Activation of factor VII-activating protease in human inflammation: a sensor for cell death

INTRODUCTION

Cell death is a central event in the pathogenesis of sepsis and is reflected by circulating nucleosomes. Circulating nucleosomes were suggested to play an important role in inflammation and were demonstrated to correlate with severity and outcome in sepsis patients. We recently showed that plasma can release nucleosomes from late apoptotic cells. Factor VII-activating protease (FSAP) was identified to be the plasma serine protease responsible for nucleosome release. The aim of this study was to investigate FSAP activation in patients suffering from various inflammatory diseases of increasing severity.

METHODS

We developed ELISAs to measure FSAP-C1-inhibitor and FSAP-α2-antiplasmin complexes in plasma. FSAP-inhibitor complexes were measured in the plasma of 20 adult patients undergoing transhiatal esophagectomy, 32 adult patients suffering from severe sepsis and 8 from septic shock and 38 children suffering from meningococcal sepsis.

RESULTS

We demonstrate plasma FSAP to be activated upon contact with apoptotic and necrotic cells by an assay detecting complexes between FSAP and its target serpins α2-antiplasmin and C1-inhibitor, respectively. By means of that assay we demonstrate FSAP activation in post-surgery patients, patients suffering from severe sepsis, septic shock and meningococcal sepsis. Levels of FSAP-inhibitor complexes correlate with nucleosome levels and correlate with severity and mortality in these patients.

CONCLUSIONS

These results suggest FSAP activation to be a sensor for cell death in the circulation and that FSAP activation in sepsis might be involved in nucleosome release, thereby contributing to lethality.

Single-drug therapy or selective decontamination of the digestive tract as antifungal prophylaxis in critically ill patients: a systematic review

Introduction

The objective of this study was to determine and compare the effectiveness of different prophylactic antifungal therapies in critically ill patients on the incidence of yeast colonisation, infection, candidemia, and hospital mortality.

Methods

A systematic review was conducted of prospective trials including adult non-neutropenic patients, comparing single-drug antifungal prophylaxis (SAP) or selective decontamination of the digestive tract (SDD) with controls and with each other.

Results

Thirty-three studies were included (11 SAP and 22 SDD; 5,529 patients). Compared with control groups, both SAP and SDD reduced the incidence of yeast colonisation (SAP: odds ratio [OR] 0.38, 95% confidence interval [CI] 0.20 to 0.70; SDD: OR 0.12, 95% CI 0.05 to 0.29) and infection (SAP: OR 0.54, 95% CI 0.39 to 0.75; SDD: OR 0.29, 95% CI 0.18 to 0.45). Treatment effects were significantly larger in SDD trials than in SAP trials. The incidence of candidemia was reduced by SAP (OR 0.32, 95% CI 0.12 to 0.82) but not by SDD (OR 0.59, 95% CI 0.25 to 1.40). In-hospital mortality was reduced predominantly by SDD (OR 0.73, 95% CI 0.59 to 0.93, numbers needed to treat 15; SAP: OR 0.80, 95% CI 0.64 to 1.00). Effectiveness of prophylaxis reduced with an increased proportion of included surgical patients.

Conclusion

Antifungal prophylaxis (SAP or SDD) is effective in reducing yeast colonisation and infections across a range of critically ill patients. Indirect comparisons suggest that SDD is more effective in reducing yeast-related outcomes, except for candidemia.