The Burden of Hereditary Angioedema in a Large Family in Brazil.

INTRODUCTION: Hereditary angioedema (HAE) is a rare genetic disease characterized by submucosal and subcutaneous edema with high morbidity and possibility of mortality. This study presents the sociodemographic characteristics of a large Brazilian family with HAE. METHODS: Descriptive cross-sectional study with patients from two family branches coming from the same city and HAE diagnosis was carried out. Clinical, laboratory, and treatment data of patients have been collected. Genetic testing was performed on some individuals. Correlation tests and comparisons between variables were applied using IBM SPSS Statistics® 2.0 program. RESULTS: We provide a detailed characterization of two families affected by HAE due to C1-INH deficiency, residing in a small town in southern Brazil. These families harbor an identified mutation in the SERPING1 gene (c.1104del, p.Asp369ThrfsTer2). The mean age at HAE diagnosis was 16.7 (±14.0) years, with the mean onset of symptoms at 6.0 (±6.1) years of age. A correlation was observed between patients' current age and age at HAE diagnosis, with older patients being diagnosed later than younger individuals (p < 0.0001). On average, there were 16.8 emergency visits in the past year (±24.8), and 53.5% of patients reported at least one lifetime hospitalization. Notably, treatment modalities often diverged from consensus recommendations regarding optimal prophylaxis and management of HAE attacks. CONCLUSIONS: This study describes one of the largest known families with HAE in Brazil and highlights the significant impact of unfavorable social conditions on disease control.

The Challenges in the Follow-Up and Treatment of Brazilian Children with Hereditary Angioedema.

INTRODUCTION: Hereditary angioedema (HAE) with C1 inhibitor (C1-INH) deficiency is a rare autosomal dominant disease. Although the first symptoms can appear in childhood, the diagnosis's delay has a strong impact on the patient's quality of life. We analyzed clinical and laboratory characteristics and the drug therapy of pediatric patients with HAE in Brazil. METHODS: Medical records from 18 reference centers of HAE patients under 18 years of age were evaluated after confirmed diagnosis was performed by quantitative and/or functional C1-INH. RESULTS: A total of 95 participants (51 M:44 F; mean age: 7 years old) out of 17 centers were included; 15 asymptomatic cases were identified through family history and genetic screening. Angioedema attacks affected the extremities (73.5%), gastrointestinal tract (57%), face (50%), lips (42.5%), eyelids (23.7%), genitals (23.7%), upper airways (10%), and tongue (6.3%). Family history was present in 84% of patients, and the mean delay in the diagnosis was 3.9 years. Long-term prophylaxis (51/80) was performed with tranexamic acid (39/80) and androgens (13/80); and short-term prophylaxis (9/80) was performed with tranexamic acid (6/80) and danazol (3/80). On-demand therapy (35/80) was prescribed: icatibant in 7/35, fresh frozen plasma in 16/35, C1-INH plasma-derived in 11/35, and tranexamic acid in 12/35 patients. CONCLUSIONS: This is the first study on HAE pediatric patients in Latin America. Clinical manifestations were similar to adults. Drugs such as androgens and tranexamic acid were indicated off-label, probably due to restricted access to specific drugs. Educational programs should address pediatricians to reduce late diagnosis and tailored child therapy.

COVID-19 and hereditary angioedema: Incidence, outcomes, and mechanistic implications.

