Primary Thrombophilia in México XI: Activated Protein C Resistance Phenotypes are Multifactorial

Activated protein C resistance (aPCR) phenotypes represent around 20% of the laboratory findings in Mexican Mestizos having suffered thrombosis and displaying clinical markers of thrombophilia. In a single institution for a 276-month period, 96 Mexican mestizos with a history of thrombosis and clinical markers of a primary thrombophilic state were prospectively studied to identify a thrombophilic condition. An abnormal aPCR phenotype was identified in 18 individuals. Evaluation of those with an abnormal aPCR phenotype, identified that 44% had factor V Leiden mutation, 22% increased levels of factor VIII, 16% anti-phospholipid antibodies and 6% a lupus anticoagulant. In the remaining 22%, the use of direct oral anticoagulants (DOACs) in the past period of 12–24 h was recorded. We found significant associations between abnormal aPCR phenotype and the factor V Leiden mutation ( p = 0022), between abnormal aPCR phenotype and the use of DOACs ( p = 0.006) and between antiphospholipid antibodies and lupus anticoagulant ( p