Case Of Hereditary Angioedema Research Articles

Hereditary or acquired? Comprehensive genetic testing assists in stratifying angioedema patients

Hereditary angioedema (HAE) poses diagnostic challenges due to its episodic, non-specific symptoms and overlapping conditions. This study focuses on the genetic basis of HAE, particularly focusing on unresolved cases and those with normal C1-inhibitor levels (nC1-INH HAE). This study reveals that conventional testing identified pathogenic variants in only 10 patients (n = 32), emphasizing the necessity for an integrative approach using genome, exome, and transcriptome sequencing. Despite extensive genetic analyses, the diagnostic yield for nC1-INH HAE remains low in our study, the pathogenic variant for nC1-INH HAE was identified in only 1 patient (n = 21). Investigation into candidate genes yielded no pathogenic variants, prompting a re-evaluation of patients’ diagnoses. This study advocates for a nuanced approach to genetic testing, recognizing its limitations and emphasizing the need for continuous clinical assessment. The complex genetic landscape of nC1-INH HAE necessitates further research for a more comprehensive understanding. In conclusion, this study contributes valuable insights into the genetic intricacies of HAE, highlighting the challenges in diagnosis and the evolving nature of the disease. The findings underscore the importance of advanced sequencing techniques and an integrated diagnostic strategy in unravelling the complexities of HAE, particularly in nС1-INH HAE cases.

Association between Hereditary Angioedema and Venous Thromboembolism in a Large Population-Based Case-Control Study

Introduction: Hereditary Angioedema (HAE) is a rare congenital disorder primarily caused by mutations in the SERPING1 gene that results in C1 inhibitor (C1INH) deficiency or dysfunction. C1INH is a multifunctional serine protease inhibitor that functions as a major endogenous negative regulator of the kallikrein-kinin, contact pathway of coagulation and complement systems. HAE typically presents with episodes of unpredictable subcutaneous and submucosal swelling. However, HAE patients also have evidence of systemic activation of coagulation including elevated plasma prothrombin fragments, thrombin antithrombin complexes and D-dimers. Further, patients with HAE have recently been reported to have an increased risk of venous thromboembolism (VTE). Methods: To evaluate the risk of VTE in patients with HAE we conducted a large population-based case-control study leveraging data from the United Kingdom Clinical Practice Research Datalink (CPRD). The CPRD Aurum dataset used here maintains anonymized electronic medical records of over 40 million individuals from over 1600 primary care practices in the United Kingdom. SNOMED CT medical codes were used to identify a cohort of 2,198 patients diagnosed with HAE between 1992 and 2022 in the CPRD Aurum dataset with a matched (age, gender, family practice, and index date for HAE) cohort of 4,376 controls selected. VTE events including deep vein thrombosis (DVT) and pulmonary embolism in the HAE case and control cohorts were identified using SNOMED CT medical codes. The Cox proportional hazards model was used to determine hazard ratios (HR) for VTE events in HAE cases versus controls adjusting for covariates age, sex, body mass index, blood pressure, smoking status and a number of co-morbidities specifically; neoplasm, type 2 diabetes, ischemic heart disease, chronic obstructive pulmonary disease, chronic kidney disease, autoimmune disorders and depression. Results: A greater proportion of the HAE cases were female (62%) with a mean age at HAE diagnosis of 37 years. The median follow-up period for both cases and controls was 17 years (interquartile range (IQR):8-28 years). The overall incidence of VTE in HAE cases was 1.1/1000 patient years versus 0.6/1000 patient years in the control cohort. In unadjusted analyses HAE was associated with a significantly increased risk of VTE (HR 1.70, 95% CI 1.37-2.22, P<0.0001). Importantly, in adjusted analyses HAE remained significantly associated with an increased risk of VTE (HR 1.44, 95% CI 1.12-1.83, P=0.004, Figure 1). Of note, this association is similar in magnitude to that previously reported for heterozygous carriers of FV Leiden, the prothrombin gene mutation and high confidence loss of function mutations in Protein C and Protein S in comparable population-based case-control studies. In adjusted sub-analyses HAE was associated with a significantly increased risk of DVT (HR: 1.42, 95% CI 1.09-1.87, P=0.01) with a trend towards an increased risk of PE (HR 1.37, 95% CI 0.84-2.27, P=0.2). Conclusions: The results of this population-based case-control study, roughly an order of magnitude larger in size than prior reports, demonstrate that HAE is associated with a significantly increased risk of VTE similar to that reported for common hereditary thrombophilias. These findings reinforce the important role of endogenous C1INH as a negative regulator of prothrombotic processes involved in VTE in the setting of HAE.