Background: Patients with hereditary angioedema (HAE) have been postulated to be at increased risk for coronavirus disease 2019 (COVID-19) infection due to inherent dysregulation of the plasma kallikrein-kinin system. Only limited data have been available to explore this hypothesis. Objective: To assess the interrelationship(s) between COVID-19 and HAE. Methods: Self-reported COVID-19 infection, complications, morbidity, and mortality were surveyed by using an online questionnaire. The participants included subjects with HAE with C1 inhibitor (C1INH) deficiency (HAE-C1INH) and subjects with HAE with normal C1-inhibitor (HAE-nl-C1INH), and household controls (normal controls). The impact of HAE medications was examined. Results: A total of 1162 participants who completed the survey were analyzed, including: 695 subjects with HAE-C1INH, 175 subjects with HAE-nl-C1INH, and 292 normal controls. The incidence of reported COVID-19 was not significantly different between the normal controls (9%) and the subjects with HAE-C1INH (11%) but was greater in the subjects with HAE-nl-C1INH (19%; p = 0.006). Obesity was positively correlated with COVID-19 across the overall population (p = 0.012), with a similar but nonsignificant trend in the subjects with HAE-C1INH. Comorbid autoimmune disease was a risk factor for COVID-19 in the subjects with HAE-C1INH (p = 0.047). COVID-19 severity and complications were similar in all the groups. Reported COVID-19 was reduced in the subjects with HAE-C1INH who received prophylactic subcutaneous C1INH (5.6%; p = 0.0371) or on-demand icatibant (7.8%; p = 0.0016). The subjects with HAE-C1INH and not on any HAE medications had an increased risk of COVID-19 compared with the normal controls (24.5%; p = 0.006). Conclusion: The subjects with HAE-C1INH who were not taking HAE medications had a significantly higher rate of reported COVID-19 infection. Subcutaneous C1INH and icatibant use were associated with a significantly reduced rate of reported COVID-19. The results implicated potential roles for the complement cascade and tissue kallikrein-kinin pathways in the pathogenesis of COVID-19 in patients with HAE-C1INH.

Genetic analysis of hereditary angioedema in a Brazilian family by targeted next generation sequencing.

Hereditary angioedema (HAE) is accompanied by an overproduction of bradykinin (BK) as the primary mediator of swelling. Although many proteins may be involved in regulating the wide spectrum of HAE symptoms, most studies have only focused on C1-INH and FXII. For the first time, a next generation sequencing (NGS) method was applied to develop a robust, time- and cost-effective diagnostic and research tool to analyze selected genes related to HAE. The entire coding region and the exon-intron boundaries of 15 genes from 23 subjects of a Brazilian family, nine of whom were symptomatic, were analyzed by NGS. One new mutation found uniquely in the nine symptomatic patients, p.Ala457Pro in the SERPING1 gene, was estimated as likely to be pathogenic (PolyPhen-2 software analysis) and is the main candidate to be responsible for HAE in these patients. Alterations identified in a few asymptomatic individuals but also found in almost all symptomatic patients, such as p.Ile197Met (HMWK), p.Glu298Asp (NOS3) and p.Gly354Glu (B2R), may also be involved in modulating patient-specific symptoms. This NGS gene panel has proven to be a valuable tool for a quick and accurate molecular diagnosis of HAE and efficient to indicate modulators of HAE symptoms.

Leveraging Genetics for Hereditary Angioedema: A Road Map to Precision Medicine.

Biochemical studies performed during the last decades resulted in the development of various innovative medicinal products for hereditary angioedema (HAE). These therapeutic agents target the production or the function of bradykinin-the main mediator of HAE due to C1-inhibitor (C1-INH) deficiency. However, despite these remarkable achievements, current knowledge cannot provide convincing explanations for the clinical variability of the disease. As a consequence, treatment indications apply for drugs available for C1-INH deficiency. The advent of high-throughput next-generation sequencing technologies may assist in covering the missing part of our understanding of HAE pathogenesis. During the last 3 years alone, several new entities were added to the already described genotypes. The recent discovery of four novel target genes expands our understanding of other causes which may explain recurrent angioedema in individuals and families with normal C1-INH activity. Furthermore, new genetic technologies allowed the recognition of deep intronic variants associated with the disease, and elegant functional studies characterized new variants for the C1-INH gene. Thus, evidence has been provided regarding pathogenetic aspects remaining obscure for many years, such as the defective intracellular transport of mutant C1-INH, and environmental effect on the disease expression. Therefore, it seems that the stage for Precision Medicine era in HAE management is ready. Disease endotypes are expected to be uncovered and specified targets for therapeutic intervention will be detected, promising a more effective, individualized management of the disease.

The Expanding Spectrum of Mutations in Hereditary Angioedema.

