Vascular endothelial growth factor gene polymorphisms and serum levels in Behcet's disease

Vascular endothelial growth factor (VEGF) is important for angiogenesis and inflammation, both of which are codependent and contribute to the pathophysiology of Behcet's disease (BD). In this report, we sought to investigate whether the selected VEGF polymorphisms [-634 C/G, +936 C/T and an 18 bp insertion/deletion (I/D) at -2549 of the VEGF promoter region] are associated with susceptibility and severity of BD in the Tunisian population. One hundred and thirty-five Tunisian BD patients and 157 healthy controls were recruited. The VEGF gene was genotyped by polymerase chain reaction followed by digestion with restriction endonucleases. VEGF serum levels of BD patients and healthy controls were measured by enzyme-linked immunosorbent assay. We found no association between the VEGF polymorphisms and the susceptibility to BD. However, when data were analysed according to the presence of each symptom, we found a positive association between VEGF 18 bp I/D polymorphism and ocular involvement as well as BD severity. Indeed, among the BD patients, the frequency of the 18 bp I/I genotype was less in patients with ocular inflammation (6.1% vs 24.6%, P = 0.007) and in patients with severe BD (9.2% vs 21.4%, P = 0.0014). Moreover, the mean serum VEGF level was considerably higher in BD patients (P < 0.01) than in healthy controls. We suggest that VEGF gene polymorphisms may be involved in the development of the ocular BD as well as the severity of the disease.