SESSION TITLE: Severe Sepsis & Septic Shock SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, November 1, 2017 at 01:30 PM - 02:30 PM PURPOSE: Serum albumin plays a critical role in body fluid balance and the transport of nutrients. We previously demonstrated that the binding activity of serum albumin (specific fraction of albumin or SFA), which is mediated by the enzymatic inflammatory response protein, secretory phospholipase A2 (sPLA2), was totally depleted in sera obtained from patients with sepsis (Translational Medicine 2015; 5:1-9). The objective of this study was to determine whether total depletion of SFA binding activity was sepsis-specific. METHODS: Serum samples were collected from peripheral venous blood withdrawn from healthy volunteers and stable patients with non-infectious respiratory disorders. Serum samples of patients with evolving sepsis were obtained when admitted to the intensive care unit (ICU) for diagnosis and treatment. The sPLA2-mediated SFA activity in the serum was determined by a fluorescent assay (Translational Medicine 2015; 5:1-9). The serum samples of septic patients were collected either on the day of patient admission to the ICU (day 1) or after 2-3 days in the ICU. RESULTS: The average value of the SFA binding activity was -8.03 + 0.62 for 10 healthy, never-smoking subjects (HS), -5.16 + 1.19 for 26 patients with stable fibrotic interstitial lung disease (ILD), -6.31 + 0.78 for 7 patients with cystic fibrosis (CF), and -4.75 + 2.37 for five patients with stable chronic obstructive pulmonary disease (COPD). The average SFA activity of 16 patients with sepsis was -0.89 + 6.92, significantly lower than that in HS (p-value<0.0001), ILD (p-value=0.0005), CF (p-value=0.0017), or COPD (p-value=0.043). The SFA activity was present in all non-sepsis serum samples, but was completely absent in 8 serum samples of the 16 septic patients including 2 serum samples collected on day 1, suggesting that total depletion of SFA activity was sepsis-specific and might occur within 24 hours of the onset of sepsis. CONCLUSIONS: Although patients with stable lung disease had some decrease in SFA activity as compared to healthy subjects, only patients with sepsis showed a progressive reduction of the SFA activity to non-detectable levels. We suggest that total absence of SFA activity may be associated with massive cell death in sepsis, and SFA may be a useful sepsis-specific biomarker. CLINICAL IMPLICATIONS: Sepsis is a systemic inflammatory response syndrome triggered by infection. The pathogenesis of sepsis is characterized by an overwhelming release of large amounts of pro-inflammatory cytokines into the circulation that causes massive cell death with resultant tissue and organ damage, and sepsis is a leading cause of death among critically ill patients. To date, there is no effective method that can determine in a timely manner whether patients with acute illness are developing a septic response to an infection. DISCLOSURE: The following authors have nothing to disclose: Keith Meyer, Francis Tsao, Zhanhai Li, Amy Amessoudji, Dunia Jawdat, Musharaf Sadat, Yaseen Arabi No Product/Research Disclosure Information