A follow-up survey of patients with acquired angioedema due to C1-inhibitor deficiency

Angioedema Due to Acquired C1-Inhibitor Deficiency Without Hematological Condition: A Multicenter French Cohort Study of 34 Patients

BACKGROUND

Angioedema (AE) due to acquired C1-inhibitor deficiency (AAE-C1-INH) is a rare disease associating recurrent edema of the mucosa and skin. Several underlying diseases have been reported, mainly lymphoproliferative diseases and monoclonal gammopathy. However, 15% to 20% of patients never exhibit such a hematological condition.

OBJECTIVE

To analyze specific features of patients with AAE-C1-INH without a hematological condition.

METHODS

This is a multicenter, retrospective cohort study of patients with AAE-C1-INH without a hematological condition included from January 1999 to May 2024 in the French national CREAK (Centre de reference des angioedèmes à kinine) registry. The clinical and biological characteristics of patients were detailed and then compared with those of patients with AAE-C1-INH associated with lymphoid hemopathies or monoclonal gammopathy.

RESULTS

Thirty-four patients were included. All patients displayed a functional C1-INH below 50% of the reference value, 26 (76%) also had a decreased C1-INH antigen level, and 26 (76%) displayed anti-C1-INH antibodies. After a median follow-up of 65 months, 4 (12%) patients were in spontaneous complete remission of AE; 15 (44%) were in complete response under long-term prophylactic treatment. Compared with 75 patients with lymphoma-associated AAE-C1-INH, patients with AAE-C1-INH without a hematological condition displayed a higher incidence of anti-C1-INH antibodies and received more frequently symptomatic or prophylactic treatment with a lower remission rate at last follow-up. Clinical and biological features of patients with AAE-C1-INH without a hematological condition were similar to those of 30 patients with monoclonal gammopathy-associated AAE-C1-INH.

CONCLUSIONS

AAE-C1-INH without a hematological condition displays a different clinical and biological presentation from lymphoma-associated AAE-C1-INH. No autoimmune disease was identified. Unlike rituximab, long-term prophylaxis seems to prevent AE attacks among these patients.

Hereditary Angioedema: The Clinical Picture of Excessive Contact Activation

Hereditary angioedema is a rare, genetic disorder characterized by painful, debilitating and potentially life-threatening angioedema attacks in subcutaneous and submucosal tissue. While usually unpredictable, attacks can be provoked by a variety of triggers including physical injury and certain medication and are often preceded by prodromal symptoms. Hereditary angioedema has a profound influence on the patients' lives. The fundamental cause of hereditary angioedema in almost all patients is a mutation in the SERPING1 gene leading to a deficiency in C1-inhibitor. Subsequently, the contact activation cascade and kallikrein-kinin pathway are insufficiently inhibited, resulting in excessive bradykinin production triggering vascular leakage. While C1-inhibitor is an important regulator of the intrinsic coagulation pathway, fibrinolytic system and complement cascade, patients do not have an increased risk of coagulopathy, autoimmune conditions or immunodeficiency disorders. Hereditary angioedema is diagnosed based on C1-inhibitor level and function. Genetic analysis is only required in rare cases where hereditary angioedema with normal C1-inhibitor is found. In recent years, new, highly specific therapies have greatly improved disease control and angioedema-related quality of life. This article reviews the clinical picture of hereditary angioedema, the underlying pathophysiology, diagnostic process and currently available as well as investigational therapeutic options.

Acquired Angioedema Due to C1-Inhibitor Deficiency (AAE-C1-INH)-A Bicenter Retrospective Study on Diagnosis, Course, and Therapy

BACKGROUND

Acquired angioedema with C1-inhibitor deficiency (AAE-C1-INH) is a rare condition resembling hereditary angioedema (HAE), but with late onset and low C1-inhibitor (C1-INH) due to consumption potentially caused by autoimmune diseases and mainly lymphatic malignancies. Being about 10-fold rarer than HAE, there is limited knowledge and no licensed therapy.

OBJECTIVE

To report clinical and biological data from a newly described population of 20 patients with AAE-C1-INH assessing diagnostic delay, AAE-C1-INH:HAE-ratio, underlying conditions, and therapeutic management in Germany.

METHODS

Retrospective data analysis of 20 patients from 2 angioedema centers in southern Germany.

