Acquired inhibitor deficiency in lymphosarcoma

An unusual case of acquired angioedema associated with monoclonal gammopathies of uncertain significance

Acquired angioedema (AAE) is a rare disease due to the C1 esterase inhibitor (C1-INH) deficiency. Clinically, its symptoms are similar to hereditary angioedema (HAE) with hereditary C1-INH deficiency. Both conditions have the potential to cause upper airway obstruction, which can be fatal in clinical practice and thus require intense attention. Here, we'd like to discuss the clinical presentation, diagnosis and follow up of a special case of AAE associated with monoclonal gammopathies of unknown significance (MGUS) with recurrent upper airway obstruction. The patient was regularly followed up after being discharged from our ward. Measurements of C3-C4 levels were carried out by a hematological test. Due to the rarity of such a disease, especially in Chinese people, relevant diagnosis methods are missing in this patient, so the patient was only diagnosed with AAE-C1-INH associated with MGUS clinically. The latest follow up showed that he still underwent recurrent upper airway obstruction; thus, he remained in a tracheostomy state due to a lack of proper medication prophylaxis and died eventually. This unusual case reminds emergency physicians to pay attention to such disease during clinical practice, and relevant diagnosis method should be improved.

Acquired angioedema: an unusual presentation of haematological malignancy

A previously healthy man in his 60s being worked up for splenomegaly presented to the emergency department with recurrent episodes of angioedema. Each episode was attributed to a precipitating cause, and consequently, the predisposing C1 esterase inhibitor (C1-INH) deficiency remained undiagnosed until the third presentation. The aetiology of acquired C1-INH deficiency would be primarily obscure and require further investigations to identify. A clonal B cell population was finally isolated by flow cytometry after multiple repeat marrow samples, and a diagnosis of splenic marginal zone lymphoma was subsequently reached. Response to single-agent rituximab was observed with resolution of splenomegaly, disappearance of the antibody and restoration of C1-INH levels.

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 Panorama of Primary Angioedema in the Brazilian Population

BACKGROUND

Primary angioedema (PA) is a complex disorder, presenting multiple hereditary (hereditary angioedema) and acquired subtypes (acquired angioedema). Despite a very similar clinical presentation among subtypes, the differential diagnosis is limited by the difficulty to identify bradykinin-mediated PA and the lack of specific biomarkers.

OBJECTIVES

To report the clinical and genetic features of Brazilian patients with PA.

METHODS

Brazilian patients referred from 50 centers were diagnosed on the basis of clinical symptoms, C1 inhibitor (C1-INH) and C4 plasma measurements, and DNA sequencing of genes associated with hereditary angioedema.

RESULTS

We characterized 92 patients with acquired angioedema and 425 with HAE: 125 with C1-INH deficiency, 180 with F12 mutations, and 120 of unknown cause. Thirty-one different mutations were identified in SERPING1 and 2 in F12, in addition to 2 mutations of uncertain significance in the ANGPT1 gene. The molecular diagnosis was decisive for 34 patients with HAE without family history, and for 39% of patients with inconsistent biochemical measurements. The median delay in diagnosis was 10 years, with a maximum of 18 years for HAE with C1-INH deficiency. Androgens and tranexamic acid were the most used drugs for long-term prophylaxis in all the PA subtypes, and they were used on demand by 15% of patients. Only 10% of patients reported the use of specific medication for HAE during attacks.

CONCLUSIONS

Our analysis exposes a broad picture of PA diagnosis and management in a developing country. Complement measurements presented considerable inconsistencies, increasing the diagnosis delay, while patients with PA with normal C1-INH remain with an inaccurate diagnosis and unspecific treatment.

Acquired Angioedema: A Rare Manifestation of Angioimmunoblastic T Cell Lymphoma

The clinical presentation except age of onset is similar in different types of angioedema. A lymphoproliferative disorder like angioimmunoblastic T cell lymphoma (AITL) rarely presents with symptoms of angioedema. We present extremely rare case of elderly male with recurrent tongue swelling, pruritus with normal levels of complements and C1 esterase inhibitor protein featuring as acquired angioedema, a rare manifestation of AITL. Initial response to corticosteroids may be misleading and occurs as a result of immunosuppression of AITL. High index of suspicion may prompt need for histopathological diagnosis of lymph node biopsy. Definitive chemotherapeutic treatment may achieve long term remission.

The rash that presents as a red swollen face

A red swollen face can be a skin sign of a potentially life-threatening condition. We present in detail the main clinical presentations, diagnostic tests, and management of some of the most severe conditions that can frequently present as a red and swollen face: acute or recurrent angioedema, mast cell-driven or bradykinin-mediated angioedema, nonhereditary and hereditary angioedema, allergic or photoallergic facial contact dermatitis, contact urticaria, severe adverse drug reactions (particularly drug reaction with eosinophilia and systemic symptoms [DRESS]), skin infections (erysipelas, cellulitis, necrotizing fasciitis), and autoimmune diseases (dermatomyositis). There are many other conditions that also have to be considered in the differential diagnosis of a red swollen face.

