Homozygous GDF2-Related Hereditary Hemorrhagic Telangiectasia in a Chinese Family.

Hereditary hemorrhagic telangiectasia (HHT) can be clinically diagnosed, but children often lack characteristic features. We report a family with homozygous growth differentiation factor 2 (GDF2)-related HHT diagnosed by genetic testing. A boy aged 5 years and 2 months presented with isolated hypoxemia. He was the product of a consanguineous marriage; his parents were second cousins. Physical examination revealed cyanosis of nail beds and clubbed fingers. Pulse oxygen saturation was 84% to 89%. Lung function, contrast-enhanced lung computed tomography, and noncontrast echocardiography were normal. A pulmonary perfusion scan revealed radioactivity in the brain and bilateral kidney, suggesting the existence of a intrapulmonary shunt. Whole-exome sequencing revealed a homozygous variant [c.1060_1062delinsAG (p.Tyr354ArgfsTer15)] in GDF2, which was found to be inherited from his heterozygous parents. At the age of 8 years, he developed epistaxis, and an angiogram revealed diffuse pulmonary arteriovenous malformations. At the age of 9 years, he was treated with sirolimus, and his condition improved significantly. However, his now 7-year-old sister with the same homozygous variant currently has no symptoms. Physical examinations revealed 1 pinpoint-sized telangiectasia on the chest of his mother and a vascular lesion on the forehead of his sister. Additionally, the patient's father and great-uncle had a history of mild to moderate epistaxis. Mutation in GDF2 is a rare cause of HHT. Ours is the first report of homozygous GDF2-related HHT; in addition, this variant has not been reported previously. In our report, we also confirm variable expressivity, even with the same pathogenic variant in GDF2-related HHT.

Ammonia Predicts Hepatic Involvement and Pulmonary Hypertension in Patients With Hereditary Hemorrhagic Telangiectasia.

INTRODUCTION: Hepatic involvement in hereditary hemorrhagic telangiectasia (HHT) is common and can be associated with severe clinical consequences, including portal hypertension, cardiac failure, and encephalopathy. However, there are no reliable clinical predictors of hepatic involvement and its associated complications, limiting appropriate identification of these patients. In this work, we define the utility of serum ammonia and liver biochemical tests (LFTs) in predicting hepatic HHT involvement and its complications. METHODS: We performed a retrospective study examining a well-characterized cohort of patients with HHT. Clinical characteristics, laboratory tests, liver imaging, transthoracic echocardiography assessment of right ventricular systolic pressure (RVSP), and history of other HHT-related outcomes were assessed. Patients were followed for the development of encephalopathy. RESULTS: Of 45 patients with definite HHT, 18 (40%) had elevated ammonia levels. An elevated ammonia associated with the presence of hepatic arteriovenous malformations (AVMs) on imaging (P < 0.03) and when combined with elevated liver tests increased the sensitivity for hepatic AVMs by 18% (55% for LFTs vs 73% for LFTs plus ammonia). Furthermore, an elevated serum ammonia in patients with HHT associated with an elevated RVSP (>35 mm Hg), providing an 80% sensitivity and 71% specificity for predicting the presence of pulmonary hypertension. In contrast, there was no association with an elevated serum ammonia and encephalopathy over a total of 859 months of follow-up. DISCUSSION: Elevated ammonia in a cohort of patients with HHT was associated with the presence of hepatic AVMs and elevated RVSP, but no other complications of HHT, including encephalopathy.

Plasma VEGF - a candidate biomarker for response to treatment with bevacizumab in HHT patients.

BACKGROUND: Recurrent epistaxis is the principal symptom of hereditary hemorrhagic telangiectasia (HHT). Currently, there is no standard therapy for this condition. Bevacizumab (anti-VEGF) treatment has been under intense investigation but treatment effects vary greatly between individuals. There are currently no markers to predict anti-VEGF therapeutic response in HHT patients. METHODS: We evaluated plasma VEGF levels in 13 HHT patients and correlated values with i) degree of epistaxis, measured by visual analog scale (VAS), epistaxis severity score (ESS), and patient bleeding diaries ii) the prevalence of extranasal manifestations, iii) the HHT subtype and iv) the treatment response to intranasal submucosal bevacizumab. RESULTS: Plasma VEGF was elevated in all 13 HHT patients compared to reference levels and showed a moderate correlation with VAS and duration of moderate bleeding events. In patients treated with intranasal submucosal bevacizumab plasma VEGF levels showed a strong correlation with the degree of reduction of mild bleeding events and VAS. CONCLUSIONS: The role of plasma VEGF as a potential predictive biomarker for therapeutic response to bevacizumab treatment warrants further investigation in larger prospective studies.

