Recessive SERPING1 Variant Leads to Kinin-Kallikrein System Control Failure in a Consanguineous Brazilian Family with Hereditary Angioedema.

Background: Hereditary angioedema (HAE) is a severe and potentially life-threatening disease. The most common forms are caused by variants in SERPING1, resulting in C1-inhibitor (C1-INH) deficiency (HAE-C1-INH). C1-INH is a serine protease inhibitor (SERPIN) that regulates multiple proteases pathways, including the kallikrein-kinin system (KKS) and its complement. In HAE-C1-INH patients, C1-INH deficiencies affect KKS control, resulting in the development of kallikrein activity in plasma and the subsequent release of bradykinin (BK). While the overwhelming majority of disease-causing SERPING1 variants are dominant, very few recessive variants have been described. We present a large Brazilian HAE-C1-INH family with a recessive form of HAE-C1-INH. Methods: Blood samples of family members were investigated for protein levels of C1-INH, C4, C1q, and C1-INH function. The SERPING1 gene was sequenced. Results: In two severely affected sisters, we identified a homozygous missense variant in SERPING1 (NM_000062.3:c.964G>A;p.Val322Met). Fourteen family members were asymptomatic heterozygous carriers of the variant. Data regarding C1-INH function in the plasma showed that homozygous p.Val322Met strongly impacts C1-INH function to inhibit C1s and kallikrein (PKa). When heterozygously expressed, it affects the C1-INH control of C1s more than that of PKa. Conclusions: These studies of the variant's effects on the structure-function relationship reinforce prior observations suggesting that C1-INH deficiency is a conformational disease.

[Hereditary bradykinin angioedema. Case report]. / Angioedema hereditario por bradicinina. Reporte de Caso.

INTRODUCTION: Hereditary angioedema is an autosomal dominant genetic disease, associated with increased levels of bradykinin. It is classified into 3 types according to the C1-INH enzyme. The diagnosis is clinical and laboratory. Its treatment is divided into short- and long-term and crisis prophylaxis. CASE REPORT: 40-year-old female patient who came to the emergency service for labial edema without resolution with corticosteroids. The tests for IgE, C4 and C1 esterase inhibitors had a low result. She currently uses danazol prophylactically and fresh frozen plasma in crises. CONCLUSIONS: Since it is a disease that considerably affects the quality of life, hereditary angioedema must be diagnosed and an effective treatment plan made to prevent or reduce its complications.

INTRODUCCIÓN: El angioedema hereditario es una enfermedad genética autosómica dominante, asociada con aumento de las concentraciones de bradicinina. Se clasifica en tres tipos, de acuerdo con la enzima C1-INH. El diagnóstico se establece por las manifestaciones clínicas y los estudios de laboratorio. El tratamiento consiste profilaxis a corto y largo plazo, y protocolo para el control de las crisis. REPORTE DEL CASO: Paciente femenina de 40 años, que acudió al servicio de Urgencias por edema labial, sin reacción al tratamiento con corticosteroides. Se detectaron concentraciones bajas de IgE, C4 e inhibidores de la esterasa C1. Se estableció el diagnóstico de angioedema hereditario. Actualmente se mantiene en tratamiento profiláctico con danazol y plasma fresco congelado para el control de las crisis. CONCLUSIONES: El angioedema hereditario es una enfermedad que afecta considerablemente la calidad de vida; por tanto, debe diagnosticarse de forma oportuna y establecer un plan de tratamiento eficaz, con la intención de prevenir o reducir las complicaciones.

Decreasing Attacks and Improving Quality of Life through a Systematic Management Program for Patients with Hereditary Angioedema.