RESULTS

Median age at symptoms' onset was 64 years (60% females), with predominant swellings of the face (85%) and low levels for C1-INH in almost all patients. The ratio AAE-C1-INH:HAE was 1:9.7. From symptoms' onset to diagnosis of AAE-C1-INH, the median delay was 7.5 months, and between AAE-C1-INH symptoms' onset and diagnosis of the underlying hematological condition (n = 9) it was 4 months (median). Four patients had a history of solid neoplasm, 1 had a papillary thyroid carcinoma as the only potential cause for AAE-C1-INH, with treatment of the malignancy resulting in resolution of AAE-C1-INH. All the symptomatic patients were treated with off-label on-demand icatibant subcutaneously or C1-INH concentrate intravenously, and 6 severely affected patients needed off-label long-term prophylaxis with good symptom control.

CONCLUSIONS

AAE-C1-INH is characterized by late-onset swellings mainly involving the face and low C1-INH levels. Diagnostic delay for AAE-C1-INH is further decreasing despite being about 10-fold rarer than HAE. Patients severely affected without underlying condition or no indication for treatment could benefit from off-label therapy.

Concomitant medication in patients with bradykinin-mediated angioedema - there's more than ACE inhibitors

Bradykinin-mediated angioedema is a rare, non-allergic, potentially life-threatening disease. ACE inhibitor-induced angioedema and hereditary angioedema (HAE) are the two most common presentations. Therapeutic options, pathophysiology and diagnosis continue to be investigated, with considerable progress in HAE over the last few decades. For all patients with bradykinin-mediated angioedema, there are several medications that should be avoided or administered with caution. Some of the triggering medications are well known, while others are suspected or of unknown significance. A common denominator is that there is no approved therapy for bradykinin-mediated angioedema as a drug side effect. Some medications, such as tissue plasminogen activator, have a higher incidence of angioedema with potential airway compromise than ACE inhibitors, although this fact is widely underappreciated. In this review, we aim to summarize what is currently known and recommended about concomitant medication in HAE patients and the interaction of other bradykinin-influencing drugs.

Medikamente als Auslöser Bradykinin-vermittelter Angioödeme - mehr als ACE-Hemmer

Bradykinin‐vermittelte Angioödeme sind seltene, nichtallergische und potenziell lebensbedrohliche Krankheiten. Die beiden bekanntesten Formen sind das ACE‐Hemmer‐induzierte Angioödem und das hereditäre Angioödem (HAE). Die therapeutischen Möglichkeiten, die Pathophysiologie und die Diagnostik werden weiter erforscht, wobei beim HAE in den letzten Jahrzehnten erhebliche Fortschritte erzielt wurden. Für alle Patienten mit Bradykinin‐vermittelten Angioödemen gibt es Medikamente, die vermieden oder mit Vorsicht verabreicht werden sollten. Einige dieser auslösenden Medikamente sind gut bekannt, bei anderen wird ein Zusammenhang vermutet oder ihre Bedeutung ist unbekannt. Ein gemeinsamer Nenner ist, dass es keine zugelassene Therapie für das Bradykinin‐vermittelte Angioödem als Arzneimittelnebenwirkung gibt. Bei einigen Medikamenten, wie dem gewebespezifischen Plasminogenaktivator, ist die Inzidenz von Angioödemen mit möglicher Beeinträchtigung der Atemwege höher als bei ACE‐Hemmern, wobei diese Tatsache weitgehend unterschätzt wird. In dieser Übersichtsarbeit fassen wir zusammen, was derzeit über die Begleitmedikation bei HAE‐Patienten und die Interaktion mit anderen Bradykinin‐beeinflussenden Medikamenten bekannt ist und empfohlen wird.

C1-inhibitor/C1-inhibitor antibody complexes in acquired angioedema due to C1-inhibitor deficiency

BACKGROUND

Autoantibodies against C1-inhibitor (C1-INH-Ab) have a diagnostic value in acquired angioedema due to C1-inhibitor deficiency (C1-INH-AAE), even though antibodies can circulate in complexes, which can be undetectable by proven methods. Our aim was to measure C1-INH/C1-INH-Ab complexes (CAC) and investigate their connection to C1-INH-Ab and the changes in their titer over time.

RESULTS

19 patients were diagnosed with C1-INH-AAE in the Hungarian Angioedema Center of Reference and Excellence; 79% of them had an underlying disease. Samples were examined with a newly developed in-house complex ELISA method. Patients with high C1-INH-Ab titer had a CAC titer which did not exceed the normal level and the ones with high CAC titer had a C1-INH-Ab titer which did not exceed the normal level. In case of those patients who had C1-INH-Ab and CAC of the same type of immunoglobulin, the increasing titer of C1-INH-Ab went together with the decreasing level of CAC and vice versa. CAC titer was already increased before the diagnosis of the underlying disease.

