title: Antibodies to actin in autoimmune haemolytic anaemia.
abstract: BACKGROUND
  In autoimmune haemolytic anaemia (AIHA), autoreactive antibodies directed against red blood cells are up-regulated, leading to erythrocyte death. Mycoplasma suis infections in pigs induce AIHA of both the warm and cold types. The aim of this study was to identify the target autoantigens of warm autoreactive IgG antibodies. Sera from experimentally M. suis-infected pigs were screened for autoreactivity.
  
  
  RESULTS
  Actin-reactive antibodies were found in the sera of 95% of all animals tested. The reactivity was species-specific, i.e. reactivity with porcine actin was significantly higher than with rabbit actin. Sera of animals previously immunised with the M. suis adhesion protein MSG1 showed reactivity with actin prior to infection with M. suis indicating that molecular mimicry is involved in the specific autoreactive mechanism. A potentially cross-reactive epitope was detected.
  
  
  CONCLUSIONS
  This is the first report of autoreactive anti-actin antibodies involved in the pathogenesis of autoimmune haemolytic anaemia.
authors.affiliation: Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Zurich, Switzerland.
authors.forename: Kathrin M
authors.initials: KM
authors.lastname: Felder
authors.forename: Katharina
authors.initials: K
authors.lastname: Hoelzle
authors.forename: Karl
authors.initials: K
authors.lastname: Heinritzi
authors.forename: Mathias
authors.initials: M
authors.lastname: Ritzmann
authors.forename: Ludwig E
authors.initials: LE
authors.lastname: Hoelzle
mesh_terms: D000199:Actins / Q000276:immunology*; D000744:Anemia, Hemolytic, Autoimmune / Q000209:etiology / Q000276:immunology / Q000662:veterinary*; D000818:Animals; D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D009175:Mycoplasma Infections / Q000150:complications / Q000662:veterinary; D011817:Rabbits; D013156:Splenectomy; D013552:Swine; D013553:Swine Diseases / Q000276:immunology*
chemical_list: D000199:Actins; D007074:Immunoglobulin G