Angioedema as a systemic disease

Angioedema is a clinical entity defined as self-limiting edema localized in the deeper layers of the skin and mucosa and lasting for several days. Angioedema can be provoked by bradykinin and/or mast cell mediators, including histamine. Four types of acquired and three types of hereditary angioedema have been identified. The most obvious form of angioedema associated with other systemic disease is acquired angioedema due to C1-inhibitor deficiency. It is characterized by acquired consumption of C1 inhibitor and various underlying disorders, such as multiple myeloma, chronic lymphocytic leukemia, rectal carcinoma, and non-Hodgkin lymphoma. Suspected cases need an accurate differential diagnosis to exclude all other types of acquired and hereditary angioedema.

Acquired C1-inhibitor deficiency presenting with nephrotic syndrome

Acquired C1-inhibitor (C1-INH) deficiency is a rare and potentially life-threatening disorder, which presents with recurrent attacks of non-pitting oedema to the face, airway, limbs or gastrointestinal tract. It is often associated with underlying B-cell lymphoproliferative disorders. We describe a case of a 73-year-old man with acquired C1-INH deficiency who presented with nephrotic syndrome due to glomerular IgM deposition, secondary to an underlying secretory lymphoplasmacytic lymphoma. Both the acquired C1-INH deficiency and the nephrotic syndrome resolved when the underlying B-cell lymphoma was treated with rituximab and bendamustine, suggesting the underlying lymphoproliferative malignancy was driving both disorders.

Hereditary Angioedema: Insights into inflammation and allergy

Hereditary Angioedema (HAE) is a rare autosomal recessive bradykinin (BK)-mediated disease characterized by local episodes of non-pitting swelling. Initially considered a complement-mediated disease, novel pathogenic mechanisms uncovered in the last decade have revealed new HAE-associated genes and tight physiological relationships among complement, contact, coagulation, fibrinolysis and inflammation. Uncontrolled production of BK due to inefficient regulation of the plasma contact system, increased activity of contact and coagulation factors or a deficient regulation of BK receptor-triggered intracellular signalling are on the basis of HAE pathology. In this new scenario, HAE can result from different mechanisms that may generate distinct clinical phenotypes of the disease. This review focuses in the recent advances and unsolved challenges in our comprehension of this ever increasingly complex pathology.

Evaluation and Management of Angioedema in the Emergency Department

Angioedema is defined by non-dependent, non-pitting edema that affects several different sites and is potentially life-threatening due to laryngeal edema. This narrative review provides emergency physicians with a focused overview of the evaluation and management of angioedema. Two primary forms include histamine-mediated and bradykinin-mediated angioedema. Histamine-mediated forms present similarly to anaphylaxis, while bradykinin-mediated angioedema presents with greater face and oropharyngeal involvement and higher risk of progression. Initial evaluation and management should focus on evaluation of the airway, followed by obtaining relevant historical features, including family history, medications, and prior episodes. Histamine-mediated angioedema should be treated with epinephrine intramuscularly, antihistaminergic medications, and steroids. These medications are not effective for bradykinin-mediated forms. Other medications include C1-INH protein replacement, kallikrein inhibitor, and bradykinin receptor antagonists. Evidence is controversial concerning the efficacy of these medications in an acute episode, and airway management is the most important intervention when indicated. Airway intervention may require fiberoptic or video laryngoscopy, with preparation for cricothyrotomy. Disposition is dependent on patient's airway and respiratory status, as well as the sites involved.

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.

Nine year follow-up of a rare case of angioedema due to acquired C1-inhibitor deficiency with late onset and good response to attenuated androgen

Background

Angioedema due to acquired deficiency of C1-inhibitor (C1-INH-AAE) is a rare disease sharing some clinical and laboratory similarities with hereditary angioedema, but with late onset and no positive family history. The underlining cause may be malignant or due to autoimmune diseases, but some cases remain idiopathic.

Case presentation

We report a case of a 75 year old woman suffering from recurrent episodes of angioedema since the age of 66, considered first induced by treatment with angiotensin-converting-enzyme inhibitors (ACEI). She continued to have angioedema attacks during 6 years after discontinuation of ACEI, until evaluation in our clinic in 2014, when C1 inhibitor esterase (C1-INH) deficiency was confirmed. The extended medical evaluation for inflammatory, allergic, autoimmune and neoplasic diseases was negative. C1-INH and complement fraction C4 plasma levels were significantly decreased at all measurements, but no diagnostic criteria for diseases known to induce C1-INH deficiency could be found. We first initiated daily prophylactic treatment with tranexamic acid, with no amelioration after 3 months. During the last and most severe attack, with the first facial and laryngeal edema, we have switched to attenuated androgen danazol. The evolution was very good, with prompt remission of angioedema and significant increase of C1-INH and C4 plasma levels after 2 weeks of daily danazol use. She completed 3 years of continuous treatment with low daily maintenance dose of danazol (ongoing), with no angioedema attack. We closely monitored C1-INH and C4 plasma levels, possible danazol side effects and any signs suggesting late onset of C1-INH deficiency causal disease.

