Project description:Hereditary hemorrhagic telangiectasias (HHT), also known as Osler-Weber-Rendu syndrome, is an uncommon genetic disorder. It is inherited as an autosomal dominant disorder with varying penetrance and expression. The diagnosis of HHT requires the presence of at least three out of four clinical criteria. These so-called Curaçao criteria include epistaxis, telangiectasias, visceral involvement, and a family history of HHT in a first-degree relative. Visceral involvement can involve the gastrointestinal (GI) tract, resulting in the development of GI telangiectasias. One of the complications is anemia due to the chronic blood loss from these vascular malformations. Here, we present a case of a 26-year-old male who was diagnosed with HHT. He initially had episodes of epistaxis but now presented to us with features of anemia. According to the patient, he didn't have epistaxis for the past many months and on his esophagogastroduodenoscopy (EGD) and colonoscopy, there was evidence of multiple small telangiectasias seen in his stomach, duodenum, and colon. He was managed with blood transfusion and was discharged on oral iron supplementation. This is a rare cause of anemia and should be evaluated if other features of HHT are present.
Project description:Hereditary hemorrhagic telangiectasia (HHT) is a rare angiogenic disorder causing chronic gastrointestinal bleeding, epistaxis, and severe anemia. Pazopanib is an oral multi-kinase angiogenesis inhibitor with promise to treat bleeding in HHT. We analyzed outcomes of HHT patients with the most severe bleeding causing RBC transfusion dependence treated on a predefined institutional pazopanib treatment pathway (with data collected retrospectively). The primary endpoint was achievement of transfusion independence. Secondary endpoints included hemoglobin, epistaxis severity score, RBC transfusion and iron infusion requirements, number of local hemostatic procedures, ferritin and transferrin saturation, compared using paired and repeated measures mean tests. Thirteen transfusion-dependent HHT patients received pazopanib [median (range) dose 150 (25-300) mg daily)] for a median of 22 months. All patients achieved transfusion independence. Compared with pretreatment, pazopanib increased mean hemoglobin by 4.8 (95% CI, 3.6-5.9) g/dL (7.8 vs. 12.7 g/dL, P < 0.0001) and decreased mean epistaxis severity score by 4.77 (3.11-6.44) points (7.20 vs. 2.43 points, P < 0.0001) after 12 months of treatment. Compared with 3 months of pretreatment, RBC transfusions decreased by 93% (median of 16.0 vs. 0.0 units, P < 0.0001) and elemental iron infusion decreased by 92% (median of 4500 vs. 0 mg, P = 0.005) during the first 3 months of treatment; improvements were maintained over time. Pazopanib was well-tolerated: hypertension, lymphocytopenia, and fatigue were the most common TEAEs. In conclusion, pazopanib was safe and effective to manage severe bleeding in HHT, liberating all patients from transfusion dependence and normalizing hematologic parameters at doses lower than used to treat malignancies. These findings require confirmation in a randomized trial.
Project description:This pictorial review is based on our experience of the follow-up of 120 patients at our multidisciplinary center for hereditary hemorrhagic telangiectasia (HHT). Rendu-Osler-Weber disease or HHT is a multiorgan autosomal dominant disorder with high penetrance, characterized by epistaxis, mucocutaneous telangiectasis, and visceral arteriovenous malformations (AVMs). The research on gene mutations is fundamental and family screening by clinical examination, chest X-ray, research of pulmonary shunting, and abdominal color Doppler sonography is absolutely necessary. The angioarchitecture of pulmonary AVMs can be studied by unenhanced multidetector computed tomography; however, all other explorations of liver, digestive bowels, or brain require administration of contrast media. Magnetic resonance angiography is helpful for central nervous system screening, in particular for the spinal cord, but also for pulmonary, hepatic, and pelvic AVMs. Knowledge of the multiorgan involvement of HHT, mechanism of complications, and radiologic findings is fundamental for the correct management of these patients.