Genetic Diagnosis of Hereditary Hemorrhagic Telangiectasia: Four Novel Pathogenic Variations in Turkish Patients

Aims: Hereditary hemorrhagic telangiectasia is an autosomal dominant disorder characterized by telangiectasia, epistaxis, and vascular malformations. Pathogenic mutations were found in ENG, AVCRL1, SMAD4, and GDF genes. In this study, we present our database of patients with hereditary hemorrhagic telangiectasia regarding the phenotype-genotype relations and discuss two novel ENG gene pathogenic variations in two unrelated families. Methods: Next Generation Sequencing analysis was performed on the peripheral blood of nine patients with hereditary hemorrhagic telangiectasia in four unrelated families. All patients were diagnosed with hereditary hemorrhagic telangiectasia according to the Curaçao criteria. Data on treatment and screenings of visceral involvement were recorded from files. Results: We have found a pathogenic variation in either the ENG or ACVRL1 gene in each family. Two novel pathogenic variations in the ENG gene, including NM_000118.3 (ENG): c.416delC (p.P139fs*24) and NM_000118.3(ENG): c.1139dupT (p.Leu380PhefsTer16), were found in the same family. The NM_000020.2(ACVRL1): c.1298C>T (p.Pro433Leu) pathogenic variation in the ACVRL1 gene in our first family and a novel heterozygous likely pathogenic NM_000020.2(ACVRL1): c.95T>C (p.Val32Ala) variation was found in our second family. Seven of the nine patients were treated with thalidomide for controlling bleeding episodes. All patients responded to thalidomide. In one patient, the response to thalidomide was lost and switched to bevacizumab. Conclusion: In HHT certain type of mutations correlates with disease phenotypes and with next generation sequencing method, new pathogenic variations can be revealed which might help managing HHT patients.

Pazopanib may reduce bleeding in hereditary hemorrhagic telangiectasia.

Pazopanib (Votrient) is an orally administered tyrosine kinase inhibitor that blocks VEGF receptors potentially serving as anti-angiogenic treatment for hereditary hemorrhagic telangiectasia (HHT). We report a prospective, multi-center, open-label, dose-escalating study [50 mg, 100 mg, 200 mg, and 400 mg], designed as a proof-of-concept study to demonstrate efficacy of pazopanib on HHT-related bleeding, and to measure safety. Patients, recruited at 5 HHT Centers, required ≥ 2 Curacao criteria AND [anemia OR severe epistaxis with iron deficiency]. Co-primary outcomes, hemoglobin (Hgb) and epistaxis severity, were measured during and after treatment, and compared to baseline. Safety monitoring occurred every 1.5 weeks. Seven patients were treated with 50 mg pazopanib daily. Six/seven showed at least 50% decrease in epistaxis duration relative to baseline at some point during study; 3 showed at least 50% decrease in duration during Weeks 11 and 12. Six patients showed a decrease in ESS of > 0.71 (MID) relative to baseline at some point during study; 3/6 showed a sustained improvement. Four patients showed > 2 gm improvement in Hgb relative to baseline at one or more points during study. Health-related QOL scores improved on all SF-36 domains at Week 6 and/or Week 12, except general health (unchanged). There were 19 adverse events (AE) including one severe AE (elevated LFTs, withdrawn from dosing at 43 days); with no serious AE. In conclusion, we observed an improvement in Hgb and/or epistaxis in all treated patients. This occurred at a dose much lower than typically used for oncologic indications, with no serious AE. Further studies of pazopanib efficacy are warranted.

Systemic bevacizumab for the treatment of chronic bleeding in hereditary haemorrhagic telangiectasia.

