JAK2V617F allele burden and thrombosis: A direct comparison in essential thrombocythemia and polycythemia vera

Carobbio, Alessandra; Finazzi, Guido; Antonioli, Elisabetta; Guglielmelli, Paola; Vannucchi, Alessandro M.; Dellacasa, Chiara M.; Salmoiraghi, Silvia; Delaini, Federica; Rambaldi, Alessandro; Barbui, Tiziano

doi:10.1016/j.exphem.2009.06.006

« Previous Next »Experimental Hematology
Volume 37, Issue 9 , Pages 1016-1021, September 2009

JAK2V617F allele burden and thrombosis: A direct comparison in essential thrombocythemia and polycythemia vera

Alessandra Carobbio
- Hematology Department, Ospedali Riuniti di Bergamo, Bergamo, Italy
Guido Finazzi
- Hematology Department, Ospedali Riuniti di Bergamo, Bergamo, Italy
Elisabetta Antonioli
- Hematology Department, Università degli Studi di Firenze, Florence, Italy
Paola Guglielmelli
- Hematology Department, Università degli Studi di Firenze, Florence, Italy
Alessandro M. Vannucchi
- Hematology Department, Università degli Studi di Firenze, Florence, Italy
Chiara M. Dellacasa
- Hematology Department, Ospedali Riuniti di Bergamo, Bergamo, Italy
Silvia Salmoiraghi
- Hematology Department, Ospedali Riuniti di Bergamo, Bergamo, Italy
Federica Delaini
- Hematology Department, Ospedali Riuniti di Bergamo, Bergamo, Italy
Alessandro Rambaldi
- Hematology Department, Ospedali Riuniti di Bergamo, Bergamo, Italy
Tiziano Barbui
- Hematology Department, Ospedali Riuniti di Bergamo, Bergamo, Italy
- Offprint requests to: Tiziano Barbui, M.D., Ospedali Riuniti di Bergamo, Largo Barozzi 1 24128 Bergamo, Italy

Received 20 April 2009; received in revised form 16 June 2009; accepted 17 June 2009. published online 25 June 2009.

Objective

A direct comparison of the incidence and risk factors of major thrombosis in essential thrombocythemia (ET) and polycythemia vera (PV) according to their respective JAK2V617F allele burden is the object of this study.

Materials and Methods

We compared the rate (%/patients/year) of major thrombosis in 867 ET patients (57% JAK2V617F) with that of 415 PV patients (all JAK2V617F) and examined risk factors.

Results

Patients with ET wild-type, ET V617F, and PV showed a rate of thrombosis of 1.4%, 2.1%, and 2.7%/patients/year, respectively. The latter was found to progressively increase according to time of diagnosis. Actuarial probability of arterial and venous thrombosis in the first 5 years of diagnosis was roughly similar in the three groups. While in the subsequent periods, the curves of mutated ET patients diverged from wild-type, and after 10 to 15 years the ET-mutated arm approached PV.

Conclusion

These findings support the concept of a continuum between ET JAK2 mutated and PV, not only in reference to the hematological phenotype, but also in terms of vascular events.