Toll-like receptor 4 (TLR4) gene polymorphisms in giant cell arteritis

Objective. To investigate potential associations between toll-like receptor 4 (TLR4) gene polymorphisms and susceptibility to, and clinical features of giant cell arteritis (GCA). Methods. A total of 155 patients with biopsy-proven GCA who were residents of Reggio Emilia, Italy, and 210 population-based controls from the same geographical area were genotyped for two coding single nucleotide polymorphisms of TLR4 (Asp299Gly and Thr399Ile) by molecular methods. The patients were subgrouped according to the presence or absence of polymyalgia rheumatica and severe ischemic complications (visual loss and/or cerebrovascular accidents). Results. The distribution of allele and genotype frequencies did not differ significantly between GCA patients and healthy controls. Carriers of the -299 G allele (G/A+ G/G) [odds ratio (OR) 1.78, 95% confidence intervals (CI) 0.90-3.50)] were more frequent among GCA patients than among the controls, but the difference was not statistically significant. No significant associations were found when GCA patients with and without PMR or with and without severe ischemic complications were compared. Conclusion. Our data suggest that the TLR4 gene polymorphisms are not associated with susceptibility to, and clinical expression of, GCA in Italian patients.