A comparison of cellulose acetate immunofixation with polyacrylamide gel electrophoresis for the detection of oligoclonal bands in unconcentrated cerebrospinal fluid

A prospective study of "undiagnosed" isolated myelopathy: II. Value of magnetic resonance imaging, evoked potentials and CSF analysis

We aimed to determine the sensitivity of available "diagnostic" tests in detecting subclinical abnormalities characteristic of multiple sclerosis (MS) in patients with unexplained isolated myelopathy, and any relationship between test results and level of disability. The trial investigations were carried out in 69 prospectively selected patients with acute or chronic noncompressive myelopathies. Magnetic resonance scans were the most sensitive individual tests, revealing asymptomatic brain lesions in 51 patients (74%, C.I. 64-84). An abnormal IgG/albumin ratio (IgG/A) was present in 29 (42%, C.I. 30-54), oligoclonal bands (OCB) in 27 (39%, C.I. 17-39) and abnormal evoked potentials (EP) (visual and/or auditory brain stem) in 19 cases (28%, C.I. 17-39). OCB and abnormal EP were found significantly less often than in control patients with clinically definite MS (CDMS) and significantly more often than in patients with myelopathy due to other conditions. The number of anatomical brain areas with lesions on magnetic resonance imaging (MRI) was significantly associated with CSF abnormalities; abnormal EP were correlated with abnormal MRI and elevated CSF immunoglobulins. Clinical classifications, age, symptom duration, disability levels and genetic factors did not appear to influence the prevalence of abnormal MRI or CSF. For the exclusion of compressive and structural diseases of the spinal cord, myelography has been superceded by cervical and thoracic MRI. In addition, MRI of the brain is the investigation of choice in patients with myelopathies that remain unexplained after spinal MRI. However, whether used alone or in combination with other tests, the specificity and predictive value of brain MRI abnormalities for the risk of developing MS, as well as the associated "false positive" rates, remain to be defined by long-term follow-up of prospectively ascertained and representative cases.

Detection of oligoclonal IgG bands in cerebrospinal fluid by immunofixation after isoelectric focusing on polyacrylamide gels with the PhastSystem

This paper describes the detection of oligoclonal bands of IgG immunoglobulins in cerebrospinal fluids (CSF) using isoelectric focusing (IEF) and immunofixation with the PhastSystem equipment. The proteins were separated by IEF on polyacrylamide gels, pH 3-9. The IgG immunoglobulins were then fixed by overlaying the gel with antihuman IgG antiserum. Fixed immunoglobulins were detected with silver staining in the PhastSystem Development Unit. One microliter of serum or CSF containing 15 mg/L of IgG was found to be optimal. The procedure had good reproducibility both with regard to IEF and silver staining of the fixed immunoglobulins. The manpower need was reduced, and the procedure has been found to be useful in the clinical laboratory.

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.

High electroendosmotic agarose electrophoresis and nitrocellulose immobilisation for the detection of oligoclonal bands in unconcentrated cerebrospinal fluid

A sensitive (1 microL of unconcentrated sample), specific (IgG Fc) and economical (10 p/test) method for the detection of oligoclonal bands in cerebrospinal fluid is presented. Using commonly available technology (agarose gel electrophoresis) and giving results within 6 h, the approach used here is a powerful tool in the investigation of immunoglobulin abnormalities in many biological fluids.