Main demographic, hematologic, and clinical findings at diagnosis, biologic markers, treatment, and clinical outcomes of thrombocythemic children analyzed in the present study
| Demographic and hematologic characteristics . | ST (n = 34) . | HT (n = 16) . | P . |
|---|---|---|---|
| Males/females | 10/24 | 7/9 | .35 |
| Median age, y (range) | 15 (5-19) | 12 (3mos-17) | .0418 |
| Median WBCs, × 109/L (range) | 9.88 (5.62-22.22) | 8.43 (5.17-16.06) | .215 |
| Median Hct, % (range) | 41.65 (29-53) | 36.15 (32.3-42) | .0047 |
| Median platelets, × 109/L (range) | 1.109 (633-2.800) | 990.5 (611-2.950) | .303 |
| BM biopsy, n (%) | 34/34 (100%) | 5/16 (31%) | |
| Hypercellularity, n (%) | 15/34 (44%) | 1/5 (20%) | 1.00 |
| Giants megakaryocytes, n (%) | 5/34 (15%) | 0/5 | 1.00 |
| Reticulin fibrosis 0-1/1, n (%) | 7/34 (20.5%) | 1/5 (20%) | 1.00 |
| Clinical findings at first presentation | |||
| Symptoms, n (%) | 12 (35%) | 4 (25%) | .526 |
| Headache | 10 | 3 | |
| Paresthesias | 2 | 1 | |
| Splenomegaly, n (%) | 6/32 (19%) | 2/15 (13%) | .702 |
| Hepatomegaly, n (%) | 2/32 (6%) | ||
| Thrombotic events, n (%) | 0 | 0 | |
| Bleeding events, n (%) | 0 | 0 | |
| Biologic markers | (n = 21) | (n = 16) | |
| EEC positive, n (%) | 11/19 (58%) | 5/12 (42%) | .472 |
| JAK2V617F, n (%) | 10/21 (48%) | 0/13 | .0049 |
| V617F allele burden, n | 8/10 | ||
| Median allele burden (range) | 21% (6%-50%) | ||
| Clonal hemopoiesis, no. of females, % | 7/11 (64%) | 0/7 | .0128 |
| MPL mutations, n (%) | 0/15 | 15/16 (94%) | < .00001 |
| Treatment | (n = 34) | (n = 16) | |
| Antiplatelet drugs, n (%) | 27/34 (79%) | 9/16 (56%) | .105 |
| Cytoreductive therapy, n (%) | 23/34 (68%) | 2/16 (12.5%) | .0006 |
| Antiplatelet drugs at last follow-up, n (%) | 6/34 (15%) | 3/16 (19%) | 1.000 |
| Cytoreductive therapy at last follow-up, n (%) | 19/34 (56%) | 1/16 (6%) | .0007 |
| ANA | 7/19 (37%) | ||
| HU | 7/19 (37%) | ||
| IFN-α | 4/19 (21%) | 1 | |
| IFN-α + HU | 119 (5%) | ||
| Clinical outcome | |||
| Splenomegaly + reticulin fibrosis 1-2, n (%) | 3/34 (9%) | 0 | .542 |
| Time to evolution, mo | (37, 108, 119) | ||
| Thrombotic events, n (%) | 1/34 (3%) | 2/16 (12.5%) | .236 |
| Time to thrombosis, mo | (64) | (28, 64) | |
| No. of pregnancies/no. of patients | 15/6 | 3/2 | |
| Abortions | 6 | 0 | |
| Spontaneous | 2 | ||
| Elective | 4 | ||
| Childbirths | 9/15 | 3/3 | .678 |
| Malignancies, n (%) | 1 (3 %) | 1 (6 %) | |
| Splenectomy, n (%) | 1 (3%) | 0 | |
| Lost to follow-up, n (%) | 10 (29%) | 3 (19%) | |
| Median follow-up, mo (range) | 128 (13-332) | 137 (27-327) | |
