Table 1.
Baseline characteristics by overall immune status.
| Baseline characteristics | Overall (N = 26) | Ab + (n = 13) | Ab − (n = 13) | NAb + (n = 9) | NAb − (n = 17) |
|---|---|---|---|---|---|
| Age category, n (%) | |||||
| < 12 years | 17 (65.4) | 10 (76.9) | 7 (53.8) | 7 (77.8) | 10 (58.8) |
| ≥ 12 years | 9 (34.6) | 3 (23.1) | 6 (46.2) | 2 (22.2) | 7 (41.2) |
| Age at entry, y | |||||
| Mean (SD) | 12.8 (8.0) | 9.3 (2.9) | 16.3 (9.9) | 9.5 (3.1) | 14.6 (9.3) |
| Median | 10.0 | 9.4 | 11.2 | 9.4 | 10.1 |
| Min, Max | 5.1, 35.5 | 5.8, 14.5 | 5.1, 35.5 | 6.2, 14.5 | 5.1, 35.5 |
| Age at diagnosis, y | |||||
| Mean (SD) | 4.4 (3.9) | 3.5 (1.7) | 5.3 (5.2) | 3.3 (1.8) | 5.0 (4.6) |
| Median | 3.8 | 4.1 | 3.0 | 3.5 | 4.1 |
| Min, Max | 0.1, 20.0 | 0.1, 5.5 | 0.1, 20.0 | 0.1, 5.5 | 0.1, 20.0 |
| Idursulfase ERT exposure before baseline, mo | |||||
| Mean (SD) | 39.9 (21.5) | 32.9 (17.9) | 47.0 (23.0) | 36.6 (19.8) | 41.7 (22.7) |
| Median | 35.8 | 29.1 | 42.6 | 29.5 | 35.9 |
| Min, Max | 6.2, 77.5 | 10.6, 75.7 | 6.2, 77.5 | 10.6, 75.7 | 6.2, 77.5 |
| Presence of cognitive impairmenta, n (%) | |||||
| Yes | 13 (54.2)b | 8 (61.5) | 5 (38.5) | 7 (53.8) | 6 (46.2) |
| No | 11 (45.8)b | 4 (36.4) | 7 (63.6) | 2 (18.2) | 9 (81.8) |
All patients were on weekly 0.5 mg/kg intravenous idursulfase.
Overall antibody status was defined as positive if one or more IgG results were found to be positive during the study.
Ab +, antibody positive; Ab −, antibody negative; ERT, enzyme replacement therapy; NAb +, neutralizing antibody positive; NAb −, neutralizing antibody negative.
a
Assessed prior to or within 6 months after entry into study.
b
N = 24.