Conclusion

We reported a particular case of rare angioedema due to acquired deficiency of C1-inhibitor, which has no clear cause after long follow-up, but good response to attenuated androgen. We concluded that the awareness of angioedema due to C1-INH deficiency should be increased within medical community and therapeutic options should be more clearly indicated and available for all diagnosed cases.

The international WAO/EAACI guideline for the management of hereditary angioedema-The 2017 revision and update

Hereditary Angioedema (HAE) is a rare and disabling disease. Early diagnosis and appropriate therapy are essential. This update and revision of the global guideline for HAE provides up-to-date consensus recommendations for the management of HAE. In the development of this update and revision of the guideline, an international expert panel reviewed the existing evidence and developed 20 recommendations that were discussed, finalized and consented during the guideline consensus conference in June 2016 in Vienna. The final version of this update and revision of the guideline incorporates the contributions of a board of expert reviewers and the endorsing societies. The goal of this guideline update and revision is to provide clinicians and their patients with guidance that will assist them in making rational decisions in the management of HAE with deficient C1-inhibitor (type 1) and HAE with dysfunctional C1-inhibitor (type 2). The key clinical questions covered by these recommendations are: (1) How should HAE-1/2 be defined and classified?, (2) How should HAE-1/2 be diagnosed?, (3) Should HAE-1/2 patients receive prophylactic and/or on-demand treatment and what treatment options should be used?, (4) Should HAE-1/2 management be different for special HAE-1/2 patient groups such as pregnant/lactating women or children?, and (5) Should HAE-1/2 management incorporate self-administration of therapies and patient support measures?

Acquired angioedema in juvenile systemic lupus erythematosus: case-based review

An acquired form of angioedema that is clinically similar but scarcer than the hereditary form may be caused, even more rarely, by the presence of an underlying autoimmune disease. We report a previously healthy 16-year-old girl with an acquired angioedema as a rare and initial presentation of systemic lupus erythematosus. The patient had no previous angioedema attack and no family history. She did not have any chronic diseases and did not use any medicine regularly. The patient was diagnosed with systemic lupus erythematosus with the presence of polyarthralgia, angioedema, leucopenia, and positivity of immunologic criteria. Her edema resolved with high-dose methylprednisolone and hydroxychloroquine slowly. In conclusion, new-onset angioedema in adolescent girls should be investigated to evaluate autoimmunity and the possibility of systemic lupus erythematosus. The related literature on acquired angioedema associated with systemic lupus erythematosus is also reviewed.

Case report presenting the diagnostic challenges in a patient with recurrent acquired angioedema, antiphospholipid antibodies and undetectable C2 levels

Background

Angioedema secondary to acquired C1 inhibitor deficiency (AAE) is a rare disease. It usually is associated with lymphoproliferative disorders. We present a case of AAE in a patient with antiphospholipid syndrome (APS), a non-Hodgkin lymphoproliferative disorder (NHL) with undetectable levels of C2, C4, and an undetectable CH50. The co-existence of AAE, APS, and NHL, with an undetectable C2 level, to the best of our knowledge, has never before reported together in the same patient.

Case presentation

A patient with a recent history of thrombosis presented with recurrent episodes of angioedema. The workup revealed undetectable levels of C2, C4 and undetectable CH50. Quantitative levels of C1 inhibitor and C1q were low. C1 inhibitor function was less than 40%. Anti-cardiolipin antibodies were found. The patient was initially treated on demand with intravenous plasma-derived human C1-INH concentrates, (Cinryze^® Shire). Later the patient received prophylactic therapy with danazol. She was diagnosed with lymphoma 3 years after her first episode of angioedema. Single agent therapy with rituximab was not only effective in treating her lymphoma but also preventing further episodes of angioedema. Anti-cardiolipin antibody titers also declined. Additionally, marked early primary pathway complement component abnormalities and CH50 also corrected, although incomplete normalization of C4 proved to be due to a heterozygous C4 deficiency.

Conclusion

This case shows the unique association of AAE, APS and NHL in a patient with undetectable levels of early complement components. Additionally, this case also shows for the first time the effectiveness of rituximab therapy in all three disease states while co-existing simultaneously in the same patient.

