Prospective evaluation of the SeptiCyte® Rapid assay for the identification of systemic infectious diseases in patients with suspected sepsis

Question: Sepsis is a pathophysiologically complex condition with severe implications for patients and health care systems. In patients with suspected sepsis, the differentation between an infectious and non-infectious aetiology is challenging. Against this background, the SeptiCyte® Rapid assay was developed: This test detects two specific mRNA transcripts (PLA2G7 and PLAC8) that are part of the host"s immune response and that are differentially expressed during the early phase of systemic infection. While this test is commercially available, real-life clinical performance data are scarce.

Methods: Since November 2022, we prospectively enrolled patients with the clinical suspicion of sepsis (defined as an increase in sequential organ failure assessment (SOFA) score of ≥2 within 24 hours) and with antiinfective therapy for ≤ 48 hours on one ICU. Blood samples from the patients were collected using PAXgene RNA tubes and subjected to the SeptiCyte® Rapid assay. The test result is provided as a so-called SeptiScore, ranging from 0-15, with values ≥ 7.4 indicating a high suspicion of systemic infection. In parallel, samples from non-septic control patients from the same ICU were also analysed. Clinicians were blinded to the results.

Results: Until 30 January 2024, a total 50 patients were recruited, of which 36 belonged to the study group. 56% of the patients were male and the mean age was 65.1 years. In the preliminary dataset, symptomatic patients had an average SOFA score of 9.6. In 21/36 of symptomatic patients, a probable causative pathogen was detected, most frequently Escherichia coli. The average SeptiScore among clinically septic patients was considerably higher than in control patients (8.7 vs. 4.8, see also Figure 1). In patients with suspected sepsis, those with an identified causative agent had slightly higher scores than those without (9.0 vs. 8.2).

Conclusions: The SeptiScore Rapid assay was higher in patients with suspected sepsis than in control patients. Patient recruitment and further analysis are ongoing to evaluate whether the SeptiScore accurately differentiates those individuals with an infectious aetiology from those with other causes.