Prevalence of JAK29V617F) mutation in intra-abdominal venous thrombosis.

BACKGROUND AND AIM

Myeloproliferative disorders (MPD) (like polycythemia vera, essential thrombocythemia and primary myelofibrosis) are responsible for 50% cases of Budd-Chiari syndrome (BCS) and 35% cases of portal venous thrombosis (PVT) in western series. A point mutation at Val617Phe of Janus kinase 2 tyrosine kinase gene (JAK2(V617F) mutation) occurs in high proportion with MPD. This may be useful in diagnosing overt and latent form of MPD in intra-abdominal venous thrombosis (IAVT), consisting of BCS and PVT.

METHODS

In a 4 year prospective study from 2006 to 2009, JAK2 mutations were assessed in all patients diagnosed with MPD and IAVT attending our institution. Twenty three healthy individuals and 31 patients with non-MPD hematological disorders served as controls. All patients of idiopathic IAVT were tested for the mutation. Test for JAK2(V617F) mutation was carried out by allele specific polymerase chain reaction.

RESULTS

JAK2(V617F) mutation was significantly more common in MPD patients (76%) than in non-MPD hematological disorders (0%) and healthy controls (0%). There was no statistical difference in presence of JAK2(V617F) mutation in patients of MPD with or without thrombosis (80% vs. 74%). In 58 patients with IAVT, the JAK2(V617F) mutation was present in 40% with BCS, 14% with PVT and 100% combined BCS+PVT).

CONCLUSIONS

The JAK2(V617F) mutation occurs at high frequency in patients with MPD and IAVT. All idiopathic IAVT patients must be screened for JAK2(V617F) mutation to detect latent MPD. Detection of latent MPD by JAK2(V61F) mutation in BCS may change treatment strategy and outcome.