title: Low-density lipoprotein receptor-related protein 1 polymorphism 663 C > T affects clotting factor VIII activity and increases the risk of venous thromboembolism.
abstract: BACKGROUND
  Clotting factor (F) VIII is an independent risk factor for primary and recurrent venous thromboembolism (VTE). The causes for high plasma FVIII levels are not fully understood, but an involvement of genetic factors has been demonstrated. A multifunctional endocytic receptor, low-density lipoprotein receptor-related protein 1 (LRP1), mediates cellular uptake and subsequent degradation of FVIII and may contribute to variations in FVIII levels.
  
  
  OBJECTIVE
  We assessed the association of a genetic variation of LRP1 (663C > T) with basal FVIII levels and the risk of venous thrombosis in a group of high-risk patients and in healthy controls.
  
  
  METHODS
  One hundred and fifty-two patients with a history of recurrent VTE (median age 56 years, 47% women) were compared with 198 age- and sex-matched controls (median age 53 years, 50% women). The LRP1 663C > T genotype was analyzed by mutagenic separated polymerase chain reaction assay and heterozygosity was confirmed by sequence analysis.
  
  
  RESULTS
  LRP1 663C > T genotype distribution differed significantly between patients (663CC n = 138, 663CT n = 14) and controls (663CC n = 190, 663CT n = 8; P = 0.048). In multivariable linear regression analysis including LRP1 663C > T, ABO blood group, von Willebrand factor antigen, C-reactive protein and age, LRP1 663CT was independently associated with FVIII activity (P = 0.02). LRP1 663CT was also associated with increased odds for VTE following adjustment for blood group O, FV Leiden and the prothrombin variation 20210G > A in multivariate analysis (odds ratio 3.3, 95% CI 1.3-8.5).
  
  
  CONCLUSIONS
  According to our data the LRP1 663C > T polymorphism influences plasma FVIII levels independently of blood group, C-reactive protein and von Willebrand factor and is significantly associated with the risk of VTE.
authors.affiliation: Division of Haematology and Haemostaseology, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Vormittag
authors.forename: P
authors.initials: P
authors.lastname: Bencur
authors.forename: C
authors.initials: C
authors.lastname: Ay
authors.forename: T
authors.initials: T
authors.lastname: Tengler
authors.forename: T
authors.initials: T
authors.lastname: Vukovich
authors.forename: P
authors.initials: P
authors.lastname: Quehenberger
authors.forename: C
authors.initials: C
authors.lastname: Mannhalter
authors.forename: I
authors.initials: I
authors.lastname: Pabinger
mesh_terms: D016022:Case-Control Studies; D003596:Cytosine; D005169:Factor VIII / Q000378:metabolism*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D016014:Linear Models; D026503:Low Density Lipoprotein Receptor-Related Protein-1 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D013923:Thromboembolism / Q000235:genetics* / Q000378:metabolism; D013941:Thymine; D020246:Venous Thrombosis / Q000235:genetics* / Q000378:metabolism
chemical_list: D026503:Low Density Lipoprotein Receptor-Related Protein-1; D003596:Cytosine; D005169:Factor VIII; D013941:Thymine