A new portable device can quickly find markers of deadly, unpredictable sepsis infection from a single drop of blood.
A team of researchers from the University of Illinois and Carle Foundation Hospital in Urbana, Illinois, completed a clinical study of the device, which is the first to provide rapid, point-of-care measurement of the immune system’s response, without any need to process the blood.
This can help doctors identify sepsis at its onset, monitor infected patients and could even point to a prognosis, 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.
Sepsis is triggered by an infection in the body. The body’s immune system releases chemicals that fight the infection, but also cause widespread inflammation that can rapidly lead to organ failure and death.
Sepsis strikes roughly 20 percent of patients admitted to hospital intensive care units, yet it is difficult to predict the inflammatory response in time to prevent organ failure, said Dr. Karen White, an intensive care physician at Carle Foundation Hospital. White led the clinical side of the study.
“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,” White said.
Sepsis is routinely detected by monitoring patients’ vital signs – 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.
“We are looking at the immune response, rather than focusing on identifying the source of the infection,” Bashir said. “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 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.
The researchers tested the device with blood samples from Carle patients in the 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 researchers, 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. Researchers found that the results from the rapid test correlated well with the results from the traditional tests and with the patients’ vital signs.
“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,” said Umer Hassan, a postdoctoral researcher at Illinois and the first author of the study. “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.”
Bashir’s 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.

University of Illinois
news.illinois.edu/blog/view/6367/526347

Currently, testing for Zika requires that a blood sample be refrigerated and shipped to a medical centre or laboratory, delaying diagnosis and possible treatment. Although the new proof-of-concept technology has yet to be produced for use in medical situations, the test’s results can be determined in minutes. Further, the materials required for the test do not require refrigeration and may be applicable in testing for other emerging infectious diseases.
The researchers tested blood samples taken from four people who had been infected with Zika virus and compared it to blood from five people known not to have the virus. Blood from Zika-infected patients tested positive, but blood from Zika-negative controls did not. The assay produced no false-positive results.
Among the reasons such a test is needed, according to the researchers, is that many people infected with Zika don’t know they’re infected. Although symptoms include fever, joint pain, muscle pain and rash, many people don’t feel ill after being bitten by an infected mosquito. Testing is particularly important for pregnant women because Zika infection can cause congenital Zika syndrome, which contributes to several neurologic problems in the foetus or newborn infant.
“Zika infection is often either asymptomatic or mildly symptomatic,” said Evan D. Kharasch, MD, PhD, one of the study’s three senior investigators. “The most effective way to diagnose the disease is not to wait for people to develop symptoms but to do population screening.”
That strategy requires inexpensive, easy-to-use and easy-to-transport tests. Kharasch, the Russell D. and Mary B. Shelden Professor of Anesthesiology, collaborated with Srikanth Singamaneni, PhD, an associate professor of mechanical engineering & materials science, and Jeremiah J. Morrissey, PhD, a research professor of anesthesiology, to create the test, which uses gold nanorods mounted on paper to detect Zika infection within a few minutes.
“If an assay requires electricity and refrigeration, it defeats the purpose of developing something to use in a resource-limited setting, especially in tropical areas of the world,” said Singamaneni. “We wanted to make the test immune from variations in temperature and humidity.”
The test relies on a protein made by Zika virus that causes an immune response in infected individuals. The protein is attached to tiny gold nanorods mounted on a piece of paper. The paper then is completely covered with tiny, protective nanocrystals. The nanocrystals allow the diagnostic nanorods to be shipped and stored without refrigeration prior to use.
To use the test, a technician rinses the paper with slightly acidic water, removing the protective crystals and exposing the protein mounted on the nanorods. Then, a drop of the patient’s blood is applied. If the patient has come into contact with the virus, the blood will contain immunoglobulins that react with the protein.
“We’re taking advantage of the fact that patients mount an immune attack against this viral protein,” said Morrissey. “The immunoglobulins persist in the blood for a few months, and when they come into contact with the gold nanorods, the nanorods undergo a slight color change that can be detected with a hand-held spectrophotometer.
“With this test, results will be clear before the patient leaves the clinic, allowing immediate counselling and access to treatment.”
The colour change cannot be seen with the naked eye, but the scientists are working to change that. They’re also working on developing ways to use saliva rather than blood.
Although the test uses gold, the nanorods are very small. The researchers estimate that the cost of the gold used in one of the assays would be 10 to 15 cents.
As other infectious diseases emerge around the world, similar strategies potentially could be used to develop tests to detect the presence of viruses that may become problematic, according to the researchers.

