Consequences of Misdiagnosed and Mismanaged Hereditary Angioedema Laryngeal Attacks: An Overview of Cases from the Romanian Registry

Safety Aspects and Rational Use of Lanadelumab Injections in the Treatment of Hereditary Angioedema (HAE): Clinical Insights

Hereditary angioedema (HAE) is a rare genetic disorder characterized by recurrent episodes of skin/mucosal swelling, and/or attacks of severe abdominal pain when it affects the gastrointestinal tract. The disease might be unexpectedly fatal when the upper airways are compromised. HAE clinical presentation, disease course and prognosis are associated with significant disease burden and severely impaired quality of life. Lanadelumab is a breakthrough therapy for the prevention of attacks in HAE type 1 and 2 patients. This revolutionary approach to administer a single subcutaneous injection (once every two to four weeks) and achieve complete disease control has dramatically improved patient care resulting in significant change in the life of affected families. Current data support the drug's tolerability in adult and adolescent patients without notable safety concerns in both clinical research and real-world settings. Rational use of prophylactic treatments of HAE searches for a socio-economic balance, taking into account the life-long course of the disease, the public health funds who pay the monetary price, and the patients who might need to receive the therapy for a period longer than investigated during the development program. In this review, we address the current evidence on lanadelumab's tolerability, highlighting aspects of the drug's rationale use in clinical practice. Further studies need to investigate whether this therapy might be appropriate in other forms of angioedema, such as idiopathic primary angioedema and HAE with normal C1 inhibitor. Future efforts must focus to improve modern drugs' accessibility in more countries. Although modern prophylactic options lessen the risk of fatal laryngeal attacks, patients must be equipped with reliable on-demand therapies and be trained how to use them as such a risk cannot be fully diminished with potentially life-threatening attacks occurring even in subjects with successful and stable long-term prophylaxis. Notwithstanding, further studies are needed to identify early responders from non-responders and develop therapies for the latter.

Investigation of Mortality of Hereditary Angioedema in a Reference Center in Brazil

BACKGROUND

Hereditary angioedema (HAE) is known for mortality when it is not treated properly. Many advances have occurred over the past decades that affected patients' lives. However, not all patient populations have access to the same diagnosis and treatment resources.

OBJECTIVE

To evaluate mortality from HAE in a large cohort in a reference center in Brazil. Furthermore, the research intended to describe patients' life span, the asphyxia evolution, and factors related to the fatal outcome.

METHODS

A cohort of 433 patients from 46 families was evaluated in this prospective and retrospective study. Families were organized in clusters and were given a verbal autopsy to arrange data collection for the deaths and analyze symptoms during life. Causes of death were classified as deaths from laryngeal edema (LE) or other causes.

RESULTS

Of 433 patients evaluated, 254 were not given the diagnosis of HAE. A total of 75 fatal events were evaluated. Only 10 of 75 patients were given the diagnosis of HAE before death, and the HAE diagnosis was made after death in 65 of 75 patients using verbal autopsy. The final cause of death after the investigation was asphyxiation owing to LE in 39 of 75 (52%) and deaths owing to other causes in 36 of 75 (48%). Ten deaths had occurred in the past decade. Time from onset of symptoms to seeking medical assistance was a median of 4 hours, and the time to death was a median of 8 hours. Three patients received fresh-frozen plasma and none received medications specific to HAE attacks. Throat pain or discomfort was the most common symptom, experienced by 71.8% of patients. The most common mistaken diagnosis at the original death certificate was allergy or anaphylaxis. The life span of patients who died of LE was reduced by 20 years compared with those who died of other causes.

CONCLUSIONS

Hereditary angioedema remains a threat to life in the studied population. The large number of patients who do not receive a diagnosis makes the situation even more severe and is responsible for most deaths. Death analyses add knowledge to an understanding of the diseases and their impact on patients' lives, improving the targeting of public health efforts.

The Mortality from Hereditary Angioedema Worldwide: a Review of the Real-World Data Literature

This study aims to review the global mortality secondary to laryngeal edema in patients diagnosed with hereditary angioedema and their relatives over the years, as well as to describe epidemiological and clinical findings associated with this outcome. An extensive search of the literature was made in PubMed, Scopus, and Embase to identify mortality rates secondary to laryngeal edema in patients with hereditary angioedema. The search was carried out in September of 2020 and in April of 2021, and keywords based on the MeSH terms were searched in three databases. The filter of language was used for finding only articles in English, and there was no limit to the year of publication. A total of twenty-three articles fulfilled the inclusion criteria for review and data extraction. The analyzed studies included 3292 patients and 411 deaths from asphyxia due to laryngeal edema. One hundred and three deaths in close relatives were described as secondary to the same cause. The main findings were summarized in tables: year and place of publication, the number of patients and deaths from laryngeal edema, patients previously diagnosed, and death age. Death rates from laryngeal edema had an average of one death for every 20 patients. Eight studies reported deaths in relatives. For every 7.4 patients in these studies, one relative died. The percentage among deaths in general associated with laryngeal edema was evaluated in three studies (32.7%, 44.4%, and 56%). The high frequency of this outcome suggests that deaths still occur, and improvement of hereditary angioedema treatment still needs to be met.

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.

Advances in drug allergy, urticaria, angioedema, and anaphylaxis in 2018

Many notable advances in drug allergy, urticaria, angioedema, and anaphylaxis were reported in 2018. Broad-spectrum antibiotic use and, consequently, antibiotic resistance are widespread, and algorithms to clarify β-lactam allergy and optimize antibiotic use were described. Meaningful data emerged on the pathogenesis of delayed drug hypersensitivity reactions. Progress not only in defining biomarkers but also in understanding the effect on quality of life and developing better treatments has been made for patients with chronic idiopathic urticaria. Patients with hereditary angioedema (HAE) have gained additional access to highly efficacious therapies, with associated improvements in quality of life, and some progress was made in our understanding of recurrent angioedema in patients with normal laboratory results. Guidelines have defined clear goals to help providers optimize therapies in patients with HAE. The epidemiology and triggers of anaphylaxis and the mechanisms underlying anaphylaxis were elucidated further. In summary, these disorders (and labels) cause substantial burdens for individual persons and even society. Fortunately, publications in 2018 have informed on advancements in diagnosis and management and have provided better understanding of mechanisms that potentially could yield new therapies. This progress should lead to better health outcomes and paths forward in patients with drug allergy, urticaria, HAE, and anaphylaxis.