PlGF levels correlate with endothelin-1 levels, are elevated in adult patients with SCD, and are associated with features of PH. (A) PlGF levels in plasma of patients with SCD. (B) High PlGF levels are associated with anemia, markers of hemolysis, and inflammation. (C-D) PlGF plasma levels and endothelin-1 (ET-1) levels directly correlated with each other (P = .01) and were strongly associated with increasing TRV. r indicates Spearman correlation coefficient; and ESR, erythrocyte sedimentation rate. Bar graphs represent mean and SEM. P values were obtained by Kruskal-Wallis analysis.