CONCLUSIONS

Free circulating and complex antibodies are in a dynamically changing equilibrium. CAC measurements can help to predict the development of an underlying disease. The efficiency of the treatment for underlying disease can be monitored by the decreasing CAC titers. Our results show that the CAC can be of important additional information besides the complement panel examination in case of C1-INH-AAE. Measurement of CAC is recommended to be done parallelly with C1-INH-Ab, so as to detect both free and bound antibodies.

Angioedema Due to Acquired Deficiency of C1-Inhibitor: A Cohort Study in Spain and a Comparison With Other Series

BACKGROUND

Data on acquired angioedema due to C1-inhibitor deficiency (C1-INH-AAE) from 4 European countries (France, Italy, Germany, and Hungary) were recently published.

OBJECTIVE

To report data from a group of 50 patients with acquired C1-INH deficiency from Spain, of whom 46 had angioedema, and compare them with other European series.

METHODS

We performed a retrospective observational study of 46 patients with C1-INH-AAE and 4 asymptomatic patients. Clinical and biological characteristics and associated diseases were assessed and compared with other European series.

RESULTS

Women accounted for 73.9% of cases. The prevalence of C1-INH-AAE related to hereditary forms was 1/10.1. Overall, 8.7% patients were aged <40 years. Diagnostic delay was 1.1 years. Angioedema mainly affected the face (91.3%), followed by the oropharynx (63%), extremities (50%), and abdomen (37%). Only 1 patient underwent orotracheal intubation. Erythema marginatum was present in 1 patient. A hematologic disorder was recorded in 50% of patients. Angioedema preceded all benign conditions, mostly monoclonal gammopathy of undetermined significance, but appeared very close to or after malignant hematologic diseases (median, 2.2 and 0.29 years). Autoimmune diseases were associated in 50% (autoimmune thyroiditis, 21.5%; systemic lupus erythematosus, 10.9%). Half of them coexisted with hematologic disorders. Anti-C1-INH antibodies were found in 67% of tested patients and were not related to the associated disease. Long-term prophylaxis was necessary in 52.2%, most of whom responded to tranexamic acid.

CONCLUSIONS

This study emphasizes the possibility of C1-INH-AAE in patients younger than 40 and in autoimmune diseases other than systemic lupus erythematosus such as autoimmune thyroiditis.

The international WAO/EAACI guideline for the management of hereditary angioedema - The 2021 revision and update

Hereditary Angioedema (HAE) is a rare and disabling disease for which early diagnosis and effective therapy are critical. This revision and update of the global WAO/EAACI guideline on the diagnosis and management of HAE provides up-to-date guidance for the management of HAE. For this update and revision of the guideline, an international panel of experts reviewed the existing evidence, developed 28 recommendations, and established consensus by an online DELPHI process. The goal of these recommendations and guideline is to help physicians and their patients in making rational decisions in the management of HAE with deficient C1-inhibitor (type 1) and HAE with dysfunctional C1-inhibitor (type 2), by providing guidance on common and important clinical issues, such as: 1) How should HAE be diagnosed? 2) When should HAE patients receive prophylactic on top of on-demand treatment and what treatments should be used? 3) What are the goals of treatment? 4) Should HAE management be different for special HAE patient groups such as children or pregnant/breast feeding women? 5) How should HAE patients monitor their disease activity, impact, and control? It is also the intention of this guideline to help establish global standards for the management of HAE and to encourage and facilitate the use of recommended diagnostics and therapies for all patients.

The international WAO/EAACI guideline for the management of hereditary angioedema-The 2021 revision and update

Hereditary angioedema (HAE) is a rare and disabling disease for which early diagnosis and effective therapy are critical. This revision and update of the global WAO/EAACI guideline on the diagnosis and management of HAE provides up-to-date guidance for the management of HAE. For this update and revision of the guideline, an international panel of experts reviewed the existing evidence, developed 28 recommendations, and established consensus by an online DELPHI process. The goal of these recommendations and guideline is to help physicians and their patients in making rational decisions in the management of HAE with deficient C1 inhibitor (type 1) and HAE with dysfunctional C1 inhibitor (type 2), by providing guidance on common and important clinical issues, such as: (1) How should HAE be diagnosed? (2) When should HAE patients receive prophylactic on top of on-demand treatment and what treatments should be used? (3) What are the goals of treatment? (4) Should HAE management be different for special HAE patient groups such as children or pregnant/breast-feeding women? and (5) How should HAE patients monitor their disease activity, impact, and control? It is also the intention of this guideline to help establish global standards for the management of HAE and to encourage and facilitate the use of recommended diagnostics and therapies for all patients.