Forms of Hereditary Angioedema That Are Independent of Kallikrein and Factor XIIa System

Hereditary angioedema (HAE) is an inherited disorder characterized by recurrent episodes of severe soft tissue swelling involving skin and mucous membranes. In most cases, edema is caused by excessive formation of the vasoactive nanopeptide bradykinin (BK) due to dysregulation of the plasma kallikrein-kinin system (KKS). The KKS consists of the zymogens prekallikrein (PK) and factor XII (FXII) and the cofactor/substrate high-molecular-weight kininogen (HK). PK and FXII reciprocally convert each other to the proteases plasma kallikrein (PKa) and FXIIa. PKa cleaves HK after Lys362 and Arg371 to release bradykinin. In most cases of HAE, increased KKS activation is due to low plasma activity of C1-Inhibitor (C1-INH), the main regulator of PKa and FXIIa. However, ~10% of HAE patients have normal C1-INH activity (HAEnC1). A relationship between fibrinolysis and kinin formation was first described in 1971. The fibrinolytic protease plasmin activates FXII and cleaves HK, although it is unclear that this results in significant bradykinin generation. Recently mutations in the PLG gene encoding plasminogen (Lys311Glu) and the KNG1 gene encoding HK and the related protein low-molecular-weight kininogen (LK, Met361Lys) were identified in patients with HAEnC1. Here we describe how the fibrinolytic system contributes to angioedema in patients with these mutations. Human Glu-plasminogen (Plg), HK and LK were expressed in HEK293 cells. Lys311 in plasminogen was changed to glutamic acid, and Met361 in HK and LK were changed to lysine, by site directed mutagenesis. Wild type (Plg-Lys311) and variant (Plg-Glu311) plasminogen were converted to plasmin (Plm-Lys311 and Plm-Glu311) with urokinase. The capacity of plasmin to cleave HK and LK were studied with SDS-PAGE, western blots and kinin ELISA. Cleavage of wild type HK-Met361 and LK-Met361 and variant HK-Lys361 and LK-Lys361 by PKa and plasmin were assessed in a similar manner. The types of kinin released during reactions were determined by mass spectroscopy. Normal plasma was supplemented with Plg-Lys311 or Plg-Glu311, and tPA was added to generate plasmin. Bradykinin release was substantially greater with Plm-Glu311 than Plm-Lys311. This held when reactions were run in plasma lacking FXII or PK, indicating activation of the KKS was not responsible for kinin production. Using plasma-derived proteins, PKa released bradykinin 100-fold faster from HK than LK, and released bradykinin from HK ~50-fold faster than did plasmin. PKa and plasmin released bradykinin at comparable relatively slow rates from LK. Plm-Glu311 released bradykinin from HK 10-fold faster, and from LK 3-fold faster, than in reactions with Plm-Lys311. In experiments in which kininogen deficient plasma was supplemented with either HK or LK to a physiologic concentration, the majority of bradykinin released by Plm-Glu311 was from LK. PKa-catalyzed release of bradykinin from wild type HK-Met361 and variant HK-Lys361 comparably. The same held for LK-Met361 and LK-Lys361. However, plasmin released kinin from HK-Lys361 and LK-Lys361 3.3-fold and 13-fold faster than from HK-Met361 and LK-Met361. While the kinin released from HK-Met361 and LK-Met361 was bradykinin, plasmin released the decapeptide Lys-bradykinin (kallidin) from HK-Lys361 and LK-Lys36. Our studies indicate that angioedema in some patients with HAEnC1 may be due to fibrinolytic activity, and not to KKS activity. Both HK and LK may be substrates in such patients. As the plasma LK concentration is ~4-fold higher than HK, it may be the main pathologic kinin source. The plasmin Lys311Glu substitution converts the protease into a more efficient kininogenase. Fibrinolytic activity is normally brisk in the mouth, perhaps explaining why patients with the Lys311Glu mutation primarily suffer from oral-lingual angioedema. The findings raise the possibility that oral-lingual edema after tPA infusion or ACE inhibitor administration may also be due to plasmin-mediated cleavage of LK and HK. The Met361Lys substitution in HK and LK introduces a novel protease cleavage site immediately upstream from a normal PKa cleavage site. The novel site is preferred over the normal site by plasmin, but not PKa. Several treatments for HAE directed at neutralizing PKa or FXIIa activity have been developed. Our results suggest that such drugs may be less effective in patients with HAEnC1 in which disease mechanisms operate independently of the KKS.

