Laboratory diagnosis of multiple sclerosis: immunological and biochemical aspects

Beta-arrestin and arrestin are recognized by autoantibodies in sera from multiple sclerosis patients

Multiple sclerosis (MS), one of the most common chronic neurologic diseases, is characterized by the presence of multiple plaques of demyelination throughout the central nervous system. Although the etiology of the disease has not been established, it is believed to involve autoimmune mechanisms. We have examined sera from patients with MS for the presence of antibodies to antigens from brain and retina. Immunoblot analysis of soluble fraction of proteins from bovine brain revealed a prominent band at 45 kDa stained with sera of 8-14 patients with MS. In two patients with MS, serum antibody titers during relapse were higher compared with those when the patients were in remission. These antibodies were undetectable in cerebrospinal fluid of our MS patients and additionally were absent in sera of patients with other neurological diseases and normal control subjects. Furthermore, immunoblot analysis of the soluble fraction from bovine retinal rod outer segments revealed a prominent protein band at 48 kDa stained with MS sera. This antigen was purified to homogeneity from bovine retinal outer segments and identified as arrestin. Additionally, sera from MS patients reacted with purified beta-arrestin 1, a 45-kDa protein homologous to arrestin that is found in various tissues. Using limited proteolysis of arrestin and a competitive ELISA test with a synthetic peptide, we identified the recognition site(s) for antibodies in sera of MS patients at a dominant immunogenic site on arrestin located at the C-terminal region of the molecule. We suggest that the presence of circulating antibodies reactive with beta-arrestin or arrestin may be related to the course of MS progression.

The predictive value of intrathecal immunoglobulin synthesis and magnetic resonance imaging in acute isolated syndromes for subsequent development of multiple sclerosis

The intrathecal synthesis of IgM in patients presenting with acute monosymptomatic syndromes may be relevant in predicting eventual progression to multiple sclerosis but has not been previously evaluated. We undertook a prospective 18-month combined clinical, cerebrospinal fluid, and magnetic resonance imaging study of 45 patients who had presented with acute isolated lesions of brainstem and spinal cord to evaluate the predictive value of intrathecal synthesis of IgM and IgG (through the detection of cerebrospinal fluid oligoclonal bands) and magnetic resonance imaging brain lesions at presentation, for the subsequent progression to multiple sclerosis. Results indicate that the highest risk of developing multiple sclerosis is seen in patients who are positive for oligoclonal IgM and IgG bands and who have disseminated cerebral white matter magnetic resonance imaging lesions at the initial presentation. Oligoclonal IgM bands predict progression to multiple sclerosis more frequently than oligoclonal IgG or magnetic resonance imaging alone. Our results confirm and further extend previous reports, and indicate that detection of cerebrospinal fluid oligoclonal IgM bands at presentation is a valuable prognostic indicator in patients presenting with acute isolated brainstem or spinal cord syndromes.

The separation and detection of alkaline oligoclonal IgG bands in cerebrospinal fluid using immobilised pH gradients

A method is described for the separation and detection of highly alkaline IgG bands in unconcentrated cerebrospinal fluid (CSF). These bands are frequently found in the cerebrospinal fluid of patients with inflammatory diseases of the central nervous system, particularly in the case of multiple sclerosis, and their detection is an important aid in clinical diagnosis. An isoelectric focusing technique using an immobilised pH gradient in polyacrylamide gel has been developed over the pH range 7-10, producing a linear and stable pH gradient with excellent resolution. After electrofocusing, the protein patterns were blotted onto polyvinylidene difluoride membranes and visualised using anti-human IgG followed by an enzyme-labelled second antibody. Blotting could be carried out by capillary diffusion for up to 16 h duration without any loss in resolution. Using this method, highly alkaline intrathecal IgG bands were found in the cerebrospinal fluid of all of the 14 multiple sclerosis patients. There were also 2 patients with alkaline IgG bands in their cerebrospinal fluid who were not diagnosed as multiple sclerosis. By contrast, no alkaline IgG bands with an isoelectric point (pI) greater than 8.6 were found in any of the serum samples studied (n = 50) from patients with various neurological disorders including multiple sclerosis.

