Main clinical and hematologic features, treatment, and outcome in 21 children with ST grouped according to JAK2 mutational status
| Clinical and hematologic features . | JAK2V617F(n = 10) . | JAK2 wild-type (n = 11) . | P . |
|---|---|---|---|
| Male sex, n (%) | 4 (40%) | 4 (36%) | 1.00 |
| Female sex, n (%) | 6 (60%) | 7 (64%) | |
| Median age, y (range) | 18 (6-19) | 15 (5-19) | .511 |
| Median WBCs, × 109/L (range) | 10.8 (7.36-22.22) | 10.8 (6.44-18.87) | .468 |
| Median Hct, % (range) | 41.8 (29-53) | 41.2 (38.1-47.3) | 1.00 |
| Median hemoglobin, g/dL (range) | 14.2 (9.7-17.5) | 13.5 (11.7-15.5) | .533 |
| Median platelets, × 109/L (range) | 1.020 (633-2.640) | 1.400 (794-2.800) | .319 |
| BM biopsy, n (%) | |||
| Hypercellularity, | 7/10 (70%) | 5/11 (45.5%) | .6499 |
| Giant megakaryocytes | 3/10 (30%) | 1/11 (9%) | .582 |
| Reticulin fibrosis 0-1/1 | 3/10 (30%) | 3/11 (27%) | 1.00 |
| Symptoms, n (%) | 4 (40%) | 4 (36%) | 1.00 |
| Splenomegaly + hepatomegaly, n (%) | 3/10 (30%) | 2/11 (18%) | .635 |
| EEC positive, n (%) | 5/8 (62.5%) | 6 (54.5%) | 1.00 |
| Monoclonal/female patients, % | 5/7 (71%) | 2/4 (50%) | .412 |
| Treatment and clinical outcomes | |||
| Antiplatelet drugs, n (%) | 9/10 (90%) | 10/11 (91%) | 1.00 |
| Cytoreductive therapy, n (%) | 6/10 (60%) | 9/11 (82%) | .3615 |
| Antiplatelet drugs at last follow-up, n (%) | 4/10 (40%) | 1/11 (9%) | .1486 |
| Cytoreductive therapy at last follow-up, n (%) | 6/10 (60%) | 8/11 (72%) | .6594 |
| ANA | 3/6 (50%) | 5/8 (62.5%) | |
| HU | 2/6 (33%) | 2/8 (25%) | |
| IFN-α | 1/6 (17%) | 1/8 (12.5%) | |
| Subsequent splenomegaly + reticulin fibrosis 2, n (%) | 1 (10%) | 1 (9%) | 1.00 |
| Thrombosis during follow-up, n (%) | 1 (10%) | 0 | .4762 |
| Malignancies, n | 0 | 1 | .4762 |
| Median follow-up, mo (range) | 150 (13-289) | 193 (31-331) | .6032 |
| Clinical and hematologic features . | JAK2V617F(n = 10) . | JAK2 wild-type (n = 11) . | P . |
|---|---|---|---|
| Male sex, n (%) | 4 (40%) | 4 (36%) | 1.00 |
| Female sex, n (%) | 6 (60%) | 7 (64%) | |
| Median age, y (range) | 18 (6-19) | 15 (5-19) | .511 |
| Median WBCs, × 109/L (range) | 10.8 (7.36-22.22) | 10.8 (6.44-18.87) | .468 |
| Median Hct, % (range) | 41.8 (29-53) | 41.2 (38.1-47.3) | 1.00 |
| Median hemoglobin, g/dL (range) | 14.2 (9.7-17.5) | 13.5 (11.7-15.5) | .533 |
| Median platelets, × 109/L (range) | 1.020 (633-2.640) | 1.400 (794-2.800) | .319 |
| BM biopsy, n (%) | |||
| Hypercellularity, | 7/10 (70%) | 5/11 (45.5%) | .6499 |
| Giant megakaryocytes | 3/10 (30%) | 1/11 (9%) | .582 |
| Reticulin fibrosis 0-1/1 | 3/10 (30%) | 3/11 (27%) | 1.00 |
| Symptoms, n (%) | 4 (40%) | 4 (36%) | 1.00 |
| Splenomegaly + hepatomegaly, n (%) | 3/10 (30%) | 2/11 (18%) | .635 |
| EEC positive, n (%) | 5/8 (62.5%) | 6 (54.5%) | 1.00 |
| Monoclonal/female patients, % | 5/7 (71%) | 2/4 (50%) | .412 |
| Treatment and clinical outcomes | |||
| Antiplatelet drugs, n (%) | 9/10 (90%) | 10/11 (91%) | 1.00 |
| Cytoreductive therapy, n (%) | 6/10 (60%) | 9/11 (82%) | .3615 |
| Antiplatelet drugs at last follow-up, n (%) | 4/10 (40%) | 1/11 (9%) | .1486 |
| Cytoreductive therapy at last follow-up, n (%) | 6/10 (60%) | 8/11 (72%) | .6594 |
| ANA | 3/6 (50%) | 5/8 (62.5%) | |
| HU | 2/6 (33%) | 2/8 (25%) | |
| IFN-α | 1/6 (17%) | 1/8 (12.5%) | |
| Subsequent splenomegaly + reticulin fibrosis 2, n (%) | 1 (10%) | 1 (9%) | 1.00 |
| Thrombosis during follow-up, n (%) | 1 (10%) | 0 | .4762 |
| Malignancies, n | 0 | 1 | .4762 |
| Median follow-up, mo (range) | 150 (13-289) | 193 (31-331) | .6032 |
EEC indicates endogenous erythroid colony; n, number of patients; ANA, anagrelide; HU, hydroxyurea; and IFN-α, interferon-α.