Myoferline gene mutation associated with recurrent angioedema.

Hereditary angioedema (HAE) is a rare genetically determined disease characterized by the recurrent angioedema of various localizations with no response to systemic glucocorticosteroids, antihistamines.
 In the majority of HAE cases C1-inhibitor level or its functional activity is decreased due to a mutation in the SERPING1 gene. In recent years, the expansion of genetic diagnostic recourses significantly changed the understanding of the pathogenesis of HAE without of C1-inhibitor deficiency with previously unknown mutations. Currently mutations in six different genes have been identified as causing HAE: factor XII (F12), plasminogen (PLG), angiopoietin 1 (ANGPT1), Kininogen 1 (KNG1), Myoferlin (MYOF), and heparan sulfate (HS)-glucosamine 3-O-sulfotransferase 6 (HS3ST6). Moreover, the last 3 of them are referred to a separate phenotype intrinsic endothelial dysfunction.
 In 2020 a series of clinical cases in patients with MYOF gene mutation in an Italian family were published. This type is exceptionally rare -only 3 female relatives from the same family are described.
 This article presents a review of the actual international literature and describes the first clinical case of a male patient with a mutation in the myoferlin gene confirmed by genetic testing.

Managing Diagnosis, Treatment, and Burden of Disease in Hereditary Angioedema Patients with Normal C1-Esterase Inhibitor.

Hereditary angioedema (HAE) is a rare, chronic, and debilitating genetic disorder characterized by recurrent and unpredictable swelling episodes that primarily affect the subcutaneous and/or submucosal tissues of the extremities, larynx, face, abdomen, and genitals. Most cases of HAE are caused by mutations in the serpin family G member 1 gene (SERPING1), which encodes C1-esterase inhibitor (C1-INH) protein. Mutations in SERPING1 lead to deficient (type I HAE-C1-INH) or dysfunctional (type II HAE-C1-INH) C1-INH protein and subsequent dysregulation of the kallikrein-bradykinin cascade. However, some patients present with a third type of HAE (HAE-nI-C1-INH), which was first described in the year 2000 and is characterized by an absence of mutations in SERPING1. Although mutations in the coagulation factor XII, angiopoietin-1, plasminogen, kininogen-1, myoferlin, and heparan sulfate-glucosamine 3-O-sulfotransferase-6 genes have been identified in some patients with HAE-nI-C1-INH, genetic cause is still unknown in many cases, hindering full elucidation of the pathology of this HAE subtype. Diagnosis of HAE-nI-C1-INH is also further complicated by the fact that patients typically demonstrate normal plasma levels of C1-INH and complement component 4 protein and normal C1-INH functionality during laboratory analysis. Therefore, we review the challenges associated with diagnosing, treating, and living with HAE-nI-C1-INH. We conclude that raising awareness of the presenting features of HAE-nI-C1-INH within the clinical setting and among the general public is critical to aid earlier suspicion and diagnosis of the disease. Furthermore, adopting an individualized approach to HAE-nI-C1-INH treatment is essential to help address the current and significant unmet needs in this patient population.

