Table 6.
Staging of JAK2V617F positive prodromal polycythemia vera, erythrocythemic polycythemia vera, and five stages of PV according to WHO-ECMP criteria related to therapy anno 2014[10,13,34-37]
| PV: WHO-ECMP stage | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
| WHO-ECMP clinical diagnosis | Prodromal PV | Erythrocy-themic PV | Early PV | Overt PV Classical PV | PV PMF Masked PV | Post-PV MF Spent PV | Leukemic PV MDS/AL |
| LAP-score | ↑ | ↑ | ↑ | ↑ | ↑/↑↑ | Variable | Variable |
| Red cell mass | N | ↑ | ↑ | ↑ | ↑ | Variable | N/↓ |
| Serum EPO | N/↓ | N/↓ | ↓ | ↓ | ↓ | Variable | N/↓ |
| Erythrocytes × 1012/L | < 5.8 | > 5.8 | > 5.8 | > 5.8 | < 5.8 | Variable | N/↓ |
| Leukocytes × 109/L | < 12 | < 12 | < or > 12 | < or- > 15 | > 15 | > 20 | > 20 |
| Platelets × 109/L | > 400 | 400 | < or > 400 | > 400 | < or > 1000 | Variable | Variable |
| WHO-ECMP bone marrow | Early PV | Early PV | Early PV | Trilinear PV | Trilinear PV | Myelofibrosis | Leukemic |
| Bone marrow cellularity (%) | 50-80 | 50-80 | 60-100 | 80-100 | 80-100 | Decreased | Increased |
| Grading reticulin fibrosis: RF | RF 0-1 | RF 0-1 | RF 0-1 | RF 0/1, | RCF 2/3 | RCF 3/4 | |
| Grading myelofibrosis: MF57 | MF 0 | MF 0 | MF 0 | MF 0 | MF 1/2 | MF 2/3 | |
| Splenomegaly on palpation | No/+ | No | No/+ | + | ++/+++ | /Large | Large |
| Spleen size, echogram cm | < 12-15 | < 13 | 12-15 | 12-18 | 18 - > 20 | > 20 | > 20 |
| Spleen size on palpation cm | 0-3 | NP | 0-3 | 4-6 | > 6 | > 8 | > 8 |
| JAK2V617F in Granulocytes % | low | low | Moderate < 50 | High > 50 | High > 50 | High > 50 | No or ++ |
| JAK2V617F in BFU-e (exon 12) | +(++) | +(++) | +(++) | ++ | ++ | ++ | |
| Therapeutic implications | Low risk | Low risk | Low risk | Intermediate risk PV | High risk PV-MF | Post-PV MF Spent phase PV | Leukemia |
| Anno 2014 | |||||||
| First line aspirin/Phlebotomy Second line IFN vs HU Third line JAK2 inhibitor | Aspirin Phlebotomy | Aspirin Phlebotomy | Phlebotomy Aspirin Low dose IFN → responsive | Phlebotomy1 Aspirin IFN à resistant → HU | If IFN resistant → HU or JAK2 inhibitor | JAK2 Inhibitor → Bone marrow transplantation | Chemotherapy Bone marrow transplantation? Supportive |
1
↑: Increased; ↓: Decreased; N: Normal; +: Present or heterozygous; ++: Homozygous; HU: Hydroxyurea; PV: Polycythemia vera; MF: Myelofibrosis; WHO-ECMP: World Health Organization and European Cliical Molecular and Pathological; LAP: Leukocyte alkaline phosphatase; EPO: Erythropoietin.