Cerebrospinal fluid biochemistry in the diagnosis of multiple sclerosis

The Poser criteria for diagnosing multiple sclerosis (MS) includes clinical, paraclinical and laboratory information. We studied the influence of cerebrospinal fluid (CSF) biochemistry results on the categorisation of patients with suspected MS. A retrospective study was made of 138 patients who had CSF samples sent over a 1 year period to the laboratory for examination for oligoclonal bands. Using the Poser criteria, 23 patients were diagnosed as having definite MS and one patient as probable MS. Cerebrospinal fluid biochemistry upgraded the categorisation from probable to definite MS in 16 of these 24 patients (66%). In this study, we found oligoclonal bands to be more sensitive in the diagnosis of MS (96%) than either the concentration of IgG in the CSF (43.5%) or the IgG expressed as a percentage of the total protein in the CSF (71%). We conclude that CSF biochemistry is a valuable investigation in the evaluation of patients with suspected MS.

Cerebrospinal fluid protein analysis in diseases of the nervous system

Electrophoretic studies of human CSF proteins from patients with diseases of the NS are reviewed. Various 1-DE methods are of similar value in identifying the non-specific OBs, which are helpful in the diagnosis of MS and recurrent GBS. In early and subclinical MS, OBs are of prognostic value, with IEF gels having the greater resolution. Silver-stained 2-DE gels provide the equivalent information to the OBs on 1-DE gels, with even greater sensitivity, and yield additional disease-associated protein data. Two proteins have proven to have diagnostic value in CJD and other changes that are still being evaluated have been identified in Parkinson's disease, GBS, Alzheimer's disease, schizophrenia and Herpes simplex encephalitis. The vastly improved CSF protein information obtained with silver-stained 2-DE gels heralds both a change from the relatively limited applications with 1-DE methods and also the need to adopt this approach in the routine clinical laboratory.

Circulating immune complexes in serum and in cerebrospinal fluid of patients with multiple sclerosis. Characterization and correlation with the clinical course

We studied circulating immune complexes (IC) in the serum and cerebrospinal fluid (CSF) of patients with clinically defined multiple sclerosis (MS), in order to establish a correlation with the clinical course of the disease and to investigate the molecular composition of the IC isolated from patients in active phase of the disease. Serum IC levels were found to be significantly increased in patients from the progressive and active relapsing-remittent subgroups with both the CIC-conglutinin and C1q-binding methods. High levels of IC in CSF were detected only in the subgroup consisting of the relapsing-remittent patients in disease exacerbation when IC were determined by the C1q-binding test. No significant increase in serum or in CSF were found using the mRF-I test. The preliminary results of a qualitative investigation on serum IC in MS indicated that they are heterogeneous in nature, their size is mainly of the intermediate type, and they contain IgG, IgM, complement components and beta 2-microglobulins, the latter presenting an observation both new and interesting for studies on serum IC in MS patients.

The clinical use of cerebrospinal fluid studies in demyelinating neurological diseases

The clinical diagnosis of definite multiple sclerosis is supported by abnormalities in the cerebrospinal fluid: variable mild pleocytosis and elevation of total protein, moderately elevated total IgG in most patients, and the almost invariable presence of discrete immunoglobulins after electrophoresis, the oligoclonal bands. The oligoclonal bands are non-specific, and are seen in most diseases of the nervous system, but their temporal uniformity in each patient with multiple sclerosis is characteristic. Prognostically, patients with a single episode of optic neuritis or paraesthesia who have oligoclonal bands are more likely to develop multiple sclerosis than if the spinal fluid were normal. In the Guillain-Barré syndrome, the spinal fluid total protein is transiently elevated, with no pleocytosis. Oligoclonal bands are usually found in the acute phase and only persist in those patients with chronic or relapsing polyneuropathy.

Comparison of polyacrylamide and agarose support media for detection of oligoclonal IgG bands in CSF

Parallel samples of cerebrospinal fluid (CSF) from 120 patients clinically suspected of having multiple sclerosis were electrophoresed using agarose or 7% polyacrylamide. 57 samples showed oligoclonal IgG patterns in polyacrylamide but only 34 showed bands after concentration and electrophoresis in agarose. The concentrations of IgG and albumin were also measured in each sample and IgG/albumin ratios calculated. The sensitivities of the three methods for the detection of intrathecally synthesised IgG were compared. Electrophoresis in 7% polyacrylamide gave the highest proportion of significant results. In an attempt to increase the sensitivity of the agarose method, silver staining was performed on unconcentrated samples run in agarose. This did not alter the pattern of electrophoresis in samples containing oligoclonal IgG, but the sensitivity of the technique was lower than that of polyacrylamide.