The evolution in the knowledge of rare genetic diseases such as hereditary angioedema (HAE) has increased at a parallel pace with the development of new molecular tools. The deficiency of C1 inhibitor (C1-INH) has been recognized as the main cause of HAE (HAE-C1-INH) since the 1960s, but the discovery of the wide spectrum of mutations affecting the C1-INH gene (SERPING1) was possible only from the late 1980s, when Sanger sequencing became available and more accessible worldwide. Nevertheless, the involvement of other genes in HAE was discovered only in 2006 with the description of mutations in the F12 gene in patients with HAE and normal C1-INH. In the last 3 years, advanced next-generation sequencing techniques allowed the identification of mutations in 5 new genes being associated with HAE and normal C1-INH: ANGPT1 (angiopoietin-1), PLG (plasminogen), KNG1 (kininogen), MYOF (myoferlin), and HS3ST6 (heparan sulfate-glucosamine 3-O-sulfotransferase 6). The knowledge provided by the new era of genomic studies was pivotal in the discovery of mutations in new genes responsible for this complex pathogenesis. Genomics advances promise a better understanding of unknown mechanisms leading to HAE, the establishment of new molecular targets for novel therapeutic agents, and personalized treatment.

The Panorama of Primary Angioedema in the Brazilian Population.

BACKGROUND: Primary angioedema (PA) is a complex disorder, presenting multiple hereditary (hereditary angioedema) and acquired subtypes (acquired angioedema). Despite a very similar clinical presentation among subtypes, the differential diagnosis is limited by the difficulty to identify bradykinin-mediated PA and the lack of specific biomarkers. OBJECTIVES: To report the clinical and genetic features of Brazilian patients with PA. METHODS: Brazilian patients referred from 50 centers were diagnosed on the basis of clinical symptoms, C1 inhibitor (C1-INH) and C4 plasma measurements, and DNA sequencing of genes associated with hereditary angioedema. RESULTS: We characterized 92 patients with acquired angioedema and 425 with HAE: 125 with C1-INH deficiency, 180 with F12 mutations, and 120 of unknown cause. Thirty-one different mutations were identified in SERPING1 and 2 in F12, in addition to 2 mutations of uncertain significance in the ANGPT1 gene. The molecular diagnosis was decisive for 34 patients with HAE without family history, and for 39% of patients with inconsistent biochemical measurements. The median delay in diagnosis was 10 years, with a maximum of 18 years for HAE with C1-INH deficiency. Androgens and tranexamic acid were the most used drugs for long-term prophylaxis in all the PA subtypes, and they were used on demand by 15% of patients. Only 10% of patients reported the use of specific medication for HAE during attacks. CONCLUSIONS: Our analysis exposes a broad picture of PA diagnosis and management in a developing country. Complement measurements presented considerable inconsistencies, increasing the diagnosis delay, while patients with PA with normal C1-INH remain with an inaccurate diagnosis and unspecific treatment.

Angioedema without urticaria: novel findings which must be measured in clinical setting.

PURPOSE OF REVIEW: Angioedema without urticaria is composed of an increasing subtype's variety and presents a challenging diagnosis. This review summarizes the subtypes recently described and subsequent new findings helpful within their classification. RECENT FINDINGS: New methods to measure cleaved high molecular weight kininogen and activated plasma kallikrein have emerged as potential biochemical tests to identify bradykinin-mediated angioedema. Three new subtypes of hereditary angioedema (HAE) with normal C1 inhibitor were described in the past two years: HAE due to mutation in plasminogen gene, in kininogen gene, and in angiopoietin-1 gene; implicating the fibrinolytic and contact systems, and the regulation of vasculature, respectively. The understanding of some mechanisms in angioedema has been improved, compatible to the dominant-negative for some C1 inhibitor variants; furthermore, the increased activation of truncated F12 mutants by plasma kallikrein; and the diminished binding of angiopoietin-1 to its receptor. SUMMARY: The validation of biomarkers for the contact system activation could be beneficial in differentiating bradykinin - from histaminergic-mediated angioedema. Currently, the available laboratorial tests are still somewhat restricted to the evaluation of the complement activation and the mediators of nonhistaminergic and nonbradykinin-mediated angioedema remain to be identified.

International Consensus on the Use of Genetics in the Management of Hereditary Angioedema.

