Hereditary hemorrhagic telangiectasia involving portal venous system:A case report and review of the literature

BACKGROUND Hereditary hemorrhagic telangiectasia(HHT)is an autosomal dominant genetic disorder with an incidence of approximately 1 in 5000 in the general population.It is characterized by vasodilation,which affects specific organs,such as the skin,mucous membranes,brain,lungs,gastrointestinal tract,liver,and others.However,HHT rarely involves the portal venous system to cause serious clinical compli-cations.CASE SUMMARY A 68-year-old woman was admitted to the emergency department due to four consecutive days of abdominal pain and bloody stool and was subsequently diagnosed with HHT.Computed tomography angiography confirmed the presence of an arteriovenous fistula(AVFs).Considering this specific manifestation,whole exome sequencing was performed.After a comprehensive evaluation,a selective superior mesenteric artery embolization was prioritized to avoid intestinal ischemia.The postoperative symptoms of the patient were quickly relieved.Unfortunately,two months post-procedure the patient died from intestinal necrosis and abdominal infection related to remaining AVFs.CONCLUSION For patients with diffuse superior mesenteric AVFs,selective mesenteric arterial embolization may lead to positive short-term outcomes.

Multi-organ hereditary hemorrhagic telangiectasia:A case report

BACKGROUND Type 2 hereditary hemorrhagic telangiectasia(HHT)is a rare autosomal dominant disease and is associated with ALK1 gene mutations.Type 2 HHT patients primarily suffer from recurrent bleeding.There is currently no promising treatment.CASE SUMMARY A 5-year-old Chinese patient(III23)was admitted to Zhongshan Hospital for recurrent melena occurring over 2 mo.She had been experiencing epistaxis for years and had been diagnosed with idiopathic pulmonary hypertension 4 mo before presentation.Abdominal computed tomography examination showed hepatic arteriovenous malformation.Gene testing revealed a c.1121G>A mutation on the ALK1 gene.According to the international diagnostic criteria,this patient was diagnosed with HHT.In addition,8 more family members exhibited HHT symptoms to varying degrees.Gene testing in 5 family members(2 with HHT symptoms and 3 without HHT symptoms)revealed the ALK1 c.1121G>A mutation in the 2 family members with HHT symptoms.This missense mutation results in the substitution of arginine for glutamine at amino acid position 374(R374Q)in the conserved functional kinase domain of ALK1.Biological studies revealed that this mutation decreased the kinase activity of ALK1 and impeded the phosphorylation of its substrate Smad1.Moreover,the R374Q mutant downregulated the protein level of collagen-1,a fibrogenic factor,indicating abnormal fiber generation during vascular formation.CONCLUSION The R374Q mutant of ALK1 and its subsequent influence on fiber generation highly indicated its pathogenic role in this family with type 2 HHT.Detection of this gene mutation will facilitate early diagnosis of suspected type 2 HHT patients,and mechanistic studies will provide insights for future therapy.

Pulmonary arterial hyper-tension in a patient with hereditary hemorrhagic telangiectasia and family gene analysis:A case report

BACKGROUND Hereditary hemorrhagic telangiectasia(HHT)is a rare autosomal dominant genetic disease.Very few patients suffering from HHT present with associated pulmonary arterial hypertension(PAH),which may result in a poor prognosis.Here,we report a case of HHT with PAH.The patient’s clinical manifestations and treatment as well as genetic analysis of family members are reviewed,in order to raise awareness of this multimorbidity.CASE SUMMARY A 45-year-old Chinese woman was admitted to the hospital to address a complaint of intermittent shortness of breath,which had lasted over the past 2 years.She also had a 30-year history of recurrent epistaxis and 5-year history of anemia.She reported that the shortness of breath had aggravated gradually over the 2 years.Physical examination discovered anemia and detected gallop rhythm in the precordium.Chest computerized tomography and cardiac ultrasound demonstrated PAH and hepatic arteriovenous malformation.The formal clinical diagnosis was HHT combined with PAH.The patient was treated with ambrisentan and her condition improved for a time.She died half a year after the diagnosis.Genetic testing revealed the patient and some family members to carry an activin A receptor-like type 1 mutation(c.1232G>A,p.Arg411Gln);the family was thus identified as an HHT family.CONCLUSION We report a novel gene mutation(c.1232G>A,p.Arg411Gln)in a Chinese HHT patient with PAH.

Thalidomide Effects in Patients with Hereditary Hemorrhagic Telangiectasia During Therapeutic Treatment and in Fli-EGFP Transgenic Zebrafish Model

