Factor II Activity is similarly increased in patients with elevated apolipoprotein CIII and in carriers of the factor II 20210A allele.

BACKGROUND: Few studies have so far investigated the relationship betweenapolipoprotein CIII (Apo CIII) and coagulation pathway in subjects with orwithout coronary artery disease (CAD).METHODS AND RESULTS: Serum Apo CIII concentrations and plasma coagulantactivities of factor II (FII:c), factor V (FV:c), and factor VIII (FVIII:c), and activated factor VII (FVIIa) were analyzed in a total of 933 subjects, with(n=687) or without (n=246) angiographically demonstrated CAD and not takinganticoagulant drugs. Activated factor X (FXa) generation assay was performed onplasma from subgroups of subjects with low and high levels of Apo CIII. Astatistical incremental concentration of FII:c, FV:c, and FVIIa levels wasobserved through the quartiles of Apo CIII distribution in the populationconsidered as a whole. Significant results were confirmed for FII:c in CAD andCAD-free subgroup when separately considered. Subjects within the highest ApoCIII quartile (>12.6 mg/dL) had high FII:c levels not statistically differentfrom those of carriers of 20210A allele (n=40; 4.28%). In a multiple linearmodel, Apo CIII was the best predictor of FII:c variability, after adjustment forage, gender, plasma lipids, CRP, creatinine, diagnosis, and carriership of 20210Aallele. FXa generation was increased and its lag time shortened in plasmas withhigh Apo CIII levels. However, after thrombin inhibition by hirudin, differences between low and high Apo C-III samples disappeared.CONCLUSIONS: Elevated concentrations of Apo CIII are associated with an increase of thrombin activity to an extent comparable with the carriership of G20210A genevariant and mainly modulating the thrombin generation.