European Journal of Clinical Investigation (2004) 34, 94–99 © 2004 Blackwell Publishing Ltd Blackwell Publishing, Ltd. Toll-like receptor-4 Asp299Gly polymorphism does not influence progression of atherosclerosis in patients with familial hypercholesterolaemia M. G. Netea *† , A. Hijmans * , S. van Wissen ‡ , T. J. Smilde * , M. D. Trip ‡ , B. J. Kullberg *† , T. de Boo * , J. W. M. Van der Meer *‡ , J. J. P. Kastelein † and A. F. H. Stalenhorf * * University Medical Center, St. Radboud, and † Nijmegen University Center of Infectious Diseases, Nijmegen, and ‡ Academic Medical Center, Amsterdam, the Netherlands Abstract Background Toll-like receptor-4 (TLR4) is a major receptor for inflammatory stimuli potentially involved in the pathogenesis of atherosclerosis, such as lipopolysaccharide (LPS) and heat-shock proteins. The Asp299Gly polymorphism of the TLR4 gene has been associated with a reduced intima-media thickness (IMT) of the common carotid artery in healthy individuals. We have investigated whether the presence of the Asp299Gly polymor- phism in patients with familial hypercholesterolaemia (FH) has a similar protective effect, and whether it influences the effects of HMG-CoA reductase treatment. Materials and methods A cohort of 293 FH patients and 200 healthy volunteers were genotyped for the presence of the Asp299Gly allele using polymerase chain reaction followed by restriction fragment length polymorphism analysis. Intima-media thickness measurements, inflammatory parameters and the effect of HMG-CoA reductase inhibitors were compared between the patients with and without Asp299Gly allele. Results The Asp299Gly allele was present in 10·6% of the FH patients and 11·0% of the healthy individuals. Whereas the FH patients carrying the Asp299Gly allele displayed a reduced absolute IMT value compared with the FH patients carrying the wild-type allelle, the difference did not reach statistical significance. In addition, the effect of treatment with HMG-CoA reductase inhibitors was not influenced by the presence of Asp299Gly allele. Conclusion The presence of the Asp299Gly allele of the TLR4 gene does not seem to exert a major influence on the progression of atherosclerosis in patients with FH. Keywords Atherosclerosis, C-reactive protein, cytokines, familial hypercholesterolaemia, inflammation, Toll-like receptors. Eur J Clin Invest 2004; 34 (2): 94–99 Introduction The contribution of inflammation to atherogenesis has been proposed for several decades, but only recently has stronger evidence for this concept become available [1,2]. Recently, a family of pattern-recognition receptors, the Toll-like receptors (TLRs), has proved to be crucial for the induction of inflammatory reactions upon recognition of both exogenous and endogenous ligands [3]. A variety of ligands for TLR4, such as chlamydial lipopolysaccharide (LPS) or heat shock protein (hsp) 60, as well as human hsp60, hsp70 and fibrinogen, were shown to be involved in the induction of atherosclerosis [4–6]. In addition, TLR4 has been shown to be present in larger quantities in atheroscle- rotic plaques compared with the healthy vessel wall, where its expression is amplified by oxidized LDL [7]. These data Departments of Medicine (M. G. Netea, A. Hijmans, T. J. Smilde, B. J. Kullberg, J. W. M. Van der Meer), and Epidemiology and Biostatistics (T. de Boo), University Medical Center, St. Radboud, Nijmegen; Nijmegen University Center of Infectious Diseases (M. G. Netea, B. J. Kullberg, J. W. M. Van der Meer), Nijmegen; Department of Vascular Medicine, Academic Medical Center, Amsterdam (S. van Wissen, M. D. Trip, J. J. P. Kastelein), the Netherlands. Correspondence to: Prof. Dr Anton F. H. Stalenhoef, Department of Medicine (541), University Medical Center St. Radboud, PO Box 9101, Geert Grooteplein 8, 6500 HB Nijmegen, the Netherlands. Tel.: +31–24–3618819; fax: +31–24–3541734; e-mail: A.Stalenhoef@aig.umcn.nl Received 31 July 2004; accepted 13 December 2004