Distinct features of circulating microparticles and their relationship to clinical manifestations in systemic lupus erythematosus

Arthritis Rheum. 2011 Oct;63(10):3067-77. doi: 10.1002/art.30499.


Objective: Characterization of the abundance, origin, and annexin V (AnxV)-binding capabilities of circulating microparticles (MPs) in SLE patients and healthy controls and to determine any associations with clinical parameters.

Methods: Seventy unselected SLE patients and 29 sex- and age-matched healthy control subjects were included in the study. MPs were isolated from citrate-treated plasma and characterized by flow cytometry using AnxV or antibodies to platelet, leukocyte, or endothelial cell surface markers.

Results: SLE patients had significantly increased concentrations of AnxV-nonbinding (AnxV-) MPs (P<0.0001), while the concentrations of total MPs (P=0.011) and AnxV-binding (AnxV+) MPs (P<0.0001) were decreased, as compared with controls. Based on flow cytometric characteristics, 2 subgroups of AnxV- MPs could be discerned: AnxV- cell-derived MPs (CDMPs) and AnxV- MPs of unknown nature (UNMPs). Both fractions were significantly increased in SLE patients (P=0.007 and P=0.0018, respectively). Platelet- and leukocyte-derived MPs were decreased in the SLE patients (P<0.0001), whereas no difference was observed for endothelial cell-derived MPs (P=0.14). The concentrations of AnxV- CDMPs correlated with the concentrations of endothelial cell-derived MPs, the disease activity score, active nephritis, hypertension, history of arterial thrombosis, and triglyceride levels (P<0.05 for all comparisons).

Conclusion: The concentrations and composition of MPs in SLE patients differ markedly from those in healthy subjects. Overall MP numbers were significantly decreased, but two distinct subpopulations of AnxV- MPs were significantly increased. These findings call for further characterization of MPs in SLE patients to elucidate their role in disease pathogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Annexin A5 / metabolism
  • Biomarkers / blood
  • Blood Platelets / metabolism
  • Cell-Derived Microparticles / metabolism*
  • Cross-Sectional Studies
  • Endothelial Cells / metabolism
  • Female
  • Flow Cytometry
  • Humans
  • Lupus Erythematosus, Systemic / blood*
  • Lupus Erythematosus, Systemic / diagnosis
  • Male
  • Middle Aged


  • Annexin A5
  • Biomarkers