A STUDY OF IMMUNOGLOBULIN G IN THE CEREBROSPINAL FLUID OF 1007 PATIENTS WITH SUSPECTED NEUROLOGICAL DISEASE USING ISOELECTRIC FOCUSING AND THE LOG IgG-INDEX

Abstract

Cerebrospinal fluid and serum immunoglobulin G from 1007 patients with suspected neurological disease were analysed by 2 methods: isoelectric focusing for the detection of oligoclonal banding, and quantitative measurement of IgG and albumin for the formulation of a Log IgG-Index. A comparison of the 2 methods in the detection of local synthesis of IgG showed that isoelectric focusing not only gave a much higher yield overall, with 282 patients showing local synthesis versus 225 for the Log IgG-Index, but also a higher specificity, with a false positive rate of 0% versus 3.5%. In addition, of the 282 patients positive by isoelectric focusing only 163 (58%) were positive by the Log IgG-Index. Of the 1007 patients studied, 206 had multiple sclerosis (MS), and isoelectric focusing showed local synthesis in 95% of clinically definite cases, with a 90% detection rate overall. The Log IgG-Index was positive in only 67% of clinically definite cases, with an overall 59% detection rate. Thus with the exceptions noted above, local synthesis of IgG as defined by isoelectric focusing is confined to demyelinating, inflammatory, infectious and postinfectious disorders. Our results compare very favourably with the published sensitivities of magnetic resonance imaging in the detection of abnormalities in multiple sclerosis, and better than those for evoked potentials. Where both these investigations are readily available isoelectric focusing provides a useful adjunct. For the majority of physicians and neurologists who do not have ready access to magnetic resonance imaging, isoelectric focusing is an excellent alternative. We would also recommend that it become the standard for the measurement of IgG abnormalities in the cerebrospinal fluid and that the use of quantitative data be abandoned for routine purposes.

Isoelectric Focusing in an Immobilized pH Gradient for the Detection of Intrathecal IgG in Cerebrospinal Fluid: Sensitivity and Specificity for the Diagnosis of Multiple Sclerosis

“…This high sensitivity for the diagnosis of MS is in keeping with the results of other workers who have also reported sensitivities of over 90010 using IEF.5,1, 23 In this study, the specificity of IEF using an IPG pH 7-10 for the diagnosis of MS was 98010 (96010 if the suspected MS group was included). The true specificity and sensitivity of this technique for the diagnosis of MS will depend upon the ultimate diagnosis of the patients with suspected MS (group B, Table 1) and also how many of the laboratory supported MS groups progress to clinically definite MS. To this end, these patients are being periodically followed up by reference to their clinical records to see if they develop symptoms of MS. By comparison, Kostulas et al,' examined 1114 consecutive patients using IEF and obtained a specificity of 83010 for the diagnosis of MS (82010 if their optic neuritis patients were included).…”

Neuromielitis Óptica. Patología, diagnóstico y tratamiento en el siglo XXI

“…Algunos médicos, basados en el hecho que no existe una experiencia controlada, creen que este tratamiento es inefectivo. Sin embargo, en un estudio japonés reciente el IFN -1b mostró efectos beneficiosos (4,46,47,62).…”

Multiple Sclerosis: A Family Practice Perspective

“…Motor strength in the right extremities would wax and wane, progressing from weak to complete paralysis. Final CSF results revealed a presence of the IgG Index for MS proteins, a finding commonly seen in 90% of MS patients and suggestive of intrathecal synthesis of CSF immunoglobulins [2]. Oligoclonal bands (OCB) are limited classes of antibodies in 85 to 95% of MS patients [3] and were also positive.…”

“…Another component of the CSF that is helpful in diagnosis is the oligoclonal bands (OCBs), which are a limited class of antibodies that are depicted as discrete bands on agarose gel. OCBs are found in 85 to 95% of patients with MS; however, chronic CNS infections, viral infections, and neuropathies can also elevate OCBs [2]. The 2010 McDonald criteria note CSF findings only for supporting the diagnosis of PP type of MS [3,10].…”