Pneumonia in the ImmunoCompromised - Use of the Karius Test for the Detection of Undiagnosed Pathogens

Pneumonia is a major cause of morbidity and mortality in highly immunocompromised individuals such as patients with hematologic malignancies and/or hematopoietic stem cell transplant. These patients can be infected by a broad range of potential pathogens, including viral, bacterial, and fungal etiologies and sometimes with multiple pathogens simultaneously. Diagnostic testing often fails to identify a microbial etiology for lower respiratory illness even with bronchoalveolar lavage (BAL). In fact, culture methods, PCR, and antigen testing on BAL samples yields a positive result only 30-67% of the time. Additionally, Idiopathic Pulmonary Syndrome (IPS), a non-infectious pulmonary complication of transplant, can have many overlapping symptoms with infectious pneumonia. Treatment for IPS is administration of steroids which can exacerbate infections. Given these reasons, there is a need for better diagnostics to aid in the management of immunocompromised patients with pneumonia. Karius has developed a microbial cell-free plasma next-generation sequencing test for pathogen detection capable of detecting \>1,000 organisms including DNA viruses, bacteria, yeasts, molds, and other eukaryotic pathogens. The test is performed in a CLIA-certified/CAP-accredited laboratory with results typically provided within one day from sample receipt. Given the need for a more sensitive diagnostic test for pneumonia in this population, we are evaluating the performance of the Karius Test for pathogen detection.