The role of the complement system in hereditary angioedema

Hereditary angioedema (HAE) is a rare, but potentially life-threatening disorder, characterized by acute, recurring, and self-limiting edematous episodes of the face, extremities, trunk, genitals, upper airways, or the gastrointestinal tract. HAE may be caused by the deficiency of C1-inhibitor (C1-INH-HAE) but another type of the disease, hereditary angioedema with normal C1-INH function (nC1-INH-HAE) was also described. The patient population is quite heterogeneous as regards the location, frequency, and severity of edematous attacks, presenting large intra- and inter-individual variation. Here, we review the role of the complement system in the pathomechanism of HAE and also present an overview on the complement parameters having an importance in the diagnosis or in predicting the severity of HAE.

Acquired C1 Inhibitor Deficiency

Acquired angioedema due to C1-INH deficiency (C1-INH-AAE) can occur when there are acquired (not inherited) deficiencies of C1-INH. A quantitative or functional C1-INH deficiency with negative family history and low C1q is diagnostic of C1-INH-AAE. The most common conditions associated with C1-INH-AAE are autoimmunity and B-cell lymphoproliferative disorders. A diagnosis of C1-INH-AAE can precede a diagnosis of lymphoproliferative disease and confers an increased risk for developing non-Hodgkin lymphoma. Treatment focuses on symptom control with therapies that regulate bradykinin activity (C1-INH concentrate, icatibant, ecallantide, tranexamic acid, androgens) and treatment of any underlying conditions.

Diagnosis, Course, and Management of Angioedema in Patients With Acquired C1-Inhibitor Deficiency

BACKGROUND

Acquired angioedema due to C1-inhibitor deficiency (C1-INH-AAE) is a rare disease with no prevalence data or approved therapies.

OBJECTIVE

To report data on patients with C1-INH-AAE followed at Angioedema Center, Milan (from 1976 to 2015).

METHODS

Diagnostic criteria included history of recurrent angioedema without wheals; decreased C1-INH antigen levels and/or functional activity of C1-INH and C4 antigen less than 50% of normal; late symptom onset (>40 years); no family history of angioedema and C1-INH deficiency.

RESULTS

In total, 77 patients (58% females; median age, 70 years) were diagnosed with C1-INH-AAE and 675 patients with hereditary angioedema due to C1-INH deficiency (C1-INH-HAE) (1 patient with C1-INH-AAE/8.8 patients with C1-INH-HAE). Median age at diagnosis was 64 years. Median time between symptom onset and diagnosis was 2 years. Sixteen patients (21%) died since diagnosis, including 1 because of laryngeal edema. Angioedema of the face was most common (N = 63 [82%]), followed by abdomen (N = 51 [66%]), peripheries (N = 50 [65%]), and oral mucosa and/or glottis (N = 42 [55%]). Forty-eight of 71 patients (68%) had autoantibodies to C1-INH. In total, 56 patients (70%) used on-demand treatment for angioedema including intravenous pdC1-INH 2000 U (Berinert, CSL Behring, Marburg, Germany) (N = 49) and/or subcutaneous icatibant 30 mg (Firazyr, Shire; Milano, Italy) (N = 27). Eventually, 8 of 49 patients receiving pdC1-INH became nonresponsive; all had autoantibodies. Thirty-four patients received long-term prophylaxis with tranexamic acid (effective in 29) and 20 with androgens (effective in 8).

CONCLUSIONS

The incidence of C1-INH-AAE was 1 for every 8.8 patients with C1-INH-HAE. Thirty percent of the deaths were related to the disease. Treatments approved for C1-INH-HAE are effective in C1-INH-AAE, although with minimal differences.

Angioedema as the first presentation of B-cell non-Hodgkin lymphoma--an unusual case with normal C1 esterase inhibitor level: a case report

BACKGROUND

Acquired angioedema is a rare but recognized manifestation of lymphoproliferative disorders due to deficiency in C1 esterase inhibitor. Normal level of C1 esterase inhibitor proteins in association with angioedema due to lymphoproliferative disease is a rare and an uncommon finding caused by antibodies produced from the underlying disease. Antibodies cause inactivation of C1 esterase inhibitor, thus resulting in C1 esterase inhibitor dysfunction despite of normal quantity of C1 esterase inhibitor.

CASE PRESENTATION

A 50-year-old Sri Lankan male presented with first episode of angioedema without any family history. Physical examination revealed mild pallor with swelling of tongue, lips and perioral region. On investigations, erythrocyte sedimentation rate was persistently high and bone marrow with immunohistochemistry revealed infiltration with B-cell type low grade non-Hodgkin lymphoma. Computed tomography scan of the chest and abdomen showed paratracheal and subcarinal lymphadenopathy and splenomegaly, with the findings being compatible with lymphoma. He had normal C1 esterase inhibitor protein level with reduced activity and low C1q, C4 levels indicating antibodies against C1 esterase inhibitor causing dysfunctional C1 esterase inhibitor.

