A Retrospective Cross-sectional Study on Activated Protein C Resistance (Factor V Leiden): an Independent, Gender-dependent Risk Factor for Venous Thromboembolism

Abstract Background: Activated protein C resistance (APCR) due to factor V R506Q (Leiden) mutation is a major risk factor in patients with venous thromboembolism. The present study investigated the symptoms patterns and the risk for venous thromboembolism regarding multiple clinical, laboratory, and demographic properties in APCR patients.Material and Methods: A retrospective cross-sectional analysis was conducted on a total of 288 APCR patients with age interval ranging between 1 to 80 years. In addition, 288 control samples, reported healthy after confirmatory tests, were also randomly selected. Demographic information, clinical manifestations, family and treatment history were recorded, and specific tests applied.Results: APCR was found to be 2.3 times significantly more likely in men (OR: 2.1, p < 0.05) than women. The risk of DVT and PE in APCR patients was 4.5 and 3.2 times more than the normal group, respectively (p < 0.05). However, APCR could not be an independent risk factor for arterial thrombosis and pregnancy complications. Moreover, patients were evaluated for thrombophilia panel tests and showed significantly lower protein C and S than the control group and patients without DVT (p<0.0001).Conclusion: Factor V Leiden mutation and APCR abnormality are noticeable independent risk factors for venous thromboembolism. Screening strategies for factor V Leiden mutation in patients undergoing surgery, oral contraceptive medication, and pregnancy cannot be recommended, but a phenotypic test for activated protein C resistance should be endorsed in patients with venous thromboembolism.