The characteristics of upper airway edema in hereditary and acquired angioedema with C1-inhibitor deficiency

Background

Angioedemas localized in the upper airway are potentially life threatening, and without proper treatment, they may lead to death by suffocation. Upper airway edemas (UAE) in bradykinin‐mediated angioedemas can even be the first symptoms of the disease.

Methods

Our survey was performed with a retrospective long‐term follow‐up method from the medical history of 197 hereditary (C1‐INH‐HAE) and 20 acquired C1‐inhibitor deficiency (C1‐INH‐AAE), 3 factor XII and 3 plasminogen gene mutation (FXII‐HAE, PLG‐HAE) patients treated at our center between 1990 and 2020. The UAE group included edemas localized to the mesopharynx, hypopharynx, and larynx, as narrowing of these anatomical regions can lead to suffocation.

Results

98/197 C1‐INH‐HAE (47 families) and 13/20 C1‐INH‐AAE, 1/3 PLG‐HAE, 1/3 FXII‐HAE patients had experienced UAE at least once according to their medical history. In case of C1‐INH‐HAE patients, in 6/47 families who had undiagnosed ancestors had 13 members who died of suffocation. After the diagnosis, 1‐1 member of two families died of UAE. 44/64 C1‐INH‐HAE patients did not smoke, 20/64 did. The occurrence of UAE was significantly higher in smoker patients. We analyzed 7607 HAE attacks of 56/98 patients. Out of all attacks, the incidence of UAE in the C1‐INH‐HAE group was 4%, and 9.5% in the C1‐INH‐AAE group, respectively.

Conclusion

Early diagnosis is key in bradykinin‐mediated angioedemas cases, since the patient must be provided with adequate treatment; and also it is essential to inform patients about the importance of avoiding the trigger factors and the early symptoms of UAE, as these measures could significantly decrease the incidence of lethal UAEs.

Acquired Angioedema Due to C1 inhibitor Deficiency Caused by Non-Hodgkin Lymphoma in a Patient with Myasthenia Gravis

Acquired angioedema due to C1-inhibitor deficiency is a very rare disorder that usually appears in patients with lymphoproliferative and/or autoimmune diseases. This type of swelling is bradykinin mediated and does not respond to antihistamines, corticosteroids, or epinephrine. The symptoms usually appear in patients older than 40 years with recurrent episodes of angioedema without wheals. The family history is negative. The swelling could affect any tissue, but most frequently is located at the face, lips, tongue, larynx, or extremities. In the gastrointestinal tract, it causes pain, nausea, vomiting, and diarrhea. The upper respiratory airway oedema is a potentially life-threatening condition due to asphyxiation. The oedema attacks may precede the symptoms of the causative disease for months or years. In most cases, the treatment of the underlying disease resolves the angioedema episodes. Here we report a case of C1-INH-AAE caused by non-Hodgkin lymphoma in a patient diagnosed many years before with myasthenia gravis whose angioedema symptoms resolved after the specific treatment of lymphoma.

Where we are with acquired angioedema due to C1 inhibitor deficiency: A systematic literature review

Acquired angioedema due to C1 inhibitor deficiency (C1-INH-AAE) is a rare disease characterized by adult-onset recurrent non-urticarial angioedema with low levels of C1-INH. It is associated with lymphoproliferative disorders, and treatments are off-label with variable success. We conducted a systematic literature review to include patients with C1-INH-AAE identified in PubMed and Embase databases between January 2006 and February 2021. Clinical features of these patients were summarized, and factors associated with disease remission were explored. A total of 121 patients were included in the current study with a median age at diagnosis of 64 years and 45.5% being male. An associated disease was recorded in 94 patients (77.7%), and lymphoproliferative disorder was the most reported (59/94, 62.8%). Anti-C1-INH autoantibodies were present in 45 of 71 patients (63.4%). Factors impacting disease remissions included age (odds ratio [OR] 0.951, 95% confidence interval [CI] 0.909-0.994, p = 0.027), male (OR 0.327, 95% CI 0.124-0.866, p = 0.025), presence of monoclonal gammopathy (OR 0.133, 95% CI 0.041-0.429, p = 0.001), requirement of specific on-demand treatment (OR 0.216, 95% CI 0.066-0.709, p = 0.012) and rituximab use (OR 2.865, 95% CI 1.038-7.911, p = 0.042). A total of nine patients (7.4%) died at last follow up and most were unrelated to C1-INH-AAE. Our results imply that C1-INH-AAE is primarily associated with underlying B or plasma cell abnormalities, and clone-directed therapies could be promising options for its long-term management.