(1620) SeptiCyte RAPID Performance Is Not Affected by Different Sites of Primary Infection in Sepsis

Introduction: SeptiCyte® RAPID is an FDA-cleared, host-response based assay for aiding in the identification of sepsis [1]. The assay measures differential gene expression of PLAC8 & PLA2G7 directly from blood, which provides within 1 hour a SeptiScore result ranging from 0 to 15 & falling in four Bands. Increased SeptiScore correlates with increased probability of sepsis.

Methods: The study comprised ICU patients (n=419) suspected of sepsis in 10 European & US hospitals. Consensus Retrospective physician diagnosis (RPD, sepsis-2 criteria) was used to differentiate sepsis (n=154), systemic inflammatory response syndrome [SIRS] (n=224) patients & Indeterminates (n=41). A SeptiScore was generated in 1 hour using blood samples taken within the first 24 hours of ICU admission. Retrospectively determined sepsis patients were stratified based on the study investigators’ initial impression of site of infection. Sepsis infection site categories included Pulmonary (n=66), Abdominal (n=32), Central Nervous System (CNS) (n=6), Urinary (n=30), Other (n=20). The site of infection identified at discharge was imported for patients having an initial suspected site of infection of “blood” (n=16) or a site not identified at initial assessment (n=19). SeptiCyte RAPID performance was measured using AUC when comparing sepsis from various sources to SIRS patients.

Results: Median SeptiScores were high (Band 4) for all sepsis patients with a primary Pulmonary, Abdominal, CNS or Urinary site of infection suspected with AUCs ranging from 0.81-0.94 showing good performance in a range of different sites of infection. Median SeptiScore for patients in “Other” sites of infection was in Band 3 (AUC=0.85). Indeterminate patients had a median SeptiScore in Band 3.

Conclusions: Approximately 10% of patients in this study were not retrospectively classified as sepsis or SIRS by a panel of expert physicians, & ~4.5% did not have a primary source of infection identified, indicating the difficulty that clinicians have in identifying sepsis & sources of infection. SeptiCyte RAPID can aid physicians in identifying sepsis when patients present from a variety of infection sites.

References:
[1] Balk et al. Validation of SeptiCyte RAPID to Discriminate Sepsis from Non-Infectious Systemic Inflammation. J Clin Med. 2024 Feb 20;13(5):1194.