Project description:Background and purposeThe presence of malformations of cortical development in patients with hereditary hemorrhagic telangiectasia has been reported on previous occasions. We evaluated a sample of adults with hereditary hemorrhagic telangiectasia for the presence of malformations of cortical development, spatial coincidence of malformations of cortical development and AVMs, and the coincidence of brain and pulmonary AVMs.Materials and methodsA total of 141 patients 18 years of age or older who were referred to the Augusta University hereditary hemorrhagic telangiectasia clinic and underwent brain MR imaging between January 19, 2018, and December 3, 2020, were identified. MR imaging examinations were reviewed retrospectively by 2 experienced neuroradiologists, and the presence of malformations of cortical development and AVMs was confirmed by consensus. Demographic and clinical information was collected for each case, including age, sex, hereditary hemorrhagic telangiectasia status by the Curacao Criteria, mutation type, presence of malformations of cortical development, presence of brain AVMs, presence of pulmonary AVMs, and a history of seizures or learning disabilities.ResultsFive of 141 (3.5%) patients with hereditary hemorrhagic telangiectasia had malformations of cortical development. Two of the 5 patients with polymicrogyria also had closed-lip schizencephaly. One of the patients had a porencephalic cavity partially lined with heterotopic GM. The incidence of spatially coincident polymicrogyria and brain AVMs was 40% (2/5 cases). Of the patients with hereditary hemorrhagic telangiectasia and malformations of cortical development, 4/5 (80%) had pulmonary AVMs and 2/5 (40%) had brain AVMs.ConclusionsTo our knowledge, we are the first group to report the presence of schizencephaly in patients with hereditary hemorrhagic telangiectasia. The presence of schizencephaly and porencephaly lends support to the hypothesis of regional in utero cerebral hypoxic events as the etiology of malformations of cortical development in hereditary hemorrhagic telangiectasia.
Project description:OBJECTIVE:To report our clinical experience with bevacizumab in a cohort of Hereditary Hemorrhagic Telangiectasia (HHT) patients with severe hepatic involvement and/or refractory anemia. METHODS:Observational, ambispective study of the Institutional Registry of HHT at Hospital Italiano de Buenos Aires. Patients were treated with bevacizumab due to iron deficiency refractory anemia secondary to nasal/gastrointestinal bleeding and/or high output cardiac failure. We describe basal clinical data, bevacizumab schedules, efficacy outcomes and adverse events. Wilcoxon signed ranks test and longitudinal analysis were conducted. RESULTS:Twenty adult patients were included from July 2013 to June 2019. Clinical indications were: 13 for anemia, 4 for heart failure and 3 for both. In the anemia group, median pretreatment hemoglobin was 8.1 g/dl [IQR: 7.2-8.4] and median transfusion requirement was 4 units [2-6]. In heart failure group, pretreatment median cardiac index was 4.5 L/min/m2 [4.1-5.6] and cardiac output was 8.3 L/min [7.5-9.2]. Bevacizumab 5 mg/kg/dose every 2 weeks for 6 applications was scheduled. By the end of induction, median hemoglobin at 3 months was 10.9 g/dl [9.5-12.8] (p = 0.01) and median transfusion requirement 0 units [0-1] (p<0.01), and this effect was more or less sustained during a year. Regarding heart failure group, two patients had complete hemodynamic response and achieved liver transplantation and two had partial response. No serious adverse events were registered. CONCLUSION:Bevacizumab is a promising line of treatment for HHT patients with refractory anemia. For patients with high output cardiac failure, bevacizumab may be useful as bridge therapy awaiting for liver transplantation.
Project description:Hereditary hemorrhagic telangiectasia (HHT), also known by the eponym Osler-Weber-Rendu syndrome, is a group of related disorders inherited in an autosomal dominant fashion and characterized by the development of arteriovenous malformations (AVM) in the skin, mucous membranes, and/or internal organs such as brain, lungs, and liver. Its prevalence is currently estimated at one in 5,000 to 8,000. Most cases are due to mutations in the endoglin (HHT1) or ACVRLK1 (HHT2) genes. Telangiectasias in nasal and gastrointestinal mucosa generally present with recurrent/chronic bleeding and iron deficiency anemia. Larger AVMs occur in lungs (~40%-60% of affected individuals), liver (~40%-70%), brain (~10%), and spine (~1%). Due to the devastating and potentially fatal complications of some of these lesions (for example, strokes and brain abscesses with pulmonary AVMs), presymptomatic screening and treatment are of utmost importance. However, due to the rarity of this condition, many providers lack an appreciation for the whole gamut of its manifestations and complications, age-dependent penetrance, and marked intrafamilial variation. As a result, HHT remains frequently underdiagnosed and many families do not receive the appropriate screening and treatments. This article provides an overview of the clinical features of HHT, discusses the clinical and genetic diagnostic strategies, and presents an up-to-date review of literature and detailed considerations regarding screening for visceral AVMs, preventive modalities, and treatment options.
