Circulating immune complexes and complement in the course of multiple sclerosis

Infectious Agents in Bovine Red Meat and Milk and Their Potential Role in Cancer and Other Chronic Diseases

Red meat and dairy products have frequently been suggested to represent risk factors for certain cancers, chronic neurodegenerative diseases, and autoimmune and cardiovascular disorders. This review summarizes the evidence and investigates the possible involvement of infectious factors in these diseases. The isolation of small circular single-stranded DNA molecules from serum and dairy products of Eurasian Aurochs (Bos taurus)-derived cattle, obviously persisting as episomes in infected cells, provides the basis for further investigations. Gene expression of these agents in human cells has been demonstrated, and frequent infection of humans is implicated by the detection of antibodies in a high percentage of healthy individuals. Epidemiological observations suggest their relationship to the development multiple sclerosis, to heterophile antibodies, and to N-glycolylneuraminic acid (Neu5Gc) containing cell surface receptors.

Neuropathology of multiple sclerosis-new concepts

Multiple sclerosis is a chronic inflammatory disease of the central nervous system with profound heterogeneity in clinical course, neuroradiological presentation and response to therapy. The pathological analysis of 235 actively demyelinating lesions coming from three centers revealed different structural and immunological features suggesting that different pathogenetic mechanisms are involved in lesion formation. On the basis of the presence or absence of immunoglobulin and complement deposition, myelin protein loss and the patterns of oligodendrocyte degeneration beside a T cell- and macrophage-dominated immune response, four distinct patterns of demyelination have been identified. In this short review, possible paraclinical markers for tissue destruction on the basis of the main features of myelin destruction are discussed. Furthermore, the importance of early axonal damage in multiple sclerosis is highlighted.

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

We studied circulating immune complexes (IC) in the serum and cerebrospinal fluid (CSF) of patients with clinically defined multiple sclerosis (MS), in order to establish a correlation with the clinical course of the disease and to investigate the molecular composition of the IC isolated from patients in active phase of the disease. Serum IC levels were found to be significantly increased in patients from the progressive and active relapsing-remittent subgroups with both the CIC-conglutinin and C1q-binding methods. High levels of IC in CSF were detected only in the subgroup consisting of the relapsing-remittent patients in disease exacerbation when IC were determined by the C1q-binding test. No significant increase in serum or in CSF were found using the mRF-I test. The preliminary results of a qualitative investigation on serum IC in MS indicated that they are heterogeneous in nature, their size is mainly of the intermediate type, and they contain IgG, IgM, complement components and beta 2-microglobulins, the latter presenting an observation both new and interesting for studies on serum IC in MS patients.

Relevance of platelet factor four (PF4) plasma levels in multiple sclerosis

In order to study the role of platelets in Multiple Sclerosis (MS) we assessed, in a group of patients during a quiescent phase of the disease, the plasma levels of beta-thromboglobulin (beta-TG) and platelet factor four (PF4) both in absence of treatment and during administration of aspirin (ASA) at the dose of 50 mg/daily. In the MS patients studied, the basal plasma levels of beta-TG and PF4 were significantly higher than in control subjects. The increase in the beta-TG plasma levels occurred independently of the age, sex and severity of the disease, whereas the modification in the PF4 plasma levels was significantly correlated with the severity of the disease. Administration to the patients of ASA, at the dose that does not affect prostacyclin production, determined a decrease of beta-TG in 77% of the patients. Mean PF4 plasma levels remained unchanged. These results suggest that PF4 in the plasma of MS patients may originate not only from the platelets but also from the mast cells following platelet aggregating factor (PAF) stimulation and immunocomplex formation.

