Prevalence of the activating JAK2 tyrosine kinase mutation in chronic porto-splenomesenteric venous thrombosis

David W Orr (1) , Raj Patel (1) , Nicholas Lea (1) , Rachel Westbrook (1) , Nigel Heaton (1) , John O'Grady (1) , Antonio Pagliuca (1) , Ghulam Mufti (1) , Michael A Heneghan (1)

1 KCH - King's College Hospital

Background: Occult myeloproliferative disorders (MPD) are present in 25% of patients with chronic portal, splenic and mesenteric venous thrombosis (PSMVT). A somatic mutation of JAK2 (JAK2V617F) can be used to identify patients with latent MPD. Aims: We evaluated the prevalence and clinical significance of JAK2V617F in patients with chronic PSMVT. Methods: Allele specific PCR was performed to screen for JAK2V617F. Results: Thirty-five patients were tested for JAK2V617F. The underlying pro-coagulant condition was MPD in 7/35 (20.0%); other aetiologies included hereditary thrombophilia (n=5), chronic pancreatitis (n=2), liver abscess (n=1) and umbilical vein sepsis (n=3). The remainder were labelled idiopathic 17/35 (48.6%). JAK2V617F was detected in 16/35 (45.7%) patients; 7/7 (100%) with MPD; 2/11 (18.1%) with non-MPD acquired conditions and 7/17 (41.2%) with ‘idiopathic' chronic PSMVT. Mean haemoglobin concentration (p=0.04), haematocrit (p=0.04), white cell count (p=0.002) and platelet count (p=0.05) were significantly higher in patients with JAK2V617F. None of the 7 patients with latent MPD have progressed to overt MPD over median follow up of 85-months. Conclusion: JAK2V617F occurs in a 41% of patients with idiopathic chronic PSMVT, confirming the presence of latent MPD and should form part of the routine pro-coagulant screen.

Mots clés: Medicine

David W Orr, Raj Patel, Nicholas Lea, Rachel Westbrook, Nigel Heaton, et al.. Prevalence of the activating JAK2 tyrosine kinase mutation in chronic porto-splenomesenteric venous thrombosis. Alimentary Pharmacology and Therapeutics, 2010, 31 (12), pp.1330. ⟨10.1111/j.1365-2036.2010.04299.x⟩. ⟨hal-00552549⟩