Antibody responses to Acinetobacter (five strains), Pseudomonas aeruginosa, Escherichia coli, myelin basic protein (MBP), and neurofilaments were measured in sera from 26 multiple sclerosis (MS) patients, 20 patients with cerebrovascular accidents (CVA), 10 patients with viral encephalitis, and 25 healthy blood donors. In MS patients, elevated levels of antibodies against all strains of Acinetobacter tested were present, as well as antibodies against P. aeruginosa, MBP, and neurofilaments, but not antibodies to E. coli, compared to the CVA group and controls. The myelin-Acinetobacter-neurofilament antibody index appears to distinguish MS patients from patients with CVAs or healthy controls. The relevance of such antibodies to the neuropathology of MS requires further evaluation.Multiple sclerosis (MS) is the most common demyelinating disease of the central nervous system, affecting approximately 80,000 individuals in the United Kingdom and 400,000 in the United States. It is generally thought to be an autoimmune disease that is triggered by an infectious agent, possibly through a molecular mimicry mechanism of induction (1), similar to the situation occurring in the pathology of rheumatic fever (8).A number of different microbial sequences, including Pseudomonas peptides, are capable of activating myelin basic protein (MBP)-specific T-cell clones from MS patients (19), thereby indicating that several microorganisms may carry mimicry epitopes of myelin. This could explain the difficulty of linking the immunopathogenesis of MS to a single microbial agent, suggesting that several such bacteria could be involved in initiating the autoimmune process (6).It was decided to investigate MS patients for possible immune responses to pathogens that carry molecular mimicry sequences resembling brain components, such as Acinetobacter species and Pseudomonas aeruginosa. We have identified an amino acid sequence similarity between the encephalitogenic peptide of bovine MBP (5) and a sequence present in 4-carboxymuconolactone decarboxylase of Acinetobacter calcoaceticus (3). A similar sequence was also found in ␥-carboxymuconolactone decarboxylase of P. aeruginosa (Swissprot).The aims of this study were to determine whether MS patients have elevated levels of antibodies to five different strains of Acinetobacter as well as to P. aeruginosa, Escherichia coli, MBP, and neurofilaments, compared to cerebrovascular-accident (CVA) patients and control healthy blood donors. A further study was carried out, incorporating an inflammatory non-MS disease control, viral encephalitis, and a new set of control subjects, to assess whether MS patients have elevated levels of immunoglobulin G (IgG) antibodies to A. calcoaceticus 16904.
MATERIALS AND METHODSSerum samples. Sera from 26 MS patients (nine males and 17 females; mean age, 42 years; range, 29 to 55 years) were obtained from the Institute of Neurology at the Hospital for Nervous Diseases, London, United Kingdom. Diagnosis was made according to the Poser criteria (13). Benign MS patients...
