Outcome of patients with splanchnic venous thrombosis presenting without overt MPN: a role for the JAK2 V617F mutation re-evaluation.

Introduction: Although investigation for JAK2 V617F mutation is recommended in patients presenting with splanchnic venous thrombosis (SVT), no specific clinical advice is given to SVT patients presenting without myeloproliferative neoplasms (MPN) and JAK2 V617F mutation. In MPN-free SVT patients, to investigate the clinical outcome, the clinical impact of re-evaluation for the JAK2 V617F mutation, and relationships with the occurrence and time to diagnosis of MPN.
Materials and Methods: A cohort of non-cirrhotic SVT patients, enrolled at a single centre and prospectively analyzed.
Results: In 121 SVT patients prospectively followed from 1994 to 2012, a MPN was present in 28 (23.1%). Additional 13 patients (10.7%) showed only the JAK2 V617F mutation. During the follow-up, the JAK2 V617F mutation and/or MPN were identified in 8 patients (median time of development: 21 months, range 6-120), whereas 72 remained (MPN and JAK2 V617F)-free until the end of the observation. The mortality rate was higher among patients presenting with MPN and/or the JAK2 V617F mutation than in patients who developed later or remained disease-free (p=0.032). The thrombosis-free survival was lower in patients with (p=0.04) or developing later MPN and the JAK2 V617F mutation (p=0.005) than in patients (MPN and JAK2 V617F)-free. The incidence of bleeding was similar among groups.
Conclusions: MPN with or without circulating positive clones for JAK2 V617F mutation can occur long after a SVT, identifying at risk patients for new thrombotic events. If confirmed in other studies, re-evaluation for JAK2 V617F mutation may be of help in early MPN detection and clinical management of SVT patients.
(© 2013.)