Hereditary angioedema (HAE) is becoming much more genetically complex than was initially considered. Thus, the role of HAE genetics is expanding beyond research laboratories, and the genotyping of subjects suffering from HAE has become diagnostically indispensable in clinical practice. The synthesis and interpretation of the clinical and biochemical analyses to facilitate appropriate genetic test selection has thus also become significantly more complex. With this in mind, an international multidisciplinary group of 14 experts in HAE genetics and disease management was convened in October 2018. The objective was to develop clear, actionable, evidence- and consensus-based statements aiming to facilitate the communication between physicians treating patients with HAE and clinical geneticists, and thus promote the effective use of genetics in the management of the disease. Eleven consensus statements were generated, encompassing considerations regarding the clinical indications for genotyping patients with angioedema, the methods of detection of HAE-causative variants, the variant pathogenicity curation, the genotyping of patients with HAE in the clinic, and genetic counseling. These statements are intended both to guide clinicians and to serve as a framework for future educational and further genetic testing developments as the field continues to evolve rapidly.

Hereditary Angioedema-Associated Acute Pancreatitis in C1-Inhibitor Deficient and Normal C1-Inhibitor Patients: Case Reports and Literature Review.

Abdominal pain due to intestinal swellings is one of the most common manifestations in hereditary angioedema (HAE). Bowel swellings can cause severe abdominal pain, nausea, vomiting, and diarrhea, which may lead to misdiagnosis of gastrointestinal disorders. In rare cases, HAE abdominal attacks can be accompanied by acute pancreatitis. Here, we report 3 patients with HAE and acute pancreatitis and present a literature review of similar cases. Patients with confirmed diagnosis of HAE secondary to C1-inhibitor (C1-INH) deficiency (n = 2) and HAE with normal C1-INH and F12 mutation (F12-HAE) (n = 1) were included. Pancreatitis was diagnosed based on clinical symptoms and high lipase and amylase levels. Three HAE patients were diagnosed with acute pancreatitis based on increased amylase levels during severe abdominal swelling episodes. Two were previously diagnosed with HAE type I and one with F12-HAE. Pancreatitis was efficiently treated in two patients using Icatibant, with pain relief within hours. When conservatively treated, pancreatitis pain took longer time to resolve. Eighteen pancreatitis cases in HAE with C1-INH deficiency were previously reported and none in F12-HAE. Most patients (12/18) underwent invasive procedures and/or diagnostic methods. Although rare, severe abdominal HAE attacks could cause pancreatitis; HAE-specific treatments may be efficient for HAE-associated pancreatitis. HAE should be considered as a differential diagnosis of acute idiopathic pancreatitis. To our knowledge, this is the first report of HAE-associated pancreatitis in a F12-HAE patient treated with Icatibant.

Genetic Variation of Kallikrein-Kinin System and Related Genes in Patients With Hereditary Angioedema.

Hereditary angioedema (HAE) is an autosomal dominant disease caused by C1-INH deficiency due to mutations in SERPING1 (C1-INH-HAE) in most of the cases, or by specific mutations in factor XII gene, F12 (F12-HAE). Identification of polymorphisms in the genes encoding proteins from key pathways driving HAE can help to understand how genetic diversity contributes to its phenotypic variability. Here, 15 genes related to the Kallikrein-Kinin System (KKS) were analyzed by next generation sequencing in 59 patients with C1-INH-HAE or F12-HAE from Brazil, Denmark and Spain, and 19 healthy relatives in a total of 31 families. We identified 211 variants, from which 23 occurred only in Danish subjects and 79 were found only in Brazilian individuals, resulting in 109/211 variations in common between European and Brazilian population in the HAE families analyzed. BDKRB2 and CPM presented a large number of variants in untranslated regions, 46/49 and 19/24, respectively; whereas ACE (n = 26), SERPING1 (n = 26), CPM (n = 24), and NOS3 (n = 16) genes presented the higher number of variants directly affecting amino acid sequence. Despite the large amount of variants identified, the lack of association between genotype and phenotype indicates that the modulation of HAE symptom requires a more complex regulation, probably involving pathways beyond the KKS, epigenetics and environmental factors. Considering the new HAE types recently described, molecules involved in the regulation of vasculature and in plasminogen activation become promising targets for future genetic studies.

