UK researchers find promising biomarker for early sepsis detection

Sepsis, a life-threatening condition resulting from the immune system's overreaction to infection, remains a leading global cause of mortality, accounting for an estimated 11 million deaths annually.

Young children, especially those under five, and pregnant women are highly vulnerable due to immunological changes and increased susceptibility.

The study analysed serial blood samples from 252 patients (111 paediatric, 72 maternity, and 69 neonatal cases) with suspected sepsis.

The results showed that IL-6 consistently outperformed traditional biomarkers in distinguishing bacterial from non-bacterial infections.

"IL-6 also effectively stratified sepsis severity, distinguishing between mild infection, sepsis, and septic shock, a critical capability for guiding timely and appropriate treatment," the study showed.

The team explained how IL-6 has significant advantages over traditional biomarkers.

"IL-6 secretion rises within one to two hours, peaks at six hours, and decreases by 24 hours, whereas CRP and PCT peak much later at 48 and 24 hours, respectively. This faster, steeper response makes IL-6 a promising biomarker for earlier sepsis detection," said lead author Dr. Sean Whelan.

C-reactive protein (CRP) is a protein in the blood that indicates inflammation. PCT refers to Procalcitonin -- a biomarker for bacterial infections.

"Our findings reinforce the potential of IL-6 as a promising biomarker in sepsis diagnosis," Whelan said.

"With wider adoption and in combination with clinical assessment, IL-6 could significantly improve clinical decision-making and support timely, targeted treatment for high-risk patients," the expert added.

The study, presented at the annual Congress of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID Global 2025) in Austria, is the first to evaluate IL-6's diagnostic performance in a real-world cohort across all three populations.