Background： Hereditary hemorrhagic telangiectasia （HHT） is mucocutaneous tclangiectasia, and arteriovenous malformations an autosomal dominant disease characterized by recurrent epistaxis. The efficacy of traditional treatments for HHT is very limited. The aim of this study was to investigate the therapeutic role of thalidomide in HHT patients and the effect in FLI-EGFP transgenic zebrafish model. Methods： HHT was diagnosed according to Shovlin criteria. Five HHT patients were treated with thalidomide （ 100 mg/d）. The Epistaxis Severity Score （ESS）, telangiectasia spots, and hepatic computed tomography angiography （CTA） were used to assess the clinical efficacy of thalidomide. The Fli-EGFP zebrafish model was investigated for the effect of thalidomide on angiogenesis. Dynamic real-time polymerase chain reaction assay. ELISA and Western blotting from patient＇s peripheral blood mononuclear cells and plasma were used to detect the expression of transforming growth factor beta 3 （TGF-β3） messenger RNA （mRNA） and vascular endothelial growth factor （VEGF） protein before and after 6 months of thalidomide treatment. Results： The average ESS before and after thalidomide were 6.966 ± 3.093 and 1.799±0.627, respectively （P = 0.009）. The ＂telangiectatic spot＂ on the tongue ahnost vanished： CTA examination of case 2 indicated a smaller proximal hepatic artery and decreased or ceased hepatic artery collateral circulation. The Fli-EGFP zebrafish model manifested discontinuous vessel development and vascular occlusion （7 of 10 fishes）, and the TGF-β3 mRNA expression of five patients was lower after thalidomide therapy. The plasma VEGF protein expression was down-regulated in HHT patients. Conclusions： Thalidomide reverses telangiectasia and controls nosebleeds by down-regulating the expression of TGF-β3 and VEGF in HHT patients. It also leads to vascular remodeling in the zebrafish model.

Clinical phenotypes,ALK1 gene mutation and level of related plasma proteins in Chinese hereditary hemorrhagic telangiectasia

Background We determined the diagnosis of hereditary hemorrhagic telangiectasis (HHT) in a suspected HHT family,identified ALK1 gene mutation and established a gene diagnosis method of HHT. The level of related plasma proteins (transforming growth factor β and thrombomodulin) were also analyzed.Methods Bleeding history and family history were collected; Dilatant nasal mucosal capillaries in proband were observed under nasal cavity endoscope; exons 3,7,8 of ALK1 gene in proband and her family members were amplified with polymerase chain reaction (PCR), and the PCR products were analyzed. Using enzyme-linked immunosorbent assay (ELISA),plasma TGF-β1 and TGF-β2 concentrations were measured. Plasma thrombomodulin (TM) level was detected by Western blotting.Results Of all family members,four had epstaxis,two had evident telangiectases on skin or mucosa. Gene screening results showed that C to T substitution at position 1231 in exon 8 of ALK1 gene (CGG→TGG) existed in proband,her affected brother and their father. The mutation did not exist in proband’s sister-in-law and nephew. Plasma TGF-β1 concentrations in the affected HHT was 20538,17194,13131 pg/ml,while that of normal control and unaffected family members was 15950,20297,12836 pg/ml,respectively. Plasma TGF-β2 in HHT patients was 14502,9550,10592 and that of normal controls 8579,20297,7680 pg/ml respectively. Level of plasma TM was in HHT subjects significantly lower than in normal subjects.Conclusions Chinese HHT individuals have mutant ALK1 gene,a C1231T variation on exon 8 of ALK1 is responsible for HHT clinical phenotypes in this family. ALK1 gene analysis,together with special clinical phenotypes and family history,provides a reliable method in diagnosing HHT. In affected HHT subjects,plasma TGFβ levels were not obviously different from those of normal subject; while plasma TM concentration was significantly lower than that in normal subjects. The significance and mechanism remain to be elucidated.

Tranexamic acid may be a useful pharmacotherapy for endoscopically resistant small bowel angiodysplasia

Small bowel angiodysplasia(SBAD)is reported to account for nearly 50%of cases of small bowel bleeding.When SBAD occurs frequently,it is difficult to treat all the angiodysplasias endoscopically,and gastrointestinal bleeding often recurs.Hormone therapy,somatostatin analogs,thalidomide and vascular endothelial growth factor(VEGF)-neutralizing antibodies have been reported to reduce gastrointestinal angiodysplasia(GIAD)bleeding.However,there is no strong evidence to recommend them.Also,there are no guidelines for their use.Hereditary hemorrhagic telangiectasia(HHT)is a hereditary disease caused by abnormalities in VEGF,resulting in multiple GIADs.A treatment guideline has been created for GIAD in HHT,and the use of tranexamic acid,an antifibrinolytic agent,is the first recommendation pharmacotherapy for GIAD with gastrointestinal bleeding that is difficult to treat endoscopically.It has been reported that fibrinolysis is accelerated in GIAD patients who are not HHT,similar to HHT patients.The use of tranexamic acid for gastric antral vascular ectasia in GIAD has been reported to be useful.However,there are very few reports of its use for SBAD.There are concerns with tranexamic acid use regarding the development of thrombosis/embolism,but there are few reports of such side effects.Future clinical trials including tranexamic acid for SBAD are desired.

Role of octreotide in small bowel bleeding

Gastrointestinal bleeding accounts for a drastic negative impact on the quality of the patients’lives as it requires multiple diagnostic and therapeutic interventions to identify the source of the bleeding.Small bowel bleeding is the least common cause of gastrointestinal bleeding.However,it is responsible for the majority of complaints from patients with persisting or recurring bleeding where the primary source of bleeding cannot be identified despite investigation.A somatostatin analog known as octreotide is among the medical treatment modalities currently used to manage small bowel bleeding.This medication helps control symptoms of gastrointestinal bleeding by augmenting platelet aggregation,decreasing splanchnic blood flow,and antagonizing angiogenesis.In this review article,we will highlight the clinical efficacy of octreotide in small bowel bleeding and its subsequent effect on morbidity and mortality.