New Diagnostic Detects Sepsis in Three Hours

Sepsis, a serious complication of infection, affects more than one million Americans per year and is the most expensive hospital-treated condition, costing hospitals $20 billion in 2011. Early detection and treatment is key when it comes to sepsis, but current methods can be slow and about 40 percent of cases are fatal. Bioscience Technology sat down with Tom Lowery, Ph.D. chief scientific officer of T2 Biosystems, to talk about a new diagnostic tool that can test and detect sepsis in as little as three hours, compared to a traditional blood culture that can take two to five days.

Time is of the essence

Each hour that a patient with sepsis is not treated, the rate of mortality increases by 8 percent, Lowery said. Doctors typically can’t get results of a sepsis test for two to five days, so they put all patients suspected of sepsis on broad-spectrum antibiotics; however, about 20 to 30 percent of those patients won’t respond to that therapy.

In addition to an increasing mortality rate in those who do not respond to therapy, it breeds resistance due to the use of antimicrobials.

“Really, the physicians have adequate therapies today [to treat sepsis], they just don’t know what therapy to pull out of their options to give the patient rapidly and appropriately,” Lowery said.

The T2MR (magnetic resonance) technology that was developed for the platform is able to identify five clinically relevant species of Candida directly from a patient’s blood sample—with a limit of detection at 1 CFU/Ml compared to 100 or 1,000 CFU/Ml in traditional PCR-based assays. The instrument utilizes a miniaturized magnetic resonance-based technology that measures how water molecules react in the presence of magnetic fields.

“Unlike other types of detection methods T2MR can measure the water molecules in the sample and doesn’t get interference from sample background and sample matrix,” Lowery said. “The detection doesn’t require any purification and this is key because these blood samples from patients that suffer from sepsis have extremely dilute concentration of organism in their blood, and if you have to purify that organism before you detect, you lose a significant portion of your target, up to 90 percent of it.”

High sensitivity

The ability to get sensitivity to one colony-forming unit (CFU) per ML is what makes the rapid detection possible. In clinical trials the T2Candida Panel demonstrated over 99.4 percent clinical specificity and 91.1 percent sensitivity. The Federal Drug Administration (FDA) cleared the diagnostic in September 2014. It is the first molecular diagnostic panel that does not require a blood culture.

“One of the fundamental problems of blood cultures is that it’s only 50 to 60 percent sensitive, so that means 40 to 50 percent of patients have a false negative,” Lowery said.

A study, conducted by IMS Health focusing on the financial benefit estimated a hospital that had 5,100 high risk patients could save millions of dollars by detecting and treating early, thereby reducing the length of stay, which is typically 40 days for a sepsis patient, and decreasing use of antimicrobials. The article also found the T2Candida diagnostic could prevent 60 percent of Candida-related deaths.

“It’s a really big problem in the U.S., a challenging problem and we’re really excited to bring some new technology that can directly address this problem and dramatically reduce mortality rates,” Lowery said.

In addition to expanding its sepsis focus, T2 Biosystems is also developing a test panel for rapid detection of Lyme disease. The company was founded in 2006 by scientists from MIT and Mass General Hospital.

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