Figure 2.

Bioactive metabolite analysis of SSc-PAH vs IPAH. A, Volcano plot of metabolites distinguishing SSc-PAH from IPAH in the discovery and validation cohorts. ORs and P values are derived from multivariable regression analyses. Red dots indicate metabolites significant in both discovery and validation cohorts; black dots indicate metabolites significant only in the discovery cohort; and gray dots indicate all metabolites measured in the discovery and validation cohorts. B, Waterfall plot of significant metabolites distinguishing SSc-PAH from IPAH. Values are plotted as log2 fold change of metabolite levels in SSc-PAH relative to IPAH. FAHFA = fatty acyl esters of hydroxy fatty acid; Eic = eicosanoid; IPAH = idiopathic pulmonary arterial hypertension; LTB₄ = leukotriene B₄; PGF_2α = prostaglandin F_2α; SSc-PAH = systemic sclerosis-associated pulmonary arterial hypertension.