Role of interleukin 6-174G>C polymorphism in primary open-angle glaucoma

PURPOSE. In addition to its proinflammatory effects, interleukin (IL)-6 also possesses antiapoptotic properties. Recently, IL-6 has been reported to protect retinal ganglion cells from pressure-induced apoptosis, indicating a possible role in the pathogenesis of primary open-angle glaucoma (POAG). A common polymorphism in the promoter region of IL-6 gene at position -174 characterized by a substitution from G to C has been found to decrease transcription rate of IL-6. The aim of our study was to investigate a hypothesized association between IL-6-174G>C polymorphism and POAG in Caucasian patients. METHODS. The present case-control study comprised 191 unrelated patients with POAG and 191 control subjects, matched for age and sex. Genotyping of the IL-6-174G>C polymorphism was done using polymerase chain reaction. RESULTS. Allelic frequencies and genotype distribution of IL-6-174G>C did not significantly differ between patients with POAG and control subjects (p>0.05). Presence of the IL-6-174C allele was associated with a nonsignificant odds ratio of 0.78 (95% confidence interval 0.46-1.32; p=0.78) for POAG. CONCLUSIONS. Our findings suggest that the functional IL-6-174G>C polymorphism itself is unlikely a major risk factor for POAG.