Hematologic parameters in young children with sickle cell anemia receiving extended hydroxyurea therapy
Mean values . | Baseline; n = 28 . | Year 3*; n = 19 . | Year 4; n = 17 . | Expected at ages 48 to 60 months† . | Year 5; n = 13 . | Year 6; n = 11 . |
|---|---|---|---|---|---|---|
| Hb level, g/dL | 8.5 ± 1.4 | 9.1 ± 1.3 | 9.1 ± 1.4* | 8.1 | 8.5 ± 1.6 | 9.0 ± 1.6 |
| MCV, fL | 81.7 ± 8.0 | 92.1 ± 9.7 | 95.1 ± 10.4* | 88.0 | 93.7 ± 9.3 | 96.0 ± 9.9 |
| Hb F level, % | 21.8 ± 7.8 | 22.7 ± 6.4 | 23.7 ± 7.4* | 9.0 | 22.8 ± 9.4 | 23.3 ± 7.8 |
| F cells, % | 80.6 ± 14.1 | 82.6 ± 14 | 82.6 ± 7.9* | 49.4 | NP | NP |
| Reticulocyte count, % | 9.2 ± 4.8 | 9.4 ± 9.9 | 8.2 ± 5.2* | 12.4 | 6.6 ± 4.6 | 5.5 ± 2.3 |
| WBC count, × 109/L | 12.6 ± 4.4 | 10.2 ± 5.0 | 10.1 ± 7.3* | 14.3 | 11.0 ± 6.0 | 8.9 ± 4.2 |
| Platelet count, × 109/L | 410.0 ± 169 | 374.3 ± 169.0 | 373.0 ± 238.9* | 424.0 | 333.2 ± 144.0 | 300.2 ± 133.7 |
Mean values . | Baseline; n = 28 . | Year 3*; n = 19 . | Year 4; n = 17 . | Expected at ages 48 to 60 months† . | Year 5; n = 13 . | Year 6; n = 11 . |
|---|---|---|---|---|---|---|
| Hb level, g/dL | 8.5 ± 1.4 | 9.1 ± 1.3 | 9.1 ± 1.4* | 8.1 | 8.5 ± 1.6 | 9.0 ± 1.6 |
| MCV, fL | 81.7 ± 8.0 | 92.1 ± 9.7 | 95.1 ± 10.4* | 88.0 | 93.7 ± 9.3 | 96.0 ± 9.9 |
| Hb F level, % | 21.8 ± 7.8 | 22.7 ± 6.4 | 23.7 ± 7.4* | 9.0 | 22.8 ± 9.4 | 23.3 ± 7.8 |
| F cells, % | 80.6 ± 14.1 | 82.6 ± 14 | 82.6 ± 7.9* | 49.4 | NP | NP |
| Reticulocyte count, % | 9.2 ± 4.8 | 9.4 ± 9.9 | 8.2 ± 5.2* | 12.4 | 6.6 ± 4.6 | 5.5 ± 2.3 |
| WBC count, × 109/L | 12.6 ± 4.4 | 10.2 ± 5.0 | 10.1 ± 7.3* | 14.3 | 11.0 ± 6.0 | 8.9 ± 4.2 |
| Platelet count, × 109/L | 410.0 ± 169 | 374.3 ± 169.0 | 373.0 ± 238.9* | 424.0 | 333.2 ± 144.0 | 300.2 ± 133.7 |
Baseline (pretreatment) values and annual values for years 2 to 6 of therapy are reported as mean ± SD. Years 3 and 4 of hydroxyurea therapy are compared with expected age-matched mean values for untreated children. No expected values are available for statistical comparison in years 5 and 6 of therapy.
NP indicates not performed.
P < .001
Calculated on the basis of data extracted from the CSSCD27 (see “Patients, materials, and methods”) and from the Duke University Pediatric Hematology Research Laboratory (for F cells)25