A prospective study of venous thromboembolism in relation to factor V Leiden and related factors

Blood. 2002 Apr 15;99(8):2720-5. doi: 10.1182/blood.v99.8.2720.

Abstract

The aim of this study was to examine the occurrence of venous thromboembolism (VTE) in relation to factor V-related risk factors. Using a nested case-control design combining 2 population-based prospective studies, we measured factor V Leiden, HR2 haplotype, activated protein C (APC) resistance, and plasma factor V antigen in 335 participants who developed VTE during 8 years of follow-up and 688 controls. The overall odds ratio (OR) of VTE was 3.67 (95% CI, 2.20-6.12) in participants carrying factor V Leiden compared with noncarriers. APC resistance measured after predilution with factor V-deficient plasma conferred an OR of 2.58 (95% CI, 1.62-4.10). All 3 participants homozygous for the HR2 haplotype had a VTE, and the OR of VTE for homozygosity was estimated to be 5.5 (95% CI, 2.45-12.5). Carriers of the HR2 haplotype otherwise were not at increased risk of VTE overall (OR = 1.05; 95% CI, 0.64-1.72), but double heterozygotes for HR2 and factor V Leiden carried an OR of idiopathic VTE of 16.3 (95% CI, 1.7-159) compared with noncarriers. Factor V antigen also was not associated with VTE overall, but for participants with the combination of high factor V antigen plus factor V Leiden the OR of idiopathic VTE was 11.5 (95% CI, 4.2-31.4). In the general population, APC resistance and factor V Leiden were important VTE risk factors; homozygosity for the HR2 haplotype may be a risk factor but was rare; otherwise, HR2 haplotype and factor V antigen were not risk factors except in carriers of factor V Leiden.

Publication types

  • Multicenter Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Activated Protein C Resistance
  • Aged
  • Cohort Studies
  • Factor V / analysis*
  • Genotype
  • Haplotypes
  • Humans
  • Incidence
  • Longitudinal Studies
  • Middle Aged
  • Odds Ratio
  • Prospective Studies
  • Racial Groups
  • Risk Factors
  • Thromboembolism / blood
  • Thromboembolism / epidemiology
  • Thromboembolism / etiology*
  • Venous Thrombosis / blood
  • Venous Thrombosis / epidemiology
  • Venous Thrombosis / etiology*

Substances

  • factor V Leiden
  • Factor V