Fig. 5: Proteomic alterations associated with infection severity in IE.

A Heatmap and bubble chart illustrating the two panels of plasma proteins with gradually increasing (top) or decreasing (bottom) abundance from double-positive to single-positive, double-negative, and non-IE category, along with pathway enrichment (right) and the proteins included (left). Pearson’s two-sided χ² test was used to evaluate the associations between the pathogen group and 8 variables. B Boxplots showing the high-yield and low-yield scores among the double-positive (n = 71), single-positive (n = 85), double-negative (n = 20), and non-IE (n = 50) categories. C Heatmap showing correlations among the inflammatory indicators. D, E Bar plot and heatmap illustrating the top 20 proteins for feature importance. F Venn diagram and STRING analysis illustrating the 7 proteins altered in both plasma and vegetation proteomes, along with their PPIs. G Scatter plot showing the correlations between LRG1 and the vegetation proteome. H Bar chart displaying pathways enriched by the vegetation proteins correlated with LRG1 (R > 0.3 or R < −0.2; p < 0.05). I Box plot of LRG1 concentrations in IE (n = 105) versus non-IE (n = 21) samples measured by ELISA. J Venn diagram and STRING analysis illustrating the 15 proteins correlated with LRG1 in both plasma and vegetation proteomes (R > 0.3 or R < −0.2; p < 0.05), along with their PPIs. K Scatter plot depicting the correlation between the relative abundance (log2) of LRG1 and haptoglobin (HP and HPR), hemopexin (HPX), and hemoglobin (HBB, HBG1, and HBG2). L Schematic of the potential mechanisms mediated by LRG1 influencing infection severity in IE. For boxplots (B and I), the central line represents the median, the box indicates the IQR, and whiskers extend to 1.5 × IQR, with outliers as individual points. The unpaired two-sided Wilcoxon rank-sum test and Kruskal–Wallis test were used for statistical tests. The two-sided Spearman’s correlation was used for figures (C, G, H, J, and K), with p-values adjusted for FDR. Source data are provided as Source Data files.