Summary
Toll-like receptor-4 (TLR-4) gene polymorphisms have been associated with a lower
risk of atherosclerosis. High levels of soluble P-selectin (sP-selectin) and von Willebrand
factor predict an increased risk for cardiovascular events and correlate to atherosclerotic
risk factors. The relationship between these markers and TLR-4 gene polymorphisms
was evaluated in a cohort of consecutive hypercholesterolemic outpatients. TLR-4 gene
polymorphisms were detected in 48 out of 330 (14%) patients with hypercholesterolemia.
Lipid and inflammatory markers, sP-selectin and von Willebrand were evaluated in carriers
and in 96 (ratio 2:1 to cases) age- and sex-matched TLR-4 wild-type patients randomly
selected from the same population. A cohort of normocholesterolemic outpatients (n=262)
served as the control group.sP-selectin was sensibly lower in carriers of TLR-4 variants
as compared to wild-types and controls (89 ng/ ml vs. 162 ng/ml and 163 ng/dl, respectively,
p=0.0001). Similarly, carriers showed lower von Willebrand factor values (683 mU/
ml) than wild-types (910 mU/ml; p=0.001). In multivariate analysis, TLR-4 gene polymorphisms
were positively associated with sP-selectin, whereas the relationship with von Willebrand
factor was no longer significant. HMG-CoA reductase inhibitors reduced sP-selectin
and von Willebrand factor levels independently of TLR-4 gene variants. Plasma concentrations
of these markers, however, remained lower in carriers of TLR-4 gene polymorphisms
even after cholesterol lowering. In conclusion, carriership of Asp299 andThr399IleTLR-4
gene polymorphisms is associated with lower levels of sP-selectin and von Willebrand
factor among hypercholesterolemic patients. While the underlying mechanisms remain
to be investigated, such an association may indicate a protective effect of TLR-4
variants for atherosclerosis.
Keywords
Toll-like receptor - gene polymorphism - P-selectin - von Willebrand factor - hypercholesterolemia