New Data Shows That Karius Blood Test Can Non-Invasively Detect Pathogens In Deep Infections

Karius, a life sciences company that delivers genomic insights for infectious diseases, announced new findings that show the potential clinical utility of its Karius® Test to detect pathogens causing serious infections using a simple blood draw. This includes pathogens that are otherwise difficult to culture or identify without an invasive biopsy.

The Karius Test is a non-invasive blood test based on next-generation sequencing of microbial cell-free DNA. It can identify and quantify over 1,000 clinically relevant pathogens including bacteria, DNA viruses, fungi, and parasites.

Applications include complicated pneumonia, immunocompromised patients, and endocarditis.

During an acute infection, pathogens leave microbial cell-free DNA (mcfDNA) in the blood. Even when an infection is localized, mcfDNA from the infection can be detected.

"Rigorous clinical studies of the Karius Test continue to show its ability to identify and quantify pathogens from a single blood test," said Karius Co-founder and CEO, Dr. Mickey Kertesz. "In some of the studies, this was the first time that a non-invasive method was able to identify pathogens that were previously only detectable with invasive biopsies."

Below are the five studies Karius presented at ASM Microbe 2019.

1.    Detection of Bartonella species in Culture-Negative Endocarditis using the
       Karius Test, a Plasma Next-Generation Sequencing test for Pathogen Detection

Bartonella species are fastidious, gram-negative bacteria that can cause culture-negative endocarditis (CNE), lymphadenitis, visceral abscesses, and fever of unknown origin. Diagnosis frequently requires sampling of infected tissue. Dr. Asim Ahmed, Karius Medical Director, will present the Karius Test's ability to identify Bartonella species in culture-negative endocarditis and will discuss how the quantitative aspect of the test may offer a means to monitor patient response to therapy.

2.    Next-generation Sequencing of Pathogen Cell-free DNA in Plasma (Karius Test)
       Reveals Nocardia Species Diversity in Clinical Infections

Nocardia can cause pulmonary, brain, skin, or disseminated infections in immunocompromised and immunocompetent patients. Nocardia is difficult to culture and often requires invasive methods for diagnosis. Dr. Asim Ahmed, Karius Medical Director, will present new findings that highlight the Karius Test's ability to uncover new insights on genus complexity of Nocardia species, which can potentially help inform treatment decisions.

3.    Sequencing of Plasma Cell-Free DNA for Pathogen Detection in Prosthetic
       Joint Infections

Currently, identification of pathogens causing prosthetic joint infections typically requires testing tissue directly from the site. In an evaluation of the Karius Test's ability to detect pathogens in prosthetic joint infections, David Danko of Weill Cornell Medicine will present how the Karius Test was able to identify pathogens in prosthetic joint infection cases. These findings highlight the potential of the Karius Test to serve as a non-invasive alternative to detect deep infections.

4.    Evaluation of Karius Plasma Next Generation Sequencing of Cell-free Pathogen
       DNA to Detect and Quantitate Cytomegalovirus, Epstein-Barr Virus, and BK
       polyomavirus

Dr. Tim Blauwkamp, Karius Chief Scientific Officer, will present new findings that show a high correlation between the Karius Test and industry-standard quantitative PCRs for Cytomegalovirus (CMV), Epstein-Barr Virus (EBV), and BK polyomavirus (BKV). These viruses can cause serious complications for immunocompromised patients. The findings highlight the Karius Test's ability to simultaneously detect and quantify CMV, EBV, and BKV.

5.    Improving the Clinical Specificity of the Unbiased Karius Test via Literature Mining

Dr. Lily Blair, Investigative Computational Biologist at Karius, will present the benefits of applying artificial intelligence methods to increase the utility of diagnostic tests for infectious diseases. Using machine learning algorithms, the Karius team processed more than 27 million abstracts from PubMed to compute how likely a microbe was to cause sepsis. Significant clinical specificity improvements are demonstrated by applying this method to the SEP-SEQ study, a study that validated the performance of the Karius Test in 350 patients with suspected sepsis recently published in Nature Microbiology.