Performance of microvesicles as biomarkers of clinical outcome in sepsis and trauma: A pilot study.

Sepsis remains one of the main causes of death in intensive care unit (ICU) worldwide, despite all technological and scientific advances. Microvesicles (MV) have become promising biomarkers for quick and accurate monitoring of several illnesses. The aim of this pilot study was to characterize and evaluate the performance of MV as biomarker of clinical outcome in septic and trauma patients. For this purpose, 39 subjects, both genders, aging from 18 to 85 years were included in three groups referred as Sepsis, Trauma and Healthy Control. Kinetic analysis of MV was carried out at four consecutive time points: admission (baseline)/T1, 24 h/T2, 72 h/T3 and outcome/T4 of discharge or death. At admission, an overall increase in total MV (Annexin V+) was observed in Sepsis.MV CD14+ (monocytes) was a putative biomarker to identify trauma patients, while MV CD3+ (T-cells) and CD41+ (platelets) were qualified to discriminated Trauma from Sepsis. Sepsis (Death) presented an increase in MV Annexin V+, CD45+, CD16+, CD14+, and CD41+ in comparison to Sepsis (Discharge). Moreover, Trauma (Death) presented an increase of MV CD3+ and CD235+ as compared to Trauma (Discharge). Analysing the ROC curve of specific MV evaluated according to performance, an accuracy of 100% was found to segregate the outcome in sepsis, and 95% in trauma. Our findings suggest that MV might be useful as a potential role in discriminating outcome in patients with sepsis/septic shock and trauma with high accuracy. However, further studies with a larger number of participants will be necessary to validate our findings.

Cell-derived microvesicles in infective endocarditis: Role in diagnosis and potential for risk stratification at hospital admission.

OBJECTIVES: To characterize the plasmatic profile of cell-derived microvesicles (MVs) at diagnosis and during the treatment of patients with infective endocarditis (IE). METHODS: Blood samples from 57 patients with IE were obtained on 3 consecutive moments: upon admission (T0), at 2 weeks (T1), and at the end of treatment (T2), and were compared with 22 patients with other bacterial infections. MPs were measured by flow cytometry and labeled for specific cell markers of CD45 (leukocytes), CD66b (neutrophils), CD14 (monocytes), CD41a (platelets), CD51 (endothelial cells), CD3 (T lymphocyte) and CD235a (erythrocytes). RESULTS: MVs from platelets (pltMVs), leukocytes (leukMVs), neutrophils (neutMVs), monocytes (monoMVs) and lymphocytes (lymphMVs) were significantly more elevated in the patients with IE, compared to the patients with other bacterial infections, despite comparable age, sex, blood counts and C-reactive protein levels. MVs values revealed a relatively stable pattern over time in IE, except for a significant increase in leukMVs and neutMVs in T1. LeukMVs (p = 0.011), neutMVs (p = 0.010), monoMVs (p = 0.016) and lymphMVs (p = 0.020), measured at admission, were significantly higher in IE patients that died during hospitalization in comparison with those that survived. In a multivariable analyses, the levels of neutMVs remained as an independent factor associated with mortality (odds ratio 2.203; 95% confidence interval 1.217 - 3.988; p = 0.009), adjustment for heart failure during the treatment. CONCLUSIONS: Plasma levels of pltMVs, leukMVs, neutMVs, monoMVs and lymphMVs were significantly more elevated in patients with IE than in patients with other bacterial infections at hospital admission. Furthermore, neutMVs at admission have been identified as an independent predictor of mortality in patients with IE. Thus, cell derived MPs may become an important tool in the differential diagnosis and mortality risk assessment early in the course of IE suspected cases.