Isoelectric focusing (IEF) and agarose gel electrophoresis were used to detect oligoclonal IgM bands in cerebrospinal fluid and serum samples from 850 patients with diverse neurological diseases. Oligoclonal IgM bands in cerebrospinal fluid were mainly detected in patients with infectious and inflammatory disorders of the nervous system. Both IEF and agarose electrophoresis revealed similar frequencies of oligoclonal IgM bands. Bands detected by IEF were mainly seen in the anodal range. Despite higher resolving capacity, IEF was less specific than agarose gel electrophoresis. It is concluded that oligoclonal IgM bands have important diagnostic significance and that agarose gel electrophoresis is more suitable for their detection in routine clinical work and use in differential diagnosis.

High-dose intravenous-penicillin in neurosyphilis: effect on intrathecal synthesis of IgG, IgM, IgA and IgD

We evaluated occurrence and levels of intrathecal synthesis of IgG, IgM, IgA and IgD by calculating corresponding index values in 8 patients with definite and 4 with suspected or possible neurosyphilis, prior to, during and after high-dose intravenous penicillin therapy. Four patients with active neurosyphilis displayed intrathecal synthesis of IgG, IgM and IgA. Only 2 of them showed elevated IgD index, and both had taboparesis, pleocytosis and positive VDRL in CSF, and simultaneous elevation of the IgG, IgA and especially of the IgM indices. This suggests that intrathecal synthesis of IgD may occur in patients with severe CNS inflammation in response to diffuse CNS treponemal damage. Penicillin therapy incited transitory elevation of one or more of the immunoglobulin index values in most patients, possibly in response to massive treponemal lysis inside the CNS. Thereafter, the values became mostly normalized but exceptions occurred, including one patient who had elevated IgG and IgM index which persisted 31 months after therapy. Our data indicate that determinations of immunoglobulin indices performed on consecutive specimens from individual patients with neurosyphilis may be helpful in the evaluation of treatment.

Laboratory investigation of cerebrospinal fluid proteins

Analysis of CSF proteins is useful in the diagnosis and management of neurological diseases in the following situations: 1. In inflammatory conditions when there is breakdown of blood-CSF barrier integrity. Meningitis is a medical emergency, with CSF total protein measurement being only a screening test. 2. In the detection of immune responses within the CNS. This is by far the most important application in a routine clinical setting, as it is now a firmly established criterion in the diagnosis of multiple sclerosis. Oligoclonal bands restricted to the CSF are the only reliable indicators of intrathecal immunoglobulin G synthesis and are practically always associated with inflammatory disease of the CNS. The method fo choice for detecting oligoclonal bands is isoelectric focusing with immunofixation. Quantitative measurement of IgG in the CSF is of no value in diagnostic pathology. 3. In destructive brain diseases when brain-specific proteins are released into the CSF, measurement of these proteins can give prognostic information.

Cerebrospinal fluid oligoclonal IgM in multiple sclerosis: analytical problems and clinical limitations

A method for detecting cerebrospinal fluid (CSF) oligoclonal IgM is described. Concentrated CSF was separated by agarose isoelectric-focusing and blotted with poly(vinyldifluoride). A double-antibody immunoperoxidase technique with avidin-biotin amplification was used to stain IgM. Special conditions were required to avoid cross-reaction with IgG. The method was applied to 99 patients on whom oligoclonal IgG analysis was performed. Positive IgM results occurred in 17 of the 27 patients positive for oligoclonal IgG, and in two patients negative for oligoclonal IgG, neither of whom had multiple sclerosis (MS). Fifteen of the patients positive for oligoclonal IgM had some IgM bands in their sera. Oligoclonal IgM was not found in the CSF of suspected MS patients without oligoclonal IgG, but occurred in several patients with oligoclonal IgG due to other diseases. As a test for MS, oligoclonal IgM was less sensitive than oligoclonal IgG and did not improve specificity.

Glutaraldehyde-enhanced immunofixation: a sensitive new method for detecting oligoclonal immunoglobulin M

A new, specific and economical method with enhanced sensitivity for rapid detection of IgM oligoclonal bands in unconcentrated cerebrospinal fluid (CSF) is presented. It is based on the use of glutaraldehyde during immunofixation of electrophoresed specimens and utilizes peroxidase-conjugated F(ab')2 fragment of anti-IgM antibody to avoid cross-reactivity with other CSF gamma globulins. It is able to detect 1 ng of IgM banded protein in electrophoresed CSF. Using this method, oligoclonal IgM was mainly detected in inflammatory and infectious conditions of the central nervous system.

