Lab Medicine Significance 7/10

Two-Transcript Signature Distinguishes SFTS Viral Infection from Bacterial Sepsis with AUC of 0.96

A multicenter validation study of 225 febrile, thrombocytopenic patients demonstrated that a two-gene transcript signature (IFI44L and PI3) distinguished SFTS virus infection from bacterial sepsis with an AUC of 0.961, substantially outperforming CRP (0.810) and procalcitonin (0.764). Elevated IFI44L expression also predicted fatal outcomes (AUC 0.820) and identified patients with invasive pulmonary aspergillosis. The findings support host transcriptomic signatures as a next-generation diagnostic approach for differentiating viral from bacterial etiologies in acute febrile illness.

The original study

Two-transcript signature for differentiation and clinical outcomes in severe fever with thrombocytopenia syndrome (SFTS) patients: a double-blind, multicenter, validation study.

Authors
Xu N, Wen S, Yao Y, Guan Y, Zhao L, Yang L, et al.
Journal
Journal of clinical microbiology
Type
Journal Article, Multicenter Study, Validation Study
PMID
39688402
Read the original study →

Original abstract

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with a high mortality rate that is often underdiagnosed due to the limitations of current laboratory testing. Timely diagnosis and early identification of severe cases are crucial to improving patient outcomes and overall survival rates. This study aimed to evaluate the efficacy of two transcripts, IFI44L and PI3, in the early differentiation between SFTS virus (SFTSV) infection and bacterial sepsis, as well as in the prompt identification of severe cases during epidemic seasons. In a prospective study conducted between 1 May 2021 and 30 September 2022, we enrolled 225 patients who presented with acute fever and thrombocytopenia at four hospitals in Shandong Province, China. The two-transcript signature provided a clear distinction between SFTS and bacterial infection, achieving an area under the receiver operating characteristic curve of 0.961 (95% confidence interval [95% CI] 0.916-0.986), outperforming C-reactive protein (0.810 [95% CI 0.738-0.870]) and procalcitonin (0.764 [95% CI 0.687-0.830]). Importantly, the relative expression of the IFI44L gene was significantly elevated in fatal SFTS cases, with an area under the curve (AUC) of 0.820 (95% CI 0.727-0.914), indicating its potential as an early prognostic marker. Additionally, IFI44L and PI3 were identified as potential biomarkers for distinguishing SFTS patients with and without invasive pulmonary aspergillosis, with AUC values of 0.817 and 0.753, respectively. Our findings demonstrate that the two-transcript signature effectively distinguishes SFTSV infection from bacterial sepsis and helps identify high-risk individuals, guiding appropriate treatment during SFTS outbreak.