Initial Results from a Phase 1 Single Ascending Dose Clinical Trial of STAR-0215, an Investigational Long-Acting Monoclonal Antibody Plasma Kallikrein Inhibitor for Hereditary Angioedema (HAE), in Healthy Subjects Followed for at Least 3 Months

The majority of HAE cases are caused by C1-INH deficiencies, resulting in uncontrolled activation of plasma kallikrein. STAR-0215 is an investigational humanized IgG1kappa monoclonal antibody with potent and durable (≥3 month) reduction of plasma kallikrein activity demonstrated in cynomolgus monkeys. This Phase 1 trial (NCT05477160) is assessing safety and the pharmacokinetic (PK) and pharmacodynamic (PD) activities that support subcutaneous administration of STAR-0215 to achieve potentially robust and durable suppression of HAE attacks for 3 months or longer.

Hereditary Angioedema: Diagnosis, Clinical Implications, and Pathophysiology.

Hereditary angioedema (HAE) is an autosomal dominant disorder caused by a mutation in the C1 esterase inhibitor gene. HAE affects 1/50,000 people worldwide. Three main types of HAE exist: type I, type II, and type III. Type I is characterized by a deficiency in C1-INH. C1-INH is important in the coagulation complement, contact systems, and fibrinolysis. Most HAE cases are type I. Type I and II HAE result from a mutation in the SERPING1 gene, which encodes C1-INH. Formally known as type III HAE is typically an estrogen-dependent or hereditary angioedema with normal C1-INH activity. Current guidelines now recommend subdividing hereditary angioedema with normal C1 esterase inhibitor gene (HAE-nl-C1-INH formerly known as HAE type III) based on underlying mutations such as in kininogen-1 (HAE-KNG1), plasminogen gene (PLG-HAE), myoferlin gene mutation (MYOF-HAE), heparan sulfate-glucosamine 3-sulfotransferase 6 (HS3ST6), mutation in Hageman factor (factor XII), and in angiopoietin-1 (HAE-ANGPT-1). The clinical presentation of HAE varies between patients, but it usually presents with nonpitting angioedema and occasionally abdominal pain. Young children are typically asymptomatic. Those affected by HAE usually present with symptoms in their early 20s. Symptoms can arise as a result of stress, infection, or trauma. Laboratory testing shows abnormal levels of C1-INH and high levels of bradykinin. C4 and D-dimer levels can also be monitored if an acute HAE attack is suspected. Acute treatment of HAE can include IV infusions of C1-INH, receptor antagonists, and kallikrein inhibitors. Short- and long-term prophylaxis can also be administered to patients with HAE. First-line therapies for long-term prophylaxis also include IV infusion of C1-INH. This review aims to thoroughly understand HAE, its clinical presentation, and how to treat it.

Applying bioinformatic analysis for prognostic assessment of the <i>HS3ST6</i> missense mutations clinical significance in the development of hereditary angioedema

