Table 1.
Patient characteristics (139 paediatric patients with acute lymphoblastic leukaemia)
| Sex, n (%) | |
| Male | 64 (46) |
| Female | 75 (54) |
| Age, median (IQR), years | 5.1 (3.7–10.6) |
| Follow‐up period, median (IQR), years | 5.9 (3.6–7.9) |
| Body weight, median (IQR), kg | 19.4 (15.2–37.5) |
| Body surface area, median (IQR), m2 | 0.79 (0.66–1.19) |
| Diagnosis | |
| B‐lymphoblastic leukaemia, n (%) | 131 (94) |
| T‐lymphoblastic leukaemia, n (%) | 8 (6) |
| Risk group | |
| Standard risk, n (%) | 86 (62) |
| High risk, n (%) | 53 (38) |
| Number of thiopurine metabolite measurements per patient, median (range) | 7 (1–14) |
| 6‐MP daily dose, median (IQR), mg m−2 per day | 30.1 (22.2–38.9) |
| 6‐TGN level, median (IQR), pmol per 8 × 108 RBCs | 388.5 (301.1–555.2) |
| 6‐MeMPN level, median (IQR), pmol per 8 × 108 RBCs | 5089.0 (2064.2–9363.7) |
| 6‐MeMPN/6‐TGN ratio, median (IQR) | 13.9 (5.2–23.5) |
| 6‐TGN/6‐MP dose ratio, median (IQR) | 12.8 (9.3–18.1) |
| TPMT genotype, n (%) | |
| *1/*1 | 133 (96) |
| *1/*3C | 2 (1) |
| *1/*6 | 2 (1) |
| *1/*32 | 1 (1) |
| *1/? (c.532T>C) (novel allele) | 1 (1) |
| Toxicity, n (%)a | |
| Leukopenia (WBC < 1.5 x 109 L−1) | 38 (27) |
| Neutropenia (ANC < 0.5 x 109 L−1) | 40 (29) |
| Hepatotoxicity | 64 (46) |
| Treatment interruption, n (%) | 114 (82) |
Abbreviations: ANC, absolute neutrophil count; IQR, interquartile range; WBC, white blood cell.
a
Any toxicity experienced during the follow‐up period.