Prothrombotic factors and the risk of acute onset non-cardioembolic stroke in young Asian Indians

Abstract 

Introduction

Several prothrombotic factors – both hereditary and acquired – are known to cause stroke. Commonly investigated causes are activated protein C resistance, factor V Leiden mutation, factor VIII levels, prothrombin 20210 G-to-A mutation, coagulation inhibitors such as proteins C and S, and antiphospholipid antibodies such as β₂-glycoprotein.

Objective

The literature on the prevalence of hematological defects pertaining to these variables in the Asian Indian stroke population is limited to a few isolated reports. In the current study we investigate the above-mentioned variables in 120 stroke patients (non-cardioembolic acute-onset stroke) and compare their status with the hematological profile of an equal number of healthy age- and sex-matched controls.

Material and Methods

Plasma and blood leukocytes were collected from all patients and controls for performing hematological assays and molecular tests respectively. The mutations were detected using standard polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) procedures. Statistical analysis was done using SPSS version 12.0.

Results

Factor V Leiden (prevalence 8.3% in patients) and activated protein C resistance (prevalence 19.6% in patients) both showed a high degree of association (P<0.01) with the disease condition. However, contrary to common expectations, factor V Leiden was observed much less frequently in patients showing activated protein C resistance (10 out of 23; 43.4%) than is commonly observed in the Caucasian population (almost 90%). Post-acute-phase factor VIII levels were also found to be significantly associated with stroke: 125.6+21.1% number of profitable positions (NPP) for controls and 136.2+28.8% NPP for patients (P=0.001).

Conclusion

factor V mutations, such as factor V Leiden, may be important risk factors for stroke in an Asian Indian population. Activated protein C resistance has a stronger association with stroke than factor V Leiden and may be caused by other factors such as elevated factor VIII levels in the Asian Indian population apart from factor V Leiden itself.

Keywords: Factor V Leiden mutation, Factor V HR2 Haplotype, Coagulation Inhibitors, Factor VIII levels, Acute phase, Asian-Indians