The Clinical Significance of JAK2V617F Mutation for Philadelphia–Negative Chronic Myeloproliferative Neoplasms in Patients with Splanchnic Vein Thrombosis

Researchers have confirmed that simple and rapid JAK2V617F peripheral blooding testing is a vital component of diagnosis latent myeloproliferative disease (MPD) and splanchnic vein thrombosis (SVT). Their results were published in the SOHO 2019 Meeting Proceedings Supplement in Clinical Lymphoma, Myeloma and Leukemia.

In this study, researchers analyzed assessed diagnostic value of JAK2V617F mutation in 68 patients with SVT (42 patients with patPVT, 19 with BCS, and with 7 combined PVT and BCS) under follow-up between 2007 and 2010. They used fluorescent resonance energy transfer probes and LightCycler techniques to identify JAK2V617F. Genotype assessment in this study was based on melting curve analysis.

The study results showed that JAK2V617F was present in 42.1% of BCS, 38.1% of PVT and 71.4% of combined PVT and BCS patients. It observed that 13 of 15 patients with overt MPD and 16 of 53 patients without overt MPD (patients with normal blood counts or cytopenia’s) including 6 of 16 with BCS (37.5%), 7 of 33 with PVT (21.2%) and 3 of 4 with combined BCS and PVT (75%) had JAK2V617F. Results showed that JAK2V617F was linked with significantly higher platelet and leukocyte counts. Most patients with JAK2V617F had peripheral blood counts within normal range except for higher mean values for leucocytes (10525/mm (SD 6547)). There was a trend for higher mean values for higher LDH levels in JAK2V617F mutation carriers than in noncarriers (mean 523 U/L (SD 229.1), mean 431 U/L (SD 184.5), respectively; p=0.08).

Moreover, the study observed a significant positive correlation between JAK2V617F mutation status and leukocyte and platelet counts (r=0.445 and r=0.384, respectively). The analysis of a Receiver Operating Characteristic (ROC) determined a platelet count of 190000/mm³ (area under curve; AUC=0.724, p=0.002) and a leukocyte of 8150/mm³ (AUC=0.76, p=0.001) as best cut-off values for highest sensitivity and specificity ratios of JAK2V617F mutation in SVT. The researchers observed that there was no relation between prothrombotic risk factors and JAK2V617F, sites of thrombosis (PVT or BCS), presence of combined thrombosis and Hgb, Htc, platelet and leukocyte counts.

The researchers concluded that “despite absence of overt signs of MPD, a substantial proportion of patients with SVT were shown to carry the JAK2V617F mutation.”

Read more at: Hindilerden, F, et al. The Clinical Significance of JAK2V617F Mutation for Philadelphia-Negative Chronic Myeloproliferative Neoplasms in Patients with Splanchic Vein Thrombosis. Published for the SOHO 2019 Annual Meeting; September 11-14, 2019; Houston, TX.