title: Binding specificity of anti-HNK-1 IgM M-protein in anti-MAG neuropathy: possible clinical relevance.
abstract: Anti-myelin-associated-glycoprotein (MAG) neuropathy is an intractable autoimmune polyneuropathy. The antigenic region of MAG is the human natural killer-1 (HNK-1) carbohydrate. We and others previously suggested that the extension of antibody reactivities to HNK-1-bearing proteins other than MAG was associated with treatment resistance, without statistical analyses. In this study, we established an ELISA method with recombinant proteins to test binding specificities of currently available monoclonal antibodies to MAG and another HNK-1-bearing protein, phosphacan. Using this system, we found the distinct binding specificities of anti-MAG antibody in 19 patients with anti-MAG neuropathy. Their clinical relevance was then determined retrospectively with the adjusted 10-points INCAT disability score (0 = normal and 10 = highly disable). The results showed that strong reactivities of anti-MAG antibodies to phosphacan were significantly associated with treatment resistance or progressive clinical courses, indicating a possible clinical relevance of the binding specificities.
authors.affiliation: Department of Neurology, Kinki University Faculty of Medicine, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Hamada
authors.affiliation: Department of Neurology, Kinki University Faculty of Medicine, Japan.
authors.forename: Makito
authors.initials: M
authors.lastname: Hirano
authors.affiliation: Department of Neurology, Kinki University Faculty of Medicine, Japan.
authors.forename: Motoi
authors.initials: M
authors.lastname: Kuwahara
authors.affiliation: Department of Neurology, Kinki University Faculty of Medicine, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Samukawa
authors.affiliation: Department of Neurology, Kinki University Faculty of Medicine, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Takada
authors.affiliation: Department of Biological Chemistry, Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan.
authors.forename: Jyoji
authors.initials: J
authors.lastname: Morise
authors.affiliation: Department of Biological Chemistry, Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yabuno
authors.affiliation: Department of Biological Chemistry, Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Oka
authors.affiliation: Department of Neurology, Kinki University Faculty of Medicine, Japan. Electronic address: kusunoki-tky@umin.ac.jp.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kusunoki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000378:metabolism*; D018959:CD57 Antigens / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology*; D008875:Middle Aged; D018992:Myelin-Associated Glycoprotein / Q000276:immunology*; D010265:Paraproteinemias / Q000150:complications / Q000276:immunology*; D011115:Polyneuropathies / Q000209:etiology / Q000276:immunology*; D011485:Protein Binding; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5 / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D018959:CD57 Antigens; D007075:Immunoglobulin M; C115082:MAG protein, human; D018992:Myelin-Associated Glycoprotein; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5
keywords: Anti-MAG neuropathy; HNK-1; Phosphacan