Microparticles and acute renal dysfunction in septic patients

Purpose: The role of microparticles (MPs) in the pathogenesis of sepsis is not completely elucidated. We aimed to assess changes in the number of MPs during severe sepsis to follow the effect of sepsis-related organ failures, particularly renal impairment, an independent mortality factor of sepsis. Materials and Methods: Thirty-seven severe septic patients and 20 controls were enrolled. Patient status as well as organ failure-related laboratory markers was followed up to 5 consecutive days. Microparticles (annexin V+ events in MP size gate) of platelet (CD41, CD42a, and PAC1), monocyte (CD14), and myeloid cell line (CD13) origin were measured using flow cytometry. Results: Significantly increased total MP and CD41-, CD42a-, and PAC1-positive particle numbers were found in septic patients compared with controls. Actual number of organ dysfunctions on sample collection showed no correlation with MP numbers. Septic patients with renal dysfunction showed an increase in total MP, CD41(+), and CD13(+) particle numbers on admission. Amounts of platelet-derived CD42a(+) particles from patients with sepsis-related renal injury correlated negatively with actual blood urea nitrogen and creatinine concentrations. Conclusion: The increased numbers of platelet-derived MPs in severe septic patients emphasize the possible contribution of the hemostasis system in the development of sepsis-related renal impairments. (C) 2013 Elsevier Inc. All rights reserved.