Role of the rs6822844 gene polymorphism at the IL2-IL21 region in biopsy-proven giant cell arteritis.

OBJECTIVES: To assess the influence of the interleukin (IL)2-IL21 rs6822844 G/T polymorphism in the susceptibility to biopsy-proven giant cell arteritis (GCA) and in the clinical spectrum of manifestations of this vasculitis. METHODS: Two hundred and seventy-two biopsy-proven GCA patients were included in this study. DNA from patients and matched controls (n=791) was obtained from peripheral blood. Samples were genotyped for the rs6822844 polymorphism using a predesigned TaqMan allele discrimination assay and by polymerase chain reaction amplification. RESULTS: No significant differences in the allele and genotype frequencies between biopsy-proven GCA patients and controls were observed. However, the stratification of GCA patients disclosed some differences according to gender and ischemic manifestations of the disease. In this regard, the frequency of the minor allele T was increased in males (14.8%) compared to females (8.4%) (odds ratio-OR:1.89 (95% confidence interval-CI: 1.09-3.28); p=0.02; Bonferroni adjustment p=0.12). Also, minor allele T frequency was increased in GCA patients with severe ischemic complications (12.8%) compared to those without severe ischemic complications (7.7%) (OR:1.72 (95% CI: 0.97-3.05); p=0.05; Bonferroni adjustment p=0.30), and specifically in patients with jaw claudication (13.7% versus 8.2% in those without jaw claudication; OR:1.76 (95% CI: 1.02-3.04); p=0.04; Bonferroni adjustment p=0.24). CONCLUSIONS: IL2-IL21 rs6822844 polymorphism does not appear to be a genetic risk factor for susceptibility to biopsy-proven GCA. However, this gene polymorphism may contribute to the different phenotypic expression of this vasculitis, in particular in the development of ischemic complications of the disease.

Role of the CCR5/Δ32CCR5 polymorphism in biopsy-proven giant cell arteritis.

To further explore the potential role of chemokines in giant cell arteritis (GCA), we have studied whether the CCR5/Δ32CCR5 polymorphism is implicated in the susceptibility to the disease and its specific features. A total of 352 Spanish patients with biopsy-proven GCA and 479 matched controls were assessed. DNA was obtained from peripheral blood. Samples were genotyped by PCR with specific primers spanning the 32-bp deletion region. No statistically significant difference in the Δ32CCR5 allele frequency between GCA patients (6.1%) and controls (6.8%) was observed (p = 0.58). This was also the case when the CCR5 /Δ32CCR5 genotype distribution was assessed (p = 0.49). The Δ32CCR5 allele frequency did not differ between patients with or without specific manifestations of the disease, such as polymyalgia rheumatica, visual ischemic manifestations, or irreversible occlusive disease. Hence, our results do not support a potential influence of Δ32CCR5 in the susceptibility to or clinical spectrum of GCA.

Role of rs1343151 IL23R and rs3790567 IL12RB2 polymorphisms in biopsy-proven giant cell arteritis.

OBJECTIVE: To assess the potential association between the rs1343151 IL23R and the rs3790567 IL12RB2 polymorphisms and giant cell arteritis (GCA). We also studied whether these polymorphisms might influence the phenotypic expression of GCA. METHODS: In total, 357 Spanish patients with biopsy-proven GCA and 574 matched controls were assessed. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the rs1343151 IL23R and the rs3790567 IL12RB2 polymorphisms using a predesigned TaqMan allele discrimination assay and by polymerase chain reaction amplification. RESULTS: Regarding the rs1343151 IL23R polymorphism, no significant differences in the genotype or allele frequencies between GCA patients and healthy controls were observed. The frequency of the minor allele A of the rs3790567 IL12RB2 variant was increased in GCA patients compared with controls (30.1% vs 25.7%, respectively; p = 0.039, OR 1.25, 95% CI 1.01-1.54). An increased frequency of subjects carrying the minor allele A (GA+AA genotypes) of the rs3790567 IL12RB2 polymorphism was found among GCA patients compared with controls (52.8% vs 44.4%; p = 0.013, OR 1.40, 95% CI 1.06-1.85). Although a higher frequency of the combination of minor alleles (A-A) in the subgroup of patients with visual ischemic complications compared with the combination of both major alleles (G-G; p = 0.029) or with the other allelic combinations (p = 0.035) was found, logistic regression analysis showed that this association was no longer significant after adjustment for potential confounding factors (A-A vs G-G: OR 2.10, 95% CI 0.88-5.04, p = 0.096). CONCLUSION: Our results support a potential influence of the rs3790567 IL12RB2 polymorphism in the pathogenesis of GCA.

Influence of IL2RA rs2104286 polymorphism in the risk of biopsy-proven giant cell arteritis.

OBJECTIVE: To assess the influence of the IL2RA rs2104286 A>G polymorphism on susceptibility to and clinical spectrum of manifestations of biopsy-proven giant cell arteritis (GCA). METHODS: Our study included 318 patients with biopsy-proven GCA. DNA from patients and healthy controls was obtained from peripheral blood. Samples were genotyped for the IL2RA rs2104286 A>G polymorphism using a predesigned TaqMan allele discrimination assay and by PCR amplification. RESULTS: Although GCA patients showed a higher frequency of the minor allele homozygote of IL2RA rs2104286 (GG) compared to controls (5.1% vs 2.8%, respectively; p = 0.06, odds ratio 1.84, 95% confidence interval 0.91-3.70), the allele distribution showed no significant differences between GCA patients and controls. Stratification of GCA patients according to sex or polymyalgia rheumatica, jaw claudication, visual ischemic manifestations, or other severe ischemic complications did not yield significant differences in the allele or genotype frequencies of the IL2RA rs2104286 polymorphism. CONCLUSION: IL2RA rs2104286 polymorphism does not appear to be a genetic risk factor for susceptibility to biopsy-proven GCA. Also, this polymorphism does not seem to be implicated in the clinical expression of this vasculitis.

Influence of CD40 rs1883832 polymorphism in susceptibility to and clinical manifestations of biopsy-proven giant cell arteritis.

OBJECTIVE: To assess the potential association between CD40 rs1883832 polymorphism and biopsy-proven giant cell arteritis (GCA). We also studied the influence of the polymorphism on phenotypic expression of this vasculitis, in particular the development of visual ischemic manifestations. METHODS: Three hundred five Spanish patients with biopsy-proven GCA and 788 matched controls were assessed. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the CD40 rs1883832 C/T polymorphism using a predesigned TaqMan allele discrimination assay and by polymerase chain reaction amplification. RESULTS: Patients with GCA showed a trend toward a higher frequency of the minor allele homozygote of rs1883832 (TT) compared to healthy controls (12.1% vs 8.3%, respectively; p = 0.05, OR 1.54, 95% CI 0.98-2.40). Also, a marginally significant increased frequency of the minor allele T was observed in patients with GCA who had visual ischemic manifestations (36.9%) compared to those without visual ischemic manifestations (27.7%; p = 0.04, OR 1.53, 95% CI 0.99-2.34). In this regard, patients with GCA carrying the minor allele T (either TT or TC) experienced visual ischemic manifestations more commonly than those carrying the CC genotype (58.5% vs 44.2%; p = 0.04, OR 1.78, 95% CI 0.99-3.22). CONCLUSION: Our results suggest a potential implication of the CD40 rs1883832 C/T polymorphism in susceptibility to visual ischemic manifestations in individuals with biopsy-proven GCA.