Identification of the platelet glycoprotein IIb/IIIa complex as a target antigen in primary biliary cirrhosis-associated autoimmune thrombocytopenia. Evidence that platelet-reactive autoantibodies can also bind to the mitochondrial antigen M2

J Autoimmun. 1990 Aug;3(4):473-83. doi: 10.1016/s0896-8411(05)80014-9.


A 67-year-old woman with a 4-year history of primary biliary cirrhosis (PBC) unexpectedly developed autoimmune thrombocytopenia. The platelet-bound IgG antibody was eluted from the patient's platelets to determine the platelet target antigen. The autoantibodies were found to precipitate the platelet glycoprotein complex IIb/IIIa of autologous and allogeneic platelets. A further precipitate of 70 kDa was detectable under reducing conditions. In addition, platelet-reactive antibodies bound to the 70 kDa mitochondrial antigen M2. No cross-absorption studies were performed to confirm that a single antibody reacted with both antigens. Computer analysis of published peptide sequences of the mitochondrial protein and the platelet GPIIb/IIIa complex showed partial amino acid sequence homology suggesting the possibility of a common antibody binding site. These findings suggest a relationship between the development of autoimmune thrombocytopenia in PBC and the underlying liver disease.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Amino Acid Sequence
  • Autoantibodies / blood
  • Autoantigens / blood
  • Autoimmune Diseases / etiology
  • Autoimmune Diseases / immunology*
  • Blood Platelets / immunology
  • Dihydrolipoyllysine-Residue Acetyltransferase
  • Female
  • Humans
  • Immunoglobulin G
  • Liver Cirrhosis, Biliary / complications
  • Liver Cirrhosis, Biliary / immunology*
  • Mitochondrial Proteins
  • Molecular Sequence Data
  • Platelet Membrane Glycoproteins / immunology*
  • Thrombocytopenia / etiology
  • Thrombocytopenia / immunology*


  • Autoantibodies
  • Autoantigens
  • Immunoglobulin G
  • Mitochondrial Proteins
  • Platelet Membrane Glycoproteins
  • DLAT protein, human
  • Dihydrolipoyllysine-Residue Acetyltransferase