Inflammatory and autoimmune diseases of the nervous system; possibilities of laboratory diagnostic methods in cerebrospinal fluid

Contemporary aspects of cerebrospinal fluid analysis are discussed, including the relationship to neuro-infective, autoimmune and other neurological diseases. The actual state of cerebrospinal fluid microbiological and cytological investigation and analysis of cerebrospinal fluid protein fractions are described in detail.     

The blood cerebrospinal fluid barrier orchestrates immunosurveillance,immunoprotection, and immunopathology in the central nervous system

Once characterized as an immune privileged area, recent scientific advances have demonstrated that the central nervous system (CNS) is both immunologically active and a specialized site. The anatomical and cellular features of the brain barriers, the glia limitans, and other superficial coverings of the CNS endow the brain with specificity for immune cell entry and other macro- and micro-elements to the brain. Cellular trafficking via barriers comprised of tightly junctioned non-fenestrated endothelium or tightly regulated fenestrated epithelium results in different phenotypic and cellular changes in the brain, that is, inflammatory versus regulatory changes. Based on emerging evidence, we described the unique ability of the blood cerebrospinal fluid barrier (BCSFB) to recruit, skew, and suppress immune cells. Additionally, we sum up the current knowledge on both cellular and molecular mechanisms governed by the choroid plexus and the cerebrospinal fluid at the BCSFB for immunosurveillance, immunoprotection, and immunopathology.     

Determination of myelin marker enzymes in the blood serum in peripheral nervous system diseases

The activity of 2',3'-cyclonucleotide-3-phosphohydrolase (CNP) and leucine aminopeptidase (LAP) was studied for the first time in the blood of patients with diseases of the peripheral nervous system. A spectrophotometric method for CNP activity detection was described. The activity absent from the blood of normal subjects was detectable with statistical significance in the patients with the diseases in question. Analogous results were obtained in the animals with an experimental injury to the myelin coat of the peripheral nerves. Study into the activity of LAP in the pathological conditions under consideration revealed no significant deviations. It is emphasized that CNP may transfer to the blood serum from myelin decay foci and that the method described may be used for diagnostic purposes.     

Critical evaluation of the biological role of IgM in cerebrospinal fluid in inflammatory and other diseases of the nervous system

In a group of 10,156 patients with neurological diseases, the IgM level was assessed (using laser nephelometry) both in cerebrospinal fluid (CSF) and serum; concentration of other 17 protein fractions was also simultaneously determined: albumin, immunoglobulins, acute phase reactants, complement components, apolipoproteins, proteinase inhibitors and alpha1-microglobulin. Total protein, element counts and glucose level were also evaluated. In patients with normal CSF findings, only limited statistically significant correlations were demonstrated between IgM and other CSF protein fractions while, in the group of patients with pathological CSF findings, significant correlations were found between CSF(IgM) and other immunoglobulins, complement fractions and the rate of intrathecal synthesis of immunoglobulins. Correlations were also found between CSF(IgM) and CSF antithrombin-III and alpha1-microglobulin. Correlations between CSF(IgM) and CSF apolipoproteins support the theory of CNS tissue destruction whenever the concentration of CSF apolipoproteins is elevated. Our data substantially contribute to establishing the diagnosis in patients with neurological diseases; simultaneous measurement of a high number of CSF proteins is becoming inevitable for a reasonable assessment of the CSF Protein Status.     

Anticonvulsant properties of the cerebrospinal fluid during activation of the antiepileptic system of the brain

Cerebrospinal fluid (CSF) was obtained after 30-40 sessions of daily electrical stimulation of the cat cerebellum vermis. The intraventricular injection of CSF (10 microliters) to Wistar rats increased the latent period of initial seizure manifestations, significantly reduced the number of animals with seizures and reduced the severity of seizures induced by korazol injection (40 mg/kg). Analogous seizure changes were observed in rats after intraventricular injection of CSF (10 microliters) from cats subject to 3-10 electroshock seizure fits. Intraventricular injection of CSF (250 microliters) obtained from cats after electroshock to cats with strychnine-induced epileptic foci in the brain cortex led to the suppression of the epileptic activity. The conclusion was made that different ways of antiepileptic system activation cause the accumulation of endogenous antiepileptic substances in CSF.     

