Table 1.
Baseline and immunologic data for patients treated therapeutically (patients 1 and 2) for an established antibody response as well as patients treated prophylactically (patients 3 and 4) in parallel to starting enzyme replacement therapy
| Therapeutic tolerance induction | Prophylactic tolerance induction | |||
|---|---|---|---|---|
| Patient 1 | Patient 2 | Patient 3 | Patient 4 | |
| Age of diagnosis | 5 weeks | 12 days | 8 weeks | 10 weeks |
| Sex | M | F | F | M |
| Race | African American | Caucasian | Caucasian | Caucasian |
| Consanguinity | No | No | Yes | No |
| GAA mutation | Homozygous c.2560C>T | c.1128–1129delinsC/ c.2237G>A |
Homozygous c.341insT | c.1548G>A and c.525delT |
| GAA activity | Absent | Absent | Absent | Absent |
| Initiation of ERT | 7 weeks | 16 days | 16 weeks | 15 weeks |
| Seroconversion | 6 weeks | 4 weeks | 38 weeks | None |
| Onset of immune tolerance after ERT |
18 weeks | 6 weeks | 0 weeks | 0 weeks |
| Current immune therapy | None | None | None | None |
| Anti-rhGAA titer | ||||
| Peak titer (time after ERT) | 1:1,600 (4 months) | 1:12,800 (1 month) | 1:1,600 (9 months) | Negative |
| Time to antibody elimination | 3 months | 19 months | Not eliminated | N/A |
| Last titer | Negative | Negative | 1:200 | Negative |
| B-cell recovery | Yes | Yes | Yes | Yes |
| Urinary Glc4 level (mmol/mol CN) | ||||
| Baseline | 26 | 23 | NA | NA |
| 6 months | 39 | 20 | NA | 29 |
| 12 months | 48 | 10 | NA | 38 |
| Last | 47 (53 months) | 17 (35 months) | 21 (33 months) | 69 (22 months) |
ERT, enzyme replacement therapy; GAA, acid α-glucosidase; Glc4, glucose tetrasaccharide; rhGAA, recombinant human GAA.