Patient characteristics of the 64 t(1;19)-positive patients with high or low Mer expression levels for which correlation analyses with clinical parameters were performed
| . | Merlow, n = 31 . | Merhigh, n = 33 . | P . |
|---|---|---|---|
| Sex* | .3275 | ||
| Male | 12 | 17 | |
| Female | 19 | 16 | |
| Median age (95% CI) at diagnosis, y** | 6.5 (6.1-9.1) | 10.4 (8.2-11.7) | .0390 |
| WBC count*† | .0829 | ||
| <50 000/μL | 25 | 15 | |
| ≥50 000/μL | 6 | 11 | |
| Prednisone response*‡ | 1.0000 | ||
| Good | 26 | 28 | |
| Poor | 5 | 5 | |
| Risk group***§ | .9678 | ||
| MRD-SR | 13 | 13 | |
| MRD-IR | 13 | 14 | |
| MRD-HR | 5 | 6 | |
| Mean cell count (range) in diagnostic LP**** | 1.3 (0-14) | 11.2 (0-142) | .0485 |
| Blasts in LP cytospin*|| | .0393 | ||
| No | 24 | 17 | |
| Yes | 7 | 16 | |
| CNS status***|| | .0448 | ||
| CNS1 | 24 | 16 | |
| CNS2 | 6 | 12 | |
| CNS3 (CNS3c)¶ | 1 (1) | 5 (3) | |
| Relapse and death*# | .4926 | ||
| No | 31 | 31 | |
| Yes | 0 | 2 |
| . | Merlow, n = 31 . | Merhigh, n = 33 . | P . |
|---|---|---|---|
| Sex* | .3275 | ||
| Male | 12 | 17 | |
| Female | 19 | 16 | |
| Median age (95% CI) at diagnosis, y** | 6.5 (6.1-9.1) | 10.4 (8.2-11.7) | .0390 |
| WBC count*† | .0829 | ||
| <50 000/μL | 25 | 15 | |
| ≥50 000/μL | 6 | 11 | |
| Prednisone response*‡ | 1.0000 | ||
| Good | 26 | 28 | |
| Poor | 5 | 5 | |
| Risk group***§ | .9678 | ||
| MRD-SR | 13 | 13 | |
| MRD-IR | 13 | 14 | |
| MRD-HR | 5 | 6 | |
| Mean cell count (range) in diagnostic LP**** | 1.3 (0-14) | 11.2 (0-142) | .0485 |
| Blasts in LP cytospin*|| | .0393 | ||
| No | 24 | 17 | |
| Yes | 7 | 16 | |
| CNS status***|| | .0448 | ||
| CNS1 | 24 | 16 | |
| CNS2 | 6 | 12 | |
| CNS3 (CNS3c)¶ | 1 (1) | 5 (3) | |
| Relapse and death*# | .4926 | ||
| No | 31 | 31 | |
| Yes | 0 | 2 |
CI, confidence interval; HR, high risk; IR, intermediate risk; LP, lumbar puncture; RBC, red blood cell; SR, standard risk; TP, time point; WBC, white blood cell.
Fisher exact test, 2-sided P value; **unpaired t test with Welsh correction; ***χ2 test; ****Mann-Whitney test, 1-sided P value.
Seven patients in the Merhigh group had no available data on initial leukocyte count.
Good: <1000 leukemic blood blasts per microliter on treatment day 8, poor: >1000 per microliter.
Risk stratification according to MRD risk groups: MRD-SR = TP1+2 negative; MRD-IR = TP1 and/or TP2 <10−3; MRD-HR = TP2 ≥10−3. Prednisone-poor responders were stratified into the HR treatment group.
CNS status is defined as follows:
CNS1 = no clinical nor radiological signs of CNS involvement AND no blasts in the CSF cytospin.
CNS2 = no clinical nor radiological signs of CNS involvement AND CNS2a: <10 per microliter RBC and no macroscopic blood; ≤5 per microliter WBC; positive blasts in cytospin.
CNS2b = macroscopic blood and/or ≥10 per microliter RBC; ≤5 per microliter WBC; positive blasts in cytospin.
CNS2c = macroscopic blood and/or ≥10 per microliter RBC; >5 per microliter WBC; positive blasts in cytospin; negative according to algorithm (WBCL/RBCL)/(WBCB/RBCB) >2.
CNS3-CNS3a = <10 per microliter RBC and no macroscopic blood; >5 per microliter WBC; positive blasts in cytospin.
CNS3b = macroscopic blood and/or ≥10 per microliter RBC; >5 per microliter WBC; positive according to algorithm (WBCL/RBCL)/(WBCB/RBCB) >2.
CNS3c = clinical sings of CNS involvement, radiologically detectable cerebral lesion, retinal infiltrations.
In the CNS3c group, 3 of 4 patients had cerebral lesion and 1 of 4 patients in the Merhigh group had retinal infiltration. One of 4 CNS3c patients had no blasts in the CSF cytospin but cerebral lesion.
Both relapses were isolated bone marrow relapses.