Plasma cells in cerebrospinal fluid and multiple sclerosis: diagnostic yield and clinicobiological correlations

Cerebrospinal fluid (CSF) cytocentrifugation was performed for plasma cells' demonstration in parallel with white cell count (WCC) and quantitative protein assays. Over a 5-year period, 154 consecutive multiple sclerosis (MS) patients were studied and compared to 28 other inflammatory neurological disease, 85 non-inflammatory neurological disease and 29 non-neurological disease cases. CSF cytology was easy to perform, gave definitive results within 2 h and was abnormal in 80 MS patients, 26 of whom had a normal WCC. Its sensitivity in MS was 0.57, i.e. higher than for WCC (0.45) but lower than for IgG index (0.70) and IgG synthesis rate (0.71). Its specificity was 0.86, not significantly different from specificity of WCC, IgG index and IgG synthesis rate. Plasma cells demonstration in MS CSF was neither a disease activity nor a prognosis marker. It was significantly correlated with pleiocytosis and intrathecal IgG synthesis. If these morphologically defined plasma cells are actual B cells, they could represent circulating individuals of the lymphocyte clones active in MS plaques and have a pathogenetic significance.

Oligoclonal "fingerprint" of CSF IgG in multiple sclerosis patients is not modified following intrathecal administration of natural beta-interferon

The IgG pattern in CSF was studied in 11 patients with multiple sclerosis who exhibited an oligoclonal banding upon thin-layer polyacrylamide gel isoelectric focusing followed by silver stain of unconcentrated CSF. Each patient received beta-interferon intrathecally during a 2 month period. No modification was observed over a 6 month period. In addition, the oligoclonal pattern was remarkably unique for each individual representing a typical "fingerprint" which allowed the identification of any single CSF.

Identification of the inflammatory cells in the central nervous system of patients with adrenoleukodystrophy

Adrenoleukodystrophy is a disorder of long-chain fatty acid metabolism associated with adrenal cortical insufficiency and central nervous system demyelination. The central nervous system disease is unusual in that it is abrupt in onset and accompanied by a considerable infiltration of mononuclear inflammatory cells. To determine the nature of these inflammatory cells, immunocytochemical staining was carried out on the mononuclear cells in the brain and cerebrospinal fluid of patients with adrenoleukodystrophy. Monoclonal antibodies to T lymphocytes (T11), the helper/inducer (T4) and cytotoxic/suppressor (T8) subsets of T lymphocytes, B lymphocytes (B1), and monocyte/macrophages (M1 or esterase) were used. Mononuclear cells in the perivascular cuffs of autopsy material from 4 patients were, on average, 59% T cells, 34% T4 cells, 16% T8 cells, 24% B cells, and 11% monocyte/macrophages. Cerebrospinal fluid from 8 of 10 patients had increased IgG concentrations. Mononuclear cells in the cerebrospinal fluid of 6 patients with active disease were, on average, 61% T cells, 40% T4 cells, 16% T8 cells, 3% B cells, and 18% monocyte/macrophages. This distribution of cells is similar to that found in the central nervous system during a cellular immune response and suggests the possibility that one component of this disease is immunologically mediated.

Free light chains in the cerebrospinal fluid: an indicator of recent immunological stimulation

A group of 38 patients with immunoglobulin free light chains (kappa and/or lambda) in the cerebrospinal fluid was studied. Only five of them showed one band of kappa free light chains, 36 of them showed one or more bands of lambda free light chains. There were 33 multiple sclerosis patients among them and they were compared with 33 control multiple sclerosis patients who did not have free light chains but only showed an oligoclonal pattern of immunoglobulins in their CSF. Of several clinical and pathological parameters, only three were statistically significant: (A) for all patients, as well as for the multiple sclerosis patients alone, elevated numbers of free light chains of type lambda were associated with the elevated numbers of white blood cells in the CSF (p less than 0.003), (B) for multiple sclerosis patients, elevated numbers of free light chains of type lambda were associated with associated with shorter time intervals between the last relapse and the date of the lumbar puncture (p less than 0.004) and (C) also with shorter duration of the disease (p less than 0.01). The presence of lambda free light chains in the cerebrospinal fluid seems to indicate that recent antigenic stimulation has occurred within the central nervous system following exacerbation. The inverse association of the number of lambda free light chains with the duration of the disease is suggestive of a pathological expression of the "burning out" phenomenon of the multiple sclerosis process.

