Fig. 2: Gene marking and hemoglobin expression.

a VCN kinetics in neutrophils. b Hb concentrations in patients’ blood. c Kinetics of HbAS3, as assessed by CE-HPLC analysis. d Proportions of Hb species (as assessed by CE-HPLC) in reticulocytes vs. RBCs. M, months after GT. e Proportion of HbAS3+ circulating RBCs measured by flow cytometry after intracellular co-staining using specific fluorescent monoclonal antibodies directed against HbS and HbA (the latter antibody also recognizes HbA2, which, however, is expressed at very low levels, and HbAS3). Results were obtained by considering only the HbS+ sub-populations to exclude RBCs from transfusion. The p-value for the difference between P1 and P3 is equal to 0.0199, between P2 and P3 is <0.0001 and between P2 and P4 is equal to 0.0239. f Mean proportion of HbAS3 per RBC, expressed in percentage of total hemoglobin, in HbAS3+ cells (calculated using the formula: HbAS3%-assessed by HPLC/HbAS3+-RBC%-assessed by flow cytometry × 100). The p-value for the difference between P2 and P3 is inferior to <0.0001 and between P2 and P4 is equal to 0.0031. g Mean amount of HbAS3 per RBC, expressed in picograms, in HbAS3+ cells (calculated using the formula: HbAS3%-assessed by HPLC × MCH/HbAS3 + -RBC%-assessed by flow cytometry). The p-value between for the difference P2 and P3 is equal to 0.0032 and between P2 and P4 is equal to 0.0009. h Correlation between the mean amount of HbAS3 per RBC and the VCN in CD15+ cells. i Difference in the proportion of HbAS3+ reticulocytes (CD71+ cells), measured by flow cytometry. Histograms in (e–i) represent mean ± standard deviation of multiple time-points measured from month 5 post-GT (time at which HbA from RBC transfusions was no longer detectable in P1 and P2). The p-value for the difference between P2 and P3 is equal to 0.0026 and between P2 and P4 is equal to 0.0010. *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001 by Kruskal-Wallis test. Source data are provided as a Source Data file.