Hereditary angioedema (HAE) is a genetically determined disease characterized by recurrent attacks of edema affecting the subcutaneous and/or submucosal layers of tissue, face, lips, neck, extremities of the body, oral cavity, intestine and/or larynx. In the latter case, the disease becomes life-threatening. The majority of HAE cases are associated with decreased levels of C1 (C1-esterase inhibitor), there are also descriptions of HAE with dysfunctional C1 inhibitor and HAE with normal C1 inhibitor. In the first and second variants, mutations in the C1NH gene are the cause of the disease. HAE with normal quantitative and functional levels of C1-inhibitor has the same clinical manifestations but with mutations in other genes, including F12, PLG, ANGPT1, KNG1, MYOF, and HS3ST6. Currently, mutations in the HS3ST6 gene remain poorly understood; only one missense mutation (p.Thr144Ser, rs746467957) associated with the development of HAE has been described.The aim of our work was to study new mutations in the HS3ST6 gene and analyze in silico their prognostic nature and clinical significance for the development of hereditary angioedema.The material was whole blood samples obtained from 13 patients with symptoms of hereditary angioedema without reduced levels and function of C1-INH.Whole exome sequencing of patients, bioinformatic analysis of HS3ST6 gene mutations using a number of databases and Web resources to predict the effect of mutations on the protein and assess the conservatism of the positions of the mutations detected was involved in study methods.Mutations in the HS3ST6 gene were identified in four patients, including two cases with two mutations simultaneously. Application of bioinformatic analysis allowed us to obtain new data on four missense mutations in the studied gene. Potential pathogenetic significance was determined for three of them. The mutation NC_000016.9:g.1962132G>A (p.A163V) is most likely to be involved in pathogenesis of HAE by indirect disruption of heparan sulfate O-sulfation directly within the protein. The NC_000016.9:g.1962024G>A mutation (p.P199L) appears to lead to the development of the disease through disruption of docking with SDC2 heparan sulfate. In the NC_000016.9:g.1962046C>T (p.A192T) mutation, destabilization of the 192 amino acid position next to PAPS, may contribute to disruption of heparan sulfate O-sulfation through disruption of protein functional activity and, therefore, catalysis transfer of sulfo group to heparan sulfate syndecan-2. Thus, in all three cases, the formation of HAE appears to be possible due to disruption of the O-sulfation steps of heparan sulfate syndecan-2.Considering that in silico methods offer new opportunities to assess the pathogenetic significance of mutations, the application of bioinformatic analysis can contribute to a detailed investigation of the causes of hereditary angioedema. The present work convincingly demonstrates that rare mutations in the HS3ST6 gene may be involved in the pathogenesis of HAE and provoke edema due to increased bradykinin release.

Interventions for the long-term prevention of hereditary angioedema attacks.

Hereditary angioedema (HAE) is a serious and potentially life-threatening condition that causes acute attacks of swelling, pain and reduced quality of life. People with Type I HAE (approximately 80% of all HAE cases) have insufficient amounts of C1 esterase inhibitor (C1-INH) protein; people with Type II HAE (approximately 20% of all cases) may have normal C1-INH concentrations, but, due to genetic mutations, these do not function properly. A few people, predominantly females, experience HAE despite having normal C1-INH levels and C1-INH function (rare Type III HAE). Several new drugs have been developed to treat acute attacks and prevent recurrence of attacks. There is currently no systematic review and meta-analysis that included all preventive medications for HAE. To assess the benefits and harms of interventions for the long-term prevention of HAE attacks in people with Type I, Type II or Type III HAE. We used standard, extensive Cochrane search methods. The latest search date was 3 August 2021. We included randomised controlled trials in children or adults with HAE that used medications to prevent HAE attacks. The comparators could be placebo or active comparator, or both; approved and experimental drug trials were eligible for inclusion. There were no restrictions on dose, frequency or intensity of treatment. The minimum length of four weeks of treatment was required for inclusion; this criterion excluded the acute treatment of HAE attacks. We used standard Cochrane methods. Our primary outcomes were 1. HAE attacks (number of attacks per person, per population) and change in number of HAE attacks; 2. mortality and 3. serious adverse events (e.g. hepatic dysfunction, hepatic toxicity and deleterious changes in blood tests). Our secondary outcomes were 4. quality of life; 5. severity of breakthrough attacks; 6. disability and 7. adverse events (e.g. weight gain, mild psychological changes and body hair). We used GRADE to assess certainty of evidence for each outcome. We identified 15 studies (912 participants) that met the inclusion criteria. The studies included people with Type I and II HAE. The studies investigated avoralstat, berotralstat, subcutaneous C1-INH, plasma-derived C1-INH, nanofiltered C1-INH, recombinant human C1-INH, danazol, and lanadelumab for the prevention of HAE attacks. We did not find any studies on the use of tranexamic acid for prevention of HAE attacks. All drugs except avoralstat reduced the number of HAE attacks compared with placebo. For breakthrough attacks that occurred despite prophylactic treatment, intravenous and subcutaneous forms of C1-INH and lanadelumab reduced attack severity. It is not known whether other drugs have a similar effect, as the severity of breakthrough attacks in people taking drugs other than C1-INH and lanadelumab was not reported. For quality of life, avoralstat, berotralstat, C1-INH (all forms) and lanadelumab increased quality of life compared with placebo; there were no data for danazol. Four studies reported on changes in disability during treatment with C1-INH, berotralstat and lanadelumab; all three drugs decreased disability compared with placebo. Adverse events, including serious adverse events, did not occur at a rate higher than placebo. However, serious adverse event data and other adverse event data were not available for danazol, which prevented us from drawing conclusions about the absolute or relative safety of this drug. No deaths were reported in the included studies. The analysis was limited by the small number of studies, the small number of participants in each study and the lack of data on older drugs, therefore the certainty of the evidence is low. Given the rarity of HAE, it is not surprising that drugs were rarely directly compared, which does not allow conclusions on the comparative efficacy of the various drugs for people with HAE. Finally, we did not identify any studies that included people with Type III HAE. Therefore, we cannot draw any conclusions about the efficacy or safety of any drug in people with this form of HAE. The available data suggest that berotralstat, C1-INH (subcutaneous, plasma-derived, nanofiltered and recombinant), danazol and lanadelumab are effective in lowering the risk or incidence (or both) of HAE attacks. In addition, C1-INH and lanadelumab decrease the severity of breakthrough attacks (data for other drugs were not available). Avoralstat, berotralstat, C1-INH (all forms) and lanadelumab increase quality of life and do not increase the risk of adverse events, including serious adverse events. It is possible that danazol, subcutaneous C1-INH and recombinant human C1-INH are more effective than berotralstat and lanadelumab in reducing the risk of breakthrough attacks, but the small number of studies and the small size of the studies means that the certainty of the evidence is low. This and the lack of head-to-head trials prevented us from drawing firm conclusions on the relative efficacy of the drugs.

