title: Lack of KIR4.1 autoantibodies in Japanese patients with MS and NMO.
abstract: OBJECTIVE
  To examine anti-KIR4.1 antibodies by 2 different assays in Japanese patients with multiple sclerosis (MS) or neuromyelitis optica (NMO).
  
  
  METHODS
  One hundred sixty serum samples from 57 patients with MS, 40 patients with NMO/NMO spectrum disorder (NMOSD), and 50 healthy controls (all were Japanese) were tested with ELISA using a synthetic peptide of the first extracellular portion of human KIR4.1. In addition, we attempted to detect anti-KIR4.1 immunoglobulin G in the serum by the luciferase immunoprecipitation systems (LIPS) with the full length of human KIR4.1 produced in a human cell line, which is highly sensitive to single or multiple epitopes.
  
  
  RESULTS
  We failed to detect antibodies to the peptide fragment KIR4.1(83-120) in any case of MS and NMO/NMOSD using ELISA. Antibodies to the recombinant full length of KIR4.1 protein were detected in only 2 patients with MS and none in the patients with NMO/NMOSD by the LIPS assay.
  
  
  CONCLUSIONS
  We developed 2 different methods (ELISA and LIPS) to measure autoantibodies to KIR4.1 in serum. We detected anti-KIR4.1 immunoglobulin G at a very low frequency in Japanese patients with MS or NMO/NMOSD. Serologic testing for human KIR4.1-specific antibodies is unlikely to improve the diagnosis of MS or NMO/NMOSD in Japanese patients.
authors.affiliation: Departments of Clinical Research (O.H., S.N., Y.M.) and Neurology (S.N., W.S., Y.M., H.M.), Nagasaki Kawatana Medical Center; Departments of Clinical Research (M.N.) and Neurology (S.K.), Hokkaido Medical Center; Department of Multiple Sclerosis Therapeutics (T.T., K.F.), Tohoku University Graduate School of Medicine; Department of Neurology (T.T.), Yonezawa National Hospital; and Department of Neurology (T.F.), Sapporo Neurology Clinic, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Higuchi
authors.affiliation: Departments of Clinical Research (O.H., S.N., Y.M.) and Neurology (S.N., W.S., Y.M., H.M.), Nagasaki Kawatana Medical Center; Departments of Clinical Research (M.N.) and Neurology (S.K.), Hokkaido Medical Center; Department of Multiple Sclerosis Therapeutics (T.T., K.F.), Tohoku University Graduate School of Medicine; Department of Neurology (T.T.), Yonezawa National Hospital; and Department of Neurology (T.F.), Sapporo Neurology Clinic, Japan.
authors.forename: Shunya
authors.initials: S
authors.lastname: Nakane
authors.affiliation: Departments of Clinical Research (O.H., S.N., Y.M.) and Neurology (S.N., W.S., Y.M., H.M.), Nagasaki Kawatana Medical Center; Departments of Clinical Research (M.N.) and Neurology (S.K.), Hokkaido Medical Center; Department of Multiple Sclerosis Therapeutics (T.T., K.F.), Tohoku University Graduate School of Medicine; Department of Neurology (T.T.), Yonezawa National Hospital; and Department of Neurology (T.F.), Sapporo Neurology Clinic, Japan.
authors.forename: Waka
authors.initials: W
authors.lastname: Sakai
authors.affiliation: Departments of Clinical Research (O.H., S.N., Y.M.) and Neurology (S.N., W.S., Y.M., H.M.), Nagasaki Kawatana Medical Center; Departments of Clinical Research (M.N.) and Neurology (S.K.), Hokkaido Medical Center; Department of Multiple Sclerosis Therapeutics (T.T., K.F.), Tohoku University Graduate School of Medicine; Department of Neurology (T.T.), Yonezawa National Hospital; and Department of Neurology (T.F.), Sapporo Neurology Clinic, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Maeda
authors.affiliation: Departments of Clinical Research (O.H., S.N., Y.M.) and Neurology (S.N., W.S., Y.M., H.M.), Nagasaki Kawatana Medical Center; Departments of Clinical Research (M.N.) and Neurology (S.K.), Hokkaido Medical Center; Department of Multiple Sclerosis Therapeutics (T.T., K.F.), Tohoku University Graduate School of Medicine; Department of Neurology (T.T.), Yonezawa National Hospital; and Department of Neurology (T.F.), Sapporo Neurology Clinic, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Niino
authors.affiliation: Departments of Clinical Research (O.H., S.N., Y.M.) and Neurology (S.N., W.S., Y.M., H.M.), Nagasaki Kawatana Medical Center; Departments of Clinical Research (M.N.) and Neurology (S.K.), Hokkaido Medical Center; Department of Multiple Sclerosis Therapeutics (T.T., K.F.), Tohoku University Graduate School of Medicine; Department of Neurology (T.T.), Yonezawa National Hospital; and Department of Neurology (T.F.), Sapporo Neurology Clinic, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Departments of Clinical Research (O.H., S.N., Y.M.) and Neurology (S.N., W.S., Y.M., H.M.), Nagasaki Kawatana Medical Center; Departments of Clinical Research (M.N.) and Neurology (S.K.), Hokkaido Medical Center; Department of Multiple Sclerosis Therapeutics (T.T., K.F.), Tohoku University Graduate School of Medicine; Department of Neurology (T.T.), Yonezawa National Hospital; and Department of Neurology (T.F.), Sapporo Neurology Clinic, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Fukazawa
authors.affiliation: Departments of Clinical Research (O.H., S.N., Y.M.) and Neurology (S.N., W.S., Y.M., H.M.), Nagasaki Kawatana Medical Center; Departments of Clinical Research (M.N.) and Neurology (S.K.), Hokkaido Medical Center; Department of Multiple Sclerosis Therapeutics (T.T., K.F.), Tohoku University Graduate School of Medicine; Department of Neurology (T.T.), Yonezawa National Hospital; and Department of Neurology (T.F.), Sapporo Neurology Clinic, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Kikuchi
authors.affiliation: Departments of Clinical Research (O.H., S.N., Y.M.) and Neurology (S.N., W.S., Y.M., H.M.), Nagasaki Kawatana Medical Center; Departments of Clinical Research (M.N.) and Neurology (S.K.), Hokkaido Medical Center; Department of Multiple Sclerosis Therapeutics (T.T., K.F.), Tohoku University Graduate School of Medicine; Department of Neurology (T.T.), Yonezawa National Hospital; and Department of Neurology (T.F.), Sapporo Neurology Clinic, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Fujihara
authors.affiliation: Departments of Clinical Research (O.H., S.N., Y.M.) and Neurology (S.N., W.S., Y.M., H.M.), Nagasaki Kawatana Medical Center; Departments of Clinical Research (M.N.) and Neurology (S.K.), Hokkaido Medical Center; Department of Multiple Sclerosis Therapeutics (T.T., K.F.), Tohoku University Graduate School of Medicine; Department of Neurology (T.T.), Yonezawa National Hospital; and Department of Neurology (T.F.), Sapporo Neurology Clinic, Japan.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Matsuo