Table 1.
Blood samples available for thiopurine analysis
| Total | TG | MP | |
|---|---|---|---|
| Individual children | 1565 | ||
| Individual TPMT genotypes | 1320 (84%) | ||
| Individual children at disease diagnosis | |||
| TPMT activity measured | 1150 | ||
| TPMT genotypes | 950 (83%) | ||
| Individual children during chemotherapy | |||
| TPMT activity measured | 1131 | 428 | 703 |
| TPMT activity and genotype | 1117 (99%) | 423 | 694 |
| TPMT activity and metabolites | 1114 (98%) | 424 | 690 |
| TPMT activity, genotype and metabolites | 1100 (97%) | 419 | 681 |
| TPMT activities measured at diagnosis and during chemotherapy | 755 (67%) | ||
| TPMT genotypes available in the above cohort | 741 (66%) | ||
| Children with multiple samples at the protocol directed time intervals | 378 (33%) | 134 | 244 |
MP, mercaptopurine cohort; TG, thioguanine cohort; TPMT, thiopurine methyltransferase. TPMT activity was used in the analysis if it was measured in blood samples processed within 5 days of sampling. Metabolite values were used in analysis if they were measured in whole blood samples up to 6 days old or, for washed red cells, up to 3 days old. For chemotherapy samples the total number is split between those taking TG or taking MP. Two TPMT deficient children are included in this table, one randomized to TG and one to MP.