Hereditary angioedema with C1 inhibitor (C1-INH) deficit: the strength of recognition (51 cases)

A real-world study of hereditary angioedema patients due to C1 inhibitor deficiency treated with danazol in the Brazilian Public Health System

Introduction

Hereditary angioedema (HAE) due to C1 inhibitor (C1-INH) deficiency is an ultra-rare autosomal dominant inherited disease that affects 1 in 67,000 people in the world. The attacks are based on subcutaneous and submucosal edema that can lead to death if not properly managed. Considering the lack of information on the clinical management of Brazilian patients with HAE, this study aimed to identify and characterize patients with HAE-C1-INH that used danazol prophylactic treatment in the Brazilian Public Health System (SUS) and the healthcare resource utilization (HCRU).

Methods

This was an observational retrospective database study with patients treated with danazol from January 2011 until December 2021 within the SUS. The HAE cohort included patients with 12 years or older with at least one record for ICD-10 D84.1, one claim for danazol record, and at least 6 months of available history in the database.

Results

Our study included 799 patients treated in the SUS, with a mean (SD) age at danazol initiation of 40 years (16). The number of patients with HAE showed a similar distribution over this 10-year period analyzed with the highest number of patients in 2015 (n = 509) and 2016 (n = 480). A total of 253 (32%) patients had a record of at least one attack. Of those, 45 (17.8%) had at least one procedure HAE-related hospital admission, and 128 (50.6%) had at least one HAE-related hospital admission. The mean (SD) hospitalization length of stay was 5 (8) days. Over 14% (n = 36) of HAE patients with attack (n = 253) had at least one HAE-related ICU admission.

Conclusion

This database study is the strategy used to allow us to find and describe the characteristics of patients with HAE who use danazol for long-term prophylaxis in the SUS and identify HCRU outcomes of interest such as hospitalizations, inpatient, and outpatient settings. The high rate of attacks, hospitalizations, and general resource uses highlights the necessity to increase awareness of new strategies and accurate approaches to treat HAE patients. Therefore, our findings are important indicators that our health system and guidelines need to be revised and improved to properly diagnose, treat, and assist patients with HAE.

Epidemiology, economic, and humanistic burden of hereditary angioedema: a systematic review

BACKGROUND

This systematic study aims to assess the global epidemiologic, economic, and humanistic burden of illness associated with all types of hereditary angioedema.

METHODS

A systematic search for articles reporting the epidemiologic, economic, and humanistic burden associated with patients with HAE was conducted using English and Chinese literature databases from the inception to May 23, 2022. The selected studies were assessed for their quality and risk of bias. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022352377).

RESULTS

In total, 65 articles that met the search inclusion criteria reported 10,310 patients with HAE, of whom 5861 were female patients. Altogether, 4312 patients (81%) and 479 patients (9%) had type 1 and type 2 HAE, respectively, whereas 422 patients (8%) had HAE-normal C1-INH. The overall prevalence of all types of HAE was between 0.13 and 1.6 cases per 100,000. The mean or median delay from the first onset of a symptom of HAE to confirmed diagnosis ranged from 3.9 to 26 years. The estimated risk of death from asphyxiation was 8.6% for patients with HAE. Hospitalization, medication, unnecessary surgeries, doctor visits, specialist services, and nursing costs are direct expenses that contribute to the growing economic burden. The indirect cost accounted mostly due to missing work ($3402/year) and loss of productivity ($5750/year). Furthermore, impairment of QoL as reported by patient-reported outcomes was observed. QoL measures identified depression, anxiety, and stress to be the most common symptoms for adult patients and children.

CONCLUSION

This study highlights the importance of early diagnosis and the need for improving awareness among health care professionals to reduce the burden of HAE on patients and society.

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.

Consider Hereditary Angioedema in the Differential Diagnosis for Unexplained Recurring Abdominal Pain

Health care providers are likely to encounter patients with recurrent unexplained abdominal pain. Because hereditary angioedema (HAE) is a rare disease, it may not be part of the differential diagnosis, especially for patients who do not have concurrent skin swelling in addition to abdominal symptoms. Abdominal pain is very common in patients with HAE, occurring in up to 93% of patients, with recurrent abdominal pain reported in up to 80% of patients. In 49% of HAE attacks with abdominal symptoms, isolated abdominal pain was the only symptom. Other abdominal symptoms that commonly present in patients with HAE include distension, cramping, nausea, vomiting, and diarrhea. The average time from onset of symptoms to diagnosis is 6 to 23 years. Under-recognition of HAE in patients presenting with predominant gastrointestinal symptoms is a key factor contributing to the delay in diagnosis, increasing the likelihood of unnecessary or exploratory surgeries or procedures and the potential risk of related complications. HAE should be considered in the differential diagnosis for patients with unexplained abdominal pain, nausea, vomiting, and/or diarrhea who have complete resolution of symptoms between episodes. As highly effective targeted therapies for HAE exist, recognition and diagnosis of HAE in patients presenting with isolated abdominal pain may significantly improve morbidity and mortality for these individuals.

The prevalence of hereditary angioedema in a Chinese cohort with decreased complement 4 levels

Objective

Hereditary angioedema (HAE) is a rare, life-threatening autosomal dominant disorder. We aimed to investigate the prevalence of HAE in a Chinese population with a decreased Complement 4 (C4) level.

Methods

All the patients present in Tongji Hospital with C4 below lower normal range were included from January 2019 to June 2020. The individual data were extracted from the database and categorized by diagnosis. Patients suspected of HAE were further evaluated by C1 inhibitor level and function test to confirm the HAE diagnosis.

