title: Inherited factor XI deficiency confers no protection against acute myocardial infarction.
abstract: OBJECTIVE
  Factor XI (FXI) contributes to thrombin generation thereby affecting fibrin formation and to down regulation of fibrinolysis by activation of thrombin-activatable fibrinolysis inhibitor (TAFI). The purpose of this study was to evaluate whether patients with severe FXI deficiency are protected against acute myocardial infarction (AMI).
  
  
  METHODS
  The incidence of AMI in patients with severe FXI deficiency (FXI activity less than 15 U dL(-1)) whose age was 35 years or more was compared to the incidence of AMI in age and gender matched persons of the general population. Atherosclerotic risk factors were assessed in FXI deficient patients and blood was tested for prothrombotic parameters such as FV Leiden, prothrombin G20210A, lupus anticoagulant, and platelet membrane polymorphisms. The common mutations causing FXI deficiency in Jews were also examined.
  
  
  RESULTS
  Of 96 patients with severe FXI deficiency (55 women and 41 men) 16 had a history of AMI (6 women and 10 men). The median age at the time of AMI was 64.5 for women and 58 for men. The calculated annual rate of AMI in men was similar to the expected in the general Israeli population, whereas in women it was almost 2-fold higher, but this difference did not reach statistical significance. One or more atherosclerotic risk factors were observed in 13 of 16 patients (81.3%) with AMI compared to 44 of 79 patients (55.7%) without AMI (P < 0.001). The frequency distributions of platelet polymorphisms and of prothrombotic polymorphisms were not different between patients with severe FXI deficiency who experienced or not an AMI. None of the patients had lupus anticoagulant. The common genotypes which cause FXI deficiency in Jews were similarly distributed in patients with and without AMI.
  
  
  CONCLUSIONS
  Severe FXI deficiency does not confer protection against AMI.
authors.affiliation: Institute of Thrombosis and Hemostasis, Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine, Tel Aviv, Israel.
authors.forename: O
authors.initials: O
authors.lastname: Salomon
authors.forename: D M
authors.initials: DM
authors.lastname: Steinberg
authors.forename: R
authors.initials: R
authors.lastname: Dardik
authors.forename: N
authors.initials: N
authors.lastname: Rosenberg
authors.forename: A
authors.initials: A
authors.lastname: Zivelin
authors.forename: I
authors.initials: I
authors.lastname: Tamarin
authors.forename: B
authors.initials: B
authors.lastname: Ravid
authors.forename: S
authors.initials: S
authors.lastname: Berliner
authors.forename: U
authors.initials: U
authors.lastname: Seligsohn
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001161:Arteriosclerosis / Q000453:epidemiology / Q000235:genetics; D005173:Factor XI Deficiency / Q000453:epidemiology* / Q000235:genetics; D005192:Family Health; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D007557:Israel / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000235:genetics; D010980:Platelet Membrane Glycoproteins / Q000235:genetics; D011110:Polymorphism, Genetic; D012307:Risk Factors; D019851:Thrombophilia / Q000453:epidemiology / Q000235:genetics
chemical_list: D010980:Platelet Membrane Glycoproteins