BACKGROUND AND PURPOSE:

• Highly accurate prognostic markers for patients with COVID-19 admitted to the ICU are currently available
• Gutmann et al. (Nature Communications, 2021) assessed whether RNAemia (RNA detected in plasma or serum) may be useful as a possible predictive marker for mortality due to COVID-19

METHODS:

• Participants
  • COVID-19 patients admitted to the ICU
  • Controls
    • Hospitalized, non-ICU patients with and without COVID-19
    • SARS-CoV-2-negative ICU sepsis patients
• Study design
  • Serum and plasma samples collected within 24 hours of admission to ICU and during week 1, week 2, and before discharge
  • Following lab measurements obtained
    • RNAemia and protein levels
    • Established protein markers of acute respiratory distress syndrome (e.g. PTX3)
• Primary outcome
  • 28-day ICU mortality

RESULTS:

• 474 blood samples
  • Hospitalized COVID-19 patients: 123 individuals
  • Non-COVID-19 ICU sepsis patients: 25 individuals
  • Healthy controls: 30 individuals
• SARS-CoV-2 RNA was detected in plasma or serum of COVID-19 ICU patients
  • Detectable RNAemia within 6 days of admission: 23% of patients
  • RNAemia was more common early after symptom onset
• RNAemia within 6 days of admission to ICU was more common in non-survivors than survivors
  • Non-survivors: 56%
  • Survivors: 13%
  • P=0.0006
• RNAemia was associated with a higher risk of 28-day mortality
  • Hazard ratio 2.05 (95% CI, 1.38 to 3.04)
• RNAemia positive samples had lower anti-SARS-CoV-2 spike IgG levels and lower SARS-CoV-2 neutralization capacity
• Machine learning identified the following as the best binary signatures associated with 28-day mortality
  • ‘Age, RNAemia’
  • ‘Age, PTX3’ (activator of the complement pathway of the innate immune system)
• Proteomics data
  • Galectin-3-binding protein (LGALS3BP) identified as interaction partners of SARS-CoV-2 spike glycoprotein

CONCLUSION:

• RNAemia in COVID-19 ICU patients is associated with an increased risk of mortality
• Novel protein, LGALS3BP, may have therapeutic implications
• The authors state

…RNAemia in COVID-19 ICU patients is associated with a higher risk of death, an observation that could potentially be a disease-specific enrichment biomarker for antiviral medications, given the lack of benefit of these drugs in unselected ICU patients with COVID-19

Learn More – Primary Sources:

SARS-CoV-2 RNAemia and proteomic trajectories inform prognostication in COVID-19 patients admitted to intensive care

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