FIGURE 1.

Oxygen gradient ektacytometry‐derived biomarkers are associated with VOC and improve with standard of care therapy. A, Point of Sickling (PoS) is significantly higher in patients with SCD in the adult cohort who experienced one or more VOC in the past 2 years (VOC+). Colors show different treatment regimens: untreated (red), HU treatment (purple), chronic transfusion (blue), HU and chronic transfusion (turquoise). B, Minimum deformability (EI_min) is significantly higher in patients who did not experience a VOC in the past 2 years (VOC−) compared to patients who did, in the adult cohort. C, PoS is significantly higher in the VOC+ group in the pediatric cohort. D, EI_minis significantly lower in the VOC+ group. The effect of starting HU therapy was measured in 15 patients with SCD at baseline, and after 1, 3 and 6 months of HU therapy. E, Representative curve of a patient before and during hydroxyurea (HU) titration to maximum tolerated dose. F, Median values of point of sickling (PoS) before and during HU therapy. PoS significantly decreases after 3 and 6 months compared to baseline values. G, Median values of minimum deformability upon deoxygenation (EI_min) before and during HU therapy. EI_minsignificantly increases after 3 and 6 months of HU therapy compared to baseline values. Seven patients with SCD were followed just before and after transfusion therapy. H, Median values of PoS are significantly decreased after transfusion, compared to before transfusion values. Median values of EI_minI, are significantly increased by transfusion. Twenty‐one patients with SCD were followed during HU and HU with CTf therapy. J, Median values of PoS before and on CTf that significantly decreases during CTf. Median values of EI_minK, are increased with CTf. Error bars represent interquartile range. ****P < .0001, ***P < .001, **P < .01, *P < .05