Project description:A founder effect can result from the establishment of a new population by individuals from a larger population or bottleneck events. Certain alleles may be found at much higher frequencies because of genetic drift immediately after the founder event. We provide a systematic literature review of the sporadically reported founder effects in hereditary hemorrhagic telangiectasia (HHT). All publications from the ACVRL1, ENG and SMAD4 Mutation Databases and publications searched for terms "hereditary hemorrhagic telangiectasia" and "founder" in PubMed and Scopus, respectively, were extracted. Following duplicate removal, 141 publications were searched for the terms "founder" and "founding" and the etymon "ancest". Finally, 67 publications between 1992 and 2020 were reviewed. Founder effects were graded upon shared area of ancestry/residence, shared core haplotypes, genealogy and prevalence. Twenty-six ACVRL1 and 12 ENG variants with a potential founder effect were identified. The bigger the cluster of families with a founder mutation, the more remarkable is its influence to the populational ACVRL1/ENG ratio, affecting HHT phenotype. Being aware of founder effects might simplify the diagnosis of HHT by establishing local genetic algorithms. Families sharing a common core haplotype might serve as a basis to study potential second-hits in the etiology of HHT.
Project description:Hereditary Hemorrhagic Telangiectasia (HHT), also known as Rendu-Osler syndrome, is a genetic vascular disorder affecting 1 in 5000-8000 individuals worldwide. This rare disease is characterized by various vascular defects including epistaxis, blood vessel dilations (telangiectasia) and arteriovenous malformations (AVM) in several organs. About 90% of the cases are associated with heterozygous mutations of ACVRL1 or ENG genes, that respectively encode a bone morphogenetic protein receptor (activin receptor-like kinase 1, ALK1) and a co-receptor named endoglin. Less frequent mutations found in the remaining 10% of patients also affect the gene SMAD4 which is part of the transcriptional complex directly activated by this pathway. Presently, the therapeutic treatments for HHT are intended to reduce the symptoms of the disease. However, recent progress has been made using drugs that target VEGF (vascular endothelial growth factor) and the angiogenic pathway with the use of bevacizumab (anti-VEGF antibody). Furthermore, several exciting high-throughput screenings and preclinical studies have identified new molecular targets directly related to the signaling pathways affected in the disease. These include FKBP12, PI3-kinase and angiopoietin-2. This review aims at reporting these recent developments that should soon allow a better care of HHT patients.
Project description:Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal-dominant disease characterized by pathologic angiogenesis that provokes vascular overgrowth. The evidence about the influence of Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) in patients with rare diseases is scarce. We aimed to know the prevalence of coronavirus disease 2019 (COVID-19) in HHT patients. The HHT pathogenic angiogenesis and endothelial injury in COVID-19 are discussed using data from RiHHTa (Computerized Registry of Hereditary Hemorrhagic Telangiectasia) registry. RiHHTa is an open, multicenter, prospective, observational registry including adult patients with HHT. A 27-item survey that captured clinical data of admitted HHT patients for COVID-19 was distributed to all RiHHTa investigators from June 8th to June 24th 2020. Only one out of 1177 HHT patients was admitted for COVID-19 pneumonia. She is a 74 years-old woman with a pathogenic variant in ACVRL1 gene. Her clinical course did not involve mechanical ventilation or worsening epistaxis, and she was successfully discharged after two weeks. The endothelial damage and the consequent angiogenic process in COVID-19 patients deserve further investigation.
Project description:Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic disorder that presents with telangiectases in skin and mucosae, and arteriovenous malformations (AVMs) in internal organs such as lungs, liver, and brain. Mutations in ENG (endoglin), ACVRL1 (ALK1), and MADH4 (Smad4) genes account for over 95% of HHT. Localized telangiectases and AVMs are present in different organs, with frequencies which differ among affected individuals. By itself, HHT gene heterozygosity does not account for the focal nature and varying presentation of the vascular lesions leading to the hypothesis of a "second-hit" that triggers the lesions. Accumulating research has identified a variety of triggers that may synergize with HHT gene heterozygosity to generate the vascular lesions. Among the postulated second-hits are: mechanical trauma, light, inflammation, vascular injury, angiogenic stimuli, shear stress, modifier genes, and somatic mutations in the wildtype HHT gene allele. The aim of this review is to summarize these triggers, as well as the functional mechanisms involved.