Isoelectric focusing of CSF proteins in neurological diseases

Comparison between agarose gel electrophoresis and isoelectric focusing of CSF for demonstration of oligoclonal immunoglobulin bands in neurological disorders

Isoelectric focusing and agarose gel electrophoresis of CSF and serum revealed similar frequencies of oligoclonal bands in multiple sclerosis (100% with both methods), infectious CNS disorders (38 and 23%) and other neurological diseases (8 and 10%). In selected cases with unsure CSF oligoclonal bands on agarose gel electrophoresis, isoelectric focusing displayed definite oligoclonal bands. In contrast to agarose gel electrophoresis, isoelectric focusing revealed evidence for oligoclonal bands in serum as well as in CSF in 41% of the multiple sclerosis patients, indicating diffusion from CSF to serum. In 4 cases with gammaglobulin bands appearing in both CSF and serum on agarose gel electrophoresis, isoelectric focusing revealed normal CSF and serum protein patterns at pH above 6.4 where most IgG is migrating.

Localization of the immunoglobulins G, A and M, beta-trace protein and gamma-trace protein on isoelectric focusing of serum and cerebrospinal fluid by immunofixation

The mobility of the immunoglobulins G, A and M, beta-trace protein and gramma-trace protein on isoleectric focusing of serum and CSF was determined by immunofixation using specific antisera. Polyclonal IgG migrated as multiple bands between pH 4.7--8.6, polyclonal IgA as multiple bands between pH 4.9--6.1 in CSF and serum. IgM could not be identified in normal CSF or serum. beta-trace protein gave three bands at pH 8.0, 8.4 and 7.4--7.5, respectively, while gamma-trace protein gave one single band at pH 9.5--greater than 9.5. Oligoclonal IgG in CSF in multiple sclerosis and neurosyphilis migrated between pH 8.6--greater than 9.5 and was easily discriminated from other proteins.

Serum protein binding of lead in vitro in amyotrophic lateral sclerosis patients and controls

The binding of lead to serum proteins was studied in vitro in ALS-patients and controls. Serum was incubated with 210Pb, the proteins were separated by isoelectric focusing and the radioactivity in the different protein fractions was determined by liquid scintillation counting. The activity was concentrated in the orosomucoid (acid alpha1-glycoprotein) fraction both in ALS-patients and controls under the present experimental conditions and the capacity of this protein to bind lead was demonstrated in a control experiment. The findings are discussed in relation to our earlier observations on increased concentrations of lead in cerebrospinal fluid and plasma in ALS-patients and the hypothetical role of the retrograde axonal transport in motoneurons in the pathogenesis of ALS. The present observations do not lend support to the idea that the increased plasma concentrations of lead in the disease would be related to qualitative differences in serum protein binding.

Provoked visual impairment in multiple sclerosis studied by visual evoked responses

Pattern-reversal VERs were studied during the visual impairment provoked by exercise in 2 patients with demyelinating optic neuritis. It was found that the transient reduction in visual acuity was correlated to a transient decrease in the amplitude of the major positive component of the VER, whereas no significant changes could be observed in the latency of the response. The normal VER was not influenced by exercise.

The normal cerebrospinal fluid proteins identified by means of thin-layer isoelectric focusing and crossed immunoelectrofocusing

The cerebrospinal fluid and serum proteins from 32 healthy individuals have been examined by isoelectric focusing in a pH-gradient from 3.5--11.0. Seventeen normal proteins have been identified by means of crossed immunoelectrofocusing. The pI-values of the main fractions of these proteins have been determined. On crossed immunoelectrofocusing microheterogeneity was observed for all of the proteins except haemopexin, gamma-trace protein of CSF and prealbumin of serum. Differences between serum and CSF were observed for 6 of the proteins. Prealbumin of CSF had a lower pI-value than in serum and showed partial immunological identity with prealbumin of serum. Transferrin of CSF included several components with lower sialic acid contents than in serum. The conversion of C'3-complement from beta-1-C to beta 1-A was slower in CSF than in serum. Qualitative differences between CSF and serum were also noticed for alpha2-macroglobulin and haptoglobin. IgM was not detected in CSF. In CSF the gamma-trace protein was found on isoelectric focusing in one third of the subjects. Two subjects had 2 close tau-fractions and another two had one unidentified band in the anodal IgG-area. The gamma-trace protein did not show any proteolytic activity, nor any resemblance in charge to 4 basic enzymes or with the histones tested.

Lumbo-omental shunt for drainage of cerebrospinal fluid in hydrocephalus

A new cerebrospinal fluid (CSF) shunting procedure is presented. By transposing a pedicle graft of the greater omentum to the lumbar CSF compartment, the CSF absorption capacity of the omentum is utilized. The operation is applicable to the treatment of communicating hydrocephalus. The technical problems and physiological effects of the operation have been studied earlier in dogs. This paper presents the first case of an intended clinical series. The patient was studied for 18 months postoperatively by different examinations, including psychometric tests, cisternography, computer tomography, echo-ventriculography, and carotid angiography with measurement of the cerebral blood flow. A gradual improvement in his clinical state was registered after the operation.