Hereditary angioedema is associated with an increased risk of venous thromboembolism

Hereditary angioedema is associated with an increased risk of venous thromboembolism

Successful Use of Lanadelumab in an Older Patient With Type II Hereditary Angioedema.

Type II hereditary angioedema (HAE) is a rare, genetic disorder characterized by recurring subcutaneous and/or submucosal edema throughout the body and causes significant morbidity and mortality. Lanadelumab is a novel, long-term prophylactic treatment option for HAE and has proven to be an effective treatment option. However, data are limited in patients with type II HAE or aged ≥ 65 years. We present a case of HAE treated with lanadelumab in a patient of an underrepresented population. An 81-year-old male patient was diagnosed with type II HAE at the age of 75 years. Initially, he described having attacks of abdominal pain weekly that could last up to several days. At age 77 years, he began an on-demand treatment, icatibant, which diminished pain. However, after increasing frequency of attacks, the patient started receiving lanadelumab 300 mg subcutaneously every 2 weeks. He went from requiring on-demand treatment 2 to 3 times per month to once in 6 months. Long-term prophylaxis is critical for managing HAE patients, but data are limited for patients with type II HAE and aged ≥ 65 years. Our case supports the use of lanadelumab in these populations.

A case of normal C1 esterase inhibitor hereditary angioedema successfully treated with berotralstat

A case of normal C1 esterase inhibitor hereditary angioedema successfully treated with berotralstat

Screening for Plasminogen Mutations in Hereditary Angioedema Patients.

Hereditary angioedema (HAE) is a rare disease belonging to the group of bradykinin-mediated angioedemas, characterized by recurring edematous episodes involving the subcutaneous and/or submucosal tissues. Most cases of HAE are caused by mutations in the SERPING1 gene encoding C1-inhibitor (C1-INH-HAE); however, mutation analysis identified seven further types of HAE: HAE with Factor XII mutation (FXII-HAE), with plasminogen gene mutation (PLG-HAE), with angiopoietin-1 gene mutation (ANGPT1-HAE), with kininogen-1 gene mutation (KNG1-HAE), with a myoferlin gene mutation (MYOF-HAE), with a heparan sulfate-glucosamine 3-sulfotransferase 6 (HS3ST6) mutation, and hereditary angioedema of unknown origin (U-HAE). We sequenced DNA samples stored from 124 U-HAE patients in the biorepository for exon 9 of the PLG gene. One of the 124 subjects carried the mutation causing a lysine to glutamic acid amino acid exchange at position 330 (K330E). Later, the same PLG mutation was identified in the patient’s son. The introduction of new techniques into genetic testing has increased the number of genes identified. As shown by this study, a biorepository creates the means for the ex-post analysis of recently identified genes in stored DNA samples of the patients. This makes the diagnosis more accurate with the possibility of subsequent family screening and the introduction of appropriate therapy.

