Hereditary angioedema presenting in late middle age after angiotensin-converting enzyme inhibitor treatment

Targeting factor XIIa for therapeutic interference with hereditary angioedema

Hereditary angioedema (HAE) is a rare, potentially life-threatening genetic disorder characterized by recurrent attacks of swelling. Local vasodilation and vascular leakage are stimulated by the vasoactive peptide bradykinin, which is excessively produced due to dysregulation of the activated factor XII (FXIIa)-driven kallikrein-kinin system. There is a need for novel treatments for HAE that provide greater efficacy, improved quality of life, minimal adverse effects, and reduced treatment burden over current first-line therapies. FXIIa is emerging as an attractive therapeutic target for interference with HAE attacks. In this review, we draw on preclinical, experimental animal, and in vitro studies, providing an overview on targeting FXIIa as the basis for pharmacologic interference in HAE. We highlight that there is a range of FXIIa inhibitors in development for different therapeutic areas. Of these, garadacimab, an FXIIa-targeted inhibitory monoclonal antibody, is the most advanced and has shown potential as a novel long-term prophylactic treatment for patients with HAE in clinical trials. The evidence from these trials is summarized and discussed, and we propose areas for future research where targeting FXIIa may have therapeutic potential beyond HAE.

Successful treatment with Cinryze® replacement therapy of a pregnant patient with hereditary angioedema: a case report

Background

Hereditary angioedema (HAE) is a rare disease characterized with recurrent swelling of subcutaneous or mucosal tissue that resolves in approximately 3 days. It can be presented with peripheral edema, abdominal and life-threatening laryngeal angioedema. A variety of triggers are known to cause episodes of angioedema including estrogen exposure. There are different reports regarding the effect of pregnancy on HAE attacks, and in some patients, the pregnancy is a recognized triggering factor.

Case presentation

We present a female Caucasian patient with pre-existing HAE and disease exacerbations during pregnancy, requiring prophylactic use of plasma-derived C1 inhibitor concentrate. She was treated with Cinryze® replacement therapy throughout the pregnancy 1000 IU i.v. 48 times. She gave birth to a healthy male infant, via C-section. After the delivery, the patient was symptom-free for 6 months and required no treatment for HAE.

Conclusions

In the case presented, the angioedema attacks worsened as the pregnancy progressed. The treatment with Cinryze® replacement therapy was effective and safe during pregnancy, with no adverse effects on the infant.

Hereditary Angio-Oedema for Dermatologists

Among angio-oedema patients, hereditary angio-oedema (HAE) should not be overlooked. Besides skin swellings, these patients might have very painful abdominal attacks and potentially life-threatening angio-oedema of the upper airway. They will not respond to traditional anti-allergic therapy with antihistamines, corticosteroids, and adrenaline, and instead need specific drugs targeting the kallikrein-kinin pathway. Classically, patients with HAE have a quantitative or qualitative deficiency of the C1 inhibitor (C1INH) due to different mutations in SERPING1, although a new subtype with normal C1INH has been recognised more recently. This latter variant is diagnosed based on clinical features, family history, or molecular genetic testing for mutations in F12, ANGPT1,or PLG.The diagnosis of HAE is often delayed due to a general unfamiliarity with this orphan disease. However, undiagnosed patients are at an increased risk of unnecessary surgical interventions or life-threatening laryngeal swellings. Within the last decade, new and effective therapies have been developed and launched for acute and prophylactic therapy. Even more drugs are under evaluation in clinical trials. It is therefore of utmost importance that patients with HAE are diagnosed as soon as possible and offered relevant therapy with orphan drugs to reduce morbidity, prevent mortality, and improve quality of life.

Hereditary angioedema: a bradykinin-mediated swelling disorder

Edema is tissue swelling and is a common symptom in a variety of diseases. Edema form due to accumulation of fluids, either through reduced drainage or increased vascular permeability. There are multiple vascular signalling pathways that regulate vessel permeability. An important mediator that increases vascular leak is the peptide hormone bradykinin, which is the principal agent in the swelling disorder hereditary angioedema. The disease is autosomal dominant inherited and presents clinically with recurrent episodes of acute swelling that can be life-threatening involving the skin, the oropharyngeal, laryngeal, and gastrointestinal mucosa. Three different types of hereditary angiodema exist in patients. The review summarises current knowledge on the pathophysiology of hereditary angiodema and focuses on recent experimental and pharmacological findings that have led to a better understanding and new treatments for the disease.