Results

A total of 8226 patients were enrolled in our study, among whom 18 had symptoms similar to HAE and received C1 inhibitor level and function tests. Two (1 male and 1 female) of the 18 patients were identified as HAE patients. This means the prevalence of HAE was 2.43/10 000 among the C4-decreased population and 10.1/10 000 in the C4-decreased population with etiology undetermined. The 2 HAE patients had experienced skin and oropharynx edema attack and received tracheotomy. The female patient had a family history. Laboratory tests showed significant decrease of C4 and C1 inhibitor levels in the 2 patients, both of whom were diagnosed as type 1 HAE.

Conclusion

The prevalence of HAE is low in C4-decreased patients. In a large cohort, C4 level can serve as a practical indicator to screen the HAE patients, but further testing of C1 inhibitor activity and levels is needed to confirm the diagnosis of HAE.

First Census of Patients with Hereditary Angioedema in the Canary Islands

Hereditary angioedema (HAE) is a rare genetic condition whose main symptoms are recurrent swelling in the skin, mucosa, and internal organs. Recent studies suggested that the regulation of the inflammatory response and the complement cascade are two of the pathways significantly enriched in the Canary Islands, Spain. Here, we describe the first HAE patient series in this region. Forty-one patients (33 F, 8 M) and nine healthy relatives belonging to twenty-nine families were recruited for this study, obtaining their clinical and demographic features using a data collection form, as well as blood samples for biochemical analysis. The mean age of patients was 36.8 years (ranging from 4 to 72 years). Positive family history of HAE was reported in 13 patients (32.5%), and a mean diagnosis delay of 7.9 (±12.5) years was estimated, ranging from months to 50 years. Cutaneous edema was the most common symptom (53.6%), while airway symptoms was present in 11 patients. Prophylactic treatment was indicated for 23 patients, while 14 also require on-demand rescue treatment. We estimate a minimum prevalence of 1.25:100,000 for HAE due to C1-INH deficiency or dysfunction in the Canary Islands, which is higher than the estimates for mainland Spanish populations. HAE continues to be a disease poorly recognized by health care professionals due to its confusing symptoms, leading to longer diagnosis delay. Altogether, the evidence reinforces the need for a rapid and accurate diagnosis and precision medicine-based studies to improve the patient's quality of life.

Identification of the factor XII contact activation site enables sensitive coagulation diagnostics

Contact activation refers to the process of surface-induced activation of factor XII (FXII), which initiates blood coagulation and is captured by the activated partial thromboplastin time (aPTT) assay. Here, we show the mechanism and diagnostic implications of FXII contact activation. Screening of recombinant FXII mutants identified a continuous stretch of residues Gln317-Ser339 that was essential for FXII surface binding and activation, thrombin generation and coagulation. Peptides spanning these 23 residues competed with surface-induced FXII activation. Although FXII mutants lacking residues Gln317-Ser339 were susceptible to activation by plasmin and plasma kallikrein, they were ineffective in supporting arterial and venous thrombus formation in mice. Antibodies raised against the Gln317-Ser339 region induced FXII activation and triggered controllable contact activation in solution leading to thrombin generation by the intrinsic pathway of coagulation. The antibody-activated aPTT allows for standardization of particulate aPTT reagents and for sensitive monitoring of coagulation factors VIII, IX, XI.

Clinical profile of hereditary angioedema from a tertiary care centre in India

INTRODUCTION

Hereditary angioedema (HAE) is a clinical condition which could be fatal if not identified and managed appropriately. Knowledge of this condition is mostly confined to individual case reports and literature reviews in India. In this retrospective study we describe HAE cases which presented to a tertiary care centre in India over a period of three and half years.

MATERIALS AND METHODS

Clinical case records of forty-two HAE patients diagnosed based on clinical and laboratory features were accessed after due approval from the Ethics committee. C1 esterase inhibitor (C1 INH) and C4 levels were measured using nephelometry. All relevant data was entered into Microsoft EXCEL worksheet and analysed using simple statistical tools.

RESULTS

Among the 42 patients diagnosed as having HAE, 37 had low C1INH levels and were diagnosed to have type 1 HAE. The remaining 5 had normal C1 INH levels and were considered probable HAE based on family history and response to HAE specific treatment. The median age of onset of symptoms was 15 years (range 5-49) and median age at diagnosis, 27.5 years (range 5-55). The median delay in diagnosis was 10 years (range 1-27 years). Family history of HAE was observed in 52.6% and 29% reported deaths in the family with HAE like disease. Low dose androgens or tranexamic acid or both were prescribed in 64.2% of the patients. Orofacial edema was the commonest clinical presentation (76%) followed by edema of the extremities (38%), GI tract symptoms (19%) and genital involvement (11.9%).

CONCLUSION

Many cases of HAE may be going undetected in India. There is a need for clinical awareness and laboratory means to accurately identify and administer appropriate treatment.

Hereditary angioedema in children: a review and update

PURPOSE OF REVIEW

Hereditary angioedema (HAE) most often presents in the first two decades of life. Despite these patients often see multiple doctors and go many years before confirmation of the diagnosis. the impact on quality of life, productivity and risk of anxiety, depression, and posttraumatic stress emphasizes the need for early diagnosis and appropriate treatment.

RECENT FINDINGS

Over the past decade, therapy in the USA has emerged from fresh-frozen plasma and androgens to more than seven medications that are specific for bradykinin-induced disease. During the same time, treatment has evolved from intravenous to subcutaneous and the future will be a focus on oral therapy.

SUMMARY

Much optimism exists that patients with HAE will live a life with minimal disease and impact on their quality of life making it even more important to diagnose children at an early age.