Association between VEGF gene polymorphisms and the therapeutic response to bevacizumab in Diabetic Macular Edema

Abstract Introduction. Diabetic macular edema (DME) is the most frequent and disabling manifestation of diabetic retinopathy (DR). The polymorphisms of VEGFA gene has been associated with the development of DME. To investigate the relationship between the VEGFA polymorphism gene and the response to antiangiogenic treatment in DME. Methods. 82 treatment-naïve patients with type 2 diabetes mellitus (T2DM) and clinically significant DME were studied. Intravitreal bevacizumab was administered and patients were evaluated at the first and third month. DNA was obtained to identify the polymorphisms rs2010963, rs699947 and rs35569394. The direct sequencing technique was used. Friedman test were used for comparison. Distribution of genotypes and alleles were analyzed by the Chi-square test and Fisher’s exact test. P < 0.05 was considered as significant. Results. The rs2010963 polymorphism in the responders the most frequent genotype was the CG (59%) (p = 0.0036, OR 3.2), with G being the most frequent allele (p < 0.0001, OR 6.6). This indicates that G allele have a higher probability of responding to treatment with bevacizumab. No significant differences were found for the polymorphisms rs699947 and rs35569394. Conclusion. There is a relationship between genetic variability and treatment response, including intronic and promoter-region polymorphisms. We hypothesized that the allele G in the VEGF rs2010963 polymorphism is related to variability in the response to bevacizumab treatment in patients with DME.