Clinical and demographic characteristics of patients stratified by HU exposure (n = 76)
| . | Cohort (N = 76) . | HU = no (N = 41) . | HU = yes (N = 35) . | P value† (2 vs 5) . | P value† (3 vs 6) . | P value† (4 vs 7) . | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Total (1) . | Prepubertal (2) n = 32∗ . | Postpubertal (3) n = 9∗ . | Total (4) N = 41 . | Prepubertal (5) n = 18∗ . | Postpubertal (6) n = 17∗ . | Total (7) N = 35 . | ||||
| Age at OTC, y∗ | 10.2 (7.5-14.6) | 7.7 (5.4-10.4) | 17.3 (16.0-18.7) | 9.6 (6.3-12.5) | 8.7 (8.0-9.8) | 15.5 (14.4-17.5) | 12.2 (8.7-15.0) | .38 | .08 | .035 |
| History of hospitalized VOC, n (%)‡ | ||||||||||
| No | 11 (14.5) | 8 (25.0) | 0 (0.0) | 8 (19.5) | 3 (16.7) | 0 (0.0) | 3 (8.6) | .72 | NA | .15 |
| Yes | 61 (80.3) | 22 (68.8) | 8 (88.9) | 30 (73.2) | 14 (77.8) | 17 (100.0) | 31 (88.6) | |||
| Cerebral vasculopathy, n (%)‡ | ||||||||||
| No | 22 (28.9) | 6 (18.8) | 1 (11.1) | 7 (17.1) | 9 (50.0) | 6 (35.3) | 15 (42.9) | .02 | .36 | .018 |
| Yes | 50 (65.8) | 24 (75.0) | 7 (77.8) | 31 (75.6) | 8 (44.4) | 11 (64.7) | 19 (54.3) | |||
| History of splenic sequestration, n (%)‡ | ||||||||||
| No | 62 (81.6) | 24 (75.0) | 8 (88.9) | 32 (78.0) | 16 (88.9) | 14 (82.4) | 30 (85.7) | .40 | .53 | .74 |
| Yes | 10 (13.2) | 6 (18.8) | 0 (0.0) | 6 (14.6) | 1 (5.6) | 3 (17.6) | 4 (11.4) | |||
| HbF max on HU, g/dL∗ | 16.4 (9.4-19.5) | NA | NA | NA | 16.2 (15.0-16.6) | 18.5 (3.5-18.5) | 16.4 (9.4-19.5) | |||
| Missing n (%) | 66 (86.8) | 13 (37.1) | 12 (34.3) | 25 (71.4) | ||||||
| MCV max on HU, fL∗ | 96.5 (89.0-105.6) | NA | NA | NA | 100.6 (92.4-100.9) | 91.0 (86.0-107.1) | 96.5 (89.0-105.6) | |||
| Missing n (%) | 66 (86.8) | 13 (37.1) | 12 (34.3) | 25 (71.4) | ||||||
| Ferritin at OTC, μg/L∗ | 969.5 (299.3-1765.3) | 969.5 (416.3-1678.3) | 870.0 (582.0-n940.0) | 923.0 (301.0-1760.0) | 846.5 (213.3-1357.8) | 1285.0 (313.0-1816.0) | 1277.0 (299.0-1776.5) | .67 | .99 | .88 |
| Missing n (%) | 40 (52.6) | 18 (56.3) | 6 (66.7) | 24 (58.5) | 8 (44.4) | 8 (47.1) | 16 (45.7) | |||
| Transfusion = yes, n (%) | 74 (97.4) | 32 (100) | 8 (88.9) | 40 (97.6) | 17 (94.4) | 17 (100.0) | 34 (97.1) | .36 | .35 | .99 |
| No. of transfusions, n∗ | 23.5 (13.5-47.5) | 28.0 (17.3-40.8) | 18.0 (4.0-207.0) | 27.0 (15.0-53.0) | 18.5 (12.5-35.8) | 23.0 (12.0-53.0) | 19.0 (12.0-46.0) | .25 | .85 | .40 |
| HU dose (mg/kg) | NA | NA | NA | NA | 23.0 (21.5-25.0) | 23.0 (20.8-29.5) | 23.0 (20.0-25.0) | |||
| Missing n (%) | 3 (6.7) | 3 (17.6) | 6 (17.1) | |||||||
| HU exposure (mo) | NA | NA | NA | NA | 30.0 (20.0-44.0) | 56.5 (41.5-73.8) | 44.0 (24.0-54.0) | |||
| Missing n (%) | 1 (5.6) | 1 (5.9) | 2 (5.7) | |||||||
| Primordial follicle density∗ (follicles per mm2) | 5.6 (1.1-14.2) | 7.4 (1.4-17.2) | 1.0 (0.0-1.9) | 4.2 (1.1-14.4) | 10.9 (6.9-23.5) | 2.2 (0.4-5.5) | 5.8 (1.0-13.3) | .61 | .21 | .95 (.39§) |
| Growing follicle density∗ (follicles per mm2) | 0.3 (0.1-0.7) | 0.5 (0.2-1.2) | 0.2 (0.0-0.4) | 0.5 (0.2-1.0) | 0.3 (0.0-0.7) | 0.2 (0.0-0.3) | 0.2 (0.0-0.4) | .09 | .72 | .016 (.09§) |
