title: Autoantibody against erythrocyte protein 4.1 in a patient with autoimmune hemolytic anemia.
abstract: We observed the presence of a new autoantibody, anti-erythrocyte protein 4.1, in a patient with autoimmune hemolytic anemia (AIHA). Western blotting analysis revealed that IgG from the patient's plasma reacted with erythrocyte protein 4.1. However, among other patients with hemolytic diseases (six having AIHA and three each having either hereditary spherocytosis, elliptocytosis, or lead poisoning) as well as among control subjects, no antibody activity to protein 4.1 was observed. In addition to the anti-protein 4.1 antibody, two different kinds of anti-erythrocyte antibodies were detected by conventional serological studies in this patient. One of them was an anti-Ena-like antibody in the eluate from the patient's erythrocytes, while another was the anti-S-specific antibody in the plasma. An elution study and an absorption study using S antigen-positive erythrocytes demonstrated that the anti-protein 4.1 antibody differed from both the anti-Ena-like antibody and the anti-S antibody. Familial analysis of the patient revealed the same antibody in her brother, who did not have hemolytic anemia. These results demonstrate that anti-protein 4.1 antibody is considered to be included in the spectrum of anti-cytoskeleton autoantibodies, which have been observed in patients having increased cell lysis as well as in healthy subjects.
authors.affiliation: Third Department of Internal Medicine, Akita University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Wakui
authors.forename: H
authors.initials: H
authors.lastname: Imai
authors.forename: R
authors.initials: R
authors.lastname: Kobayashi
authors.forename: H
authors.initials: H
authors.lastname: Itoh
authors.forename: T
authors.initials: T
authors.lastname: Notoya
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamoto
authors.forename: A B
authors.initials: AB
authors.lastname: Miura
mesh_terms: D000744:Anemia, Hemolytic, Autoimmune / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis*; D003598:Cytoskeletal Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008565:Membrane Proteins / Q000276:immunology*; D008875:Middle Aged; D009479:Neuropeptides
chemical_list: D001323:Autoantibodies; D003598:Cytoskeletal Proteins; D007074:Immunoglobulin G; D008565:Membrane Proteins; D009479:Neuropeptides; C028841:erythrocyte membrane band 4.1 protein; C120557:erythrocyte membrane protein band 4.1-like 1