title: Effect of antithrombin, protein C and protein S on portal vein thrombosis in liver cirrhosis: a meta-analysis.
abstract: BACKGROUND
  The effects of antithrombin (AT), protein C (PC) and protein S (PS) on the pathogenesis of portal vein thrombosis (PVT) in liver cirrhosis remain controversial in different studies. In this study, a systematic review and meta-analysis to examine this issue were performed.
  
  
  METHODS
  PubMed database was employed to identify all studies in which AT, PC and PS concentrations were measured in both cirrhotic patients with and without PVT. A standardized mean difference (SMD) with 95% confidence interval (CI) was calculated to evaluate the effect of AT, PC and PS on PVT. Data were pooled using both fixed-effect and random-effect models. Only the pooled data using random-effect model were considered appropriate, when significant heterogeneity was observed.
  
  
  RESULTS
  Nine studies involving 160 cirrhotic patients with PVT and 428 cirrhotic patients without PVT were eligible. AT and PC concentrations were similar between PVT and non-PVT groups (AT: SMD = -0.21, 95% CI = -0.56 to 0.14, P = 0.24; PC: SMD = -0.23, 95% CI = -0.55 to 0.09, P = 0.16). But PS concentration was significantly lower in the PVT group than in the non-PVT group (SMD = -0.29, 95% CI = -0.49 to -0.08, P = 0.006). Subgroup analyses were further conducted in 4 studies in which baseline liver function was similar between cirrhotic patients with and without PVT, showing similar AT, PC and PS concentrations between the 2 groups (AT: SMD = -0.10, 95% CI = -0.36 to 0.16, P = 0.57; PC: SMD = -0.18, 95% CI = -0.62 to 0.25, P = 0.41; PS: SMD = -0.10, 95% CI = -0.59 to 0.39, P = 0.69).
  
  
  CONCLUSIONS
  AT, PC and PS concentrations might not be associated with the pathogenesis of PVT in liver cirrhosis, especially when the impact of liver function was excluded.
authors.affiliation: Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, China.
authors.forename: Xingshun
authors.initials: X
authors.lastname: Qi
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Guohong
authors.initials: G
authors.lastname: Han
mesh_terms: D000991:Antithrombins / Q000627:therapeutic use*; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications*; D011169:Portal Vein / Q000473:pathology*; D011486:Protein C / Q000627:therapeutic use*; D017293:Protein S / Q000627:therapeutic use*; D013927:Thrombosis / Q000188:drug therapy* / Q000209:etiology
chemical_list: D000991:Antithrombins; D011486:Protein C; D017293:Protein S