Although blood donation is a significant issue often left out of important discussions, this piece is about something else of equal importance.
Sepsis is a life-threatening condition triggered by an infection in the body, occurring when the body’s immune system releases chemicals to fight an infection, causing widespread inflammation. If it’s addressed too late, it can result in organ failure and ultimately death.
Sepsis strikes roughly 20 percent of patients admitted to hospital intensive care units, and yet it is difficult to predict the inflammatory response in time to prevent organ failure.
Ordinarily, sepsis is diagnosed by monitoring a patient’s vitals such as blood pressure, oxygen levels and body temperature. Should sepsis be indicated, doctors will then set about trying to determine the source of the infection.
A novel lab-on-chip device designed by researchers at the University of Illinois and Carle Foundation Hospital in Urbana, Illinois, aims to provide rapid, point-of-care measurement of the immune system’s response, without any need to process the blood, rather than identifying the source. This can help doctors identify sepsis at its onset, monitor infected patients and could even point to a prognosis.
“Sepsis is one of the most serious, life-threatening problems in the ICU. It can become
deadly quickly, so a bedside test that can monitor patient’s inflammatory status in real time would help us treat it sooner with better accuracy,” Said Dr. Karen White, an intensive care physician at Carle Foundation Hospital. White led the clinical side of the study.The portable device works by counting the WBCs in total as well as white blood cells called the neutrophils, and measures a protein marker called CD64 on the surface of these neutrophils. The levels of CD64 surge as the patient’s immune response increases.
“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.” Said research team leader Rashid Bashir, a professor of bioengineering at the U. of I. and the interim vice dean of the Carle Illinois College of Medicine.
In a test of the system, the researchers received drops of blood drawn from patients in the intensive care unit and emergency room of the Carle Foundation Hospital. When a doctor suspected infection and ordered a blood test, a small drop of the patient’s blood was given to the researchers. They then monitored the patient’s CD64 levels over time, which were correlated against their vital signs.
The researchers found that the results from the rapid test ‘correlated well’ with those from traditional diagnosis methods and the patients’ vital signs.
“We want to move the diagnosis point backward in time,” Bashir said. “The big challenge in sepsis is that no one knows when you get infected. Usually you go to the hospital when you already feel sick. So the goal is that someday you can be testing this at home, to detect infection even earlier if you can.”
Bashir’s team is now working on incorporating measurements for other inflammation markers into the rapid-testing device to improve its sensitivity, by upgrading it to “read” other immune response biomarkers besides white cells and CD64, so they can obtain a more complete picture of the body’s response.
