There are no clear markers to identify sepsis and acute lung injury at early stage in clinical settings which would result in improved survival of the patients. In collaboration with the research team led by Dr. Zhang at St. Michael's Hospital, Toronto, we have initiated a pilot study looking for biological markers to detect severe sepsis and ARDS. We have found that human neutrophils peptides (a-defensins), certain coagulation variables and cytokine levels are very sensitive markers to differentiate severe sepsis, ARDS from cardiovascular diseases in ICU patients. These findings may provide valuable information for therapeutic guideline in clinical practice. The present study will focus on testing 'biological markers' to identify patients with sepsis and acute lung injury. We will examine the roles of three components of markers including inflammation, neutrophil activation and coagulation. We are hoping that this proposed translational research will help develop novel therapeutic strategy in sepsis and acute lung injury patients.