Portable device diagnoses sepsis within 15 minutes

The device, being developed by Leicester-based engineering company Magna Parva with funding from Innovate UK, uses antibodies to detect biomarkers for sepsis within blood samples.

Sepsis is a common yet deadly condition in which an infection triggers an extreme immune response, resulting in widespread inflammation, blood clotting and swelling. If left untreated, it can lead to organ failure and death.

Around six million people worldwide are killed by the condition each year. In the UK alone, sepsis is thought to kill 37,000 people every year, more than three times the number killed by breast or prostate cancer. Between a third and a half of hospital deaths are attributed to the condition, which costs the UK and US around £20bn each year.

Despite this, there is currently no effective tool for diagnosing the disease.

The RAPPID diagnostic tool is designed to detect markers for the disease from a sample within 15 minutes. A sample preparation tool first removes the plasma from the cellular material within the blood. It then concentrates the remaining plasma by vacuum boiling, ready for it to be fed into the biosensor.

The plasma is then washed over a chip containing the antibodies. If there are any sepsis antigens within the sample, they will bind to the antibodies, causing the system to resonate at a particular frequency under certain wavelengths of light, said company director Andrew Bowyer.

“There are a phenomenal number of biosensors out there but they all need sample preparation, meaning the sample has to be cleaned up or concentrated first, and that has to be done within a laboratory environment,” said Bowyer. “With the RAPPID device we are doing it all in one system.”

The device not only identifies the existence of the pathogen within blood samples, but also measures the levels of several key markers, to identify at what stage in the disease the patient is, and ensure the right treatment is given. “What clinicians want to know is how far along you are in the sepsis curve, and whether you would respond to antibiotics or steroids,” said Bowyer. “So this is a diagnostic tool to aid that clinical decision-making process.”

Following the completion of the preliminary trials, the device will now need to be tested in further large-scale clinical trials, to ensure it can be reliably used as an effective diagnostic tool. The company also plans to integrate the sample preparation system into the biosensor itself, as the two are currently separate devices.

In the meantime, the sample preparation tool is also being separately developed as the front end of a tumour profiling device, which will generate results directly from human tissue samples within 30 minutes.