Cerebrospinal fluid immunoelectrophoresis in multiple sclerosis

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.

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.

On the relationship of CSF pleocytosis to immunoglobulin levels as estimated by different techniques

One might expect a positive correlation between the number of CSF lymphocytes and the relative amount of CSF IgG, especially in cases of local synthesis of IgG within the CNS. However, previous attempts at correlating the number of CSF lymphocytes with IgG levels have yielded varying results. Since it is known that the estimation of CSF IgG levels can vary according to the method of immunoglobulin determination used, we decided to perform the analyses by three separate methods: (1) the commonly used, immunoprecipitation technique of radial immunodiffusion; (2) physico-chemical separation on the basis of hydrated size/charge using alkaline electrophoresis through the molecular sieving effects of polyacrylamide gels, followed by densitometry of the gamma region of Coomassie Blue-stained proteins; (3) separation into constituent Ig heavy chains and light chains on the basis of unfolded chain lengths by molecular sieving using sodium dodecyl sulphate (SDS), followed by densitometry of heavy chains of immunoglobulins having been labelled with the fluorescent dye dansyl chloride. Our results show a correlation of white count with the latter two techniques but not the former. Possible reasons for discrepancies in the literature are discussed with regard to the peculiar physical properties of the selected CSF IgG molecules.