Free light chains in the CSF in multiple sclerosis

The presence of free light chains (FLC) was investigated in 32 patients with clinically definite or laboratory supported definite multiple sclerosis (MS), 2 patients with neurosyphilis and 10 normal controls. The detection of FLC in unconcentrated cerebrospinal fluid (CSF) was performed by means of agarose isoelectric focusing, followed by transfer of proteins to nitrocellulose membranes, double immunofixation, avidin-biotin amplification and peroxidase staining. Bands due to FLC were clearly demonstrated in the CSF of 28 MS patients; 3 of them showed only kappa FLC, 10 only lambda FLC, while 15 had both kappa and lambda FLC. The CSF of 4 MS patients was FLC negative. In both cases of neurosyphilis FLC bands were observed. FLC were never found in normal CSF. Among the indexes of intrathecal immunological activity (IgG oligoclonal bands, FLC, IgG index, intra-blood-brain barrier IgG synthesis rate, pleocytosis) the FLC proved to be the second most frequent abnormality in MS CSF, the presence of IgG oligoclonal bands being the first. In one MS case an FLC band was found, while all the other indexes of intrathecal IgG production were negative. A high correlation was found between an elevated number of FLC and pleocytosis. The presence of FLC in MS CSF seems to indicate a recent immunological stimulation leading to increased synthesis of FLC within the CNS.

Oligoclonal antibodies in CSF of patients with meningopolyneuritis Garin-Bujadoux-Bannwarth: Ig class, light chain type and specificity

Detection of intrathecally produced antibodies in cerebrospinal fluid (CSF) of patients with meningopolyneuritis Garin-Bujadoux-Bannwarth (MPN-GBB) is well documented. Analysis of CSF has revealed the oligoclonal nature of these antibodies. We investigated oligoclonal antibodies (OA) in CSF and serum of MPN-GBB patients with regard to immunoglobulin class, light chain type and specificity and compared the findings with those in other neurological diseases (OND). For this purpose an immunofixation (IF) technique after agarosegel electrophoresis (AE) of concentrated CSF was used. 87% of patients with MPN-GBB demonstrated in the acute stage of their disease oligoclonal bands (OB) in their CSF which could not be detected in paired serum samples. IF revealed in most cases of MPN-GBB IgG banding. While IgM banding was a common finding in CSF of MPN-GBB patients, this was not the case in OND. Specificity of CSF OA against components of Borrelia burgdorferi could be demonstrated by agarose isoelectric focusing (AIEF), transfer to nitrocellulose paper and reaction with 125I labelled B. burgdorferi antigen.

Cryptococcal meningoencephalitis: intrathecal immunological response

The intrathecal immune response is reported in a patient with cryptococcal meningoencephalitis. CSF IgM and IgG levels were significantly related to the favourable clinical evolution. IgM response was specifically directed against the pathological agent, while IgG were mostly non-specific. The data are discussed and compared with the other chronic infections of the central nervous system.

Viruses, neurodevelopmental disorder and childhood psychosis

Four cases are described of prepubertal boys in whom the convergence of neurodevelopmental disorder, viral infection and psychosis seemed more than coincidental. Review of the literature highlights the possibility that viral infection of the central nervous system may play a contributory role in childhood psychosis. Whilst it is essential to avoid a reductionist stance when investigating these difficult conditions, the emergence of potent anti-viral treatments and sophisticated methods of identifying the presence of viral infection should encourage us to consider more carefully the relevance of viruses in childhood psychosis.

Two-dimensional electrophoresis of cerebrospinal fluid proteins in normal and pathological conditions

The two-dimensional polyacrylamide gel electrophoresis technique has been adapted for the analysis of human cerebrospinal fluid proteins. Proteins were detected by Coomassie brilliant blue stain and/or by silver stain. Highly reproducible protein patterns were obtained. We analyzed ten normal CSF specimens, thirty pathological CSF specimens and the corresponding sera. We mapped the protein patterns observed by examination of serum/CSF differences and by immunofixation. Preliminary observations on the changes in protein patterns in CSF specimens from patients with neurological disorders are reported.

CFS oligoclonal bands in MS and other neurological diseases detected by agarose isoelectric focusing and electrophoresis

Agarose gel isoelectric focusing (IEF) and electrophoresis (EF) were compared for detection of CSF oligoclonal bands in multiple sclerosis (MS) and other neurological diseases. The CSF IgG/albumin ratio, the IgG-Index and the IgG synthesis per day in the CNS were also considered. IEF was highly sensitive, revealing oligoclonal bands in 100% of CSF from 40 clinically definite MS, while EF had a sensitivity of 70%. In 90 patients with other neurological diseases, IEF revealed oligoclonal bands in 25.5%, EF in 11.1%. The IgG-index was the most sensitive of the quantitative parameters.

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

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.