title: Outcome of patients with splanchnic venous thrombosis presenting without overt MPN: a role for the JAK2 V617F mutation re-evaluation.
abstract: BACKGROUND
  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.
  
  
  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.
authors.affiliation: Unita' di Aterosclerosi e Trombosi, I.R.C.C.S. "Casa Sollievo della Sofferenza", S. Giovanni Rotondo, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Colaizzo
authors.forename: Lucio
authors.initials: L
authors.lastname: Amitrano
authors.forename: Maria Anna
authors.initials: MA
authors.lastname: Guardascione
authors.forename: Giovanni Luca
authors.initials: GL
authors.lastname: Tiscia
authors.forename: Giovanna
authors.initials: G
authors.lastname: D'Andrea
authors.forename: Vittoria A C
authors.initials: VA
authors.lastname: Longo
authors.forename: Elvira
authors.initials: E
authors.lastname: Grandone
authors.forename: Maurizio
authors.initials: M
authors.lastname: Margaglione
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009196:Myeloproliferative Disorders / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D011379:Prognosis; D012307:Risk Factors; D013152:Splanchnic Circulation; D016896:Treatment Outcome; D020246:Venous Thrombosis / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D055815:Young Adult
chemical_list: C507924:JAK2 protein, human; D053614:Janus Kinase 2
keywords: Mutation; Myeloproliferative disease; Risk factors; Splanchnic circulation; Venous thrombosis