Image: University of Illinois researchers and physicians at Carle Foundation Hospital developed a rapid test for sepsis that counts white blood cells and certain protein markers on their surface to monitor a patient\'s immune response (Photo courtesy of Janet Sinn-Hanlon).
A new portable device can quickly find markers of deadly, unpredictable sepsis infection from a single drop of blood, which is the first to provide rapid, point-of-care measurement of the immune system's response, without any need to process the blood.
Sepsis is routinely detected by monitoring patients' vital signs, such as blood pressure, oxygen levels, temperature and others. If a patient shows signs of being septic, the doctors try to identify the source of the infection with blood cultures and other tests that can take days, time the patient may not have. The new device takes a different approach.
Scientists at the University of Illinois at Urbana-Champaign (Urbana, IL, USA) and their colleagues tested the device with blood samples from patients in the intensive care unit (ICU) and emergency room. When a physician suspected infection and ordered a blood test, a small drop of the blood drawn was given to the team, stripped of identifying information to preserve patient confidentiality. The team was able to monitor CD64 levels over time, correlating them with the patient's vital signs. They found that the results from the rapid test correlated well with the results from the traditional tests and with the patients' vital signs. The small, lab-on-a-chip device counts white blood cells in total as well as specific white blood cells called neutrophils, and measures a protein marker called CD64 on the surface of neutrophils. The levels of CD64 surge as the patient's immune response increases.
Rashid Bashir, PhD, a professor of bioengineering and lead investigator, said, “We are looking at the immune response, rather than focusing on identifying the source of the infection. One person's immune system might respond differently from somebody else's to the same infection. In some cases, the immune system will respond before the infection is detectable. This test can complement bacterial detection and identification. We think we need both approaches: detect the pathogen, but also monitor the immune response.”
The team is working to incorporate measurements for other inflammation markers into the rapid-testing device to give a more complete picture of the body's response, and to enable earlier detection. They also have a startup company, Prenosis Inc (Champaign, IL, USA) that is working to commercialize the device. The study was published on July 3, 2017, in the journal Nature Communications.
University of Illinois at Urbana-Champaign