Relationship of microparticles with beta 2-glycoprotein I and P-selectin positivity to anticardiolipin antibodies in immune thrombocytopenic purpura

Ann Hematol. 1995 Jan;70(1):25-30. doi: 10.1007/BF01715378.

Abstract

We investigated the association of beta 2-glycoprotein I and P-selectin with platelet-derived microparticles in 48 patients with immune thrombocytopenic purpura and 20 normal controls using two-color flow cytometric analysis. In addition, anticardiolipin antibodies were detected by an enzyme-linked immunosorbent assay. Platelet microparticles from the patients showed a higher positivity for beta 2-glycoprotein I than those from the normal controls (23.1 +/- 15.4% vs. 5.3 +/- 3.1%, p < 0.01), but this positivity was not related to the presence of platelet-associated IgG or to the severity of thrombocytopenia. In the 18 patients with more than 20% P-selectin-positive microparticles, beta 2-glycoprotein I positivity was significantly higher than in the 30 patients with less than 20% P-selectin-positive microparticles (37.1 +/- 20.5% vs. 21.5 +/- 17.3%, p < 0.01). In addition, anticardiolipin antibodies were detected in eight patients, and they had a significantly higher level of beta 2-glycoprotein I-positive microparticles than the patients without such antibodies (42.0 +/- 22.9% vs. 22.6 +/- 18.9%, p < 0.05). Our results suggest that anticardiolipin antibodies activate platelets in immune thrombocytopenic purpura and cause the generation of microparticles rich in beta 2-glycoprotein I and P-selectin. These microparticles may then act to regulate coagulation abnormalities in patients with anticardiolipin antibodies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibodies, Anticardiolipin / immunology*
  • Blood Coagulation
  • Blood Platelets / immunology*
  • Blood Platelets / physiology
  • Blood Platelets / ultrastructure
  • Cell Fractionation
  • Cell Membrane / immunology
  • Cell Membrane / physiology
  • Cell Membrane / ultrastructure
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Flow Cytometry
  • Glycoproteins / analysis
  • Glycoproteins / immunology*
  • Humans
  • Male
  • Middle Aged
  • P-Selectin
  • Platelet Membrane Glycoproteins / analysis
  • Platelet Membrane Glycoproteins / immunology*
  • Purpura, Thrombocytopenic, Idiopathic / blood
  • Purpura, Thrombocytopenic, Idiopathic / immunology*
  • beta 2-Glycoprotein I

Substances

  • Antibodies, Anticardiolipin
  • Glycoproteins
  • P-Selectin
  • Platelet Membrane Glycoproteins
  • beta 2-Glycoprotein I