Figure 2. Metabolomic profiling of plasma in sepsis.

(A, B) Venn diagrams of overlap of biochemicals (A) and annotated metabolites (B) measured by MS in discovery plasma samples at t₀ (n=150) and t₂₄ (n=132) and 52 Validation (V) patients at t₀ and t₂₄. 160 metabolites were removed from the analysis because they were detected in ≥ 50% of the patients. (C–E) Comparison of Creatinine (C), Lactate (D) and Glucose (E) concentrations as determined in serum by clinical chemical analyzer and in plasma by MS in 149, 115 and 149 patients, respectively. Differences in n-values were due to omissions in clinical values – a large group of patients did not require blood lactate values as part of their clinical care. MS values are normalized, log-transformed intensities. Clinical chemistry values (mg/dl) are log-transformed. (F) Z-score scatter plots of plasma metabolites from non-infected SIRS, uncomplicated sepsis, severe sepsis, septic shock or sepsis nonsurvivor patients. Zero on the X-axis represents the mean of the control group. Each data point is expressed as the number of standard deviations from the mean of the controls. The Y-axis shows all values for each biochemical on the same horizontal line. Z-score values are standard deviations from the control mean, revealing changes relative to control. The boxed values are mScores, which are averages of the absolute values of Z-scores for all metabolites, calculated using non-truncated, non-imputed values. (G) The variance in plasma metabolite concentrations at the time of emergency department enrollment (t₀) that was attributable to sepsis outcome decreased with increasing days-to-death (X-axis).