Scientists have designed a simple test that can detect sepsis from a single drop of blood
Sepsis, a life-threatening condition in which the body’s extreme response to severe infection damages tissues and organs, is reportedly misdiagnosed in approximately 30% of patients.
Current tests have poor specificity and are slow, taking days to provide results, say researchers.
Daniel Irimia and colleagues from Massachusetts General Hospital in the US have designed a device in which a drop of blood fills a maze of microscopic channels.
A machine-learning algorithm then correlates the movement of neutrophils — the immune system’s ‘first responders’ — in the maze with sepsis severity to calculate a ‘sepsis score’.
Neutrophil biomarkers have been found to be sensitive to infections and major inflammatory stats.
Many other markers fail to differentiate between sepsis and systemic inflammatory responses and have therefore had limited practical effects, while microbiological cultures help to diagnose sepsis, but require extended periods of time (two to three days) to grow out the bacteria.
In a double-blind, prospective case-control study measuring the performance of the assay in two independent cohorts of critically ill patients suspected of sepsis, the test identified sepsis patients with 97% sensitivity and 98% specificity.
The test reportedly runs in only a few hours.
Although the test needs to be validated using a larger and more diverse set of patients, it has the potential to increase the survival rates of patients at high risk of sepsis and to reduce antibiotic overuse, say the researchers.
Their results were published in Nature Biomedical Engineering.