The Janus kinase 2 (JAK2) Mutation Burden is Related to Hematological Outcomes in Thai Patients with Myeloproliferative Neoplasms.

BACKGROUND

At present, data on the Janus kinase 2 (JAK2) mutation allele burden in Thai patients are limited. The aim of this study was to determine the prevalence of JAK2 V617F mutations and their association with the clinicohematological parameters of Thai patients with myeloproliferative neoplasms (MPNs).

METHODS

JAK2 V617F mutation status and allele burden were analyzed in 394 MPN patients using TaqMan polymerase chain reaction (PCR) probes and ARMS technology-based technique using the Ipsogen JAK2 RGQ PCR Kit.

RESULTS

The JAK2 V617F mutation was detected in 130 of 394 patients (32.9%). Subtype-specific JAK2 V617F detection rates were 48.1% for essential thrombocythemia (ET), 24.5% for polycythemia vera (PV), 22.2% for primary myelofibrosis (PMF) and 42.8% for Unspecified MPN patients. JAK2 V617F-positive PV and ET subtypes had a significantly higher mean age than JAK2 V617F-negative patients (p = 0.0002 and p = 0.029, respectively). The platelet (Plt) counts of JAK2 V617F-positive PV, Unspecified MPN and All groups were significantly higher than those in JAK2 V617F-negative patients (p < 0.0001, p = 0.0006 and p < 0.0001, respectively). The PMF subgroup had the highest mean JAK2 V617F allele burden (52.43 ± 34.74) compared with Unspecified MPN (51.81 ± 25.63), PV (47.38 ± 28.78) and ET patients (21.12 ± 16.34) (p < 0.0001). According to JAK2 V617F allele burden subtypes, only PV patients showed a significant increase in the white blood cell (WBC) count and hematocrit (Hct) related to incremental increases in the V617F allele burden (p < 0.0001).

CONCLUSIONS

The allele burden of JAK2 V617F was significantly lower in ET than in PV and PMF. Only the WBC, Hct and Plt counts were significantly different among the JAK2 V617F allele burden subgroups. Measuring the JAK2 V617F allele burden quantitatively might be an additional tool for predicting the hematological outcomes of MPNs.