Washington University School of Medicine
medicine.wustl.edu/news/test-uses-nanotechnology-quickly-diagnose-zika-virus/

A new five-year study of nearly 1,600 patients finds that genetic testing can help determine the safest dose of the blood thinner warfarin, with fewer side effects, in patients undergoing joint replacement surgery.
Considering a patient’s genetic makeup when prescribing warfarin—a blood thinner commonly prescribed to prevent life-threatening blood clots—can mean fewer adverse side effects like haemorrhage, researchers found.
Warfarin is a commonly prescribed, very effective anticlotting medicine — but it’s often associated with adverse complications and each patient requires a different dosage to achieve the desired treatment effect.
That unique dosing is based in part on an individual’s genetics, and great interest exists in understanding whether an individual’s genetics can guide how to best prescribe warfarin to reach the optimal therapeutic range.
Now, researchers from Intermountain Medical Center, along with four other research centers, including Washington University School of Medicine in St. Louis, which led the national study, have shown that outcomes greatly improve for older patients who undergo elective hip or knee replacement when the dose of warfarin is based on how a patient’s liver metabolizes the blood thinner, which can be discovered using a blood test.
Researchers say study findings from the GIFT study (Genetics Informatics Trial of Warfarin to Prevent Deep Venous Thrombosis) are significant. Compared to patients who received a standard dose, patients who received genetically-dosed warfarin had a 27 percent reduction in complications.
Specifically, their major bleeding was reduced by 75 percent, the incidence of excessive international normalized ratios was reduced by about 30 percent, and blood clots occurred 15 percent less often. No patients died during the study.
The findings from the GIFT study are published and could be used immediately. The Food and Drug Administration has since 2007 included language in its warfarin packaging that encourages the use of genetic guidance, if it’s available.
“Differences can be identified by looking at a patient’s genetic makeup, and specifically at the genes that are responsible for the liver’s metabolism of the drug,” said Scott Woller, MD, co-director of the Thrombosis Program at Intermountain Medical Center and principal investigator for Intermountain Healthcare.

Intermountain Healthcare
intermountainhealthcare.org/news/2017/10/genetic-testing-can-help-determine-safest-dose-of-warfarin-for-joint-surgery-patients/

They discovered a previously unknown group of regulatory T cells linked to the disease and DNA features that affect patients’ response to treatment
A team of scientists and doctors from the SingHealth Duke-NUS Academic Medical Centre (AMC) has uncovered a new group of regulatory T (Treg) cells and DNA features associated with juvenile idiopathic arthritis (JIA), the most common form of arthritis among children under the age of 16. Their findings could potentially enhance diagnosis of the disease and prediction of therapy outcomes for improved treatment successes.
JIA is a disease of the immune system that causes inflammation leading to pain, stiffness and swelling in patients’ joints. It affects around one in 1,000 children in the world.
Juvenile arthritis has no cure and young patients can only alleviate pain or prevent joint deterioration through use of medication or therapy. In advancing care for JIA, researchers are keen to identify the culprit cells or genetic signatures behind the disease in order to tackle it.
In its first discovery, the SingHealth Duke-NUS AMC research team identified a previously unknown group of Treg cells that is associated with inflammation in JIA. Treg cells are a subset of white blood cells that regulate the body’s immune system. When the body has an imbalanced number of Treg cells, its immune tolerance can fail and experience autoimmune disorders such as arthritis.
The team found that the identified Treg cells play a role in JIA progression. During the active disease stage of JIA, these cells expand, grow in number, re-circulate through inflamed areas of patients’ body, and migrate to the connective tissue of patients’ joints. Additionally, a larger quantity of these cells can be found in JIA patients who cannot control arthritis inflammation and are unresponsive to therapy as compared to those who are.
"Clinicians could potentially use this novel group of cells as a marker to diagnose JIA in patients, as well as to predict or monitor patients’ responsiveness to therapy. Importantly, these cells are readily detectable in patients’ bloodstream, allowing for any clinical tests to be minimally invasive and pain-free for patients," said Professor Salvatore Albani, Director, SingHealth Translational Immunology and Inflammation Centre (STIIC), Professor, Duke-NUS Medical School and Senior Clinician Scientist, KK Women’s and Children’s Hospital (KKH), who is the principal investigator of the study.
 
2nd discovery: Patients’ DNA affects JIA treatment outcomes
Currently, only about one-third of JIA patients get better after medication or therapy, while the rest continue to see their condition flare up even after treatment.
To accurately predict treatment outcomes, the research team studied JIA patients’ treatment responses and found that epigenetics – or individuals’ DNA and the way each body uses its genes – determined one’s clinical "fate". In other words, the key is not in individuals’ genetic make-up but rather, in how their bodies employ genes. Even patients with identical genetic backgrounds could experience different clinical outcomes based on their DNA features that activate genes differently.
One of the research paper’s co-author, Associate Professor Thaschawee Arkachaisri, Head & Senior Consultant, Rheumatology and Immunology Service, KKH and Associate Professor, Duke-NUS, said "These discoveries could enable doctors to predict treatment responses and personalise treatment for patients. This is especially relevant for difficult JIA cases which may require more complex therapies, and is important to help save time and money, prevent treatment complications and ultimately, improve care outcomes."
The team’s findings are also relevant for adult rheumatoid arthritis, a similar autoimmune condition that affects one in 100 adults in the world.

EurekAlert
www.eurekalert.org/pub_releases/2017-07/s-ssp071317.php