Cerebrospinal fluid in multiple sclerosis: relationships between immunoglobulins, leucocytes and clinical features

Cerebrospinal fluid (CSF) from 120 patients with multiple sclerosis was analyzed by polyacrylamide gel electrophoresis, as well as routine laboratory microscopy and assays of total protein and immunoglobulin G (IgG). Negative correlations were found between leucocyte counts and patient age, duration of disease and time from last clinical relapse. There was a positive correlation between the leucocyte count and amount of gammaglobulin. A correlation between gammaglobulin content and degree of disability was found. With increasing duration, the gammaglobulin concentration rose only if there was increasing disability. In terms of correlations with clinical features, differences existed depending on whether IgG was assayed immunologically or by electrophoresis and densitometry. Evidence of increased blood: CSF barrier permeability (transudation of high molecular weight proteins) was found in patients with progressive disease. The presence of oligoclonal bands was the CSF abnormality most frequently encountered.

Clinical significance of immunologic and immunogenetic evaluation in multiple sclerosis

One hundred thirty-two patients were separated into clinically defined groups of definite, probable and possible multiple sclerosis (MS), the spinal cord variant of MS (SCV), and non MS neurologic disease. HLA antigens A3 and B7 occurred at increased frequencies in definite and probably MS patients when compared with neurologic controls and healthy adults. CSF elevations of either kappa/lambda ratio, IgG/total protein ratio, or IgG were seen in 65% of the definite, probable and SCV groups. Patients with HLA A3 and B7 antigens had a higher than predicted incidence of elevated kappa/lambda ratio, suggesting that there may be immunogenetic control mechanisms which influence this CSF parameter. Neither HLA antigens nor CSF protein abnormalities correlated with the age of onset, progression, or degree of disability of disease, thus limiting their prognostic usefulness.

IgG ratios and oligoclonal IgG in multiple sclerosis and other neurological disorders

The findings are reported of various CSF abnormalities, including IgG indices and oligoclonal IgG, in 160 patients with multiple sclerosis of differing diagnostic certainty and 146 patients with other neurological disorders. An abnormal IgG index, defined as the ratio of IgG/albumin in CSF to that in serum, has been found in 77.7% of definite MS cases, falling to a figure of 32.1% in the single lesion group. A tendency, reported previously, for IgG levels to be higher in disabled patients, particularly those with a short history or early onset, has been confirmed. Oligoclonal IgG, on the other hand, has been found in 56% of definite MS cases, less frequently than in most other reported series. Analysis of the literature suggests considerable variability in the finding of oligoclonal IgG in other than definite MS, and in other neurological disorders. The possibility that subjective factors are partly responsible for this variability, rather than discrepancies in patient selection requires consideration, and suggests that CSF electrophoresis and IgG estimations are complementary aids in the diagnosis of multiple sclerosis. Differences have been expressed regarding the relationship of oligoclonal IgG to clinical parameters of the disease. Further sequential analysis of the development and variability of the oligoclonal pattern in MS is required.

Binding properties of cerebrospinal fluid IgG in multiple sclerosis and other neurological diseases

A solid phase radioimmunoassay (RIA) was used to detect antibodies to myelin or myelin basic protein (MBP) in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) or other neurological diseases (OND). When measured at the same IgG concentration, MS samples had higher binding values than OND against myelin, but not against MBP. Using F(ab')2 fragments purified from pools of MS and OND CSF there was no difference in binding to myelin between MS and OND samples. These results indicate that anti-MBP antibodies are nt a feature of MS and binding of CSF IgG to myelin is not due to specific antibody, but is probably the result of non-specific binding to Fc receptors.

Essential fatty acids in the serum and cerebrospinal fluid of multiple sclerosis patients

Statistical evaluation of essential fatty acids (determined by gas chromatography) in the serum and cerebrospinal fluid of patients with definite MS and acute CCT showed marked differences as compared to healthy subjects. It was also evident that the decrease of essential fatty acids in MS patients differed from that of CCT patients. Whereas the fatty acid levels in the serum of MS patients revealed only minor differences as compared to the controls and CCT patients, MS patients did show a clear decrease, especially of linoleic and arachidonic acids, in the CSF. This difference was most pronounced in cholesterol esters in the CSF. One absorption study with safflower oil demonstrated normal enteral absorption of essential fatty acids and the ability to cross the blood-CSF barrier.