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.

Crossed immunoelectrofocusing of cerebrospinal fluid immunoglobulins

The combination of the high separation capacity of isoelectric focusing and the specificity of immunoelectrophoresis gives a valuable tool for protein studies. This technic can be applied to immunoglobulin examinations by using KOCN-treated antibodies isoelectric at pH 5 and performing the immunoelectrophoretic procedure at this pH. CSF and serum samples of patients exhibiting CSF immunoglobulin abnormalities and blood-CSF barrier damages were examined by this method.

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.

Isoelectric focusing of CSF and serum proteins in neurological disorders combined with benign and malignant proliferations of reticulocytes, lymphocytes and plasmocytes

The clinical data and the CSF and serum findings on isoelectric focusing (IEF) and electrophoresis were studied in nine patients with neurological disorders combined with proliferations of reticulocytes, lymphocytes or plasmocytes. Paraneoplastic neurological manifestations were considered in some of the subjects. CSF findings compatible with intrathecal synthesis of oligoclonal immunoglobulins were observed in two patients with lymphoreticular neoplasms. One of these had an IEF band spectrum differing from those found with multiple sclerosis (MS), while the other had changes indistingusihable from those with MS. On IEF the CSF and serum M components of the patients with plasma cell dyscrasias, as well as the serum M components of nine other patients with myelomatosis, exhibited considerable microheterogeneity with 3-18 abnormal bands. The isoelectric point (pI) of the individual bands was 5.8-9.2, mostly greater than 6.4; the band spectra exhibited pI ranges of 0.4-2.5 pH units, most frequently 0.4-1.2. The CSF findings, possible modified by the blood-CSF barrier, reflected the serum changes of plasma cell dyscrasias. The immunoglobulins produced in such disorders gave IEF band spectra differing from those of intrathecally produced immunoglobulins in MS.

Crossed immunoelectrofocusing for identification of normal and abnormal cerebrospinal fluid proteins. A preliminary report

Isoelectric focusing is a valuable method for the analysis of cerebrospinal fluid (CSF) proteins. Its high resolving power has, however, created problems in identifying the large number of protein bands separated. In an attempt to identify these bands, two-dimensional crossed immunoelectrofocusing has been used, where isoelectric focusing is combined with rocket immunoelectrophoresis. By these methods 9 of the normal proteins in the acidic pH interval have been identified. In addition the unusual CSF protein abnormalities occurring in Marie-Sanger-Brown's ataxia and alcoholic cerebellar degeneration have been shown to represent increases of different microheterogeneous forms of transferrin.

Biochemical findings in multiple sclerosis IV. Isoelectric focusing of the CSF gamma globulins in multiple sclerosis (262 cases) and other neurological diseases (272 cases)

Despite enormous efforts to find a specific laboratory test for multiple sclerosis, agar gel electrophoresis of the CSF proteins has remained the next to the best one. This study presents evidence that thin layer polyacrylamide isoelectric focusing of the CSF gamma globulins is by far superior for this purpose. In effect, about 91% of the 262 multiple sclerosis patients studied had oligoclonal fractions present in the very alkaline region of the pH gradient. Of the same group of patients only 65% did show pathological results when studied by agar gel electrophoresis. Of the 272 CSF samples from patients suffering from other neurological diseases, only about 7% showed the presence of oligoclonal bands in the same region of the pH gradient, when submitted to isoelectric focusing.

Isoelectric focusing and electrophoresis of the CSF proteins in tremor of different origins

The CSF proteins have previously been very little investigated in the cerebellar syndrome of chronic alcoholism and in essential tremor. Such studies have been carried out more thoroughly by electrophoretic methods in Parkinson's disease but generally with normal results. In the present investigation the CSF proteins were examined by isoelectric focusing and quantitative paper electrophoresis in 10 patients with the cerebellar syndrome of chronic alcoholsm, 12 patients with Parkinson's disease and 16 subjects with essential tremor. Abnormal CSF proteins of very similar appearance were found on isoelectric focusing in the acidic pH interval 5.6-5.8 in 80% of the patients with the cerebellar syndrome of chronic alcoholism. In Parkinson's disease the most common aberration was evidence of nonspecific blood-CSF-barrier damage which occurred in half of the patients. In only 17% of these cases did other alterations appear, situated in the pH range alkaline to pH 5.8. Abnormal CSF proteins were found in 94% of the patients with essential tremor. The aberrant proteins appeared in both the acidic and alkaline pH regions, most frequently with anisoelectric point at pH 5.9, 7.2 and 9.3. There was a considerably higher frequency of CSF protein abnormalities in different pH ranges in patients with tremor of more pronounced degree as compared to those with only mild symptoms. The electrophoretic examinations failed to show any conclusive alterations. Barrier-damage patterns of mild or moderate degree or slightly increased levels of CSF beta1-globulin were occasionally found in all 3 diseases. The results indicate that isoelectric focusing of the CSF proteins may be of diagnostic value in the cerebellar syndrome of chronic alcoholism and in essential tremor but does not reveal any characteristic abnormalities in Parkinson's disease.

