Laboratory and clinical features of the patients with primary myelofibrosis at the time of sample collection for JAK2 V617F assay
| . | Total population . | JAK2 V617F wild-type . | P* . | JAK2 V617F heterozygous . | P† . | JAK2 V617F homozygous . | P‡ . |
|---|---|---|---|---|---|---|---|
| No. of patients (%) | 304 | 111 (36.5) | — | 109 (35.8) | — | 84 (27.6) | — |
| Males, n (%) | 201 (66.1) | 74 (66.7) | NS | 70 (64.2) | NS | 57 (67.9) | NS |
| Age, y (IQR) | 63 (52-71.5) | 63 (54-73) | NS | 64 (53-72) | NS | 61.5 (49.5-70) | NS |
| Duration of disease, mo (IQR) | 16 (1-50) | 15 (1-60) | NS | 9 (1-30) | <.001 | 28 (3-67) | .001 |
| Hemoglobin level, g/L (IQR) | 108 (90-133) | 100 (84-118) | <.001 | 119.5 (93.5-138.5) | NS | 120 (96-143) | <.001 |
| White blood cell count, × 109/L (IQR)§ | 9.3 (5.7-14.8) | 7.5 (4.8-12.55) | NS | 9.01 (5.55-13.4) | .03 | 13.1 (7.74-18.76) | .004 |
| Immature myeloid cells in peripheral blood, % (IQR) | 5 (2-12) | 5 (2-12) | NS | 5 (0-11) | NS | 5 (1-14) | NS |
| Blasts in peripheral blood, % (IQR) | 0 (0-2) | 0.5 (0-2) | NS | 0 (0-1) | NS | 0 (0-2.5) | NS |
| Erythroblasts in peripheral blood, % (IQR) | 2 (0-3) | 2 (0-3) | NS | 1 (0-4) | NS | 1 (0-4) | NS |
| Platelet count, × 109/L (range) | 246 (126-446) | 204 (111-382) | .005 | 319 (153-594) | .009 | 224 (98-446) | NS |
| Spleen index, cm2 (IQR)‖ | 210 (130-400) | 202 (130-380) | NS | 185 (120-300) | <.001 | 287 (187-540) | <.001 |
| Serum lactate dehydrogenase, U/L (IQR) | 730 (456-1018) | 744 (438-1003) | NS | 718 (438-1045) | NS | 840 (532-1343) | NS |
| CD34+ cell no. in peripheral blood, × 106/L (IQR) | 40 (8-106) | 31 (7-118) | NS | 40 (7-106) | NS | 42 (14-106) | NS |
| Abnormal cytogenetics, no. of patients (%) | 210 (10) | 70 (15) | NS | 80 (12) | NS | 60 (7.5) | NS |
| Aquagenic pruritus, no. of patients (%) | 202 (44.9) | 40 (26.3) | .001 | 81 (48.2) | NS | 81 (62.1) | <.001 |
| Patients taking disease-modifying therapies, n (%) | 174 (25.2) | 66 (23.9) | NS | 51 (21.5) | NS | 57 (32.2) | NS |
| Patients taking cytostatic treatment, n (%) | 158 (48.2) | 42 (33.9) | NS | 54 (47.4) | .02 | 62 (68.9) | .02 |
| . | Total population . | JAK2 V617F wild-type . | P* . | JAK2 V617F heterozygous . | P† . | JAK2 V617F homozygous . | P‡ . |
|---|---|---|---|---|---|---|---|
| No. of patients (%) | 304 | 111 (36.5) | — | 109 (35.8) | — | 84 (27.6) | — |
| Males, n (%) | 201 (66.1) | 74 (66.7) | NS | 70 (64.2) | NS | 57 (67.9) | NS |
| Age, y (IQR) | 63 (52-71.5) | 63 (54-73) | NS | 64 (53-72) | NS | 61.5 (49.5-70) | NS |
| Duration of disease, mo (IQR) | 16 (1-50) | 15 (1-60) | NS | 9 (1-30) | <.001 | 28 (3-67) | .001 |
| Hemoglobin level, g/L (IQR) | 108 (90-133) | 100 (84-118) | <.001 | 119.5 (93.5-138.5) | NS | 120 (96-143) | <.001 |
| White blood cell count, × 109/L (IQR)§ | 9.3 (5.7-14.8) | 7.5 (4.8-12.55) | NS | 9.01 (5.55-13.4) | .03 | 13.1 (7.74-18.76) | .004 |
| Immature myeloid cells in peripheral blood, % (IQR) | 5 (2-12) | 5 (2-12) | NS | 5 (0-11) | NS | 5 (1-14) | NS |
| Blasts in peripheral blood, % (IQR) | 0 (0-2) | 0.5 (0-2) | NS | 0 (0-1) | NS | 0 (0-2.5) | NS |
| Erythroblasts in peripheral blood, % (IQR) | 2 (0-3) | 2 (0-3) | NS | 1 (0-4) | NS | 1 (0-4) | NS |
| Platelet count, × 109/L (range) | 246 (126-446) | 204 (111-382) | .005 | 319 (153-594) | .009 | 224 (98-446) | NS |
| Spleen index, cm2 (IQR)‖ | 210 (130-400) | 202 (130-380) | NS | 185 (120-300) | <.001 | 287 (187-540) | <.001 |
| Serum lactate dehydrogenase, U/L (IQR) | 730 (456-1018) | 744 (438-1003) | NS | 718 (438-1045) | NS | 840 (532-1343) | NS |
| CD34+ cell no. in peripheral blood, × 106/L (IQR) | 40 (8-106) | 31 (7-118) | NS | 40 (7-106) | NS | 42 (14-106) | NS |
| Abnormal cytogenetics, no. of patients (%) | 210 (10) | 70 (15) | NS | 80 (12) | NS | 60 (7.5) | NS |
| Aquagenic pruritus, no. of patients (%) | 202 (44.9) | 40 (26.3) | .001 | 81 (48.2) | NS | 81 (62.1) | <.001 |
| Patients taking disease-modifying therapies, n (%) | 174 (25.2) | 66 (23.9) | NS | 51 (21.5) | NS | 57 (32.2) | NS |
| Patients taking cytostatic treatment, n (%) | 158 (48.2) | 42 (33.9) | NS | 54 (47.4) | .02 | 62 (68.9) | .02 |
Aggregate data are medians with ranges or interquartile ranges (IQRs).
NS indicates not significant; —, not applicable.
Difference between wild-type and heterozygous patients.
Difference between heterozygous and homozygous patients.
Difference between homozygous and wild-type patients.
Corrected for the number of circulating erythroblasts.
At the time of sampling, 16 patients had undergone splenectomy. The values of spleen size refer to 288 patients.