Table 1 Comparison of clinical and laboratory parameters between “blast phase primary myelofibrosis (PMF-BP)” and “chronic phase primary myelofibrosis with 5–19% circulating blasts”

From: Validation of the WHO-defined 20% circulating blasts threshold for diagnosis of leukemic transformation in primary myelofibrosis

Variables

All patients (n = 144)

PMF-BP with ≥20% BM blasts (n = 71)

PMF-BP with<20% BM blasts but ≥20% PB blasts (n = 32)

PMF-AP with 10–19% PB blasts (n = 13)

PMF with 5–9% PB blasts (n = 28)

P value

Age in years; median (range)

68 (43–89)

68 (44–87)

66 (44–84)

64 (46–80)

69 (43–89)

0.6

Age >65 years; n (%)

81 (56%)

41 (58%)

16 (50%)

6 (46%)

18 (64%)

0.6

Sex (male); n (%)

96 (67%)

49 (69%)

23 (72%)

7 (54%)

17 (61%)

0.6

Transfusion dependent; n (%)

68 (48%)

31 (44%)

13 (42%)

7 (54%)

17 (61%)

0.4

Hemoglobin, g/dl; median (range)

9.3(6.1–13.7)

9.1 (6.1–13.7)

8.9 (6.3–11.2)

10 (7.0–11.6)

9.7 (6.6–13.5)

0.88

Platelets, ×109/L; median (range)

79 (4–984)

67 (4–568)

79 (6–670)

139 (24–885)

157 (14–984)

0.004

Leukocytes, ×109/L; median (range)

21 (0.5–219)

22.3 (0.5–208.4)

19.5 (3.0–139.5)

21.5 (2.1–75)

20.1 (1.8–219)

0.9

Karyotype “N” evaluable = 119 (83%)

     

0.03

Favorable; n (%)

64 (54%)

31 (51%)

7 (39%)

5 (38%)

21 (78%)

 

Unfavorable; n (%)

55(46%)

30 (49%) (N evaluable = 61)

11 (61%)(N evaluable = 18)

8 (62%)

6 (22%) (N evaluable = 27)

 

Karyotype “N” evaluable = 119 (83%)

     

0.02

Normal; n (%)

35 (29%)

16 (26%)

2 (11%)

3 (23%)

14 (52%)

 

Abnormal; n (%)

84 (71%)

45 (74%) (N evaluable = 61)

16 (89%) (N evaluable = 18)

10 (77%)

13 (48%) (N evaluable = 27)

 

Driver mutation status “N” evaluable = 113 (78%)

     

0.3

JAK2; n (%)

67 (59%)

32 (67%)

12 (50%)

8 (62%)

15 (53%)

 

CALR Type 1/like; n (%)

18 (16%)

9 (19%)

4 (17%

2 (15%)

3 (11%)

 

CALR Type 2/like; n (%)

9 (8%)

1 (2%)

2 (8%)

3 (23%)

3 (11%)

 

MPL; n (%)

6 (5%)

2 (4%)

1 (4%)

0 (0%)

3 (11%)

 

Triple-negative; n (%)

13 (12%)

4 (8%)(N evaluable = 48)

5 (21%)(N evaluable = 24)

0 (0%)

4 (14%)

 
  1. The values in bold indicate a significant p-value < 0.05
  2. BM bone marrow, PB peripheral blood, PMF primary myelofibrosis, PMF-BP blast phase PMF, PMF-AP accelerated phase PMF with 10–19% circulating blasts, JAK2 Janus kinase 2, CALR Calreticulin, MPL MPL proto-oncogene
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