Role of the C8orf13-BLK region in biopsy-proven giant cell arteritis

Giant cell arteritis (GCA) is a complex polygenic disease in which more than one genetic locus is likely to contribute to disease susceptibility and clinical expression. In the present study, we have analyzed for first time the implication of rs13277113 and rs2736340 variants from the C8orf13-BLK gene region in the susceptibility to GCA. A total of 220 biopsy-proven GCA patients and 486 matched controls were assessed. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the C8orf13-BLK region rs13277113 and rs2736340 using a predesigned TaqMan allele discrimination assay. No significant differences in the genotype distribution between GCA patients and controls for the rs13277113 and rs2736340 C8orf13-BLK gene variants were found. GCA patients were also stratified according to the presence of specific clinical features of the disease. In this regard, the allele A of the rs13277113 variant was overrepresented in patients with severe ischemic manifestations compared with patients without severe ischemic manifestations (p = 0.04; OR =1.65; 95% CI = 0.99-2.78). In conclusion, our results do not support a major implication of the C8orf13-BLK gene region in susceptibility to GCA. However, a potential implication of the rs13277113 variant in the development of severe ischemic complications may exist.