Effects of VEGF on phenotypic severity in children with hereditary hemorrhagic telangiectasia

The purpose of this study was to estimate vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-beta 1 serum levels in children with hereditary hemorrhagic telangiectasia (HHT) type 1 and type 2 and to correlate them to the presence of arteriovenous malformations (AVMs). High VEGF levels were initially found in an infant who had been hospitalized with intestinal bleeding and suspected HHT. This case led to the evaluation of VEGF and TGF-beta 1 by standard enzyme-linkcd immunosorbent assay in 13 children with HHT and familiarity. Patients were divided into 2 groups on the basis of the presence/absence of pulmonary AVMs. No significant difference was found for VEGF and TGF-beta 1 levels in HHT patients versus controls. Among HHT patients, serum levels of VEGF in those without AVM were significantly lower than those with AVM and normal controls. No difference for TGF-beta 1 levels was found in these patient subgroups. Low VEGF levels may represent a protection factor against the onset of pulmonary AVMs in HHT children. However, neither VEGF nor TGF-beta 1 can be used as biochemical markers for an early diagnosis in HHT. The diagnosis of HHT still requires clinical criteria, which permitted to confirm the presence of the disease in the infant with intestinal bleeding.