The degree of amelioration of the anemia of β-thalassemia correlates with the level of HbF resulting from lentiviral vector–encoded human γ-globin.
(A) Hb concentration versus HbF in animals that received transplants of β-thalassemic BM cells transduced with γ-globin lentiviral vectors. Animals with less than 4% HbF were excluded from the analysis because the levels of HbF could not be accurately determined below this level. Linear regression analysis was used to generate the trend line, which had a correlation coefficient (r2) of 0.80. (B) Hb concentration is shown as a function of the mean level of HbF in the designated groups of animals that underwent transplantation. Mock indicates animals transplanted with mock-transduced β-thalassemic BM cells; normal control, animals that received transplants of normal BM cells transduced with a lentiviral vector, CL10.1 MSCV-GFP, that encodes only GFP. Error bars represent the standard error of the mean.
