Platelet-leukocyte mixed conjugates in patients with atrial fibrillation

Silvia Alberti, Giulia Angeloni, Chiara Tamburrelli, Agnieszka Pampuch, Benedetta Izzi, Loredana Messano, Quintino Parisi, Matteo Santamaria, Maria Benedetta Donati, Giovanni De Gaetano, Chiara Cerletti

Research output: Contribution to journalArticlepeer-review


Although platelets may contribute to the inflammatory component in atrial fibrillation (AF), the impact of platelet-leukocyte mixed conjugates has not yet been determined. Seventeen patients with persistent AF (8/9 m/f; mean age 68.1 2.5 years), not on anticoagulant therapy, were recruited and compared to 34 healthy controls with normal sinus rhythm (16/18 m/f; mean age 60.8 1.2 years). Platelet-leukocyte mixed conjugates, platelet P-selectin and leukocyte activation markers (CD11b, myeloperoxidase) were measured by flow-cytometry in whole blood both in basal condition and after in vitro ADP/collagen challenge. Plasma D-dimer and soluble P-selectin were also measured. Statistical analyses were performed by Mann-Whitney or Wilcoxon U test for intergroup differences. In AF patients platelet count, as well as platelet P-selectin expression and percent platelet-leukocyte conjugates were all significantly lower both in basal condition and upon activation with ADP/collagen. In contrast, both soluble P-selectin and D-dimer were significantly higher than in controls; white blood cell count and leukocyte activation markers were unchanged. In conclusion, the formation of platelet-leukocyte mixed conjugates was unexpectedly reduced in AF, possibly due to less reactive platelets as a consequence of previous in vivo activation by ongoing formation of trace amounts of thrombin.

Original languageEnglish
Pages (from-to)235-241
Number of pages7
Issue number4
Publication statusPublished - Jun 2009


  • Atrial fibrillation
  • Coagulation
  • Leukocyte activation markers
  • P-selectin
  • Platelet-leukocyte conjugates

ASJC Scopus subject areas

  • Hematology


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