Hereditary Angioedema with Normal C1 Inhibitor and F12 Mutations in 42 Brazilian Families.

BACKGROUND: Hereditary angioedema (HAE) with normal C1 inhibitor (C1-INH) is a rare condition with clinical features similar to those of HAE with C1-INH deficiency. Mutations in the F12 gene have been identified in subsets of patients with HAE with normal C1-INH, mostly within families of European descent. OBJECTIVES: Our aim was to describe clinical characteristics observed in Brazilians from 42 families with HAE and F12 gene mutations (FXII-HAE), and to compare these findings with those from other populations. METHODS: We evaluated a group of 195 individuals, which included 102 patients clinically diagnosed with FXII-HAE and their 93 asymptomatic relatives. RESULTS: Genetic analysis revealed that of the 195 subjects, 134 individuals (77.6% females) carried a pathogenic mutation in F12. The T328K substitution was found in 132 individuals, and the c.971_1018+24del72 deletion was found in 2 patients. The mean age at onset of symptoms in patients with FXII-HAE was 21.1 years. The most common symptoms were subcutaneous edema (85.8% of patients), abdominal pain attacks (69.7%), and upper airway edema (32.3%). Of male individuals carrying F12 mutations, 53.3% (16 of 30) were symptomatic. Compared with reports from Europe, fewer female patients (68.6%) reported an influence of estrogen on symptoms. CONCLUSIONS: Our study included a large number of patients with FXII-HAE, and, as the first such study conducted in a South American population, it highlighted significant differences between this and other study populations. The high number of symptomatic males and patients with estrogen-independent FXII-HAE found here suggests that male sex and the absence of a hormonal influence should not discourage clinicians from searching for F12 mutations in cases of HAE with normal C1-INH.

Targeted Next-Generation Sequencing in Brazilian Children With Nephrotic Syndrome Submitted to Renal Transplant.

BACKGROUND: The aims of this study were to identify the genetic mutations profile in Brazilian children with nephrotic syndrome (NS) and to determine a genotype-phenotype correlation in this disease. METHODS: Next-generation sequencing and mutation analysis were performed on 24 genes related to NS in a cross-sectional study involving 95 children who underwent kidney transplantation due to NS, excluding congenital cases. RESULTS: A total of 149 variants were identified in 22 of 24 sequenced genes. The mutations were classified as pathogenic, likely pathogenic, likely benign and benign per the chance of causing the disease. NPHS2 was the most common mutated gene. We identified 8 (8.4%) patients with hereditary NS and 5 (5%) patients with probably genetically caused NS. COL4A3-5 variants were found as well, but it is not clear whether they should be considered isolated FSGS or simply a misdiagnosed type of the Alport spectrum. Considering the clinical results, hereditary NS patients presented a tendency to early disease onset when compared with the other groups (P = 0.06) and time to end stage renal disease (ESRD) was longer in this group (P = 0.03). No patients from hereditary NS group had NS recurrence after transplantation. CONCLUSIONS: This is the first study in children with steroid-resistant NS who underwent kidney transplantation using next-generation sequencing. Considering our results, we believe this study has shed some light to the uncertainties of genotype-phenotype correlation in NS, where several genes cooperate to produce or even to modify the course of the disease.

Diretrizes brasileiras do angioedema hereditário 2022 ­ Parte 1: definição, classificação e diagnóstico / 2022 Brazilian guidelines for hereditary angioedema ­ Part 1: definition, classification, and diagnosis

