Sepsis is perhaps not an especially fashionable thing to target, yet it strikes over a million Americans each year, and kills more people per year than breast cancer, prostate cancer, and AIDS combined. So it’s a big deal, and as with most health related issues, the earlier it is diagnosed, the easier it is to treat successfully.
I wrote earlier this year about an AI based approach to the problem developed by researchers from Johns Hopkins University. As with all machine learning based projects, it rests upon good access to data. The system taps into the patient record, and aims to predict the trajectory of the patient’s health. In other words, whether they get better or worse. The researchers also believe that it could help clinicians better predict how different treatments will affect the patient.
Now, a new device has been developed by researchers from the University of Illinois and Carle Foundation Hospital in Urbana, Illinois to quickly find biomarkers for an especially deadly form of sepsis from a single drop of blood. The device has recently undergone clinical research, with the results published in a new paper.
The work is believed to be the first to be able to provide rapid, point-of-care measurement of the immune system’s response without needing to process the blood.
The hope is that the devise will enable doctors to identify sepsis at the onset, whilst also monitoring patients and potentially even provide early prognoses.
“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,” the authors say.
Currently sepsis is usually detected by monitoring the patient’s vital signs, such as blood pressure and temperature. If signs are detected, the doctors attempt to identify the source by using blood cultures and other tests. Whilst these are great, they often take days to return results. The new device aims to provide a much faster turnaround.
“We are looking at the immune response, rather than focusing on identifying the source of the infection,” the team say. “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.”
Lab on a chip
The device contains a lab-on-a-chip that counts the white blood cells in the sample, as well as very specific white blood cells, known as neutrophils. It also measures a protein marker, called CD64, that is contained on the surface of the neutrophils. As the body combats sepsis, the level of CD64 surges.
The device was put through its paces using blood samples from ICU patients at the hospital. When doctors suspected sepsis and subsequently ordered a sample, a drop of the blood was given to the research team for analysis, with comparison made with the actual health of the individual over time. It emerged that the device was able to accurately correlate results with that of more traditional tests, albeit much faster.
“By measuring the CD64 and the white cell counts, we were able to correlate the diagnosis and progress of the patient – whether they were improving or not,” the team say. “We hope that this technology will be able to not only diagnose the patient but also provide a prognosis. We have more work to do on that.”
The next step is to expand the number of biomarkers the team look for in the hope that this will give a more complete picture of how the body responds to the infection. They have also created a company, called Prenosis, to bring the device to market.
“We want to move the diagnosis point backward in time,” they say. “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.”