CONCLUSION

Adult onset angioedema should prompt physicians to suspect underlying lymphoproliferative disorder despite of C1 esterase inhibitor protein level being normal. Though uncommon, presence of antibodies against C1 esterase inhibitor secondary to lymphoproliferative disorder should be considered in the presence of normal C1 esterase inhibitor protein levels with low functional capacity in the background of acquired angioedema.

Classification, diagnosis, and approach to treatment for angioedema: consensus report from the Hereditary Angioedema International Working Group

Angioedema is defined as localized and self-limiting edema of the subcutaneous and submucosal tissue, due to a temporary increase in vascular permeability caused by the release of vasoactive mediator(s). When angioedema recurs without significant wheals, the patient should be diagnosed to have angioedema as a distinct disease. In the absence of accepted classification, different types of angioedema are not uniquely identified. For this reason, the European Academy of Allergy and Clinical Immunology gave its patronage to a consensus conference aimed at classifying angioedema. Four types of acquired and three types of hereditary angioedema were identified as separate forms from the analysis of the literature and were presented in detail at the meeting. Here, we summarize the analysis of the data and the resulting classification of angioedema.

Acquired angioedema--occurrence, clinical features and associated disorders in a Danish nationwide patient cohort

BACKGROUND

The prevalence of acquired angioedema (AAE) is hitherto unknown and, to date, less than 200 patients have been reported worldwide. AAE is associated with lymphoproliferative conditions and autoantibodies against C1 inhibitor (C1INH). Rituximab (RTX) is increasingly used in the treatment of AAE patients.

METHODS

A nationwide study of AAE patients was performed in Denmark. Clinical features, associated disorders, treatments and outcomes were registered.

RESULTS

Eight AAE patients were identified. The diagnostic delay was on average 1 year and 8 months. Patients were treated with C1INH concentrate or icatibant on demand. Six patients were diagnosed with a clonal B-cell disorder during follow-up, on average 2.5 years after the first swelling. Two patients had monoclonal B-cell lymphocytosis (MBL). Two patients received RTX.

CONCLUSIONS

AAE is a rare condition occurring in less than 10% of patients with C1INH deficiency in Denmark. AAE is highly associated with haematologic disorders, and we recommend yearly follow-up visits with clinical examination and blood tests including flow cytometry to diagnose B-cell conditions at an early stage. We report 2 patients with AAE and associated MBL, which is a benign expansion of clonal B lymphocytes. MBL can be the precursor of chronic lymphocytic leukaemia or is associated with non-Hodgkin's lymphoma. If angioedema is poorly controlled with standard treatment regimens, we suggest treatment of the associated haematologic disorder. Based on a review of the literature and our own data, we recommend therapy with RTX, especially in patients with anti-C1INH autoantibodies.

Angioedema with normal C1q and C1 inhibitor: an atypical presentation of Waldenström macroglobulinemia

Angioedema is a recurrent, non-pitting, non-pruritic, transitory swelling due to transient increase of endothelial permeability in the capillaries of the deep cutaneous and mucosal layers. Angioedema is generally categorized based on etiology, and characteristic lab findings are associated with each category. Cases of acquired angioedema associated with myeloproliferative disorders have been described in the literature, but these have been associated with a characteristic low C1q, a defining laboratory finding in acquired angioedema. Here we present a case of 68-year-old female with acquired angioedema that was not associated with low C1q, but was found to have Waldenström disease. Her angioedema responded dramatically to combination therapy consisting of bortezomib, rituximab, and dexamethasone.

Acquired C1-inhibitor deficiency and lymphoproliferative disorders: a tight relationship

Angioedema due to the acquired deficiency of C1-inhibitor is a rare disease known as acquired angioedema (AAE), which was first described in a patient with high-grade lymphoma and is frequently associated with lymphoproliferative diseases, including expansion of B cell clones producing anti-C1-INH autoantibodies, monoclonal gammopathy of uncertain significance (MGUS) and non-Hodgkin lymphoma (NHL). AAE is clinically similar to hereditary angioedema (HAE), and is characterized by recurrent episodes of sub-cutaneous and sub-mucosal edema. It may affect the face, tongue, extremities, trunk and genitals. The involvement of the gastrointestinal tract causes bowel sub-occlusion with severe pain, vomiting and diarrhea, whereas laryngeal edema can be life-threatening. Unlike those with HAE, AAE patients usually have late-onset symptoms, do not have a family history of angioedema and present variable response to treatment due to the hyper-catabolism of C1-inhibitor. Reduced C1-inhibitor function leads to activation of the classic complement pathway with its consumption and activation of the contact system leading to the generation of the vasoactive peptide bradykinin, which increases vascular permeability and induces angioedema. Lymphoprolipherative diseases and AAE are tightly linked with either angioedema or limphoprolyferation being the first symptom. Experimental data indicate that neoplastic tissue and/or anti-C1-inhibitor antibodies induce C1-inhibitor consumption, and this is further supported by the observation that cytotoxic treatment of the lymphoproliferative diseases associated with AAE variably reverses the complement impairment and leads to a clinical improvement in angioedema symptoms.

