Karius Test Demonstrates Ability To Detect Bloodstream Infections In Pediatric Patients With Cancer Before Symptoms Develop

Karius, a life sciences company, announced today that JAMA Oncology published a clinical study showing that the Karius Test detected bloodstream infections before the onset of clinical symptoms in high-risk pediatric patients with relapsed or refractory leukemia. The study was performed by researchers at St. Jude Children’s Research Hospital and provides the first evidence that the Karius Test can predict infections.

The Karius Test is a non-invasive blood test that uses next-generation sequencing of microbial cell-free DNA to rapidly detect over 1,400 bacteria, DNA viruses, fungi, and parasites. The test is primarily used to detect specific causative pathogens in complicated pneumonia, cardiovascular infections, and infections in immunocompromised patients.

Infections are a leading cause of death for patients with leukemia in the United States. Patients treated with chemotherapy for cancers, such as leukemia, have a high risk of life-threatening infections. Some children with leukemia have a higher chance of dying from an infection than from the cancer itself.  Currently, broad-spectrum antimicrobial prophylaxis is used to prevent infections and then empiric antimicrobial treatment is started at the onset of signs or symptoms of infection. A non-invasive plasma-based predictive screening test for infections may allow pre-emptive targeted antimicrobial therapy before symptom onset and may improve clinical outcomes.

“Parents of children with cancer often wish that they had a crystal ball to know what’s coming next; this might just be that…” said Josh Wolf, M.D., Ph.D., co-author and Associate Member of the Department of Infectious Diseases at St. Jude Children’s Research Hospital.

Of the 47 pediatric patients enrolled in the study, 12 patients developed a total of 19 bloodstream infections, and samples for evaluation of predictive diagnosis were available for 16 episodes. The Karius Test detected a bloodstream infection in 75 percent of cases (12/16) as early as three days before patients became symptomatic.

“There is an important signal here suggesting an ability to predict infections in this vulnerable population even before the development of clinical symptoms,” said co-author and Senior Medical Director at Karius, Asim Ahmed, M.D. “The Karius Test is not currently a screening test; additional studies are needed to guide how this test can be used in the clinical work-flow to help predict and prevent infections in patients with immunocompromising conditions.”

This study will be expanded to further analyze the Karius Test’s ability to identify bloodstream infections before symptoms arise.

The research at St. Jude was funded in part by the following: Karius Inc.; the Burroughs Wellcome Fund; the Hyundai Foundation of Pediatric Cancer Research; the Leukemia and Lymphoma Society; and ALSAC, St. Jude’s fundraising and awareness organization.