Role of Factor V R2 Haplotype and Common Thrombophilia Markers as Genetic Risk Factors for Ischemic Stroke

Background: Uncertainties remain about the role of common thrombophilia markers as determinants of the ischemic stroke (IS) risk. Polymorphism His1299Arg in the FV gene, named R2 haplotype (FVHR2), has been poorly investigated. The aim of the present study was to assess the prevalence of common thrombophilia markers and of FVHR2 in a cohort of IS patients compared to a nonmatched group of healthy individuals. Methods: We studied 156 consecutive patients survivors of a first ever IS and 124 healthy controls. All subjects were investigated for the gene polymorphisms factor V (FV) Leiden, prothrombin (PTH) G20210A, MTHFR C677T, and FVHR2. Protein C (PC), protein S (PS), antithrombin (ATIII), and lupus anticoagulant (LAC) activity was measured. Homocysteinemia was assessed within 48 hours and after 30 days from stroke onset. Univariate and multivariate analyses were performed. Results: Compared with controls, patients were significantly older (mean [SD] age, 50.5 [12.9] vs 37.5 [15.5] years, P < .001), less frequently females (48.1% vs 67.7%, P = .001) and had more frequently hyperhomocysteinemia (45.9% vs 11.0%) only in the acute phase (OR 6.899, CI 95% 2.993-15.899; P < .001). No differences were found in the prevalence of FV Leiden, PTH G20210A, and MTHFR C677T between patients and controls, whereas FVHR2 was present in 34/156 (22%) stroke patients and in 5/124 (4%) controls (OR 6.632, 95% CI 2.509-17.535, P < .001). In a multivariate logistic regression analysis, the FVHR2 resulted independently associated with the occurrence of IS (OR 6.071, 95% CI 1.762-20.923; P = .004). Conclusions: In our study, hyperhomocysteinemia was confirmed to be a transient consequence of the thrombotic event. FVHR2 seems to be a possible candidate prothrombotic condition related to arterial IS irrespective of age and sex in an Italian sample population.