DHPLC-based mutation analysis of ENG and ALK-1 genes in HHT Italian population.

Hereditary haemorrhagic telangiectasia (HHT or Rendu-Osler-Weber syndrome) is an autosomal dominant disorder characterized by localized angiodysplasia due to mutations in endoglin, ALK-1 gene, and a still unidentified locus. The lack of highly recurrent mutations, locus heterogeneity, and the presence of mutations in almost all coding exons of the two genes makes the screening for mutations time-consuming and costly. In the present study, we developed a DHPLC-based protocol for mutation detection in ALK1 and ENG genes through retrospective analysis of known sequence variants, 20 causative mutations and 11 polymorphisms, and a prospective analysis on 47 probands with unknown mutation. Overall DHPLC analysis identified the causative mutation in 61 out 66 DNA samples (92.4%). We found 31 different mutations in the ALK1 gene, of which 15 are novel, and 20, of which 12 are novel, in the ENG gene, thus providing for the first time the mutational spectrum in a cohort of Italian HHT patients. In addition, we characterized the splicing pattern of ALK1 gene in lymphoblastoid cells, both in normal controls and in two individuals carrying a mutation in the non-invariant -3 position of the acceptor splice site upstream exon 6 (c.626-3C>G). Functional essay demonstrated the existence, also in normal individuals, of a small proportion of ALK1 alternative splicing, due to exon 5 skipping, and the presence of further aberrant splicing isoforms in the individuals carrying the c.626-3C>G mutation.

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.

Liver involvement in a large cohort of patients with hereditary hemorrhagic telangiectasia: echo-color-Doppler vs multislice computed tomography study.

BACKGROUND/AIMS: Hepatic arterio-venous malformations (HAVMs) have been found in 74% of hereditary hemorrhagic telangiectasia (HHT) patients with multislice CT (MSCT). This single-blind study aimed to compare the diagnostic accuracy of echo-color-Doppler with MSCT and identify the most sensitive ultrasound criteria indicating hepatic shunts. METHODS: One hundred and fifty-three HHT patients were systematically screened for HAVMs by biological tests, abdominal MSCT and echo-color-Doppler. Twenty-five normal subjects and 15 cirrhotic patients were also included as control groups. Both intrahepatic ("color spots" and hypervascularization) and extrahepatic parameters (diameter, flow velocity and tortuosity of hepatic artery and diameter and flow velocity of portal/hepatic vein) were utilized. "Color-spots" are defined as subcapsular vascular spots with a high-velocity arterial blood flow and low resistivity index and can identify extremely small HAVMs. RESULTS: CT was positive in 128/153 (84%) patients and Doppler color spots were found in 131/153 (86%) patients. The sensitivity, specificity and diagnostic accuracy of "color spots" compared to MSCT were 95.3%, 68.0% and 91.8%, respectively. The "color-spot" showed a greater correlation to CT (V(index)=0.655; p<0.0001) than extrahepatic criteria (V=0.317). In 20/29 (69%) subjects, echo-color-Doppler, confirmed by CT, identified the third criterion for definite HHT diagnosis. CONCLUSIONS: Intrahepatic criteria was superior to extrahepatic criteria for identification of HAVMs. A new Doppler parameter ("color-spots") with an optimal accuracy for detecting HAVMs is proposed for easy periodic screening of HHT patients.

Brain abscess: a need to screen for pulmonary arteriovenous malformations.

BACKGROUND: Pulmonary arteriovenous malformations (PAVMs) are direct connections between an artery and a vein in the pulmonary circulation associated with hereditary hemorrhagic telangiectasia in up to 88% of cases. Patients with PAVMs are at increased risk of brain abscess (BA). This study aimed to provide preliminary data on the prevalence of PAVMs among BA patients. METHODS: Administrative hospital discharge forms were used to identify patients with BA; possible PAVM patients were screened. RESULTS: 126 patients with BA were identified. Two patients had undiagnosed PAVMs at the time of admission for BA. The age-adjusted incidence of BA was 6.3 cases/1 million/year, with a male:female ratio of 2.0. CONCLUSION: Although PAVMs are rare conditions, they play a role in the development of BA. PAVMs are usually not recognized at the time of BA, thus exposing patients to life-threatening risks.

Health-related quality of life in a rare disease: hereditary hemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease.

The levels of the health-related quality of life (HR-QoL) were analyzed in hereditary hemorrhagic telangiectasia (HHT) patients. The Short Form-36 Health Survey (SF-36) was administered to 50 HHT patients and scores were compared to a cohort of 2301 normal subjects. Clinical variables were patient age, illness duration, number of epistaxis episodes in the previous year and hemoglobin levels. Physical functioning, physical role limitations, bodily pain, social functioning, emotional role limitations and the physical component scores were lower among females. In multivariable analyses increasing age was related to lower physical functioning (p < 0.04), physical role limitations (p < 0.008), bodily pain (p < 0.05) and emotional role limitations (p < 0.01), while higher hemoglobin levels improved physical functioning (p < 0.03). The number of epistaxis episodes was negatively associated with physical role limitations (p < 0.009), vitality (p < 0.002), social functioning (p < 0.001), physical component summary (p < 0.001) and bodily pain (p < 0.01). Illness duration was negatively related to the mental component summary (p < 0.004). HHT patients had a lower HR-QoL with respect to normal controls in all domains except for bodily pain. Females had lower scores for several domains. Epistaxis was the most important clinical variable.

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.