BACKGROUND: Hereditary haemorrhagic telangiectasia (HHT) is a rare hereditary multisystem vascular disorder causing visceral arteriovenous malformations and mucocutaneous bleeding. Chronic gastrointestinal bleeding and epistaxis often produce profound anaemia refractory to conventional treatment. Bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, may be effective in treatment of bleeding in HHT. METHODS: All HHT patients treated with systemic bevacizumab for chronic bleeding were selected for retrospective analysis. Data collected included demographics, baseline HHT characteristics, epistaxis grade, surgical interventions, bevacizumab dosing, adverse events, haemoglobin, red cell transfusions, intravenous iron infusions, and other anaemia and/or bleeding-directed therapies. RESULTS: Thirteen HHT patients were treated with bevacizumab for a median of 13.9 (range 4.9-30.1) months. Compared with pretreatment values, bevacizumab treatment increased the mean haemoglobin by 4.0 g dL-1 (95% CI, 2.6-5.3 g dL-1 ) [mean (95% CI) haemoglobin 8.5 (7.8, 9.9) g dL-1 vs. 12.5 (11.2, 13.7) g dL-1 , P < 0.001)], reduced red cell units transfused by 92% [median of 6 (range 0-59) units vs. 0 (range 0-15) units, P = 0.004] and reduced quantity of iron infused by 73% [mean (95% CI) 462 (257, 668) mg month-1 vs. 126 (75, 178) mg month-1 , P = 0.002]. Epistaxis control was achieved in 85% with bevacizumab versus 0% before treatment (P < 0.001). No patient required nasal or GI procedures during the maintenance period. Two patients (15%) developed grade 3 hypertension requiring medical management. CONCLUSION: Systemic bevacizumab was highly effective to treat chronic bleeding in HHT. Further study is needed to confirm the magnitude of benefit and further define optimal dosing, treatment duration and long-term safety.

Decreased levels of miR-28-5p and miR-361-3p and increased levels of insulin-like growth factor 1 mRNA in mononuclear cells from patients with hereditary hemorrhagic telangiectasia 1.

Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disorder inherited in an autosomal dominant manner. Patients with HHT can develop vascular dysplasias called telangiectasias and arteriovenous malformations (AVMs). Our objective was to profile and characterize micro-RNAs (miRNAs), short noncoding RNAs that regulate gene expression posttranscriptionally, in HHT patient-derived peripheral blood mononuclear cells (PBMCs). PBMCs, comprised mostly of lymphocytes and monocytes, have been reported to be dysfunctional in HHT. A total of 40 clinically confirmed HHT patients and 22 controls were enrolled in this study. PBMCs were isolated from 16 mL of peripheral blood and purified for total RNA. MiRNA expression profiling was conducted with a human miRNA array analysis. Select dysregulated miRNAs and miRNA targets were validated with reverse transcription-quantitative polymerase chain reaction. Of the 377 miRNAs screened, 41 dysregulated miRNAs were identified. Both miR-28-5p and miR-361-3p, known to target insulin-like growth factor 1 (IGF1), a potent angiogenic growth factor, were found to be significantly downregulated in HHT patients. Consequently, IGF1 mRNA levels were found to be significantly elevated. Our research successfully identified miRNA dysregulation and elevated IGF1 mRNA levels in PBMCs from HHT patients. This novel discovery represents a potential pathogenic mechanism that could be targeted to alleviate clinical manifestations of HHT.

Intravenous Bevacizumab for Refractory Hereditary Hemorrhagic Telangiectasia-Related Epistaxis and Gastrointestinal Bleeding.