Pediatric hereditary angioedema

Hereditary angioedema (HAE) is a lifelong illness characterized by recurrent swelling of the skin, intestinal tract, and, ominously, the upper airway. It is caused by inadequate activity of the protein C1-inhibitor, with dysfunction in the kallikrein/bradykinin pathway underlying the clinical symptoms. In addition to the physical symptoms, patients experience significant decrements in vocational and school achievement as well as in overall quality of life. Symptoms often begin in childhood and occur by age 20 in most patients, but life-threatening attacks are uncommon in the pediatric population. The availability of new therapies has transformed the management of HAE.

Diagnosing angioedema

Angioedema usually occurs within the setting of allergic diseases or urticaria, but situations occur in which angioedema itself represents a disease, such as in hereditary angioedema. Evaluation of patients for recurrent angioedema without wheals must take into account both specific clinical signs and symptoms and specialized laboratory testing.

Does angiotensin-converting enzyme inhibitor use exacerbate hereditary angioedema?

BACKGROUND

Approximately 2% of angioedema (AE) patients have a hereditary or an acquired deficiency of the complement 1 (C1) esterase inhibitor (C1 INH) gene. Some case reports indicate an association between angiotensin-converting enzyme inhibitor (ACEI) use and exacerbation of hereditary AE (HAE).

OBJECTIVE

The aim of this retrospective study is to investigate the association between HAE and ACEI use in a larger patient population.

METHODS

A retrospective chart review of patients who presented with AE and patients with diagnostic serum assays for functional C1 INH, C1 INH antigenic protein, C1q, C1q immune complex (C1q IC), and complement 4 (C4) regardless of medical complaint. Descriptive statistics were used to analyze the data.

RESULTS

A total of 1594 patients had complement levels measured (136 C1 INH, 55 C1q, 10 C1q IC, and 1500 C4), of which 156 (9.7%) patients presented with AE. Angiotensin-converting enzyme inhibitor use was documented in 747 (47%) patients. Low C1 INH was detected in one patient with recurrent AE who was not taking ACEI. Another patient who presented with recurrent AE was found to have systemic lupus erythematosus with abnormal C4, C1q, and C1q IC, but normal C1 INH. A low C4 level was present in 94 patients, 4 of which had AE.

CONCLUSIONS

The risk of exacerbating HAE by ACEI might be present, but we did not find any association in this retrospective study. Further studies are needed to determine the existence of this association.

[Facial edema as an earlier presenting sign of giant cell arteritis. Possible relationship with angioedema]

Giant cell arteritis (GCA) is a chronic granulomatous vasculitis of unknown etiology occurring in the elderly. New-onset headache, scalp tenderness, jaw claudication, temporal artery abnormalities on physical examination, visual symptoms and associated polymyalgia rheumatica represent the most typical and frequent features of the disease. However, facial edema is being more commonly recognized as a presenting symptom that may herald the disease. We present a case with facial edema as initial symptom and discuss if this rare symptom of GCA is due to hereditary or acquired angioedema.

Therapeutic perspective: starting an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker in a diabetic patient

There are extensive data confirming involvement of the renin-angiotensin system in microvascular and macrovascular complications of diabetes. Blockade of the system with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) is regarded as the first-line approach to managing hypertension and end-organ protection in patients with diabetes. ACE inhibitors are still the preferred agents for most patients. Dose should be lower with renal impairment unless an agent which is not excreted by the kidneys is chosen. Dose should be titrated up to the maximum tolerated to optimize end-organ protection, and intermediate-acting agents should be given in a twice daily divided dose when higher doses are used. Electrolytes should be checked before commencing, 1-2 weeks later, and after each dose increment. A modest decrease in estimated glomerular filtration rate (eGFR) and increase in creatinine often occurs with ACE inhibitors or ARBs. The agents may need to be discontinued if eGFR decreases by >15%, if creatinine increases by >20%, or if hyperkalemia develops. Cough occurs in 5-10% of patients taking ACE inhibitor, but not with ARBs. Angioedema is probably equally common with ACE inhibitor or ARBs. It is not widely appreciated that ACE inhibitors may precipitate hypoglycaemia in patients taking glucose-lowering medication. The combination of ACE inhibitor and ARB is not routinely indicated for either hypertension or end-organ protection. While patients should not be denied the undoubted benefits of these important classes of drugs, we should also guard against their indiscriminate use in patients with diabetes. We must also ensure that patients receive appropriate counselling and monitoring.