O angioedema hereditário é uma doença autossômica dominante caracterizada por crises recorrentes de edema que acometem o tecido subcutâneo e o submucoso, com envolvimento de diversos órgãos. Os principais locais afetados são face, membros superiores e inferiores, as alças intestinais e as vias respiratórias superiores. Em decorrência da falta de conhecimento dessa condição por profissionais de saúde, ocorre atraso importante no seu diagnóstico, comprometendo a qualidade de vida dos indivíduos afetados. Além disso, o retardo no diagnóstico pode resultar em aumento da mortalidade por asfixia devido ao edema de laringe. A natureza errática das crises com variação do quadro clínico e gravidade dos sintomas entre diferentes pacientes, e no mesmo paciente ao longo da vida, se constitui em desafio no cuidado dos doentes que têm angioedema hereditário. O principal tipo de angioedema hereditário é resultante de mais de 700 variantes patogênicas do gene SERPING1 com deficiência funcional ou quantitativa da proteína inibidor de C1, porém nos últimos anos outras mutações foram descritas em seis outros genes. Ocorreram avanços importantes na fisiopatologia da doença e novas drogas para o tratamento do angioedema hereditário foram desenvolvidas. Nesse contexto, o Grupo de Estudos Brasileiro em Angioedema Hereditário (GEBRAEH) em conjunto com a Associação Brasileira de Alergia e Imunologia (ASBAI) atualizou as diretrizes brasileiras do angioedema hereditário. O maior conhecimento dos diversos aspectos resultou na divisão das diretrizes em duas partes, sendo nessa primeira parte abordados a definição, a classificação e o diagnóstico.

Hereditary angioedema is an autosomal dominant disease characterized by recurrent attacks of edema that affect the subcutaneous tissue and the submucosa, involving several organs. The main affected sites are the face, upper and lower limbs, gastrointestinal tract, and upper airways. Because health professionals lack knowledge about this condition, there is a significant delay in diagnosis, compromising the quality of life of affected individuals. Furthermore, delayed diagnosis may result in increased mortality from asphyxia due to laryngeal edema. The erratic nature of the attacks with variations in clinical course and severity of symptoms among different patients and in one patient throughout life constitutes a challenge in the care of patients with hereditary angioedema. The main type of hereditary angioedema results from more than 700 pathogenic variants of the SERPING1 gene with functional or quantitative deficiency of the C1 inhibitor protein, but in recent years other mutations have been described in six other genes. Important advances have been made in the pathophysiology of the disease, and new drugs for the treatment of hereditary angioedema have been developed. In this context, the Brazilian Study Group on Hereditary Angioedema (GEBRAEH) in conjunction with the Brazilian Association of Allergy and Immunology (ASBAI) updated the Brazilian guidelines on hereditary angioedema. Greater knowledge of different aspects resulted in the division of the guidelines into two parts, with definition, classification, and diagnosis being addressed in this first part.

Diretrizes brasileiras de angioedema hereditário 2022 ­ Parte 2: terapêutica / 2022 Brazilian guidelines for hereditary angioedema ­ Part 2: therapy

O tratamento do angioedema hereditário tem início com a educação dos pacientes e familiares sobre a doença, pois é fundamental o conhecimento da imprevisibilidade das crises, assim como os seus fatores desencadeantes. O tratamento medicamentoso se divide em terapia das crises e profilaxia das manifestações clínicas. As crises devem ser tratadas o mais precocemente possível com o uso do antagonista do receptor de bradicinina, o icatibanto ou o concentrado de C1-inibidor. É necessário estabeler um plano de ação em caso de crises para todos os pacientes. A profilaxia de longo prazo dos sintomas deve ser realizada preferencialmente com medicamentos de primeira linha, como concentrado do C1-inibidor ou o anticorpo monoclonal anti-calicreína, lanadelumabe. Como segunda linha de tratamento temos os andrógenos atenuados. Na profilaxia de curto prazo, antes de procedimentos que podem desencadear crises, o uso do concentrado de C1-inibidor é preconizado. Existem algumas restrições para uso desses tratamentos em crianças e gestantes que devem ser consideradas. Novos medicamentos baseados nos avanços do conhecimento da fisiopatologia do angioedema hereditário estão em desenvolvimento, devendo melhorar a qualidade de vida dos pacientes. O uso de ferramentas padronizadas para monitorização da qualidade de vida, do controle e da atividade da doença são fundamentais no acompanhamento destes pacientes. A criação de associações de pacientes e familiares de pacientes com angioedema hereditário tem desempenhado um papel muito importante no cuidado destes pacientes no nosso país.

