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Background: There is no specific serum-based biomarker for the diagnosis or prognosis of relapsing-remitting multiple sclerosis (RRMS)., Objective: We investigated whether levels of IgM antibodies to Glc(alpha1,4)Glc(alpha) (GAGA4) or to a panel of four glucose-based glycans could differentiate MS from other neurological diseases (OND) or predict risk of early relapse following first presentation (FP) of RRMS., Methods: Retrospective analysis of 440 sera samples of three cohorts: A) FP-RRMS (n = 44), OND (n = 44); B) FP-RRMS (n = 167), OND (n = 85); and C) FP (n = 100). Anti-GAGA4 IgM levels were measured by enzyme immunoassay in cohort-A and cohort-B. Cohort-C IgM antibodies to glucose-based glycan panel were measured by immunofluorescence., Results: FP-RRMS had higher levels of anti-GAGA4 IgM than OND patients (cohort-A, P = 0.01; cohort-B, P = 0.0001). Sensitivity and specificity were 27% and 97% for cohort-A; and 26% and 90% for cohort-B, respectively. In cohort-C, 58 patients experienced early relapse (<24 months), 31 had late relapse (> or =24 months), and 11 did not experience second attack during follow-up. Kaplan-Meier curves demonstrated decrease in time to next relapse for patients positive for the antibody panel (P = 0.02, log rank)., Conclusions: Serum anti-GAGA4 IgM discerns FP-RRMS patients from OND patients. Higher levels of serum anti-alpha-glucose IgM in FP patients predict imminent early relapse.

Anti-GQ1b antibodies were assayed by an enzyme-linked immunosorbent assay in sera from patients with non-neurological disorders (N = 20), and with various neurological disorders (N = 59), including nine cases of Miller Fisher syndrome, 16 cases of Guillain-Barré syndrome and one case of acute post-infectious ophthalmoparesis. Such antibodies were found in most cases (8 out of 9) of Miller Fisher syndrome, and at very high titres, in one case of Guillain-Barré syndrome characterised by an initial ophthalmoparesis, and in the case of isolated post-infectious ophthalmoparesis. The latter was characterised by a long-lasting occurrence of these antibodies. Anti-GQ1b antibodies are specific for an immune-mediated neuropathy of the cranial, especially oculomotor, nerves.

The serum and CSF of two women with a severe subacute pancerebellar syndrome contained high titers of antibodies directed against antigens present in the perikaryon of Purkinje cells. In Western blots performed on human Purkinje cells extracts these antibodies reacted with two groups of proteins the molecular weights of which were estimated to 34-38 and 62 kilodaltons (anti-Yo antibodies). Complementary investigations revealed a tubar adenocarcinoma in the first case, an ovarian carcinoma in the second. The tubar tumoral cells also contained the protein of the highest molecular weight. Compared to the serum, the CSF contained a higher proportion of anti-Yo antibodies per mg IgG, and a fraction of the latter was likely synthesized intrathecally. These antibodies may be involved in the almost total disappearance of the Purkinje cells, as observed at autopsy of both cases.

The authors describe three patients with a chronic sensory-motor polyneuropathy associated with a monoclonal IgM gammopathy. In each case, the M-component was shown to display an antibody activity against the Myelin-Associated Glycoprotein (MAG) in a western blot technique. Sera from the three patients stained specifically the myelin sheaths of normal human peripheral nerves after incubation with rabbit anti-IgM. Motor conduction velocities were very low in each case. Morphological studies of the sural nerve from one patient revealed a moderate loss of myelinated fibres, some onion-bulbs but also a microangiopathy and signs of axonal degeneration.