Isoelectric focusing and electrophoresis of cerebrospinal fluid proteins in muscular dystrophies and spinal muscular atrophies

In the very few previous investigations of the CSF-proteins in muscular dystrophies the results have generally been reported as normal. In spinal muscular atrophies a barrier-damage pattern of CSF-proteins has been found in amyotrophic lateral sclerosis (ALS). In the present investigation the CSF-proteins were examined by isoelectric focusing and quantitative paper electrophoresis in 13 patients with muscular dystrophies and in 11 patients with spinal muscular atrophies. On isoelectric focusing, CSF-protein abnormalities were found in 85% of the cases with muscular dystrophies and in all patients with spinal muscular atrophies. Differences in the CSF-protein patterns were observed within the group of muscular dystrophies and between these and the cases of spinal muscular atrophies. In ALS and in myotonic dystrophy, abnormal CSF-protein fractions occurred mainly in the alkaline pH-range, while in limb-girdle dystrophy and the patient with facioscapulohumeral dystrophy, aberrant fractions appeared mainly in the acidic region. CSF-protein abnormalities were found in both the alkaline fractions (HAFs) with pI 9.2-9.6 and a fraction with PI 7.1 were found in half of the patients with myotonic dystrophy. The CSF electrophoresis in myotonic dystrophy showed increased levels of beta1-globulin in all cases examined. Signs of barrier-damage were commonly encountered in ALS in contrast to the muscular dystrophies, except for myotonic dystrophy. The results are discussed in terms of possible diagnostic value and with regard to pathogenetic significance, particularly in relation to the current hypothesis of a neural involvement in muscular disorders.

Analytical isotachophoresis: a new method for analysis of cerebrospinal fluid proteins. A preliminary report

Isotachophoresis of CSF proteins seems to be a very promising method. Very small CSF samples, a few mul of concentrated and 15-30 mul of unconcentrated CSF, can be quickly analysed (30-60 min), and the results immediately obtained on a recorder. Using unconcentrated CSF, losses due to concentration procedures, are avoided. Low-molecular weight compounds, e.g. in CSF ultrafiltrates, can also be examined. The method gives high resolution, is reproducible, and is easy to perform. The isotachophoretic findings have been compared with those of electrofocusing.

Protein patterns of cerebrospinal fluid in hereditary ataxias and hereditary spastic paraplegia

The CSF findings in hereditary ataxias and allief disorders have hitherto mostly been reported as normal if one excludes Refsum's syndrome. The CSF-protein patterns found on isoelectric focusing and quantitative paper electrophoresis were studied in 12 patients with hereditary ataxias and hereditary spastic paraplegia. Using a recently-developed technique of isoelectric focusing of CSF-proteins in flat beds of polyacrylamide gel, the authors could show abnormal CSF-protein patterns in all but 1 of the present cases. The aberrant CSF-protein patterns found showed differences between the syndromes studied. Two unique patterns with conspicuous fractions in the acid range were observed in patients with Marie-Sanger-Brown's ataxia (mother and daughter) and Holmes' ataxia. A third CSF-protein pattern was found in a sibship with Friedreich's ataxia including a double fraction in the acid region (pI 5.9-6.1) in all 4 subjects and a highly alkaline fraction (HAF) with pI about 9.3, in 3 of them. Similar acid fractions (pI 5.9-6.1) were also detected in 3 of 4 patients with hereditary spastic paraplegia, a brother and sister showing a very similar CSF-protein pattern. Double fractions with pI 5.9-6.1 and/or HAF may also occur in other neurological diseases, mostly, however, associated with other distinctive features of their CSF-protein patterns. A possibility in the future of distinguishing hereditary CNS-diseases by examination of the CSF-protein pattern is suggested.

Protein pattern or cerebrospinal fluid in spasmodic torticollis

The protein patterns found on isoelectric focusing and quantitative paper electrophoresis of cerebrospinal fluid were studied in three patients with spasmodic torticollis. Very alkaline end fractions were found on isoelectric focusing in the CSF-gammaglobulin region in each case. Alkaline end fractions in the CSF-gammaglobulin region with similar or same isoelectric points have also been observed in other extrapyramidal disorders, particularly Huntington's chorea, and in other neurological diseases, especially in multiple sclerosis. It has to be shown if these alkalline end fractions consist of the same or different compounds, conceivable constituents being mentioned. Examination of the CSF-protein pattern might help to distinguish organic from hysterical torticollis.