The treatment of hereditary angioedema begins with the education of patients and their families about the disease, as it is essential to know the unpredictability of attacks as well as their triggering factors. Drug treatment is divided into attack therapy and prophylaxis of clinical manifestations. Attacks should be treated as early as possible with the bradykinin receptor antagonist icatibant or C1-inhibitor concentrate. An action plan needs to be established for all patients with attacks. Long-term prophylaxis of symptoms should preferably be performed with first-line drugs such as C1-inhibitor concentrate or the anti-kallikrein monoclonal antibody lanadelumab. Attenuated androgens are the second line of treatment. In short-term prophylaxis, before procedures that can trigger attacks, the use of C1-inhibitor concentrate is recommended. There are some restrictions for the use of these treatments in children and pregnant women that should be considered. New drugs based on advances in knowledge of the pathophysiology of hereditary angioedema are under development and are expected to improve patient quality of life. The use of standardized tools for monitoring quality of life and controlling disease activity is essential in the follow-up of these patients. The creation of associations of patients and families of patients with hereditary angioedema has played a very important role in the care of these patients in Brazil.

Vacinação contra COVID-19 em pacientes portadores de angioedema hereditário: recomendações do Grupo de Estudos Brasileiro em Angioedema Hereditário (GEBRAEH) / COVID-19 vaccination in patients with hereditary angioedema: recommendations from the Brazilian Group for the Study on Hereditary Angioedema (GEBRAEH)

No curso da pandemia da COVID-19, o desenvolvimento rápido de vacinas seguras e eficazes é a principal estratégia de saúde pública para conter a propagação da doença. Nesse contexto, esclarecimentos em relação à prioridade e segurança da vacinação contra COVID-19 em pacientes portadores de angioedema hereditário (AEH), assim como de outras doenças, são necessários. Todos os pacientes devem receber a vacina seguindo a estratégia do Ministério da Saúde e manter as medidas de higiene, uso de máscaras e distanciamento social até o controle da pandemia.

During the COVID-19 pandemic, the rapid development of safe and effective vaccines is the main public health strategy to avoid the spread of the disease. In this context, clarifications regarding the priority and safety of vaccination against COVID-19 in patients with hereditary angioedema (HAE), as well as other diseases, are needed. All patients should receive the vaccine according to the Brazilian Ministry of Health strategy and adhere to measures such as maintaining general hygienic measures, wearing masks, and keeping social distance until the pandemic is controlled.

The involvement of proteoglycans in the human plasma prekallikrein interaction with the cell surface.

INTRODUCTION: The aim of this work was to evaluate the role of human plasma prekallikrein assembly and processing in cells and to determine whether proteoglycans, along with high molecular weight kininogen (H-kininogen), influence this interaction. METHODS: We used the endothelial cell line ECV304 and the epithelial cell lines CHO-K1 (wild type) and CHO-745 (deficient in proteoglycans). Prekallikrein endocytosis was studied using confocal microscopy, and prekallikrein cleavage/activation was determined by immunoblotting using an antibody directed to the prekallikrein sequence C364TTKTSTR371 and an antibody directed to the entire H-kininogen molecule. RESULTS: At 37°C, prekallikrein endocytosis was assessed in the absence and presence of exogenously applied H-kininogen and found to be 1,418.4±0.010 and 1,070.3±0.001 pixels/cell, respectively, for ECV304 and 1,319.1±0.003 and 631.3±0.001 pixels/cell, respectively, for CHO-K1. No prekallikrein internalization was observed in CHO-745 in either condition. Prekallikrein colocalized with LysoTracker in the absence and presence of exogenous H-kininogen at levels of 76.0% and 88.5%, respectively, for ECV304 and at levels of 40.7% and 57.0%, respectively, for CHO-K1. After assembly on the cell surface, a plasma kallikrein fragment of 53 kDa was predominant in the incubation buffer of all the cell lines studied, indicating specific proteolysis; plasma kallikrein fragments of 48-44 kDa and 34-32 kDa were also detected in the incubation buffer, indicating non-specific cleavage. Bradykinin free H-kininogen internalization was not detected in CHO-K1 or CHO-745 cells at 37°C. CONCLUSION: The prekallikrein interaction with the cell surface is temperature-dependent and independent of exogenously applied H-kininogen, which results in prekallikrein endocytosis promoted by proteoglycans. Prekallikrein proteolysis/activation is influenced by H-kininogen/glycosaminoglycans assembly and controls plasma kallikrein activity.