OBJECTIVE: To present a multiyear clinical experience with intravenous bevacizumab for the management of severe gastrointestinal bleeding and/or epistaxis in patients with hereditary hemorrhagic telangiectasia (HHT). PATIENTS AND METHODS: All patients treated with intravenous bevacizumab for severe hereditary hemorrhagic telangiectasia-related bleeding from June 1, 2013, through January 31, 2017, were included in this report. Severity of epistaxis (determined using the Epistaxis Severity Score questionnaire); hemoglobin, iron, and ferritin levels; and quality of life data were collected serially in all patients. RESULTS: Intravenous bevacizumab was administered to 34 patients using a standardized treatment protocol. Anemia was primarily related to severe epistaxis (n=15, 44%), severe gastrointestinal bleeding (n=4, 12%), or both (n=15, 44%), with a median baseline hemoglobin level of 9.1 g/dL (range, 8.3-10.5 gm/dL; to convert to mmol/L, multiply by 0.62). Red blood cell (RBC) transfusions had been administered to 28 patients (82%). Of these, 16 patients (47%) were RBC transfusion dependent and had received a median of 75 RBC transfusions (range, 4->500 RBC units) before bevacizumab initiation. The median length of follow-up was 17.6 months from the beginning of bevacizumab treatment (range, 3-42.5 months). There was a significant reduction in epistaxis severity scores (P<.001) and RBC transfusion requirements (P=.007) after completion of the initial bevacizumab treatment cycle. New-onset or worsened hypertension was noted in 4 patients, with 1 patient experiencing hypertensive urgency with a temporary decline in renal function. CONCLUSION: Intravenous bevacizumab is an effective treatment option for patients with severe anemia related to epistaxis and/or gastrointestinal bleeding. Further studies are needed to establish a dose-response relationship as well as clinical, genetic, and biomarker predictors of response.

SEX STEROIDS AND MACULAR TELANGIECTASIA TYPE 2.

PURPOSE: To investigate the relationship between macular telangiectasia Type 2 and systemic levels of sex steroids or their antagonization. METHODS: In a prospective single-center study, 90 patients with macular telangiectasia Type 2 were investigated. Female patients were evaluated for previous surgical (e.g., ovariectomy) and/or pharmacological (e.g., aromatase inhibitors, tamoxifen) therapy resulting in reduced action of sex steroids. In males, free serum testosterone levels were assessed in patients and controls. RESULTS: Fourteen of 49 (29%) female patients had a history of pharmacological suppression of sex steroids and/or ovariectomy. These patients were younger at disease onset when compared with those without such medical history (mean ± SD: 47.1 ± 7.8, range: 38-59, versus 60.1 ± 7.6, range: 45-76; P < 0.0001). Male patients showed significantly lower free serum testosterone levels compared with controls at younger age (P < 0.0001 and 0.04 in the first and second age quartiles, respectively), as opposed to nonsignificant differences in older patients. In men ≤ 60 years of age, a biochemical hypogonadism (free serum testosterone < 0.05 ng/mL) was present in 53% (8/15) and 4% (2/49) of patients and controls, respectively (P < 0.0001). CONCLUSION: The results indicate that steroidal sex hormones might be involved in the presumably multifactorial pathophysiology of macular telangiectasia Type 2.

A novel association between high red blood cell alloimmunization rates and hereditary hemorrhagic telangiectasia.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder associated with multiple arteriovenous malformations. HHT patients may require red blood cell (RBC) transfusion due to spontaneous hemorrhage or surgical bleeding. Because HHT-associated hemorrhage often occurs in submucosa we hypothesized that RBC alloimmunization rates in HHT patients may be higher than those observed in other transfused patients and investigated this in a retrospective study. STUDY DESIGN AND METHODS: Eighty-five patients with HHT who were transfused at our tertiary care facility were identified. A group of randomly selected, chronically transfused patients without HHT were used as controls (n = 207). RBC transfusion and alloantibody data were extracted from medical records. RESULTS: Alloimmunization rates among patients with HHT were significantly higher than those of controls (15.29% vs. 2.42%; p < 0.001), while HHT patients received fewer RBC transfusions at our institution compared to controls (4.27 units vs. 8.84 units; p < 0.0001). Anti-E, -K, and -c were the three most common alloantibodies identified in HHT patients. There was a trend for HHT patients to make more antibodies per alloimmunized patient than controls (2.38 alloantibodies vs. 1.60 alloantibodies), although this difference was not significant (p = 0.37). CONCLUSION: To our knowledge, this is the first study to evaluate RBC alloimmunization rates in patients with HHT. It is unclear whether the high alloimmunization rates observed are due to lifetime transfusion burden, underlying disease pathophysiology, or other variables. Additional studies are needed to evaluate the generalizability of our findings to other HHT populations and to consider the utility of prophylactic antigen matching for C/E/K.

Hereditary hemorrhagic telangiectasia, liver disease and elevated serum testosterone (Osler-Weber-Rendu syndrome): a case report.