Angioedema

Angioedema can be caused by either mast cell degranulation or activation of the kallikrein-kinin cascade. In the former case, angioedema can be caused by allergic reactions caused by immunoglobulin E (IgE)-mediated hypersensitivity to foods or drugs that can also result in acute urticaria or a more generalized anaphylactic reaction. Nonsteroidal anti-inflammatory drugs (cyclooxygenase 1 inhibitors, in particular) may cause angioedema with or without urticaria, and leukotrienes may have a particular role as a mediator of the swelling. Reactions to contrast agents resemble allergy with basophil and mast cell degranulation in the absence of specific IgE antibody and can be generalized, that is, anaphylactoid. Angioedema accompanies chronic urticaria in 40% of patients, and approximately half have an autoimmune mechanism in which there is IgG antibody directed to the subunit of the IgE receptor (40%) or to IgE itself (5%-10%). Bradykinin is the mediator of angioedema in hereditary angioedema types I and II (C1 inhibitor [INH] deficiency) and the newly described type III disorder some of which are caused bya mutation involving factor XII. Acquired C1 INH deficiency presents in a similar fashion to the hereditary disorder and is due either toC1 INH depletion by circulating immune complexes or to an IgG antibody directed to C1 INH. Although each of these causes excessive bradykinin formation because of activation of the plasma bradykinin-forming pathway, the angioedema due to angiotensin-converting enzyme inhibitors is caused by excessive bradykinin levels due to inhibition of bradykinin degradation. Idiopathic angioedema (ie, pathogenesis unknown) may be histaminergic, that is, caused by mast cell degranulation with histamine release, or nonhistaminergic. The mediator pathways in the latter case are yet to be defined. A minority may be associated with the same autoantibodies associated with chronic urticaria. Angioedema that is likely to be life threatening (laryngeal edema or tongue/pharyngeal edema that obstructs the airway) is seen in anaphylactic/anaphylactoid reactions and the disorders mediated by bradykinin.

Pathophysiology of Hereditary Angioedema

Background

Laryngeal angioedema may be associated with significant morbidity and even mortality. Because of the potential severity of attacks, both allergists and otolaryngologists must be knowledgeable about the recognition and treatment of laryngeal angioedema. This study describes the clinical characteristics and pathophysiology of bradykinin-mediated angioedema.

Methods

A literature review was conducted concerning the clinical characteristics and pathophysiology of types I and II hereditary angioedema (HAE), type III HAE, acquired C1 inhibitor (C1INH) deficiency, and angiotensin-converting enzyme (ACE) inhibitor–associated angioedema.

Results

The diagnosis of type I/II HAE is relatively straightforward as long as the clinician maintains a high index of suspicion. Mutations in the SERPING1 gene result in decreased secretion of functional C1INH and episodic activation of plasma kallikrein and Hageman factor (FXII) of the plasma contact system with cleavage of high molecular weight kininogen and generation of bradykinin. In contrast, there are no unequivocal criteria for making a diagnosis of type III HAE, although a minority of these patients may have a mutation in the factor XII gene. Angioedema attacks and mediator of swelling in acquired C1INH deficiency are similar to those in type I or II HAE; however, it occurs on a sporadic basis because of excessive consumption of C1INH in patients who are middle aged or older. ACE inhibitor–associated angioedema should always be considered in any patient taking an ACE inhibitor who experiences angioedema. ACE is a kininase, which when inhibited is thought to result in increased bradykinin levels. Bradykinin acts on vascular endothelial cells to enhance vascular permeability.

Conclusion

Laryngeal swelling is not infrequently encountered in bradykinin-mediated angioedema. Novel therapies are becoming available that for the first time provide effective treatment for bradykinin-mediated angioedema. Because the characteristics and treatment of these angioedemas are quite distinct from each other and from histamine-mediated angioedema, it is crucial that the physician be able to recognize and distinguish these swelling disorders.

Isolated angioedema of the bowel due to C1 esterase inhibitor deficiency: a case report and review of literature

Introduction

We report a rare, classic case of isolated angioedema of the bowel due to C1-esterase inhibitor deficiency. It is a rare presentation and very few cases have been reported worldwide. Angioedema has been classified into three categories.