INTRODUCTION: Prevention of attacks is a major goal in management of patients with hereditary angioedema (HAE). We aimed to investigate the effects of a systematic intervention for HAE patients. METHODS: Thirty-three patients with HAE with C1-inhibitor deficiency, belonging to a single family, participated in a management program coordinated by an allergist/immunologist. Angioedema attacks before intervention were ascertained by interviews and emergency room charts and recorded prospectively by patients or caregivers after enrollment. Mean number of attacks/month was compared at 12 months preintervention and 8 and 14 months within intervention. Patient-reported outcome instruments were used to assess quality of life, including HAE Quality of Life (HAE-QoL) questionnaire, psychological conditions, and work impairment, at baseline and 8 and 14 months within intervention. Data were stored in REDCap platform and analyzed by adjusted Bayesian models of double Poisson regression. RESULTS: Mean number of attacks/month significantly decreased (95% credible interval [CrI] excluding 0) from 1.15 preintervention to 0.25 and 0.23, 8 and 14 months within intervention, with mean decreases of -0.89 (95% CrI: -1.21 to -0.58) and -0.92 (95% CrI: -1.22 to -0.60), respectively. HAE-QoL scores showed mean total increases of 15.2 (95% CrI: 1.23-29.77) and 26 (95% CrI: 14.56-39.02) at 8 and 14 months within the study, as compared to baseline, revealing marked improvement in quality of life. Significant increase in role-emotional and reduction of depression, stress, and anxiety were observed at 14 months. CONCLUSION: A systematic approach integrating HAE-specific care with effective handling of psychological issues decreased the number of attacks and improved quality of life, targets for best practice in HAE.

[Hereditary angioedema in Costa Rica]. / Angioedema hereditario en Costa Rica.

BACKGROUND: Hereditary angioedema is classified as a primary immunodeficiency of the complement system because it is characterized by the absence of C1 esterase inhibitor (C1-INH) and by the periodic edema of any region of the body that involves soft tissue. OBJECTIVE: To characterize the adult patients with a confirmed diagnosis of hereditary angioedema who have been treated in the Clinical Allergology Department of Hospital México de la Caja Costarricense del Seguro Social. METHODS: The study was retrospective and observational. The information was obtained from the clinical records of the patients with a confirmed diagnosis of hereditary angioedema that were being controlled in the Allergology Department of the "Hospital México de la Caja Costarricense del Seguro Social". RESULTS: A total of 14 patients; seven men and seven women, were identified. The average was of 36.6 years of age. The most frequent clinical manifestations were peripheral edema and abdominal pain. Only three patients presented laryngeal edema at some point in their evolution. 12 cases corresponded to hereditary angioedema type I. CONCLUSION: The clinical characteristics of all the documented cases corresponded to those described for this pathology, although only a few patients had a history of severe manifestations.

Antecedentes: El angioedema hereditario se encuentra clasificado como una inmunodeficiencia primaria del sistema de complemento, debido a que se caracteriza por la ausencia de C1 inhibidor esterasa y por edema periódico de cualquier región del cuerpo que involucre tejido blando. Objetivo: Caracterizar a los pacientes adultos con diagnóstico de angioedema hereditario atendidos en el Servicio de Alergología Clínica del Hospital México de la Caja Costarricense del Seguro Social. Métodos: Estudio observacional retrospectivo. Los datos fueron obtenidos de los expedientes clínicos de los pacientes con diagnóstico confirmado de angioedema hereditario que estaban en seguimiento en el Servicio de Alergología del Hospital México, Caja Costarricense del Seguro Social. Resultados: Se identificaron 14 pacientes, siete hombres y siete mujeres. El promedio de edad fue de 36.6 años. Las manifestaciones clínicas más frecuentes fueron edema de extremidades y dolor abdominal. Solo tres pacientes en algún momento durante su evolución presentaron edema laríngeo; 12 casos correspondieron a angioedema hereditario tipo I. Conclusión: Las características clínicas de todos los casos documentados correspondieron con las descritas para angioedema, aunque solo algunos pacientes contaban con historial de manifestaciones graves.

First Analysis of SERPING1 Gene in Patients with Hereditary Angioedema in Colombia Reveals Two Genotypic Variants in a Highly Symptomatic Individual.

Hereditary angioedema (HAE) is a heterogeneous genetic disease caused by a deficit in C1 inhibitor (C1-INH) and clinically characterized by sudden events of edema, swelling, and pruritus. Here, we describe the first SERPING1 genotyping in 22 subjects from 4 non-related families, all from southern Colombia. The previously reported heterozygous gene mutations, c.1081C>T (p.Gln361*), c.1396C>G (p.Arg466Gly), c.1029+84G>A, or c.106_107del (p.Ser36Phefs*21), were found in 12 patients. Of note, a single patient clinically characterized as severe HAE type 2 expressed mutations in exon 8 and intron 6, whereas all the others have type 1 HAE and expressed one pathogenic variant. One of the subjects, a 5-year-old girl was discovered to have a pathogenic variant, and she is still asymptomatic. This is the first report focused on HAE genetic analysis in a Colombian population.