SeptiCyte RAPID Test Shows Strong Link to Positive Sepsis Cultures | 90-Minute Results

A new study published today, February 12, 2026, highlights a strong link between a patient’s risk of sepsis and the likelihood of a positive blood culture, offering a potential tool for more targeted diagnostic testing. The research focuses on SeptiCyte RAPID^®, a molecular diagnostic test that provides a sepsis probability score within 90 minutes of a blood draw.

Sepsis, a life-threatening condition arising when the body’s response to an infection spirals out of control, remains a significant challenge in healthcare. Early and accurate diagnosis is crucial, but can be difficult. Blood cultures, traditionally a cornerstone of sepsis management, are often delayed, yield negative results, or are complicated by contamination. This new study suggests SeptiCyte RAPID may help clinicians refine their approach to blood culture ordering and interpretation.

The study, titled “Likelihood of Blood Culture Positivity Using SeptiCyte RAPID,” was a retrospective analysis of data collected from three prospective observational cohorts across North America, Europe and sub-Saharan Africa. Researchers analyzed data from 506 critically ill and acute care patients with sepsis independently adjudicated and blinded to the SeptiCyte RAPID results. The findings demonstrate a clear correlation between higher SeptiScores^® – the score generated by the SeptiCyte RAPID test – and positive blood cultures.

Specifically, the study found that over 90% of patients with blood culture-positive sepsis fell into the highest SeptiScore bands. Conversely, no patients with positive blood cultures were found in the lowest SeptiScore band, indicating the test’s ability to identify individuals with a very low probability of sepsis. This suggests SeptiCyte RAPID could be particularly valuable in ruling out sepsis in certain patients, potentially avoiding unnecessary antibiotic use and reducing healthcare costs.

The diagnostic performance of SeptiCyte RAPID was also strong, with an Area Under the Curve (AUC) of 0.91 for distinguishing blood culture-positive sepsis from non-infectious systemic inflammation (SIRS). Binary cut-point analyses revealed 100% sensitivity at low SeptiScores (<5.0) and 100% specificity at high SeptiScores (>11.4) within the study dataset. These findings underscore the potential for SeptiCyte RAPID to serve as an early risk-stratification tool, helping clinicians quickly identify patients who are most likely to be experiencing sepsis.

“The study findings suggest that SeptiCyte RAPID, when used alongside clinical assessment, may help clinicians prioritize which patients are most likely to benefit from blood cultures, interpret equivocal results, and potentially reduce unnecessary testing,” stated Dr. Maik von der Forst, Department of Anesthesiology, Heidelberg University Hospital Germany. “There is a need for tools that guide the use of microbiologic diagnostics in the hospital and especially in resource-constrained healthcare settings, emergency departments and ICUs.”

SeptiCyte RAPID works by analyzing gene expression from a whole blood sample using reverse transcription polymerase chain reaction (RT-PCR). It quantifies the relative expression of two host response genes, PLAC8 and PLA2G7, and generates a SeptiScore ranging from 0 to 15. The test provides results within approximately one hour and is intended to be used in conjunction with clinical assessments, vital signs, and other laboratory findings to aid in differentiating infection-positive sepsis from non-infectious systemic inflammation.

The test is currently CE Marked in Europe and has received FDA clearance in the United States for use in hospitalized patients suspected of sepsis. It runs on the Biocartis Idylla™ platform.

Immunexpress, the company behind SeptiCyte RAPID, emphasizes its commitment to improving outcomes for patients with suspected sepsis. The company’s technology focuses on assessing a patient’s dysregulated immune response, 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 and reduce the economic burden of sepsis on healthcare systems globally.

Further information about SeptiCyte RAPID and its implementation in hospital sepsis management programs can be obtained by contacting Immunexpress at [email protected].