High-resolution peptide mapping of cerebrospinal fluid: a novel concept for diagnosis and research in central nervous system diseases

Peptides, such as many hormones, cytokines and growth factors play a central role in biological processes. Furthermore, as degradation products and processed forms of larger proteins they are part of the protein turnover. Thus, they can reflect disease-related changes in an organism's homeostasis in several ways. Since two-dimensional gel electrophoresis is restricted to analysis and display of proteins with relative molecular masses above 5000, we developed Differential Peptide Display (DPD), a new technology for analysis and visualization of peptides. Here we describe its application to cerebrospinal fluid of three subjects without a disease of the central nervous system (CNS) undergoing routine myelography and of two patients suffering from a primary CNS lymphoma. Peptides with a relative molecular mass below 20000 were extracted and analysed by a combination of chromatography and mass spectrometry. The peptide pattern of a sample was depicted as a multi-dimensional peptide mass fingerprint with each peptide's position being characterized by its molecular mass and chromatographic behaviour. Such a fingerprint of a CNS sample consists of more than 6000 different signals. Data analysis of peptide patterns from patients with CNS lymphoma compared to controls revealed obvious differences regarding the peptide content of the samples. By analysing peptides within a mass range of 750-20000, DPD extends 2D gel electrophoresis, thus offering the chance to investigate CNS diseases on the level of peptides. This represents a new approach for diagnosis and possible therapy.     

Cytology of the cerebrospinal fluid in primary malignant lymphomas of the central nervous system

Two cases of primary malignant lymphoma of the central nervous system are reported. Clinical and pathologic findings did not indicate systemic lymphomatous involvement of lymph nodes and bone marrow. The patients presented with different neurologic deficits. Cytologic examination of the cerebrospinal fluid was the first and most useful technique for establishing the diagnosis.     

Permeability of the blood cerebrospinal fluid barrier during acute immune complex disease

Changes in the permeability of the blood-brain barrier (BBB) and blood-cerebrospinal fluid (blood-CSF) barrier in rabbits were assessed by using a sensitive double isotope technique at different times after the induction of acute immune complex disease (AICD). Induction of AICD was done with a single large dose of bovine serum albumin, whereas controls received only saline. Animals were sacrificed 6, 9, 12, 15, and 18 days after induction. Extravasation of protein was measured by injecting rabbits i.v. with 131I-rabbit serum albumin (RSA) 24 hr before sacrifice. In order to correct for intravascular blood volume, 125I-RSA was injected 5 min before sacrifice. Extravascular blood equivalents (EVBE), a measure of barrier permeability, were elevated in the CSF of rabbits sacrificed on days 12 and 15. None of the brain regions from any of the animal groups showed any changes or significant differences from controls in EVBE values on these days. These results indicate that there was an increase in the permeability of the blood-CSF barrier to radiolabeled albumin but not in the BBB proper during the time that CSF IgG levels were elevated in AICD. The potential significance of these findings for the mechanisms mediating central nervous system involvement in systemic lupus erythematosus is discussed.     

Expression of microRNAs in cerebrospinal fluid of dogs with central nervous system disease

In this pilot study we investigated the expression of 14 microRNAs in the cerebrospinal fluid (CSF) of dogs with neoplastic, inflammatory and degenerative disorders affecting the central nervous system (CNS). CSF microRNA (miRNA) expression profiles were compared to those from dogs with neurological signs but no evidence of structural or inflammatory CNS disease. Seven miRNAs were easily detected in all samples: miR-10b-5p, miR-19b, miR-21-5p, miR-30b-5p, miR-103a-3p, miR-124, and miR-128-3p. Expression of miR-10b-5p was significantly higher in the neoplastic group compared to other groups. There was no relation between miRNA expression and either CSF nucleated cell count or CSF protein content. Higher expression of miR-10b-5p in the neoplastic group is consistent with previous reports in human medicine where aberrant expression of miR-10b is associated with various neoplastic diseases of the CNS.     

Abnormal protein patterns in blood serum and cerebrospinal fluid detected by capillary electrophoresis

Capillary zone electrophoresis and high-resolution agarose gel electrophoresis were compared to detect protein components in serum and cerebrospinal fluid of patients. Both electrophoretic methods proved to be useful for detection of protein abnormalities (e.g., mono- and oligoclonal bands) in biological fluids, but capillary electrophoresis offered several important advantages, such as sample application without preliminary concentration, lack of staining procedures, and on-line evaluation of patterns. Furthermore, capillary electrophoresis exhibits shorter analysis time and high resolution with low baseline noise. The results were proven to be powerful in diagnosis and monitoring of dyscrasias in routine laboratory practice.