Demonstration of cerebrospinal fluid oligoclonal banding in neurologic diseases by agarose gel electrophoresis and immunofixation

Demonstration of an oligoclonal immunoglobulin pattern in cerebrospinal fluid by a commercial agarose gel electrophoresis system and immunofixation were evaluated in the service clinical laboratory of a university hospital. In 303 patients, 45 with clinically definite multiple sclerosis and 209 with other neurologic diseases, the sensitivity of oligoclonal banding for multiple sclerosis was 71%, and the specificity, 83%. Oligoclonal banding was frequent in inflammatory disease, tumor/pseudotumor or vascular diseases of the central nervous system (35%, 36% and 26%, respectively) and less frequent in degenerative central nervous system disease and peripheral neuropathy (5.2% and 15%). No patient with non-neurologic disease had oligoclonal banding. The addition of an immunochemical step (immunofixation) did not increase sensitivity and only minimally increased specificity. It did permit distinction in selected cases between immunoglobulin and other molecules with identical electrophoretic mobility.

Oligoclonal IgG in the cerebrospinal fluid of guinea pigs with acute experimental allergic encephalomyelitis

The cerebrospinal fluid (CSF) of guniea pigs with experimental allergic encephalomyelitis was examined for the presence of oligoclonal IgG using polyacrylamide gel electrophoresis. Oligoclonal IgG (greater than or equal to 2 bands) was seen in the CSF obtained from 3/4 animals with experimental allergic encephalomyelitis induced by myelin basic protein and 2/3 with spinal cord-induced disease. It was not seen in CSF of 3 non-sensitized, 4 adjuvant-sensitized and 7 liver-sensitized guinea pigs. Scanning of stained gels confirmed the oligoclonal pattern. The bands were found in the region of gels which bound [125I]Staphylococcal Protein A. The data demonstrate that a non-infectious inflammatory reaction within the central nervous system can result in an oligoclonal IgG pattern in the CSF.

The electrophoretic demonstration of unique oligoclonal immunoglobulins in cerebrospinal fluid as a diagnostic test for multiple sclerosis

Polyacrylamide disc gel electrophoresis was performed on unconcentrated cerebrospinal fluid and serum from 132 neurological patients and from 33 patients without neurological disease. The presence of unique, discrete immunoglobulin bands in the gamma-globulin (cathodal) region of the cerebrospinal fluid gel was assessed as a diagnostic test for multiple sclerosis. The procedure exhibited a specificity for multiple sclerosis of 94% and a sensitivity of 72%, and is easier to perform than most of the other published procedures used to demonstrate oligoclonal immunoglobulins in cerebrospinal fluid. It is recommended for use in the clinical chemistry laboratory as a valuable adjunct to the diagnosis of multiple sclerosis.

Multiple tests in the diagnosis of multiple sclerosis

Visual evoked potentials (VEPs), somatosensory evoked potentials (SEPs), E-UFA test and CSF isoelectrofocusing (IEF) were applied to 42 multiple sclerosis patients. VEPs were abnormal in 29 cases. SEPs in 31 cases, E-UFA in 30 cases, CSF IEF in 38 cases. At least two tests were abnormal in 41 out of 42 patients; 16 cases revealed pathological responses in three tests (38,1%), 15 in four of them (35,7%). The authors discuss the value of using several tests in the diagnosis of multiple sclerosis and emphasize their importance for the purpose of diagnostic classification.

IgM-class rheumatoid factor in serum and cerebrospinal fluid of multiple sclerosis and matched neurological control patients

Paired serum and cerebrospinal fluid (CSF) specimens from 30 multiple sclerosis (MS) patients and 30 matched neurological control (NC) patients were quantitatively tested for IgM-class rheumatoid factor (RF). Significantly elevated RF levels were found in serum from 6 MS patients and 12 NC patients. Seven of the latter 12 patients had a diagnosis of recurrent head pain. RF was detected in CSF from 2 MS patients and 2 NC patients. In 3 of the 4 cases, this could be explained by blood-brain barrier damage or normal diffusion of RF into CSF. Intrathecal RF synthesis was found in the remaining MS patient. These results suggest that RF production may be related to underlying pathological mechanisms in at least some MS and NC patients. They also confirm that RF must be carefully accounted for in etiological studies designed to demonstrate pathogen-specific IgM antibodies in, for example, MS patients.

