Vascular endothelial growth factor serum levels are elevated in patients with hereditary hemorrhagic telangiectasia.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a genetic angiodysplasia affecting multiple organs. Two genes involved in the transduction of TGF-beta signalling are responsible for HHT. An additional role for vascular endothelial growth factor (VEGF) has been proposed. Serum VEGF, which has been evaluated in several diseases characterized by aberrant angiogenesis, has never been measured in patients with HHT. AIMS: To evaluate VEGF serum levels in HHT patients as compared to normal subjects. MATERIALS AND METHODS: 32 HHT patients (age 47.7 +/- 16.7 years) and a control group of 37 healthy subjects (age 48.2 +/- 15.5 years) were entered in the study. Each patient underwent serum VEGF dosage using a commercial ELISA specific for the human molecule. RESULTS: The serum level of VEGF in HHT patients was 196.3 +/- 103.2 pg/ml, while it was 152.0 +/- 84.1 pg/ml in the control group. Statistical analysis showed that serum VEGF was significantly higher in HHT patients than in the controls (p < 0.031). CONCLUSIONS: According to a study performed in a murine model, persistence of the activation phase of angiogenesis might be responsible for an increased production of several angiogenic factors, in particular VEGF, in HHT. Our work is the first to suggest an increased expression of VEGF in the serum of subjects with HHT in agreement with the stimulation of VEGF synthesis proposed in the murine model.

Rendu-Osler-Weber disease: experience with 56 patients.

Rendu-Osler-Weber disease, or hereditary hemorrhagic telangiectasia (HHT), is an autosomal dominant disease characterized by systemic vascular dysplasia. The prevalence varies and ranges, according to region, from 1/3500 to 1/5000. Data concerning Italy are not available. The diagnosis is based on the following criteria: family history, epistaxis, telangiectases and visceral arteriovenous malformations. The diagnosis is to be considered definite if three criteria are present and suspected if two criteria are present. From September 2000 to March 2002, 100 patients (63 males, 37 females, mean age 45.5 +/- 17.3 years) potentially affected by HHT were evaluated in the HHT Center of the "Augusto Murri" Internal Medicine Section at the University of Bari (on a day-hospital or hospitalization basis). The diagnosis of HHT was confirmed in 56 patients and suspected in 10. Magnetic resonance imaging revealed cerebral arteriovenous malformations in 8.5% of patients. In 14.6% of patients contrast echocardiography revealed pulmonary arteriovenous malformations subsequently confirmed at multislice computed tomography in all cases but one. In 48.2% of subjects hepatic vascular malformations were revealed by echo color Doppler ultrasonography, whereas abdominal multislice computed tomography was positive in 63.8% of patients. In 64% of the 25 patients, who underwent endoscopy, gastric telangiectases were found. In 3 out of 6 patients presenting with pulmonary arteriovenous malformations, embolotherapy was performed with success. In our patients, the use of tranexamic acid caused a reduction in the frequency of epistaxis. The future objectives of the HHT Center of Bari are to increase knowledge of the disease, to cooperate with other centers with the aim of increasing the number of patients studied and to avoid the limits of therapeutic and diagnostic protocols of a rare disease such as HHT.