Comparison of the transfusion data from the STOP clinical trial and posttrial follow-up
Variable . | STOP trial* . | Posttrial follow-up . |
|---|---|---|
| No. of patients | 61 | 78 |
| No. of transfusions | 1521 | 2354 |
| No. of PRBC units | 1830 | 3512 |
| Methods of transfusion, % of total | ||
| Simple | 63 | 63 |
| Exchange, full or partial | 12 | 9 |
| Combination of both | 25 | 28 |
| Mean interval of transfusion, d | 25 ± 8 | 28 ± 10 |
| Pretransfusion Hb S > 30% | ||
| Total no. of episodes (%) | 143 (9) | 721 (31) |
| Hb S 30-34.9 (%) | 70 (4) | 287 (12) |
| Hb S 35-39.9 (%) | 31 (2) | 165 (7) |
| Hb S at least 40 (%) | 42 (3) | 269 (12) |
| Ferritin, mean ng/mL ± SD | ||
| Baseline | 164 ± 155 | 190 ± 284 |
| 12 mo | 1804 ± 773 | 1762 ± 786 |
| 24 mo | 2509 ± 974 | 2797 ± 1500 |
| 36 mo | — | 2955 ± 128 |
| 48 mo | — | 3089 ± 771 |
| No. patients on iron chelation | 8 | 43 |
| Immunization rate, % (no. patients with new antibody/unit of exposure) | 0.5 (10/1830) | 0.5 (18/3512) |
| No. patients with antibodies to C, D, E, Kell | 4 (E, Kell only) | 6 |
| No. patients with antibodies to other antigens | 3 | 6 |
| No. patients with warm autoantibodies | 3 | 6 |
| Other transfusion-adverse events | 19 | 13 |
| Exposure to infectious pathogens | ||
| Hepatitis B | None | None |
| Hepatitis C | None | None |
| HIV and HTLV-1 | None | None |
Variable . | STOP trial* . | Posttrial follow-up . |
|---|---|---|
| No. of patients | 61 | 78 |
| No. of transfusions | 1521 | 2354 |
| No. of PRBC units | 1830 | 3512 |
| Methods of transfusion, % of total | ||
| Simple | 63 | 63 |
| Exchange, full or partial | 12 | 9 |
| Combination of both | 25 | 28 |
| Mean interval of transfusion, d | 25 ± 8 | 28 ± 10 |
| Pretransfusion Hb S > 30% | ||
| Total no. of episodes (%) | 143 (9) | 721 (31) |
| Hb S 30-34.9 (%) | 70 (4) | 287 (12) |
| Hb S 35-39.9 (%) | 31 (2) | 165 (7) |
| Hb S at least 40 (%) | 42 (3) | 269 (12) |
| Ferritin, mean ng/mL ± SD | ||
| Baseline | 164 ± 155 | 190 ± 284 |
| 12 mo | 1804 ± 773 | 1762 ± 786 |
| 24 mo | 2509 ± 974 | 2797 ± 1500 |
| 36 mo | — | 2955 ± 128 |
| 48 mo | — | 3089 ± 771 |
| No. patients on iron chelation | 8 | 43 |
| Immunization rate, % (no. patients with new antibody/unit of exposure) | 0.5 (10/1830) | 0.5 (18/3512) |
| No. patients with antibodies to C, D, E, Kell | 4 (E, Kell only) | 6 |
| No. patients with antibodies to other antigens | 3 | 6 |
| No. patients with warm autoantibodies | 3 | 6 |
| Other transfusion-adverse events | 19 | 13 |
| Exposure to infectious pathogens | ||
| Hepatitis B | None | None |
| Hepatitis C | None | None |
| HIV and HTLV-1 | None | None |
— indicates no data.
Data taken from Adams et al4 and Vichinsky et al.9