Case presentation

A 66-year-old Caucasian man presented with a ten-month history of episodic severe cramping abdominal pain, associated with loose stools. A colonoscopy performed during an acute attack revealed nonspecific colitis. Computed tomography of the abdomen performed at the same time showed a thickened small bowel and ascending colon with a moderate amount of free fluid in the abdomen. Levels of C4 (< 8 mg/dL; reference range 15 to 50 mg/dL), CH50 (< 10 U/mL; reference range 29 to 45 U/ml) and C1 inhibitor (< 4 mg/dL; reference range 14 to 30 mg/dL) were all low, supporting a diagnosis of acquired angioedema with isolated bowel involvement. Our patient's symptoms improved with antihistamine and supportive treatment.

Conclusion

In addition to a detailed comprehensive medical history, laboratory data and imaging studies are required to confirm a diagnosis of angioedema due to C1 esterase inhibitor deficiency.

An overview of novel therapies for acute hereditary angioedema

Hereditary angioedema is an episodic swelling disorder with autosomal dominant inheritance. Attacks are characterized by nonpitting edema of external or mucosal body surfaces. Patients often present with swelling of the extremities, abdominal pain, and swelling of the mouth and throat, which can at times lead to asphyxiation. The disease is caused by a mutation in the gene encoding the complement C1-inhibitor protein, which leads to unregulated production of bradykinin. Long-term therapy has depended on the use of attenuated androgens or plasmin inhibitors but in the US there was, until recently, no specific therapy for acute attacks. As well, many patients with hereditary angioedema in the US were either not adequately controlled on previously available therapies or required doses of medications that exposed them to the risk of serious adverse effects. Five companies have completed or are currently conducting phase III clinical trials in the development of specific therapies to terminate acute attacks or to be used as prophylaxis. These products are based on either replacement therapy with purified plasma-derived or recombinant C1-inhibitor, or inhibition of the kinin-generating pathways with a recombinant plasma kallikrein inhibitor or bradykinin type 2 receptor antagonist. Published studies thus far suggest that all of these products are likely to be effective. These new therapies will likely lead to a totally new approach in treating hereditary angioedema.

Angioedema triggered by pulp extirpation--a case report

BACKGROUND

C1-esterase inhibitor deficiency results in episodes of non-allergic edema of parts of the body. Edema of the face may be triggered by dental therapy.

CASE REPORT

We report a case of C1-esterase inhibitor deficiency which was detected in a 42-year-old woman. The patient was completely unaware that she had this disorder or of any related family history, and the patient developed an intense facial angioedema after pulp extirpation of lower premolar tooth.

DISCUSSION

In this case, the diagnosis of angioedema due to C1-esterase inhibitor deficiency was established at a later stage. The differing causes of C1-esterase inhibitor deficiency are briefly discussed and the treatment modalities outlined.

Acquired angioedema

Acquired angioedema (AAE) is characterized by acquired deficiency of C1 inhibitor (C1-INH), hyperactivation of the classical pathway of human complement and angioedema symptoms mediated by bradykinin released by inappropriate activation of the contact-kinin system. Angioedema recurs at unpredictable intervals, lasts from two to five days and presents with edema of the skin (face, limbs, genitals), severe abdominal pain with edema of the gastrointestinal mucosa, life-threateing edema of the upper respiratory tract and edema of the oral mucosa and of the tongue. AAE recurs in association with various conditions and particularly with different forms of lymphoproliferative disorders. Neutralizing autoantibodies to C1-INH are present in the majority of patients. The therapeutic approach to a patient with AAE should first be aimed to avoid fatalities due to angioedema and then to avoid the disability caused be angioedema recurrences. Acute attacks can be treated with plasma-derived C1-INH, but some patients become non-responsive and in these patients the kallikrein inhibitor ecallantide and the bradykinin receptor antagonist icatibant can be effective. Angioedema prophylaxis is performed using antifibrinolytic agents and attenuated androgens with antifibrinolytic agents providing somewhat better results. Treatment of the associated disease can resolve AAE in some patients.

Angioedema due to acquired C1-inhibitor deficiency: a bridging condition between autoimmunity and lymphoproliferation

Angioedema due to an acquired deficiency in the inhibitor of the first component of human complement (CI-INH) is a rare syndrome that is usually identified as acquired angioedema (AAE). The clinical features of C1-INH deficiency, which may also be of genetic origin (hereditary angioedema, HAE), include subcutaneous, non-pruritic swelling, involvement of the upper respiratory tract, and abdominal pain due to partial obstruction of the gastrointestinal tract. Unlike those with HAE, AAE patients have no family history of angioedema and are characterised by the late onset of symptoms and various responses to treatment due to the hypercatabolism of C1-INH. The reduction in C1-INH function leads to activation of the classical complement pathway and complement consumption, as well as activation of the contact system leading to the generation of the vasoactive peptide bradykinin, increased vascular permeability, and angioedema. AAE is frequently associated with lymphoproliferative diseases ranging from monoclonal gammopathies of uncertain significance (MGUS) to non-Hodgkin's lymphoma (NHL) and/or anti-C1-INH inactivating autoantibodies. The coexistence of true B cell malignancy, non-malignant B cell proliferation and pathogenic autoimmune responses suggests that AAE patients are all affected by altered B cell proliferation control although their clinical evolution may vary.