BACKGROUND: A Sri Lankan girl with hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) is described. CASE PRESENTATION: She presented with recurrent spontaneous epistaxis, pulmonary arterio venous malformation and oral telangiectasia. A diagnosis of Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) was made based on the presence of three Curacao criteria (out of four). Evaluations of her jaundice revealed chronic parenchymal liver disease with multiple nodules in the liver with early portal hypertension. She had a muscular build, with elevated serum testosterone but low serum dehydroepiandrosterone sulphate levels. This could be attributed to impaired sulfation of dehydroepiandrosterone due to portocaval shunting of blood, leading to hyperandrogenemia. CONCLUSIONS: Hyperandorogenemia due impaired sulfation of dehydroepiandrosterone as a result of portocaval shunting is seen in Hereditary haemorrhagic telangiectasia.

Can Iron Treatments Aggravate Epistaxis in Some Patients With Hereditary Hemorrhagic Telangiectasia?

OBJECTIVES/HYPOTHESIS: To examine whether there is a rationale for iron treatments precipitating nosebleeds (epistaxis) in a subgroup of patients with hereditary hemorrhagic telangiectasia (HHT). STUDY DESIGN: Survey evaluation of HHT patients, and a randomized control trial in healthy volunteers. METHODS: Nosebleed severity in response to iron treatments and standard investigations were evaluated by unbiased surveys in patients with HHT. Serial blood samples from a randomized controlled trial of 18 healthy volunteers were used to examine responses to a single iron tablet (ferrous sulfate, 200 mg). RESULTS: Iron tablet users were more likely to have daily nosebleeds than non-iron-users as adults, but there was no difference in the proportions reporting childhood or trauma-induced nosebleeds. Although iron and blood transfusions were commonly reported to improve nosebleeds, 35 of 732 (4.8%) iron tablet users, in addition to 17 of 261 (6.5%) iron infusion users, reported that their nosebleeds were exacerbated by the respective treatments. These rates were significantly higher than those reported for control investigations. Serum iron rose sharply in four of the volunteers ingesting ferrous sulfate (by 19.3-33.1 µmol/L in 2 hours), but not in 12 dietary controls (2-hour iron increment ranged from -2.2 to +5.0 µmol/L). High iron absorbers demonstrated greater increments in serum ferritin at 48 hours, but transient rises in circulating endothelial cells, an accepted marker of endothelial damage. CONCLUSIONS: Iron supplementation is essential to treat or prevent iron deficiency, particularly in patients with pathological hemorrhagic iron losses. However, in a small subgroup of individuals, rapid changes in serum iron may provoke endothelial changes and hemorrhage. LEVEL OF EVIDENCE: 4. Laryngoscope, 126:2468-2474, 2016.

Common bleeding disorders affecting individuals with Hereditary Hemorrhagic Telangiectasia.

PURPOSE: Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disorder affecting vasculature in different organ systems; seen at a rate of approximately 1:5000 in North America. Complications, with significant increases in health service utilization, arise from bleeding and shunts, and are particularly problematic in the lung and liver. Although these patients tend to chronically bleed from the GI tract and nasal cavities, a single bleed from arterio-venous malformations in the lungs or brain can have serious health implications and may be fatal. Bleeding due to vascular wall fragility in HHT patients can be further complicated with a concomitant bleeding disorder. METHODS: The proportion of adult patients seen in the Edmonton HHT center with a concomitant bleeding disorder, as assessed by blood test results for Factor VIII and related factors (Ristocetin Cofactor), Factor IX and Factor XI, was determined in a retrospective, single centre study. RESULTS: Of 77 individuals with HHT, four had below normal values of von Willebrand Factor, Ristocetin Cofactor or Factor VIII. Two patients had laboratory parameters diagnostic of a bleeding disorder, accounting for 2.6% of confirmed HHT subjects. These results indicate that establishing screening for bleeding disorders in HHT centers is important in managing bleeding symptomatology. CONCLUSIONS: In individuals with HHT, the presence of a second bleeding disorder can have significant clinical implications on patient management and health care utilizations. This paper highlights areas that need to be reviewed with respect to best practice protocols for the management of HHT patients.