| Demographic and hematologic characteristics . | ST (n = 34) . | HT (n = 16) . | P . |
|---|---|---|---|
| Males/females | 10/24 | 7/9 | .35 |
| Median age, y (range) | 15 (5-19) | 12 (3mos-17) | .0418 |
| Median WBCs, × 109/L (range) | 9.88 (5.62-22.22) | 8.43 (5.17-16.06) | .215 |
| Median Hct, % (range) | 41.65 (29-53) | 36.15 (32.3-42) | .0047 |
| Median platelets, × 109/L (range) | 1.109 (633-2.800) | 990.5 (611-2.950) | .303 |
| BM biopsy, n (%) | 34/34 (100%) | 5/16 (31%) | |
| Hypercellularity, n (%) | 15/34 (44%) | 1/5 (20%) | 1.00 |
| Giants megakaryocytes, n (%) | 5/34 (15%) | 0/5 | 1.00 |
| Reticulin fibrosis 0-1/1, n (%) | 7/34 (20.5%) | 1/5 (20%) | 1.00 |
| Clinical findings at first presentation | |||
| Symptoms, n (%) | 12 (35%) | 4 (25%) | .526 |
| Headache | 10 | 3 | |
| Paresthesias | 2 | 1 | |
| Splenomegaly, n (%) | 6/32 (19%) | 2/15 (13%) | .702 |
| Hepatomegaly, n (%) | 2/32 (6%) | ||
| Thrombotic events, n (%) | 0 | 0 | |
| Bleeding events, n (%) | 0 | 0 | |
| Biologic markers | (n = 21) | (n = 16) | |
| EEC positive, n (%) | 11/19 (58%) | 5/12 (42%) | .472 |
| JAK2V617F, n (%) | 10/21 (48%) | 0/13 | .0049 |
| V617F allele burden, n | 8/10 | ||
| Median allele burden (range) | 21% (6%-50%) | ||
| Clonal hemopoiesis, no. of females, % | 7/11 (64%) | 0/7 | .0128 |
| MPL mutations, n (%) | 0/15 | 15/16 (94%) | < .00001 |
| Treatment | (n = 34) | (n = 16) | |
| Antiplatelet drugs, n (%) | 27/34 (79%) | 9/16 (56%) | .105 |
| Cytoreductive therapy, n (%) | 23/34 (68%) | 2/16 (12.5%) | .0006 |
| Antiplatelet drugs at last follow-up, n (%) | 6/34 (15%) | 3/16 (19%) | 1.000 |
| Cytoreductive therapy at last follow-up, n (%) | 19/34 (56%) | 1/16 (6%) | .0007 |
| ANA | 7/19 (37%) | ||
| HU | 7/19 (37%) | ||
| IFN-α | 4/19 (21%) | 1 | |
| IFN-α + HU | 119 (5%) | ||
| Clinical outcome | |||
| Splenomegaly + reticulin fibrosis 1-2, n (%) | 3/34 (9%) | 0 | .542 |
| Time to evolution, mo | (37, 108, 119) | ||
| Thrombotic events, n (%) | 1/34 (3%) | 2/16 (12.5%) | .236 |
| Time to thrombosis, mo | (64) | (28, 64) | |
| No. of pregnancies/no. of patients | 15/6 | 3/2 | |
| Abortions | 6 | 0 | |
| Spontaneous | 2 | ||
| Elective | 4 | ||
| Childbirths | 9/15 | 3/3 | .678 |
| Malignancies, n (%) | 1 (3 %) | 1 (6 %) | |
| Splenectomy, n (%) | 1 (3%) | 0 | |
| Lost to follow-up, n (%) | 10 (29%) | 3 (19%) | |
| Median follow-up, mo (range) | 128 (13-332) | 137 (27-327) | |
ST indicates sporadic thrombocythemia; HT, hereditary thrombocytosis; n, number of patients; EEC, endogenous erythoid colony; ANA, anagrelide; HU, hydroxyurea; and IFN-α, interferon-α.