Selected baseline characteristics of the intention-to-treat population
| Characteristic . | Transfusions and chelation group, N = 66 . | Hydroxyurea and phlebotomy group, N = 67 . | P . |
|---|---|---|---|
| HbSS | 66 (100%) | 66 (99%) | > .999 |
| Sex, male | 31 (47%) | 41 (61%) | .100 |
| Age at study enrollment, y | 13.3 ± 3.8 | 13.0 ± 4.0 | .733 |
| Stroke history | |||
| Age at index stroke, y | 6.2 ± 2.8 | 5.6 ± 3.0 | .257 |
| Previous recurrent stroke | 4 (6%) | 10 (15%) | .096 |
| History of TIA | 11 (17%) | 10 (15%) | .783 |
| Baseline brain MRI/MRA | |||
| Infarction | 65 (98%) | 67 (100%) | .312 |
| Vasculopathy | 54 (82%) | 53 (79%) | .693 |
| Moya-moya | 5 (8%) | 11 (16%) | .117 |
| Transfusion history | |||
| Duration, y | 7.0 ± 3.6 | 7.4 ± 3.8 | .592 |
| Simple transfusions | 41 (62%) | 43 (64%) | .806 |
| RBC alloantibodies | 17 (26%) | 26 (39%) | .108 |
| RBC autoantibodies | 9 (14%) | 16 (24%) | .131 |
| Iron overload status | |||
| LIC, mg Fe/g dw liver | 14.5 (9.5-23.3) | 13.9 (8.7-22.9) | .721 |
| Serum ferritin, ng/mL | 3282.0 (2321.0-4306.0) | 3346.0 (2202.0-4682.0) | .984 |
| Previous desferrioxamine | 44 (70%) | 47 (71%) | .864 |
| Previous deferasirox | 55 (87%) | 57 (86%) | .875 |
| Laboratory parameters | |||
| Hemoglobin, g/dL | 9.2 (8.6-9.7) | 9.2 (8.5-9.6) | .998 |
| MCV, fL | 86.2 (83.6-87.7) | 85.8 (83.6-88.8) | .932 |
| HbA, % | 67.5 (56.3-74.5) | 66.1 (56.0-71.8) | .478 |
| HbS, % | 27.0 (21.2-38.6) | 30.3 (23.8-39.6) | .356 |
| HbF, % | 1.7 (1.0-2.5) | 1.4 (0.8-2.2) | .303 |
| ARC, ×109/L | 335.4 (246.2-391.0) | 367.0 (213.2-464.0) | .560 |
| WBC, ×109/L | 13.2 (11.0-16.6) | 14.0 (10.3-16.9) | .864 |
| ANC, ×109/L | 7.4 (6.2-9.2) | 7.1 (5.5-10.2) | .519 |
| ALT, U/L | 41.0 (36.0-58.0) | 45.0 (34.0-77.0) | .371 |
| Creatinine, mg/dL | 0.4 (0.3-0.5) | 0.4 (0.4-0.5) | .140 |
| Total bilirubin, mg/dL | 2.8 (1.8-3.9) | 2.6 (2.2-4.1) | .554 |
| Characteristic . | Transfusions and chelation group, N = 66 . | Hydroxyurea and phlebotomy group, N = 67 . | P . |
|---|---|---|---|
| HbSS | 66 (100%) | 66 (99%) | > .999 |
| Sex, male | 31 (47%) | 41 (61%) | .100 |
| Age at study enrollment, y | 13.3 ± 3.8 | 13.0 ± 4.0 | .733 |
| Stroke history | |||
| Age at index stroke, y | 6.2 ± 2.8 | 5.6 ± 3.0 | .257 |
| Previous recurrent stroke | 4 (6%) | 10 (15%) | .096 |
| History of TIA | 11 (17%) | 10 (15%) | .783 |
| Baseline brain MRI/MRA | |||
| Infarction | 65 (98%) | 67 (100%) | .312 |
| Vasculopathy | 54 (82%) | 53 (79%) | .693 |
| Moya-moya | 5 (8%) | 11 (16%) | .117 |
| Transfusion history | |||
| Duration, y | 7.0 ± 3.6 | 7.4 ± 3.8 | .592 |
| Simple transfusions | 41 (62%) | 43 (64%) | .806 |
| RBC alloantibodies | 17 (26%) | 26 (39%) | .108 |
| RBC autoantibodies | 9 (14%) | 16 (24%) | .131 |
| Iron overload status | |||
| LIC, mg Fe/g dw liver | 14.5 (9.5-23.3) | 13.9 (8.7-22.9) | .721 |
| Serum ferritin, ng/mL | 3282.0 (2321.0-4306.0) | 3346.0 (2202.0-4682.0) | .984 |
| Previous desferrioxamine | 44 (70%) | 47 (71%) | .864 |
| Previous deferasirox | 55 (87%) | 57 (86%) | .875 |
| Laboratory parameters | |||
| Hemoglobin, g/dL | 9.2 (8.6-9.7) | 9.2 (8.5-9.6) | .998 |
| MCV, fL | 86.2 (83.6-87.7) | 85.8 (83.6-88.8) | .932 |
| HbA, % | 67.5 (56.3-74.5) | 66.1 (56.0-71.8) | .478 |
| HbS, % | 27.0 (21.2-38.6) | 30.3 (23.8-39.6) | .356 |
| HbF, % | 1.7 (1.0-2.5) | 1.4 (0.8-2.2) | .303 |
| ARC, ×109/L | 335.4 (246.2-391.0) | 367.0 (213.2-464.0) | .560 |
| WBC, ×109/L | 13.2 (11.0-16.6) | 14.0 (10.3-16.9) | .864 |
| ANC, ×109/L | 7.4 (6.2-9.2) | 7.1 (5.5-10.2) | .519 |
| ALT, U/L | 41.0 (36.0-58.0) | 45.0 (34.0-77.0) | .371 |
| Creatinine, mg/dL | 0.4 (0.3-0.5) | 0.4 (0.4-0.5) | .140 |
| Total bilirubin, mg/dL | 2.8 (1.8-3.9) | 2.6 (2.2-4.1) | .554 |
Selected baseline demographic, clinical, and laboratory characteristics of the intention-to-treat population at the time of study enrollment. Measures of central tendency for laboratory values, LIC, and ferritin are listed as median (interquartile range); treatment group differences were assessed via Wilcoxon rank sum tests. Other continuous variables are summarized as mean ± SD; treatment group differences were assessed via ANOVA. Categorical values are summarized as count (%); treatment group differences were assessed via χ2 tests, with the exception that the Fisher exact test was used for sickle cell genotype. There were no significant differences in characteristics between the two study groups.
TIA indicates transient ischemic attack; MRI/MRA, magnetic resonance imaging/magnetic resonance angiography; LIC, liver iron concentration; MCV, mean corpuscular volume; ARC, absolute reticulocyte count; ANC, absolute neutrophil count; WBC, white blood cell; HbSS, homozygous sickle cell anemia; HbA, adult hemoglobin; HbS, sickle hemoglobin; HbF, fetal hemoglobin; and ALT, alanine transaminase.