Table 1.
Demographic and clinical characteristics of 48 study participants.
Fig 1.
PCA scores plot of lipidomic profiles in CAP group (including NSCAP and SCAP) and NC.
Blue, severe CAP (SCAP); Green, non-severe CAP (NSCAP); Red, non-CAP control (NC), Navy blue, quality control (QC) samples; Black, CAP. No sample was placed outside the ellipse that describes the 95% CI of Hotelling’s T-squared distribution. The three groups of lipid profiles can be clearly distinguished.
Table 2.
Evaluation parameters of our OPLS-DA model.
Fig 2.
The relative abundance of different lipids changed in the three groups of samples.
Red, green, and blue represent NC, NSCAP, and SCAP, respectively. (a) Hierarchical cluster heatmap of the relative abundance of 83 lipids in CAP (including NSCAP and SCAP) compared to NC. Distance measure: Pearson; Clustering algorithm: ward. Row represents lipids and column represents serum samples. Red, green, and blue represent NC, NSCAP, and SCAP, respectively. Light blue indicates lower relative abundance, while greater brown indicates higher intensity of lipids. (b-e) Changes in the relative abundance of PC (16:0_18:1), PC (18:2_20:4), PC (36:4) and PC (38:6) in serum between CAP group versus NC and NSCAP versus SCAP group. * p<0.05, ** p<0.01, *** p<0.001, **** p<0.0001.
Fig 3.
Flow chart of target differential lipid screening process.
CAP, Community-acquired pneumonia; NC, Non-CAP controls; NSCAP, Non-severe CAP; SCAP, Severe CAP; VIP, variable importance on projection; ROC, Receiver operating characteristic; AUC, area under the curve.
Table 3.
Comparison results of four different lipids meeting the screening criteria.
Fig 4.
The relative levels of PC (16:0_18:1), PC (18:2_20:4), PC (38:6), and PC (36:4) show significantly correlations with clinical indicators.
(a-c) The relative levels of PC (18:2_20:4) PC (38:6) and PC (36:4) were inversely correlated to FiO2 of patients with CAP. (d) The abundance of PC (16:0_18:1) had a positive linear relationship with PCT (e) The abundance of PC (18:2_20:4) was negatively correlated with PCT of CAP patients. Solid black line, the fitted regression line. Area within the dotted line lines, the 95% confidence intervals.
Table 4.
Area under the curve (AUC) and thresholds for discriminating non-survivors from patients with CAP.
Fig 5.
Comparison of the days of hospitalization between the higher abundance group and lower abundance group of PC (16:0_18:1), PC (18:2_20:4), PC (36:4), PC (38:6) and Kaplan–Meier analysis of 30-day mortality in patients with SCAP.
(a-d) There were statistical differences in the days of hospitalization between the high abundance and low abundance groups of PC (16:0_18:1), PC (18:2_20:4), PC (36:4) and PC (38:6). Red dots, high abundance group; Blue squares, low abundance group. * p<0.05, ** p<0.01 (e-h) There were statistically significant differences in 30-day mortality between the high abundance group and the low abundance group of PC (16: 0_18: 1) (e), PC (18:2_20:4) (f), PC (36: 4) (g) and PC (38:6) (h).