Anti-glycolipid antibodies and their immune complexes in multiple sclerosis

Antibody titers against myelin constituents in sera and CSF of patients with multiple sclerosis (MS) were examined by a solid-phase radioimmunoassay. Anti-GM4 and anti-galactocerebroside antibody titers were significantly elevated in the CSF of MS patients, but not anti-GM1 and anti-myelin basic protein antibodies. In sera of MS patients, the titers of antibodies against these myelin constituents were not elevated. Total IgG level was also significantly elevated in the CSF, but not in the sera of MS patients. Immune complexes from the CSF of MS patients were dissociated by acid-ultrafiltration and assayed for antibodies to GM4, GM1, and galactocerebroside. Anti-GM4 and antigalactocerebroside antibody titers were significantly enhanced after acid dissociation and ultrafiltration. These data suggest that antibodies of the IgG class against GM4 and galactocerebroside are present in CSF of MS patients, and a significant number of them exist as immune complexes with their corresponding glycolipid antigens.

Immune complexes in CSF and serum in various neurological diseases

A technique whereby immune complexes (ICs) are detected in the CSF and serum from their inhibitory effect on the agglutination of IgG-coated latex particles by rheumatoid factor (RF) has been applied to patients with the following neurological diseases: multiple sclerosis (MS), inflammatory diseases, extradural peripheral neuropathies (EPN), CNS tumors, dementia, and a control group of other neurological diseases (OND). The groups did not differ significantly in respect of IC positivity either in CSF or serum. The MS group was tested for correlations between percentage of IC positives and CSF IgG/Albumin ratio on the one hand and presence of oligoclonal bands on isoelectric focusing on the other. The specificity of ICs to the dysimmune condition is discussed.

Abnormalities of serum and plasma components in patients with multiple sclerosis

Qualitative and quantitative abnormalities in protein and non-protein components of serum and plasma in patients with multiple sclerosis have been the subjects of numerous reports. In this review many of the more recent observations are documented and evaluated. It is concluded that at present the welter of information that has been gathered does not contribute in any major, coherent way to our understanding of the etiology or pathogenesis of the disorder. Several of the abnormalities that have been observed may be future candidates for biochemical markers for multiple sclerosis; at present none is sufficiently reliable, distinctive or easily performed to warrant the status of a useful diagnostic or prognostic test.

Immune complexes in cerebrospinal fluid and serum of neurological patients. Possible intrathecal formation in bacterial meningitis and herpetic encephalitis

We assayed immune complexes (IC) by Particle Counting ImmunoAssay in the serum and cerebrospinal fluid (CSF) of patients with various neurological disorders. In pyogenic meningitis, the levels of IC sharply increased 4-8 days after onset with a fall before the 10th day of the disease. In herpetic encephalitis the IC and antibody levels started to increase about 12 days after onset. The IC persisted at high values for 3-4 weeks, whereas the high antibody titers persisted for several months during the follow-up. In these 2 groups of patients IC were probably locally produced as indicated by the lack of correlation with the IC levels in the serum. We did not detect any significant increase of IC in the serum and CSF of patients with multiple sclerosis (N = 48) or with acute idiopathic polyradiculoneuritis (N = 11). Using another technique based on the determination of IgG and C4 in polyethylene glycol precipitates we also failed to detect any significant increase of IC in multiple sclerosis sera.

Immune complexes and the complement factors C4 and C3 in cerebrospinal fluid and serum from patients with chronic progressive multiple sclerosis

Immune complexes (IC) have been found in both serum and cerebrospinal fluid (CSF) in multiple sclerosis (MS). The complement system is known to play a major role as a mediator of inflammation in immune complex disease. Therefore, we have investigated paired samples of serum and CSF from 32 patients with progressive MS for IC, the levels of the complement factors C4 and C3, and presence of their activation products (AP). IC was found in serum from 17 of the 32 MS patients (53%) and in CSF from 9 of 31 MS patients (29%). No correlation was found between the occurrence of IC in serum and in CSF. The levels of C3 in serum and CSF from the MS patients did not differ from the levels in a control group, whereas the levels of C4 in MS-serum were elevated and the C4 levels in MS-CSF reduced. A low level of CSF-C4 correlated significantly to the occurrence of CSF-IC. AP of C4 and C3 in serum were seen in 11 of the 32 patients (34%), appearing significantly more frequently among patients with circulating IC. No C4- or C3AP could be identified in CSF.