Soluble ST2 plasma concentrations predict mortality in severe sepsis.

Area of Science:

• Immunology
• Critical Care Medicine
• Biochemistry

Background:

• Sepsis survivors often exhibit immunosuppression, characterized by hyporesponsiveness to bacterial stimuli.
• Negative regulators of toll-like receptors, such as membrane-bound ST2, are implicated in sepsis-induced immunosuppression.
• Soluble ST2 (sST2) acts as a decoy receptor, inhibiting membrane-bound ST2 signaling.

Purpose of the Study:

• To investigate the release and clinical significance of soluble ST2 (sST2) during severe sepsis.
• To determine the correlation between sST2 levels and disease severity, cytokine profiles, and patient outcomes.

Main Methods:

• A cohort of 95 severe sepsis patients admitted to ICUs was studied.
• Serum samples were collected daily from admission (day 0) to day 7, and again on day 14.
• Serum sST2 and cytokine levels were measured and compared to 24 healthy controls.

Main Results:

• Sepsis patients exhibited significantly higher sST2 levels on admission compared to healthy controls (P < 0.0001).
• Elevated sST2 levels persisted throughout the 14-day observation period and correlated with disease severity scores and cytokine levels (P < 0.001).
• Nonsurvivors had markedly higher sST2 levels than survivors (P < 0.0001).

Conclusions:

• Severe sepsis leads to sustained elevation of serum sST2.
• Serum sST2 levels are a reliable indicator of sepsis severity.
• Increased sST2 levels correlate strongly with mortality in sepsis patients.