OBJECTIVETo investigate the frequency and clinical implication of JAK2 mutation in patients with myeloproliferative neoplasm(MPN)and the correlation between the mutation and thrombosis.

METHODSThe clinical and laboratory data of 107 MPN patients was retrospectively analyzed. JAK2 mutation were detected with allele-specific polymerase chain reaction (AS-PCR) and sequencing. The significance of the mutation in disease diagnosis and molecular pathogenesis and the correlation between the mutation and thrombosis was analysed.

RESULTSJAK2 mutation was detected in 71 (66.4%) and thrombosis in 34 (31.8%) of the 107 MPN patients. Thrombosis occurred in 34.8% (16/46) of polycythemia vera (PV), 32.6% (14/43) of essential thrombocythemia (ET), and 22.2% (4/18) of primany myelofibrosis (PMF) patients. The difference among the 3 groups was not significant (χ(2) = 0.96, P > 0.05). The frequency of thrombosis in JAK2(+) MPN patients (82.4%, 28/34) was higher than that in JAK2(-) MPN patients (17.6%, 6/34) (χ(2) = 5.71, P < 0.05). The frequency of thrombosis in MPN patients > 60 years was higher (41.5%, 27/65) than that in patients < 60 years (16.7%, 7/42) (χ(2) = 7.28, P < 0.01).

CONCLUSIONJAK2 V617F mutation occurs in significant percentage of Chinese patients with MPN. Patients with JAK2 mutation and older age are more succeptible to thrombosis. JAK2 mutation screening in patients with unknown thrombosis is helpful to reveal the underlying latent-MPN.