Measles antibodies, kappa-lambda light chain distribution and immunoglobulins in serum, cerebrospinal fluid and brain of a patient affected with multiple sclerosis

The serum, cerebrospinal (CSF) and brain of a patient (NAG) affected with multiple sclerosis (MS) were examined for measles antibodies with CF and HI techniques, and the kappa-lambda light chain ratios of all samples available were evaluated, kappa-lambda populations of the matched serum, CSF and brain specimens were all lambda-predominant and in agreement with each other; the light chain distribution f the brain specimens confirmed previous findings [3]. Only the serum immunoglobulins showed significant measles antibody titers, but slightly increased measles antibody titers were also observed in ventricular plaques. The amount of immunoglobulin G (IgG) synthesized per day by the central nervous system (CNS) was estimated. The IgG synthesis in CNS NAG (11.6 mg/day) was above the upper limit of the normal range (3.3 mg/day), but apparently there was no positive correlation between the intracerebral IgG synthesis and specific anti-measles IgG.

Cerebrospinal fluid and serum oligoclonal IgG bands in rabbits with experiment allergic encephalomyelitis

Rabbits sensitized with whole nervous tissue or myelin basic protein (MBP) plus adjuvant and developing experimental allergic encephalomyelitis (EAE) were studied for the presence of oligoclonal immunoglobulin (Ig) bands in spinal fluid and serum. Samples obtained prior to sensitization and at the time of sacrifice were concentrated and subjected to agar gel electrophoresis. Of 11 rabbits receiving whole nervous tissue and developing severe clinical signs of EAE, 7 showed new oligoclonal Ig bands in spinal fluid and in serum obtained 19 days or more after sensitization. With MBP sensitization, 2 of 6 rabbits exhibited new spinal fluid bands, while all 6 rabbits studied demonstrated serum banding. The bands were identified as IgG by immunochemical studies using peroxidase-labeled antisera and by Staph. protein A absorption. The majority of animals showed no banding in presensitization samples. The finding of oligoclonal IgG in EAE reveals yet another immunologic correlation between EAE and the human demyelinating disease, multiple sclerosis.

The early diagnosis of multiple sclerosis

An outline of modern views on the aetiology of multiple sclerosis is followed by a discussion of diagnosis. Examination of the cerebrospinal fluid, visual evoked potentials, and other electrophysiological tests are considered. The special problems of optic neuritis, spastic paraparesis, and psychological disorder receive more detailed attention. It is concluded that while the supplementary tests are valuable the diagnosis remains essentially clinical.

A search for antibodies against glial cells in the serum and cerebrospinal fluid of patients with multiple sclerosis and Guillain-Barré syndrome

We have used indirect immunofluorescence to examine the binding of immunoglobulin in sera from patients with multiple sclerosis, Guillain-Barré syndrome, other neurological diseases, and normal subjects to marker-identified glial cells in dissociated primary cell cultures of neonatal rat corpus callosum and sciatic nerve. In corpus callosum cultures all the sera tested showed weak surface staining of oligodendrocytes and of a small percentage of astrocytes and bright staining of fibroblasts. The cerebrospinal fluid from one patient with multiple sclerosis showed the same pattern of staining while the cerebrospinal fluid from other patients with multiple sclerosis and pathological controls only showed weak staining of fibroblasts. None of the sera stained the cytoplasm of oligodendrocytes in frozen sections of adult rat optic nerve. In sciatic nerve cultures all sera showed weak staining of Schwann cells and fibroblasts. Thus we were unable to distinguish patients with demyelinating diseases from normal individuals or from patients with other neurological diseases in terms of serum or cerebrospinal fluid anti-glial cell antibodies.

The nervous system-specific S-100 antigen in cerebrospinal fluid of multiple sclerosis patients

The nervous system-specific S-100 antigen has been found in cerebrospinal fluid (CSF) of 13 out of 18 patients with multiple sclerosis (MS), whereas it was undetectable in either of the 11 control patients with minor psychic disturbances or with neurological disorders not usually associated with apparent parenchymal lesion. The levels of the antigen appeared to be higher in CSF of patients in the acute phase of the disease. Though the small number of cases hampers final statements, the S-100 in CSF might serve as a possible index of active cell injury in the central nervous system underlying the pathogenesis of MS.

