title: PAI-1 4G-4G, MTHFR 677TT, V Leiden 506Q, and Prothrombin 20210A in Splanchnic Vein Thrombosis: Analysis of Individual Patient Data From Three Prospective Studies.
abstract: BACKGROUND
  There are no univocal opinions on the role of genetic thrombophilia on splanchnic vein thrombosis (SVT). We defined genetic thrombophilia the presence of one of these thrombophilic genetic factors (THRGFs): PAI-1 4G-4G, MTHFR 677TT, V Leiden 506Q, and prothrombin 20210A.
  
  
  OBJECTIVE
  To evaluate the frequencies of these THRGFs in SVT patients, we analyzed individual data of 482 Caucasian patients, recruited from 2000 to 2014 in three prospective studies. SVT was defined as the presence of thrombosis of portal (PVT), mesenteric (MVT), splenic (SPVT), cava (CT), and hepatic vein (Budd Chiari syndrome, BCS). Pre-hepatic SVT (pre-HSVT) was defined as PVT with or without MVT/SPVT, without BCS. Post-hepatic SVT (post-HSVT) was BCS with or without PVT/MVT/SPVT.
  
  
  METHODS
  We compared 350 patients with liver cirrhosis (LC), 47 hepatocellular carcinoma (HCC), 37 myeloproliferative neoplasm (MPN), 38 associated disease (AD), 10 without any associated disease (WAD), vs 150 healthy controls (HC); 437 patients showed pre-HSVT and 45 post-HSVT.
  
  
  RESULTS
  Thrombophilia was present in 294/482 (60.9%) patients: 189/350 LC (54.0%), 31/47 (66.0%) HCC, 29/39 (74.4%) MPN, 35/38 AD (92.1%), and 10/10 (100%) WAD, and 54/150 (36.0%) in HC. In the total group, we found 175 PAI-1 4G-4G, 130 MTHFR 677TT, 42V Leiden 506Q, and 27 prothrombin 20210A; 75 patients showed presence of >1 TRHGF; the more frequent association was PAI-1 4G-4G/MTHFR 677TT, in 36 patients. PAI-1 4G-4G and MTHFR 677TT were significantly more frequent in patients with SVT (P values <0.005), whereas V Leiden Q506 and prothrombin G20210A were not. PAI-1 4G-4G and MTHFR 677TT distributions deviated significantly from that expected from a population in Hardy-Weinberg equilibrium. Thrombophilia was significantly less frequent in patients with pre-HSVT (250/437, 57.2%) than in patients with post-HSVT (44/45, 97.8%).
  
  
  CONCLUSIONS
  Our study shows the significant prevalence of PAI-1 4G-4G and MTHFR 677TT in SVT, mainly in post-HSVT.
authors.affiliation: Department of Medicine, Clinica Candela, Via Villareale, 54, 90141 Palermo, Italy.
authors.forename: Linda
authors.initials: L
authors.lastname: Pasta
authors.affiliation: Department of Medicine, Clinica Candela, Via Villareale, 54, 90141 Palermo, Italy; Department of Biopathology and Medical Biotechnologies, University of Palermo, Via del Vespro 127, 90127, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pasta
authors.affiliation: Department of Biopathology and Medical Biotechnologies, University of Palermo, Via del Vespro 127, 90127, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: D'Amico
keywords: AD, associated disease; BCS, Budd Chiarisyndrome; CT, cava thrombosis; HC, healthy controls; HCC, hepatocellular carcinoma; LC, liver cirrhosis; MPN, myeloproliferative neoplasm; MVT, mesenteric vein thrombosis; PVT, portal vein thrombosis; Post-HSVT, post-hepatic SVT (BCS with or without other thrombosis sites); Pre-HSVT, pre-hepatic SVT (presence of PVT with or without MVT/SPVT, without BCS); SPVT, splenic vein thrombosis; SVT, splanchnic vein thrombosis; THRGF, thrombophilic genetic factor; WAD, without any associated disease; abdominal thrombosis; cryptogenic cirrhosis; hepatocellular carcinoma; myeloproliferative neoplasms; virus related cirrhosis