Trauma, extensive burns, bacterial infections, and acute pancreatitis AP are common conditions of tissue injury and immune system activation that can result in the systemic inflammatory response syndrome SIRS. Surprisingly, about half of the patients with SIRS quickly recover, while the others develop a multiorgan dysfunction syndrome MODS. SIRS and MODS do not occur immediately SIRS evolves over a 4-12 hour period, while MODS evolves over12-24 hours. Vascular leak syndrome VLS is a critical component of the transition from SIRS to MODS. Understanding the mechanism by which SIRS triggers VLS and progresses to MODS is critical to correctly model disease course thereby aiding in treatment of patients. In this report, we analyzed the serum samples for proteins that will help to understand a mechanism for cytotoxicity to endothelial cells. The results demonstrate elevated cytokine and Ang-2levels in serum samples from patients with severe AP. Also, initial mass spectrometry findings show potential biomarkers that will be explored.