A new blood test may be the key to preventing hundreds of thousands of annual deaths from sepsis, according to new research published in the journal Science Translational Medicine. The study claims the assay can predict when a patient will die from the illness, even if their symptoms initially appear mild.

Sepsis occurs when an infection in one organ — typically bacterial but also viral, fungal, or parasitic — triggers a system-wide inflammatory reaction. The body 'thinks' the germ is everywhere.

The fatal consequence is a victim's blood vessels become leaky, resulting in septic shock and organ failure when blood pressure becomes too low. It is an extremely dangerous condition and burden on the U.S. healthcare system — $17 billion annually. Sepsis is common in hospitals and frequently a complication of other disorders, like pneumonia and immunosuppression (HIV or chemotherapy patients).

Many sepsis-related fatalities are prevented when doctors figure out the right course of treatment before runaway inflammation begins. Broad implementation of these "early goal" strategies in 2001 lead to a significant drop in sepsis-related mortality over past decade — up to 46 percent in some studies.

But predicting the outcome of sepsis remains difficult. Some patients with mild symptoms suddenly perish, while other cases are serious in the beginning, but ultimately respond to treatment and quickly resolve themselves.

Thus, the condition remains the 11th leading cause of death, according to the Centers for Disease Control and Prevention, and accurate prediction remains a major barrier to reducing this disease burden.

Who's who?

To search for a predictive test for sepsis, the authors of this study turned to the blood, given it is central to the development of the disease. They collected and examined samples from 300 patients arriving at four emergency rooms that ultimately either survived or succumbed to the condition.

Over the course of eight years, the investigators looked at hundreds of protein and metabolism markers. Remarkably, they discovered specific profiles that defined if a person would die from sepsis, even if the case was in its early stages and regardless of whether the incident was mild or severe.

The study reports that people who survived were able to switch on energy production. The finding suggests mitochondria — the cell's powerhouses — are critically harmed during sepsis.

The findings provide strong support for the future use of these metabolic profiles as a way to predict life or death in sepsis patients.

Source: Langley RJ, Tsalik EL, van Velkinburgh JC, et al. An Integrated Clinico-Metabolomic Model Improves Prediction of Death in Sepsis. Science Translational Medicine. 2013.