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

B cells and antibodies in CNS demyelinating disease

There is much evidence to implicate B cells, plasma cells, and their products in the pathogenesis of MS. Despite unequivocal evidence that the animal model for MS, EAE, is initiated by myelin-specific T cells, there is accumulating evidence of a role for B cells, plasma cells, and their products in EAE pathogenesis. The role(s) played by B cells, plasma cells, and antibodies in CNS inflammatory demyelinating diseases are likely to be multifactorial and complex, involving distinct and perhaps opposing roles for B cells versus antibody.

Complement haemolytic activity, circulating immune complexes and the morbidity of sickle cell anaemia

The aim of this study was to find out if the number of crises and complications of sickle cell anaemia (SCA) relate to complement function, or the levels of circulating immune complexes (CIC), complement factor B (Bf), C3 and C4. In 73 steady-state HbSS patients and 50 HbAA control subjects, we determined the haemolytic activity of the alternative pathway of complement (AP50), of the classical pathway (CH50); and the serum concentrations of Bf, C3, C4 and CIC. By clinical examination of each patient and review of the medical records, we determined the number of complications of SCA which had occurred and the mean number of crises per year over a minimum period of 3 years. The mean+/-SD AP50 for the patients (14+/-2 U/ml) was significantly lower than the control value of 16+/-3 U/ml (p<0.001). AP50 had a significant inverse correlation with the number of crises (r=-0.30, p<0.02). Mean+/-SD CIC in patients (0.45+/-0.38 g/l) was significantly higher than in controls: 0.24+/-0.15 g/l (p<0.002). CIC showed a significant direct correlation with the number of complications of SCA (r=+/-0.28, p<0.02). Mean+/-SD Bf in SCA patients (0.19+/-0.09) was higher than in controls (0.17+/-0.05). The difference reached marginal statistical significance (p=0.049). SCA patients and controls had no significant differences in CH50, C3 and C4. These parameters and Bf did not correlate with either the number of crises or complications. The mechanisms underlying the correlations observed in this study are yet to be fully elucidated.

Identification of multiple sclerosis-associated genes

Multiple sclerosis (MS) is a complex genetic trait. Analyses to identify genetic variants that increase susceptibility to MS have primarily focused on candidate genes, either in family linkage investigations or in association (linkage disequilibrium) studies in sporadic cases and control subjects. Most of the candidate genes considered to date either influence immune function or encode structural myelin proteins. Recently, three preliminary whole genomic surveys were completed, and they reveal multiple loci of possible genetic linkage that are worthy of further study. No convincing evidence for a single strong locus has emerged from analysis of the three studies. Linkage promises to focus the future choice of candidate genes for further investigation.

Absence of brain antibodies in the sera of relapsing-remitting multiple sclerosis patients is not due to the formation of immune complexes

Using an enzyme-linked immunoadsorbent assay, we looked, whether the formation of idiotype-anti-idiotype complexes was responsible for the absence of antibodies in the sera of MS patients. We tested 18 relapsing-remitting and 26 chronic progressive patients versus 44 age- and sex-matched controls. We did not find elevated titres of immune complexes in the sera of the multiple sclerosis patients.

Analysis of circulating immune complexes isolated from plasma, cerebrospinal fluid and urine

The protein nature of soluble immune complexes (IC) from fresh plasma, cerebrospinal fluid (CSF), and urine was studied by combining several analytical and biochemical techniques. In plasma and CSF, free immunoglobulins G were separated from larger IC by gel filtration with a fast protein liquid chromatographic system. In urine, IC were separated by precipitation with polyethylene glycol. IC were further purified by protein-A and protein-G affinity chromatography and analyzed by two-dimensional gel electrophoresis. Apart from plasma samples from healthy donors, IC from cases with macrocreatine kinase type 1 and multiple sclerosis were analyzed. For CSF two cases of multiple sclerosis and for urine one case with urinary tract infection are shown. The method can be used for the examination of IC of unknown protein composition in body fluids.

The intrathecal immune response in multiple sclerosis: a different concept of 'specificity'

A hypothesis is presented in which the immune response in multiple sclerosis is conceived as a primary response to an auto-antigen located within the immune system (e.g. a certain allotype or HLA epitope) which shows subsequent or simultaneous specificity for a greater number of nominal antigens [corrected]. The increased tendency of [corrected] such antibodies to self-aggregation might play a critical role in the pathogenesis.