Molecular genetic diagnosis of hereditary angioedema

Hereditary angioedema (HAE) is a rare genetic condition currently subdivided into two groups: HAE due to C1-inhibitor deficiency (Type I) or dysfunction (Type II) (C1-INH-HAE) and HAE with normal activity of C1‐INH (nC1- INH-HAE). C1-INH-HAE is estimated to occur in approximately 99 % of cases HAE and is caused by sequence variants in the SERPING1 gene. The prevalence of nC1-INH-HAE is extremely low and accounts for about 1 % of all cases of HAE. nC1-INH-HAE currently subdivided on HAE, due to mutations in factor XII (FXII-HAE), plasminogen (PLG-HAE), angiopoietin 1 (ANGPT1-HAE), kininogen 1 gene (KNG1-HAE), or angioedema of unknown origin (U-HAE).The amplicons of the entire coding regions and splice-sites of 18 genes from 24 patients (18 female) belonging to 17 families were analyzed by Next Generation Sequencing (NGS). The median age of patients was 33.5, of onset ‒ 16 years. 15 patients had a family history of edema.We identified seven C1-INH-HAE patients and variants were detected in the SERPING1 gene. For three patients (members of the same family), a heterozygous variant was found deep in the intron of the SERPING1 gene, which is likely to affect protein synthesis. We identified two patients with changes in the PLAUR gene, which may be associated with the manifestation of symptoms angioedema. Six patients showed abnormalities in the genes AGT and KNG1, which can probably explain their early hypertension, which could provoke the appearance of edema.

A case of hereditary angioedema due to C1-inhibitor deficiency with recurrent abdominal pain diagnosed 40 years after the occurrence of the initial symptom

Hereditary angioedema due to C1-inhibitor deficiency (HAE-C1-INH) is a rare disease, which induces an acute attack of angioedema mediated by bradykinin. HAE-C1-INH can cause serious abdominal pain when severe edema develops in the gastrointestinal tract. However, because it takes a long time, 13.8 years on average in Japan, from the occurrence of the initial symptom to the diagnosis due to low awareness of the disease, undiagnosed HAE-C1-INH patients sometimes undergo unnecessary surgical procedures for severe abdominal pain. We herein present a 56-year-old patient with HAE-C1-INH, who underwent numerous abdominal operations. He frequently needed hospitalization with the administration of opioid due to severe abdominal pain. However, after he was accurately diagnosed with HAE-C1-INH at 55 years of age, he could start self-administration for an acute attack with icatibant, a selective bradykinin B2 receptor antagonist. Consequently, he did not need hospitalizing for ten months after the beginning of the treatment. A series of an accurate diagnosis and appropriate treatment for HAE-C1-INH improved his quality of life. Thus, HAE-C1-INH should be considered, when we meet patients with unidentified recurrent abdominal pain. This case highlights significance of an early diagnosis and appropriate treatment for HAE-C1-INH.

A Case of Hereditary Angioedema in Which Bronchoscopy Was Able to Be Safely Performed Without Causing Laryngeal Edema

A Case of Hereditary Angioedema in Which Bronchoscopy Was Able to Be Safely Performed Without Causing Laryngeal Edema

A Case of Hereditary Angioedema who Underwent Endoscopic Sinus Surgery Under General Anesthesia

A Case of Hereditary Angioedema who Underwent Endoscopic Sinus Surgery Under General Anesthesia