| . | Cohort (N = 76) . | HU = no (N = 41) . | HU = yes (N = 35) . | P value† (2 vs 5) . | P value† (3 vs 6) . | P value† (4 vs 7) . | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Total (1) . | Prepubertal (2) n = 32∗ . | Postpubertal (3) n = 9∗ . | Total (4) N = 41 . | Prepubertal (5) n = 18∗ . | Postpubertal (6) n = 17∗ . | Total (7) N = 35 . | ||||
| Age at OTC, y∗ | 10.2 (7.5-14.6) | 7.7 (5.4-10.4) | 17.3 (16.0-18.7) | 9.6 (6.3-12.5) | 8.7 (8.0-9.8) | 15.5 (14.4-17.5) | 12.2 (8.7-15.0) | .38 | .08 | .035 |
| History of hospitalized VOC, n (%)‡ | ||||||||||
| No | 11 (14.5) | 8 (25.0) | 0 (0.0) | 8 (19.5) | 3 (16.7) | 0 (0.0) | 3 (8.6) | .72 | NA | .15 |
| Yes | 61 (80.3) | 22 (68.8) | 8 (88.9) | 30 (73.2) | 14 (77.8) | 17 (100.0) | 31 (88.6) | |||
| Cerebral vasculopathy, n (%)‡ | ||||||||||
| No | 22 (28.9) | 6 (18.8) | 1 (11.1) | 7 (17.1) | 9 (50.0) | 6 (35.3) | 15 (42.9) | .02 | .36 | .018 |
| Yes | 50 (65.8) | 24 (75.0) | 7 (77.8) | 31 (75.6) | 8 (44.4) | 11 (64.7) | 19 (54.3) | |||
| History of splenic sequestration, n (%)‡ | ||||||||||
| No | 62 (81.6) | 24 (75.0) | 8 (88.9) | 32 (78.0) | 16 (88.9) | 14 (82.4) | 30 (85.7) | .40 | .53 | .74 |
| Yes | 10 (13.2) | 6 (18.8) | 0 (0.0) | 6 (14.6) | 1 (5.6) | 3 (17.6) | 4 (11.4) | |||
| HbF max on HU, g/dL∗ | 16.4 (9.4-19.5) | NA | NA | NA | 16.2 (15.0-16.6) | 18.5 (3.5-18.5) | 16.4 (9.4-19.5) | |||
| Missing n (%) | 66 (86.8) | 13 (37.1) | 12 (34.3) | 25 (71.4) | ||||||
| MCV max on HU, fL∗ | 96.5 (89.0-105.6) | NA | NA | NA | 100.6 (92.4-100.9) | 91.0 (86.0-107.1) | 96.5 (89.0-105.6) | |||
| Missing n (%) | 66 (86.8) | 13 (37.1) | 12 (34.3) | 25 (71.4) | ||||||
| Ferritin at OTC, μg/L∗ | 969.5 (299.3-1765.3) | 969.5 (416.3-1678.3) | 870.0 (582.0-n940.0) | 923.0 (301.0-1760.0) | 846.5 (213.3-1357.8) | 1285.0 (313.0-1816.0) | 1277.0 (299.0-1776.5) | .67 | .99 | .88 |
| Missing n (%) | 40 (52.6) | 18 (56.3) | 6 (66.7) | 24 (58.5) | 8 (44.4) | 8 (47.1) | 16 (45.7) | |||
| Transfusion = yes, n (%) | 74 (97.4) | 32 (100) | 8 (88.9) | 40 (97.6) | 17 (94.4) | 17 (100.0) | 34 (97.1) | .36 | .35 | .99 |
| No. of transfusions, n∗ | 23.5 (13.5-47.5) | 28.0 (17.3-40.8) | 18.0 (4.0-207.0) | 27.0 (15.0-53.0) | 18.5 (12.5-35.8) | 23.0 (12.0-53.0) | 19.0 (12.0-46.0) | .25 | .85 | .40 |
| HU dose (mg/kg) | NA | NA | NA | NA | 23.0 (21.5-25.0) | 23.0 (20.8-29.5) | 23.0 (20.0-25.0) | |||
| Missing n (%) | 3 (6.7) | 3 (17.6) | 6 (17.1) | |||||||
| HU exposure (mo) | NA | NA | NA | NA | 30.0 (20.0-44.0) | 56.5 (41.5-73.8) | 44.0 (24.0-54.0) | |||
| Missing n (%) | 1 (5.6) | 1 (5.9) | 2 (5.7) | |||||||
| Primordial follicle density∗ (follicles per mm2) | 5.6 (1.1-14.2) | 7.4 (1.4-17.2) | 1.0 (0.0-1.9) | 4.2 (1.1-14.4) | 10.9 (6.9-23.5) | 2.2 (0.4-5.5) | 5.8 (1.0-13.3) | .61 | .21 | .95 (.39§) |
| Growing follicle density∗ (follicles per mm2) | 0.3 (0.1-0.7) | 0.5 (0.2-1.2) | 0.2 (0.0-0.4) | 0.5 (0.2-1.0) | 0.3 (0.0-0.7) | 0.2 (0.0-0.3) | 0.2 (0.0-0.4) | .09 | .72 | .016 (.09§) |