Circulating immune complexes in serum and in cerebrospinal fluid of patients with multiple sclerosis

Abstract

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.

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

“…This is because one would expect the increased CICs to activate the classical pathway of complement, lead to consumption of C3 and C4, and to reduced CH50. An analogous observation has been made in multiple sclerosis (16). However, C3 and C4 are acute-phase proteins (19) and their levels may increase in response to tissue infarction in sickle cell anaemia, similar to our previous observation of increased C-reactive protein and other acute-phase reactants in this disease (8).…”

The structure and function of human IgA

“…There is however, compelling evidence for an important role for secretory IgA in immunity [20][21][22]. Furthermore, serum IgA levels are frequently raised in rheumatic diseases and in other autoimmune diseases as well as in liver disease and persistent infections such as bacterial endocarditis and AIDS [23][24][25]. Elevated IgA levels are associated with rises in serum polymeric IgA, circulating IgA-containing immune complexes and IgA rheumatoid factor.…”

Multiple sclerosis: a unique immunopathological syndrome of the central nervous system

“…As in inflammatory polyradiculopathy, MS CSF contains terminal complement complexes [79], and vesicles enriched in these complexes are present in MS CSF and are possibly oligodendrocyte derived [80]. In sera, these complexes are of intermediate size, contain complement, and are increased in active disease [69]. MS CSF frequently contains IgG and IgM immune complexes, but these occur only in relapsing-remitting MS.…”