Table 1.
Spleen uptake on LS scan
| Normal | Decreased | Absent | P* | CCR, % | |
|---|---|---|---|---|---|
| BABY HUG splenic function data | |||||
| No. (%) (N = 193) | 23 (12%) | 142 (73%) | 28 (15%) | — | — |
| Age, mo (range, 8.1-18) (mean ± SD) | 12.2 ± 2.5 | 12.7 ± 2.5 | 14.6 ± 2.9 | .001 | — |
| ≤ 9.0 mo (N = 12) | 3 (25%) | 8 (67%) | 1 (8%) | — | — |
| 9.1-12 mo (N = 69) | 10 (14%) | 53 (77%) | 6 (9%) | — | — |
| 12.1-15 mo (N = 68) | 6 (9%) | 55 (81%) | 7 (10%) | — | — |
| ≥ 15.1 mo (N = 44) | 4 (9%) | 26 (59%) | 14 (32%) | — | — |
| Blood counts (mean ± SD) | |||||
| Hb, g/dL | 9.9 ± 1.2 | 9.1 ± 1.2 | 8.2 ± 1.0 | < .001 | — |
| Hb F, % | 34.1 ± 6.7 | 26.2 ± 8.1 | 19.2 ± 6.5 | < .001 | — |
| ARC, × 109/L | 194 ± 62 | 301 ± 140 | 366 ± 110 | < .001 | — |
| WBC, × 109/L | 10.9 ± 3.3 | 13.9 ± 5.5 | 18.7 ± 5.6 | < .001 | — |
| ANC, × 109/L | 3.0 ± 1.1 | 4.2 ± 2.3 | 5.6 ± 2.7 | .007 | — |
| Clinical events, % of patients | — | ||||
| Vaso-occlusive events | 21.7 | 48.2 | 75.0 | < .001* | — |
| Dactylitis | 21.7 | 35.3 | 64.3 | .004* | — |
| Hospitalization not for fever | 0 | 26.4 | 40.0 | .009* | — |
| Transfusion | 0 | 13.2 | 29.6 | .006* | — |
| Acute splenic sequestration | 0 | 6.6 | 22.2 | .012* | — |
| Palpable spleen | 0 | 19.7 | 28.6 | .012* | — |
| Organ function | |||||
| TCD velocity, maximal mean (cm/s) | 106 ± 23 | 122 ± 20 | 136 ± 20 | < .001 | — |
| DTPA-GFR, mL/min per 1.73 m2 | 129 ± 48 | 124 ± 31 | 119 ± 31 | .650 | — |
| SVOL by US, mL | 94 ± 38 | 107 ± 44 | 95 ± 51 | .103 | — |
| O2 saturation, % | 98.5 | 98.9 | 98.9 | .469 | — |
| Biomarkers | |||||
| PIT, % | 1.1 ± 0.9 | 4.1 ± 4.6 | 10.1 ± 5.3 | < .001 | — |
| < 3.5% (N = 112) | 23 | 85 | 4 | — | — |
| ≥ 3.5% (N = 74) | 0 | 52 | 22 | — | — |
| ≤ 1.0% (N = 49) | 14 | 34 | 1 | — | — |
| > 1.0%-< 5.2% (N = 80) | 9 | 67 | 4 | — | — |
| ≥ 5.2% (N = 57) | 0 | 36 | 21 | — | — |
| PIT: CCR normal versus all other | — | — | — | — | 65 |
| ≤ 1.2% (N = 54) | 15 | 38 | 1 | — | — |
| > 1.2% (N = 132) | 8 | 99 | 25 | — | — |
| PIT: CCR absent versus all other | — | — | — | — | 81 |
| < 4.5% (N = 122) | 23 | 94 | 5 | — | — |
| ≥ 4.5% (N = 64) | 0 | 43 | 21 | — | — |
| HJB (per 106 RBC) | 49 ± 59 | 501 ± 683 | 1491 ± 707 | < .001 | — |
| < 300 (N = 105) | 23 | 82 | 0 | — | — |
| ≥ 300 (N = 77) | 0 | 53 | 24 | — | — |
| ≤ 42 (N = 68) | 18 | 50 | 0 | — | — |
| > 42-< 678 (N = 50) | 5 | 44 | 1 | — | — |
| ≥ 678 (N = 64) | 0 | 41 | 23 | — | — |
| HJB: CCR normal versus all other | — | — | — | 83 | |
| ≤ 55 (N = 80) | 19 | 61 | 0 | — | — |
| > 55 (N = 102) | 4 | 74 | 24 | — | — |
| HJB: CCR absent versus all other | — | — | — | — | 96 |
| < 665 (N = 118) | 23 | 94 | 1 | — | — |
| ≥ 665 (N = 64) | 0 | 41 | 23 | — | — |
| Cooperative Study of Sickle Cell Disease data4 | |||||
| No. of patients (% of total) | 44 (69%) | 5 (8%) | 15 (23%) | — | — |
| Age, mo (range) | 9.7 (8-13) | 10.9 (8-13) | 13.3 (11-13) | — | — |
| Hb, g/dL | 9.9 ± 1.0 | 9.6 ± 2.1 | 8.3 ± 1.3 | — | — |
| Hb F, % | 23.6 ± 12.4 | 26.0 ± 11.6 | 13.7 ± 6.5 | — | — |
| PIT, % | 1.9 ± 1.0 | 3.7 ± 4.3 | 7.9 ± 3.2 | — | — |
| < 3.5% (N = 45) | 43 | 2 | 0 | — | — |
| ≥ 3.5% (N = 19) | 1 | 3 | 15 | — | — |
— indicates not applicable; CCR, correct classification rate; US, ultrasound; and TCD, transcranial Doppler.
*
P values are derived from χ2 test or Fisher exact test. All other P values are derived from F test statistic calculated on the transformed variable comparing distributions among the 3 groups.