Fig. 3

Plasma lipidome signatures of Omicron infections. For all pairwise comparisons, P values from a two-sided Student’s t-test were used (n = 20 healthy controls, n = 28 first infection, n = 38 reinfection Omicron patients). (A) Radar plot of plasma lipidome diversity comprising 565 lipids from 27 classes. (B-E) Volcano plots illustrate differential plasma lipids in first infection (B) and reinfection (C) patients versus healthy controls, as well as in moderate/severe infections relative to mild infections amongst first infection (D) and reinfection (E) patients, respectively. (F) Circos plot ranks the top 30 differential lipids in moderate/severe infections (inner rim: first infection, outer rim: reinfection). * P < 0.05, ** P < 0.01, *** P < 0.001. Color bar indicates log₂(fold-change): red (increase), blue (decrease) in severe vs. mild cases. (G) Venn diagrams display the number of significant (P < 0.05) lipids that were conserved between Omicron infection (infected vs. healthy controls) and symptom severity (moderate/severe vs. mild infections) in both first infection and reinfection patients. (H) Boxplot illustrates changes in summed PE-Os across healthy controls (n = 20), first infection mild patients (n = 9), first infection moderate/severe patients (n = 19), reinfection mild patients (n = 27), reinfection moderate/severe patients (n = 11). Median is indicated by the horizontal line and the first and third quartiles are represented by the box edges. The lower and upper whiskers extend from the hinges to the smallest and largest values, respectively, with individual samples indicated as dots. P values of pairwise comparisons based on two-sided Games-Howell test were presented using letter-based representation, with two groups sharing a common letter being not statistically different at P < 0.05. (I) Heatmap displays changes in individual PE-O species across healthy controls (n = 20), first-infection mild patients (n = 9), first infection moderate/severe patients (n = 19), reinfection mild patients (n = 27), reinfection moderate/severe patients (n = 11). Lipid levels were expressed and plotted as Z-scores. BMP, bis(monoacylglycerol)phosphate; CE, Cholesterol ester; Cer, ceramides; Cer1P, ceramide-1-phosphate; DAG, diacylglycerol; FFA, free fatty acid; Gb3, globotroaosylceramide; GluCer, glucosylceramide; LacCer, lactosylceramide; LPA, lysophosphatidic acid; LPC, lysophosphatidylcholine; LPE, lysophosphatidylethanolamine; LPI, lysophosphatidylinositol; PA, phosphatidic acid; PC, phosphatidylcholine; PC-O, plasmalogen phosphatidylcholine; PE, phosphatidylethanolamine; PE-O, phosphatidylethanolamine; PG, phosphatidylglycerol; PI, phosphatidylinositol; PS, phosphatidylserine; SIP, sphingosine-1-phosphate; SL, sulfatide; SM, sphingomyelin; Sph, sphingosine; TAG, triacylglycerol.