Oligoclonal immunoglobulins and plasma cells in spinal fluid of patients with multiple sclerosis

A new modification of polyacrylamide gel electrophoresis (PAGE) was applied to cerebrospinal fluid proteins from patients with multiple sclerosis (MS). The same spinal fluids were also examined by a cytological technique. Over 90% of patients with clinically definite or early probable or latent MS showed abnormal PAGE patterns in the form of oligoclonal gammaglobulin bands. Reactive (atypical, large) lymphocytes or typical plasma cells were found in some patients. In all such cases an oligoclonal pattern was present. The findings of oligoclonal bands provides valuable supporting evidence for the diagnosis of MS in the less definite clinical categories.

Bound and free light chains in serum from patients affected with various neurological diseases

Six immunological parameters, of which the most important are the quantitative distribution of the free light chains, and the kappa-lambda ratios of both bound and free light chains, were investigated in serum of patients affected with various neurological disorders and compared to controls. Subacute sclerosing panencephalitis and viral encephalitis, which are diseases characterized by hyperimmunisation against definite antigens, are accompanied by a considerable quantitative increase in free light chains; in subacute sclerosing panencephalitis serum there is an increase of both free kappa and lambda chains, whereas in viral encephalitis serum the increase of free light chains were restricted to lambda chains. There is a good correlation between the kappa-lambda ratio of, on the one hand, bound light chains and, on the other hand, free light chains for controls and subacute sclerosing panencephalitis; but in multiple sclerosis, amyotrophic lateral sclerosis and viral encephalitis, the ratios for bound light chains are totally different from ratios for free light chains. A general kappa increase, which we earlier reported for bound light chains in 16 cases of multiple sclerosis, was not confirmed by the investigation of an additional 26 cases: kappa decrease was also noticed in a considerable number of cases.

Proteolytic enzyme activity of blood leukocytes and cerebrospinal fluid in multiple sclerosis

Upon stimulation by immune complexes, the polymorphonuclear (PMN) blood secretes lysosomal hydrolases, including neutral proteinase, which is concentrated in the PMN cell. Neutral and acid proteinase activity were increased and decreased, respectively, in the circulating white cells of patients with multiple sclerosis during an exacerbation of the disease, but there was no correlation with serum immune complex levels. Neutral proteolytic activity in the cellular fraction of the cerebrospinal fluid was also found to be elevated in acute multiple sclerosis, as monitored by digestion of myelin basic protein.

Isoelectric focusing and isotachophoresis for investigation of CSF and serum proteins in demyelinating and infectious neurological diseases

Isoelectric focusing (IEF) and isotachophoresis (ITP), two methods with excellent separation capacities, have been adapted during recent years for the analysis of CSF proteins. The fractions separated by these techniques can be further studied by e.g. immunological methods. ITP has besides its high separation capacity several valuable advantages: very small samples are needed, unconcentrated CSF can be examined, the analyses are quickly performed and the results are immediately obtained on a recorder. Examinations by thin-layer IEF in a series of about 2,000 patients have afforded much new information about the CSF and serum proteins in many neurological diseases. Different complex CSF protein aberrations have been found in the gammaglobulin range as well as in more anodal positions in MS, infectious neurological diseases and Guillain-Barré syndromes. These aberrations are probably the result of several interacting factors, e.g. the temporal and spatial characteristics of the disease, the release of decomposition products from destroyed tissues, the genetically determined reactivity of the individual and the type of etiological agent.

Multiple sclerosis: diagnostic usefulness of cerebrospinal fluid

Early, atypical, or progressive cases of multiple sclerosis (MS) may be hard to diagnose. Until recently, assays of the most common abnormalities in cerebrospinal fluid were not available in clinical diagnostic laboratories, but now they can be done with relative ease and adequate standardization. With the newer techniques the CSF is abnormal in more than 90% of clinically definite cases of MS, and determination of such changes can be a major aid in diagnosis. The most common CSF abnormalities are discussed: elevation of immunoglobulin G(IgG), expressed as percentage of total protein; elevation of the IgG/albumin index; and presence of oligoclonal IgG bands. Not only does assessment of these CSF proteins provide an improved aid to diagnosis, but their study may furnish important clues to the cause and pathogenesis of MS as well.