To investigate the potential implication of several polymorphisms of the C-reactive protein (CRP) gene in the predisposition to or clinical expression of giant cell arteritis (GCA).
A total of 125 patients diagnosed with biopsy-proven GCA and 234 ethnically matched controls from the Lugo region of Northwestern Spain were included in our study. Four functional gene polymorphisms for CRP rs1417938, rs1800947, rs1205, and rs3093059 variants were assessed using a polymerase chain reaction system with predeveloped TaqMan allelic discrimination assay.
Although we observed a significant increase in the frequency of heterozygotes for rs1417938 A/T [odds ratio (OR) = 1.70; 95% confidence interval (CI) 1.04-2.80; p = 0.03] and rs1205 C/T (OR 1.73; 95% CI 1.07-2.78; p = 0.02) in patients with GCA, no statistically significant differences in the allelic frequencies of these 2 polymorphisms were found between patients with GCA and controls. A marginal significant increase in the frequency of rs3093059 allele T in patients with GCA compared to controls was observed (OR 1.81; 95% CI 0.97-3.39; p = 0.04). However, the increased frequency of patients with GCA homozygous for rs3093059 T/T in patients with GCA compared to controls was out of the range of significance (OR 1.77; 95% CI 0.92-3.40; p = 0.07). No significant differences were found when we stratified patients with GCA according to the presence of polymyalgia rheumatica or severe ischemic complications of the disease.
The functional CRP gene polymorphisms assessed in our study do not seem to play a major role in the pathogenesis of GCA in individuals from Northwestern Spain.