A case of hereditary angioedema with late adulthood onset

Over the last years, high attention is given to the hereditary angioedema (HAO). Practitioners can identify the disease by clinical manifestations and family history even before specific laboratory testing. More than 95% of HAO cases are associated with C-1inhibitor deficiency/dysfunction caused by a mutation inSERPING1gene. In 25% of patients without C1-inhibitor deficiency HAO is associated with heterozygous mutations in geneF12coding Hageman XII factor. In 20172018 years two more genes responsible for normal C1-inhibitor HAO were discovered: genesPLGandANGPT1. In clinical practice patients do not always meet typical HAO diagnosis criteria. Diagnostic difficulties appear when clinical picture is not confirmed by related genetic testing results, for example, mutations in genes not described earlier are detected. It should be noted that app. 25% of patients do not have any HAO family history, i.e. have so called de novo mutations. Normally HAO onset takes place within 2 first life decades. 40% of patients have disease progress before the age of 5, and 75% of patients before the age of 15 y.o. However, it can appear in elderly age, which means certain diagnostic difficulties. It is important to analyze thoroughly patients comorbidity and make differential diagnosis with a secondary angioedema.

Spectrum of diagnosis of hereditary angioedema: Seven case reports

Hereditary angioedema (HAE) is a potentially life-threatening disorder, due to a mutation in complement one-inhibitor (C1-INH) gene, which blocks the activity of various components of complement – fibrinolytic and bradykinin control system. Our seven cases of HAE give different clinical presentations of TYPE I/II/III HAE as facial, abdominal, laryngeal, and genital involvement along with comorbidities (5 cases) such as hypothyroidism, rhinosinusitis, and hypothalamic–pituitary–adrenal suppression, and four cases have had history of recurrent abdominal attacks. Treatment with Pdc-INH concentrate and self-administrated Icatibant provides consistent and reliable efficacy in those who have had multiple successive HAE attacks, with the involvement of all body parts. However, if pdc-INH concentrate is not available, then fresh frozen plasma and androgens (Danazol) can be used in emergency. Our cases demonstrate the importance of diligent clinical and family history with special tests: C4, C1-INH quantitative, and C1-INH functional.

2635 Gastrointestinal Hereditary Angioedema Causing Recurrent, Self-Resolving Abdominal Pain

INTRODUCTION: Hereditary angioedema (HAE) is a type of bradykinin-mediated isolated angioedema, characterized by temporary swelling that can affect skin or walls of hollow viscera such as the oropharynx, or gastrointestinal tract (in 43 to 93% of HAE cases respectively) and occurs without pruritus. This case is reported due to its rare presentation that often results in unnecessary invasive procedures. CASE DESCRIPTION/METHODS: A 25-year-old female with a past medical history of hypothyroidism and asthma presented with acute on chronic intermittent abdominal pain and vomiting for a day bearing no relation with meals or defecation. She had recurrent hospitalizations for similar complaints but workup till date showed enteritis on imaging and exploratory laparoscopy showed adhesions with colonic biopsy negative. Extensive history taking revealed prodromal symptom of anxiety and a previous episode of self-resolving finger swelling, retrospectively suspected to be due to angioedema. Labs showed leukocytosis and elevated CRP. Repeat CECT abdomen displayed thickening of jejunal wall. Given her history of prodromal symptoms, finger swelling and a family history of similar self-resolving abdominal pain of unclear etiology in her mother prompted further testing for complements due to concern for hereditary angioedema, which was positive with low C4 and C1 inhibitor. She was referred to an allergy specialist for further management. DISCUSSION: HAE is an autosomal dominant disease that is due to decreased or impaired C1 Inhibitor. Typical GI symptoms are recurrent abdominal pain, vomiting and diarrhea caused by transient small bowel edema. Inciting events include stressful situations like fasting and infections and medicines like ACE-inhibitors. Diagnosis is clinical from history of skin swelling or respiratory distress during attacks, documenting possible triggers and family history of HAE. Physical exam and imaging is useful only during acute attacks. Recommended lab tests include C4 levels, C1 inhibitor antigenic levels, and C1INH functional levels. Endoscopy is not recommended as it may precipitate laryngoedema. Treatment includes C1 INH replacement or icatibant (bradykinin receptor antagonist) for acute attacks and attenuated androgen or lanadelumab for prophylaxis. HAE should be considered when tackling cases of undiagnosed abdominal pain in the right clinical context to prevent years of suffering, unnecessary invasive procedures and life-threatening complications from laryngeal edema or hypovolemic shock.