Njoku et al classified patients with idiopathic myelofibrosis into 4 groups based on the hemoglobin and reticulocyte count in 1983. These groups correlated with survival.
Hemoglobin in g/dL at diagnosis
Reticulocyte Count in percent at diagnosis
Class
>= 10
<= 2%
I
>= 10
> 2%
II
< 10
> 2%
III
< 10
<= 2%
IV
(after Table III, page 87)
where:
• The original table had only ">" and "<"; I've added the "=".
• The reticulocyte count was uncorrected for anemia.
• An absolute reticulocyte count of 100 * 10^9 per liter (100,000 per µL) could be used as the discriminant value (page 88). For a 2% cutoff, this would correlate with an RBC count of 5 * 10^12 per liter.
Class
Mean Survival (in 1983)
4 Year Survival (in 1983)
I
> 10 years
100%
II
6.5 years
70%
III
3.8 years
45%
IV
1.3 years
0%
(after Figure 7, page 85)
Other prognostic factors noted:
(1) plasma volume: plasma volume < 140% of predicted better than > 140%
(2) bone marrow erythropoietic activity: activity > 50% better than < 50%
To read more or access our algorithms and calculators, please log in or register.
