FIGURE 4.
Molecular signatures of carnitine metabolism. Scatter-overlaid boxplots stratified by clinical class. a) Urinary carnitine composite variable. Relative abundances of carnitine, acetylcarnitine and propionylcarnitine were log-transformed, z-scaled and summed (p=4×10−9). b) Sputum fatty acid β-oxidation gene set variance analysis (GSVA) enrichment score (ES) (p=8.02×10−6). c) Sputum fatty acid metabolism GSVA ES (p=6.29×10−6). d) Sputum SLC22A5 expression levels (p=5.69×10−5). e) Bronchial brushings (BB) SLC22A5 expression levels (p=0.0583). Open circles: observations; box: median and interquartile range (IQR); whiskers: range of data up to 1.5 times of IQR above Q3 or below Q1; black cross: outliers. Kruskal–Wallis p-values are reported with post hoc pairwise comparisons shown on the figure. HC: healthy controls; MMA: mild-to-moderate asthma; SAns: severe asthma non-smokers; SAs: severe asthma ex/smokers; L: longitudinal data; *: p<0.05; **: p<0.01; ***: p<0.001.