The Effects of VEGF-A and GSTM1/GSTT1 Variants in the Susceptibility to the Chronic Rhinosinusitis with Nasal Polyposis: A Pilot Genetic Study

Abstract

Nasal polyps (NPs) are usually part of chronic rhinosinusitis with nasal polyposis (CRSwNP). However, the exact etiology of CRSwNP is still unknown. In addition, the suggested etiological causes are infection, allergy, and immunological disorders, among others, such as genetic predisposition. Moreover, it is also suggested that oxygen-free radicals play a vital role in the pathogenesis of nasal polyposis, and inflammatory cells produce free radicals during phagocytosis, which is the primary source of ROS, controlled by the glutathione S-transferase (GST) system. Although, vascular endothelial growth factor (VEGF) plays an important role in angiogenesis, it is closely interwoven with the mobilization of inflammatory cells. This pilot study evaluated the association between genetic variant VEGF-A (rs28357093) and GSTM1/GSTT1 deletion polymorphism in susceptibility to CRSwNP. A case–control study was conducted with 61 individuals diagnosed with CRSwNP and 100 healthy subjects. VEGF-A (rs28357093) and GSTM1/GSTT1 deletion polymorphisms were genotyped by RFLP-PCR and SYBR Green real-time PCR, respectively. Individuals with allergic rhinitis carriers with AC genotype (rs28357093) presented a 4-fold increased risk to CRSwNP (OR = 4.20, 95% CI = 1.31 to 13.50; p = 0.015). This evidence shows that the increased vascular permeability probably causes an inflamed nasal area leading to extensive edema and polyp growth. On the other hand, no association was verified for each genetic variant by inheritance models. Interestingly, the GSTT1 present genotype showed a protective effect on CRSwNP. In conclusion, additional studies that have larger groups in different geographic localizations may be useful to verify and assess the association between genetic variants and CRSwNP.