Dose - response relationship of bevacizumab in hereditary hemorrhagic telangiectasia.

Hereditary hemorrhagic telangiectasia (HHT), a genetic vascular disorder associated with epistaxis and hepatic shunts, is responsible for high-output cardiac failure in rare cases. Bevacizumab, which targets vascular endothelial growth factor, was shown to decrease both cardiac index (CI) and epistaxis duration in HHT patients with severe liver involvement. The relationship between its serum concentration and change in both CI and epistaxis duration was investigated to design the bevacizumab maintenance dosing regimen of future therapeutic studies. Twenty-five HHT patients with dyspnea and high CI were included in a prospective non-comparative study. They received bevacizumab at a dose of 5 mg/kg per infusion every 14 days for a total of 6 injections. The relationships between bevacizumab serum concentration and both CI and epistaxis duration were described using transit compartments and direct inhibition pharmacokinetic-pharmacodynamic models. The performances of different maintenance regimens were evaluated using simulation. Infusions every 3, 2 and one months were predicted to maintain 41%, 45% and 50% of patients with CI <4 L/min/m(2) at 24 months, respectively. The fraction of patients with <20 min epistaxis per month was predicted to be 34%, 43% and 60%, with infusion every 3, 2 or one months, respectively. Simulations of the effects of different maintenance dosing regimens predict that monthly 5 mg/kg infusions of bevacizumab should allow sustained control of both cardiac index and epistaxis.

Pulmonary shunt fraction measurement compared to contrast echocardiography in hereditary haemorrhagic telangiectasia patients: time to abandon the 100% oxygen method?

BACKGROUND: The presence of pulmonary right-to-left shunting (RLS) is associated with severe neurological complications from paradoxical embolisation in patients with hereditary haemorrhagic telangiectasia (HHT) and screening is warranted. Pulmonary shunt fraction measurement with the 100% oxygen method can be used for the detection and quantification of functional pulmonary RLS, although transthoracic contrast echocardiography (TTCE) has emerged as the gold standard over the last few years. OBJECTIVE: The aim of this study was to determine the true diagnostic accuracy of the established 100% oxygen method in detecting pulmonary RLS, as compared to TTCE. METHODS: We analysed 628 persons screened for HHT between 2004 and 2010, all of whom underwent TTCE. A quantitative 3-point grading scale was used to differentiate between minimal, moderate or extensive pulmonary RLS on TTCE (grade 1-3, respectively). Additional shunt fraction measurement with the 100% oxygen method was pursued in cases of pO2 <13 or <12 kPa in patients younger or older than 30 years, respectively. A shunt fraction >5% was considered pathological. RESULTS: Both TTCE and the 100% oxygen method were performed in 210 subjects. Although the presence of a pathological shunt fraction correlated with an increased pulmonary shunt grade on TTCE, the 100% oxygen method confirmed a >5% shunt fraction in only 51% of patients with pulmonary RLS on TTCE (14, 20 and 72% for grade 1, 2 and 3, respectively). CONCLUSION: Pulmonary shunt fraction measurement with the 100% oxygen method is not a useful screening technique for the detection of pulmonary RLS in HHT as its sensitivity is too low and large pulmonary shunts on TTCE may remain undetected using this method.

Coincidence of Glanzmann's thrombasthenia with hereditary haemorrhagic telengiectasia in a man with gastrointestinal bleeding.

Here we report a case of a 57-year-old man referred to our hospital with weakness, lethargy, melena, and rectorrhalgia. His physical examination and past medical history showed gingival bleeding, several episodes of epistaxis and post-surgery bleeding. Primary laboratory evaluation revealed only anaemia. Gastrointestinal findings including upper endoscopy and colonoscopy documented normal status, but balloon endoscopy illustrated telengiectasia-like lesions in the mid-jejunum. The case was suspected to be haemophilia due to the past medical history, although complete haemostatic evaluation demonstrated Glanzmann's thrombasthenia. The diagnosis of co-occurrence of hereditary haemorrhagic telengiectasia and Glanzmann's thrombasthenia was confirmed. This case revealed the coincidence of two bleeding tendencies, which, although rare, is a possible phenomenon. We recommend carrying out both primary and secondary haemostatic profiles for every patient with bleeding diathesis.