MCP-1 gene haplotype association in biopsy proven giant cell arteritis

Objective. Giant cell arteritis (GCA) is the most frequent vasculitis in European and North American countries. Increased expression of monocyte chemoattractant protein 1 (MCP-1) has been observed within the inflammatory infiltrates of blood vessels and serum of patients with GCA and in other autoimmune and inflammatory conditions. MCP-1 gene polymorphisms have been reported to contribute to susceptibility to several immune and inflammatory conditions. To investigate the clinical implication of MCP-1 polymorphisms in GCA, we examined the association of 3 single nucleotide polymorphisms (SNP) in a series of patients with GCA from Northwest Spain. Methods. Seventy-nine patients with biopsy proven GCA and 99 ethnically matched controls were studied. Patients and controls were genotyped for MCP-1 polymorphisms. SNP included in this study (rs2857657, rs4586, rs139000) were located in intron 1(G/C), exon 2(TVC), and 3′UTR(C/T) region of MCP-1 gene. Results. The distribution of the alleles and genotypes for each MCP-1 polymorphism showed no significant differences between GCA patients and controls. When we compared the overall distribution of haplotype frequencies between GCA cases and controls a significant difference was observed (p = 0.005, by chi-square test from 4 x 2 contingency table). In addition, haplotype C-C was significantly increased in GCA patients compared with controls (p = 0.03, OR 2.09, 95% CI 1.09-4.02). Similarly, haplotype T-T was overrepresented in GCA patients (p = 0.005). Conclusion. Significant differences in haplotype frequencies between GCA patients and controls may indicate a role for MCP-1 gene in susceptibility to GCA.