Mauro Gallitelli

Diagnosis and Management of Gastrointestinal Bleeding in Patients With Hereditary Hemorrhagic Telangiectasia

OBJECTIVE:Our aim was to report our experience with treating GI bleeding in patients with hereditary hemorrhagic telangiectasia (HHT).METHODS:Consecutive patients with GI bleeding referred to the Yale University Vascular Malformation Center underwent clinical evaluation and endoscopy. Hb and blood transfusion requirements for 1 yr before and after evaluation were documented. Patients with a mean Hb ≤ 8 mg/dl or blood transfusion requirements ≥ 12 units packed red blood cells (PRBC)/yr were defined as patients with significant bleeding. Drug therapies, including ethinyl estradiol/norethindrone, danazol, and aminocaproic acid, were prescribed on an individual patient basis.RESULTS:The study included 43 HHT patients with a mean age of 57 yr. Endoscopy revealed telangiectases in the esophagus (1/41), stomach (33/41), duodenum (33/41), jejunum (5/9), and colon (10/32). Patients with > 20 telangiectases visualized on esophagogastroduodenoscopy had a significantly lower mean Hb of 7.9, compared with 9.4 (P = 0.007), and a trend toward higher blood transfusion requirements. Non–HHT-related causes of GI bleeding were diagnosed in four patients. During a mean follow up of 18.9 months, the group of 40 patients with HHT-related bleeding had improvements in their mean Hb and blood transfusion requirements.CONCLUSIONS:Some HHT patients with GI bleeding improve on drug therapies, but others fail. Transfusion-dependent GI bleeding is difficult to manage, and optimal management may include both medical and endoscopic treatments.

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-β 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.

Efficacy of Unusually High Doses of Tranexamic Acid for the Treatment of Epistaxis in Hereditary Hemorrhagic Telangiectasia

To the Editor: Hereditary hemorrhagic telangiectasia is an autosomal dominant disease characterized by epistaxis, cutaneous telangiectases, and visceral arteriovenous malformations.1 Aminocaproic a...

Pulmonary arteriovenous malformations, hereditary hemorrhagic telangiectasia, and brain abscess.

Hereditary hemorrhagic telangiectasia (HHT) is a systemic angiodysplasia inherited as an autosomal dominant disease. Patients with HHT and pulmonary arteriovenous malformations (PAVMs) are at increased risk for brain abscess (BA), a potentially preventable condition as effective treatment for PAVMs is available. In a center dedicated to HHT, a history of BA was found in 6 out of 128 patients with a definite diagnosis: herewith, their histories are reported focusing on mistakes in the diagnosis and management of the disease. Patients with PAVMs and BA had a higher mean hemoglobin concentration (15.1 g/dl vs. 12.2 g/dl, p < 0.006 by Student’s t test) compared to patients with PAVMs alone. Other clinical features (genetics, bacteriology, types of PAVMs, treatments, outcomes) are also discussed. Prompt diagnosis and screening for visceral involvement is pivotal for HHT patients and their relatives.

Endoglin gene mutations and polymorphisms in Italian patients with hereditary haemorrhagic telangiectasia

Autosomal‐dominant hereditary haemorrhagic telangiectasia (HHT) is a genetically heterogeneous disease caused by mutations in at least two different loci. We screened for mutations in four Italian families where segregation studies showed clear evidence of linkage to the endoglin (ENG) locus. In addition, one sporadic case and three patients with pulmonary arteriovenous malformations, belonging to small nuclear families unsuitable for linkage analysis, were included in the screening. The proband from each family was investigated using single‐strand conformation polymorphism and heteroduplex analysis; potential variants were sequenced. Four novel and one previously reported mutation were detected, as well as three new polymorphisms. The novel mutations included deletions in exon 1 (patient 581/02), exon 5 (patient 780/01) and exon 7 (patient 700/01), and a C→T229 substitution in exon 3 (patient 462/02). When analysing patient 700/01 and his affected daughter, we encountered a mutant ENG allele with two mutations – a deletion in exon 7 and a substitution in exon 12 – which converts isoleucine 575 into threonine, in a non‐conserved region. Both mutations were absent in the two healthy sons of the patient, while the polymorphic variant in exon 12 was present in his healthy father. These results and haplotype‐segregation studies suggest that a de novo deletion had occurred in the gamete of paternal origin. For the first time the parental germline in which a de novo HHT mutation occurred has been identified.

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.

HHT: A Rare Disease with A Broad Spectrum of Clinical Aspects

HHT is an autosomal dominant disease characterised by diffuse muco-cutaneous and visceral telangiectases in potentially all organs. Mutations in two different genes identify HHT type 1 and HHT type 2: endoglin located on chromosome 9q33-q34 and ALK-1 or ACVRL1 on chromosome 12q13, respectively. The existence of a third locus has also been hypothesised. HHT-1 is considered a more severe form of the disease with an earlier onset of epistaxis and telangiectases and a higher prevalence of pulmonary arteriovenous malformations than that found in HHT-2 subjects. Usually, a typical HHT patient has epistaxis, muco-cutaneous telangiectases and GI bleeding in later life, even though this clinical scenario represents only one of the possible HHT patterns. In fact, vascular malformations often remain silent until the onset of a severe complication, which frequently is the first clinical manifestation of HHT. The lung and brain are of particular concern because each may contain clinically silent lesions that can result in sudden morbidity and mortality. At present, awaiting the availability of genetic testing, only an expert in the clinical patterns and diagnostic imaging of HHT can permit a definite diagnosis in individuals at high risk for the disease.

Angiogenesis and hereditary hemorrhagic telangiectasia. Rendu-Osler-Weber disease.

To date much of the recent work on pathological angiogenesis has focused on inflammatory diseases, diabetes and cancer in particular. Hereditary hemorrhagic telangiectasia or Rendu-Osler-Weber disease provides an example of the genetic disorder of angiogenesis in which a multisystemic angiodysplasia is responsible for severe hemorrhage. The disease pathogenesis is partially explained by a defect in the TGF-β signaling system, although in more recent works a possible role of other vascular growth factors has been proposed. This paper provides a model of an aberrant angiogenesis in which multiple vascular growth factors could be involved in a diffuse angiodysplasia.