New Device Could Detect Sepsis in Minutes, Not Hours

Sepsis causes almost 250,000 deaths in hospitals in the U.S. each year. MIT researchers have developed a device that could detect sepsis in minutes—potentially helping to save lives.

Sepsis occurs when the body’s immune response goes into overdrive, triggering an inflammation chain reaction that can spike the heart rate and body temperature. The condition could lead to deadly septic shock, where blood pressure plummets and organs shut down.

Protein biomarker detection is a promising new tool for early sepsis diagnosis. Interleukin-6 (IL-6), a protein triggered by inflammation, can rise several hours before other sepsis symptoms begin to show. But current medical tools usually can’t detect elevated IL-6 levels quickly enough.

The MIT team may have found a solution: a microfluidics device that can detect IL-6 levels in the blood within about 25 minutes.

The device consists of two microfluidic channels. In one channel, micron-sized beads are coated with an antibody that attracts IL-6 and a catalyzing enzyme. The beads are mixed with a blood sample—and within about 10 minutes, IL-6 proteins have bound to the antibodies.

In the other channel, the beads with IL-6 are exposed to a compound containing a molecule that reacts with the catalyzing enzyme—creating a new substance that conducts electricity. An electrode then runs voltage through the new compound and each bead creates a minuscule current in response.

The resulting current is converted into a readable signal—and by counting the signals, the device can calculate how much IL-6 is present in the blood sample.

“For an acute disease, such as sepsis, which progresses very rapidly and can be life-threatening, it’s helpful to have a system that rapidly measures these nonabundant biomarkers,” said Dan Wu, a PhD student in MIT’s Department of Mechanical Engineering. “You can also frequently monitor the disease as it progresses.”

Conventional protein biomarker detecting machines are expensive and unwieldy, and they often need to use a milliliter of blood to produce results in several hours. While newer machines are more portable and faster than earlier models, they’re still expensive, and often aren’t sensitive enough to detect sepsis-associated biomarkers.

In contrast, the MIT team’s device is several centimeters in size and only needs about five microliters of blood to work—that’s less than a pinprick.

The researchers now plan to expand the device’s detection capabilities to other sepsis biomarkers. And the device could potentially be useful beyond detecting sepsis. It has eight microfluidics channels, and by using different enzymes and antibodies it could be customized to detect any number of biomarkers for other diseases.

“This is very general platform,” said Wu. And it has the potential to transform the way hospitals combat the threat of sepsis.