Validation of diagnostic gene sets to identify critically ill patients with sepsis

J Crit Care. 2019 Feb:49:92-98. doi: 10.1016/j.jcrc.2018.10.028. Epub 2018 Nov 1.

Abstract

Purpose: Gene expression diagnostics have been proposed to identify critically ill patients with sepsis. Three expression-based scores have been developed, but have not been compared in a prospective validation. We sought to validate these scores using an independent dataset and analysis.

Methods: We generated gene expression profiles from 61 critically ill patients. We validated the performance of 3 expression-based sepsis scores including 1) the Sepsis MetaScore (SMS); 2) the SeptiCyte™ Lab; and 3) the FAIM3:PLAC8 ratio. Sepsis was identified as the presence of definite, probable, or possible infection in the setting of organ dysfunction (SOFA score ≥ 2).

Results: For all 3 models, scores were significantly different between patients with and without sepsis. Discrimination was highest for the SMS (area under the receiver operating characteristics curve [AUROC 0.80 [95% CI 0.67-0.92]), with greater confidence in the presence of infection resulting in better model performance (max AUROC 0.93 [0.87-1.0]).

Conclusions: All three scores distinguished septic from non-septic ICU patients, with the SMS showing the best performance overall in our cohort. Our results suggest that models developed from the co-analysis of multiple cohorts are more generalizable. Further work is needed to identify expression-based biomarkers of response to specific therapies.

Keywords: Critical care; Gene expression; Precision medicine; Sepsis; Validation studies.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aged
  • Biomarkers / metabolism
  • Cohort Studies
  • Critical Illness*
  • Diagnosis, Differential
  • Female
  • Gene Expression Profiling / methods*
  • Humans
  • Male
  • Middle Aged
  • Organ Dysfunction Scores
  • Prospective Studies
  • ROC Curve
  • Sepsis / diagnosis*
  • Sepsis / genetics
  • Sepsis / metabolism
  • Systemic Inflammatory Response Syndrome / metabolism*

Substances

  • Biomarkers