Multi-Site Study Validates SeptiCyte RAPID for Differentiating Sepsis from Noninfectious Inflammation in Children

Host-response test delivered consistent performance across pediatric age groups and strengthened diagnostic accuracy when combined with routine clinical data

SEATTLE, WA, UNITED STATES, October 15, 2026 /EINPresswire.com/ — Multi-Site Study Validates SeptiCyte RAPID for Differentiating Sepsis from Noninfectious Inflammation in Children
Host-response test delivered consistent performance across pediatric age groups and strengthened diagnostic accuracy when combined with routine clinical data

Immunexpress today announced the publication of a multicenter clinical validation study demonstrating that SeptiCyte^® RAPID can help distinguish sepsis from noninfectious systemic inflammatory response syndrome (SIRS) in critically ill children suspected of sepsis. The article summarizing the study, published in Pediatric Critical Care Medicine, addresses a significant unmet need for rapid, reliable tools that can support early clinical decision making.

The lead author, Dr Jerry Zimmerman, Emeritus Professor, Pediatric Critical Care Medicine, Seattle Children’s Hospital, University of Washington, said that “Distinguishing infection-driven sepsis from noninfectious inflammation remains one of the most difficult and time-sensitive decisions in pediatric critical care. The findings in this study demonstrate the promise of a rapid host-response laboratory test to help clinicians manage diagnostic uncertainty in real time during high stakes evolution of a dynamic clinical picture—supporting early sepsis management when sepsis probability is high and consideration of alternative diagnoses and antibiotic stewardship when sepsis probability is low.”

SeptiCyte^® RAPID is a sample-to-answer, cartridge-based, host response molecular test using as little as 250uL of whole EDTA blood. SeptiCyte^® RAPID generates a SeptiScore^® (range 0-15) within approximately one hour, reported across four interpretation bands reflecting increasing likelihood of sepsis.

A number of host response-based sepsis biomarkers have recently become commercially available, but validation studies in children are lacking. The retrospective, noninterventional study evaluated 284 children, ages one month to 18 years, enrolled among four studies at leading pediatric centers in the United States and Australia. Results confirmed that SeptiCyte RAPID has strong performance characteristics similar to that previously reported for adults.

SeptiCyte RAPID differentiated sepsis from noninfectious SIRS with an area under the receiver operating characteristic curve (AUC) of 0.83 in children with a consensus clinical diagnosis, outperforming other clinical parameters used alone or in combination. Adding six routine laboratory tests, including organ dysfunction variables, the AUC improved to 0.87. Performance was consistent across infants and toddlers, children and adolescents, and no statistically significant difference was observed between the U.S. and Australian cohorts.
Among clinically adjudicated sepsis patients with positive blood cultures, 68.4% had a Band 4 (highest sepsis probability) result, reinforcing the potential value of a high SeptiScore in prognosis and in prioritizing timely diagnostic and treatment pathways.
Importantly, higher SeptiScores corresponded to a progressively greater probability of sepsis (positive likelihood ratio 3.51) and lower SeptiScores can enable ruling out sepsis (likelihood ratio 0.09).

The study authors concluded that the test may be used with available clinical and laboratory parameters, including measures of early organ dysfunction, to support earlier and more accurate identification of sepsis in children.

About SeptiCyte^® RAPID
SeptiCyte RAPID measures the patient’s immune response to infection and reports a SeptiScore within approximately one hour using a small-volume peripheral blood sample. SeptiCyte^® RAPID is intended for use in conjunction with clinical assessments, vital signs, and other laboratory findings as an aid in differentiating infection-positive sepsis from non-infectious systemic inflammation. SeptiCyte^® RAPID runs on the Biocartis Idylla™ platform and is CE Marked in Europe. The test has received FDA clearance in the United States for use in hospitalized adult patients suspected of sepsis and approved for adult and pediatric application by TGA in Australia

About Immunexpress
Immunexpress is a molecular diagnostics company based in Brisbane, Australia, and Seattle, USA, dedicated to improving outcomes for patients with suspected sepsis. The company’s SeptiCyte^® technology assesses a patient’s dysregulated immune response by quantifying gene expression from whole blood, delivering actionable information during the critical early hours of sepsis evaluation. By enabling earlier and more confident clinical decision-making, Immunexpress aims to improve patient outcomes while helping reduce the economic burden of sepsis on healthcare systems worldwide.

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Jane papadaki markley
Immunexpress, Inc
+1 714-655-4448
jane.p@immunexpress.com
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