Doing What I Like

I have spent my entire professional life at Harvard Medical School, beginning as a medical student. I have enjoyed each day of a diverse career in four medical subspecialties while following the same triad of preclinical areas of investigation—cysteinyl leukotrienes, mast cells, and complement—with occasional translational opportunities. I did not envision a career with a predominant preclinical component. Such a path simply evolved because I chose instinctively at multiple junctures to follow what proved to be propitious opportunities. My commentary notes some of the highlights for each area of interest and the mentors, collaborators, and trainees whose counsel has been immensely important at particular intervals or over an extended period.

Hereditary angioedema: a current state-of-the-art review, II: historical perspective of non-histamine-induced angioedema

OBJECTIVE

To review the evolution of our understanding of hereditary angioedema (HAE) from the first historical reference to the present day.

DATA SOURCES

MEDLINE and PubMed were searched using the following keywords: history of HAE, C1 inhibitor, complements system, genetics of HAE, mechanisms of HAE, and treatment of HAE.

STUDY SELECTION

Information was selected that outlines the advances made in complementology, the first report of HAE, and subsequent studies that elucidated the underlying mechanisms of this disease, leading to current therapy of this orphan disease.

RESULTS

Generational research efforts in HAE have focused on the following: (1) several new clinical presentations, (2) acquired forms of non-histamine-induced angioedema, (3) the genetic basis for the inherited forms, (4) the effects of C1 inhibitor on contact phases of coagulation-fibrinolytic pathways, and (5) various therapies for short- and long-term control of the disease.

CONCLUSION

The progress made in understanding the pathogenesis and treatment of HAE is an excellent example of the "bench to the bedside" paradigm involving the collaboration between clinicians and researchers.

Hereditary angiodema: a current state-of-the-art review, VII: Canadian Hungarian 2007 International Consensus Algorithm for the Diagnosis, Therapy, and Management of Hereditary Angioedema

BACKGROUND

We published the Canadian 2003 International Consensus Algorithm for the Diagnosis, Therapy, and Management of Hereditary Angioedema (HAE; C1 inhibitor [C1-INH] deficiency) in 2004.

OBJECTIVE

To ensure that this consensus remains current.

METHODS

In collaboration with the Canadian Network of Rare Blood Disorder Organizations, we held the second Canadian Consensus discussion with our international colleagues in Toronto, Ontario, on February 3, 2006, and reviewed its content at the Fifth C1 Inhibitor Deficiency Workshop in Budapest on June 2, 2007. Papers were presented by international investigators, and this consensus algorithm approach resulted.

RESULTS

This consensus algorithm outlines the approach recommended for the diagnosis, therapy, and management of HAE, which was agreed on by the authors of this report. This document is only a consensus algorithm approach and continues to require validation. As such, participants agreed to make this a living 2007 algorithm, a work in progress, and to review its content at future international HAE meetings.

CONCLUSIONS

There is a paucity of double-blind, placebo-controlled trials on the treatment of HAE, making levels of evidence to support the algorithm less than optimal. Controlled trials currently under way will provide further insight into the management of HAE. As with our Canadian 2003 Consensus, this 2007 International Consensus Algorithm for the Diagnosis, Therapy, and Management of HAE was formed through the meeting and agreement of patient care professionals along with patient group representatives and individual patients.

Acquired angioedema associated with primary antiphospholipid syndrome in a patient with antithrombin III deficiency

Acquired angioedema (AAE) due to the functional deficiency of the C1 inhibitor (C1-INH) is a rare disease characterized by recurrent bouts of edema that involve subcutaneous tissues, the larynx or the gastrointestinal tract. In the present paper, we report the case of a male patient with symptoms of AAE and recurrent deep venous and arterial thrombosis. As a trigger of AAE in the present patient, we revealed primary antiphospholipid syndrome accompanied by antithrombin III deficiency, along with malignancy in the history, and angiotensin-converting enzyme inhibitor therapy. Although anti-C1-INH titers (type I AAE) were normal initially, we observed a sharp increase in anti-C1-INH titers (suggestive of type II AAE) during follow-up. It seems that thrombosis might worsen angioedematous attacks in functional C1-INH deficiency. Thrombophilia should be considered a provoking factor of AAE and should be carefully sought for in these patients, as the key to successful management of AAE is the effective treatment of the underlying disease.