title: Heterogeneity of Polyneuropathy Associated with Anti-MAG Antibodies.
abstract: Polyneuropathy associated with IgM monoclonal gammopathy and anti-myelin associated glycoprotein (MAG) antibodies is an immune-mediated demyelinating neuropathy. The pathophysiology of this condition is likely to involve anti-MAG antibody deposition on myelin sheaths of the peripheral nerves and it is supposed to be distinct from chronic inflammatory demyelinating neuropathy (CIDP), another immune-mediated demyelinating peripheral neuropathy. In this series, we have retrospectively reviewed clinical and laboratory findings from 60 patients with polyneuropathy, IgM gammopathy, and anti-MAG antibodies. We found that the clinical picture in these patients is highly variable suggesting a direct link between the monoclonal gammopathy and the neuropathy. Conversely, one-third of patients had a CIDP-like phenotype on electrodiagnostic testing and this was correlated with a low titer of anti-MAG antibodies and the absence of widening of myelin lamellae. Our data suggest that polyneuropathy associated with anti-MAG antibodies is less homogeneous than previously said and that the pathophysiology of the condition is likely to be heterogeneous as well with the self-antigen being MAG in most of the patients but possibly being another component of myelin in the others.
authors.affiliation: Department of Neurology, Centre de Référence "Neuropathies Périphériques Rares", CHU Limoges, 2 Avenue Martin Luther-King, 87042 Limoges, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Magy
authors.affiliation: Department of Neurology, Centre de Référence "Neuropathies Périphériques Rares", CHU Limoges, 2 Avenue Martin Luther-King, 87042 Limoges, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Kaboré
authors.affiliation: Department of Neurology, CHU Poitiers, University of Poitiers, 2 Rue de la Milétrie, 86021 Poitiers, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Mathis
authors.affiliation: Department of Neurology, Centre de Référence "Neuropathies Périphériques Rares", CHU Limoges, 2 Avenue Martin Luther-King, 87042 Limoges, France.
authors.forename: Prisca
authors.initials: P
authors.lastname: Lebeau
authors.affiliation: Department of Neurology, Centre de Référence "Neuropathies Périphériques Rares", CHU Limoges, 2 Avenue Martin Luther-King, 87042 Limoges, France.
authors.forename: Karima
authors.initials: K
authors.lastname: Ghorab
authors.affiliation: Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, 69000 Lyon, France.
authors.forename: Christiane
authors.initials: C
authors.lastname: Caudie
authors.affiliation: Department of Neurology, Centre de Référence "Neuropathies Périphériques Rares", CHU Limoges, 2 Avenue Martin Luther-King, 87042 Limoges, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Vallat
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology*; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009186:Myelin Sheath / Q000276:immunology; D018992:Myelin-Associated Glycoprotein / Q000276:immunology*; D010525:Peripheral Nerves / Q000276:immunology; D011115:Polyneuropathies / Q000276:immunology*; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000276:immunology*; D012189:Retrospective Studies
chemical_list: D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D007075:Immunoglobulin M; C115082:MAG protein, human; D018992:Myelin-Associated Glycoprotein