Angioedemas, Hereditary
Angioedema
Complement C1 Inhibitor Protein
Hereditary Angioedema Types I and II
Complement C1 Inactivator Proteins
Factor XII
Clinical variability and characteristic autoantibody profile in primary C1q complement deficiency. (1/40)
OBJECTIVES: C1q deficiency is a rare inherited defect in the early part of the complement cascade. In this report, we describe the varied clinical features of patients with this condition as well as the characteristic autoantibody profile. METHODS: A large Pakistani family with a high degree of consanguinity is described in which the father and five sons have C1q deficiency, all with different clinical manifestations. RESULTS: Clinical features of C1q deficiency can vary from almost no disease to fulminant bacterial infection and localized lupus-like skin, renal or CNS disease. Autoantibodies to ribonucleoproteins such as anti-Sm and Ro, but not dsDNA, were present. CONCLUSIONS: Awareness of the spectrum of clinical disease, autoantibody profiles and tests required to confirm the diagnosis of C1q deficiency are important if this life-threatening immunodeficiency disease is to be managed correctly. (+info)Hereditary angioedema: a Taiwanese family with a novel gene mutation. (2/40)
Hereditary angioedema (HAE) is an autosomal dominant disorder caused by a deficiency of C1 esterase inhibitor (C1-INH). Affected individuals have attacks of swelling involving almost any part of the body. We studied a family with 15 living members, including a 16-year-old girl who had 3 attacks of angioedema in 2 years. Her paternal uncle had died of asphyxiation during an attack 15 years previously. We analyzed the blood of each family member for C3, C4, and C1-INH levels and sequenced the SERPING1 (formerly C1NH) gene that codes for C1-INH. Six individuals had decreased serum levels of C4 and C1-INH, and they were all found to have a single nucleotide A deletion at codon 210 of the gene, 1210fsX210, a novel mutation that accounts for the HAE in this family. (+info)The establishment and utility of Sweha-Reg: a Swedish population-based registry to understand hereditary angioedema. (3/40)
BACKGROUND: The importance of acquiring comprehensive epidemiological and clinical data on hereditary angioedema has increasingly caught the attention of physicians and scientists around the world. The development of networks and creation of comprehensive policies to improve care of people suffering from rare diseases, such as hereditary angioedema, is a stated top priority of the European Union. Hereditary angioedema is a rare disease, that it may be life-threatening. Although the exact prevalence is unknown, current estimates suggest that it is 1/10,000-1/150,000 individuals. The low prevalence requires combined efforts to gain accurate epidemiological data on the disease and so give us tools to reduce morbidity and mortality, and improve quality of life of sufferers. METHODS: Sweha-Reg is a population-based registry of hereditary angioedema in Sweden with the objectives of providing epidemiological data, and so creates a framework for the study of this disease. The registry contains individual-based data on diagnoses, treatments and outcomes. CONCLUSION: The present manuscript seeks to raise awareness of the existence of Sweha-Reg to stimulate the international collaboration of registries. A synthesis of data from similar registries across several countries is required to approach an inclusive course understanding of HAE. (+info)Metallopeptidase activities in hereditary angioedema: effect of androgen prophylaxis on plasma aminopeptidase P. (4/40)
BACKGROUND: Aminopeptidase P (APP) plays an important role in the catabolism of kinins in human plasma, mostly for des-Arg(9)-bradykinin. Impaired degradation of this active bradykinin metabolite was found to be associated with a decreased APP activity in hypertensive patients who experienced angioedema while being treated with angiotensin I-converting enzyme inhibitors. The pathophysiology of hereditary angioedema is presently attributed only to a quantitative/qualitative C1 inhibitor (CI-INH) defect with increased bradykinin release. OBJECTIVES: In the context of androgen prophylaxis, increased CI-INH function cannot fully explain protection from angioedema attacks alone because of the limited reversion of the CI-INH defects. Therefore we hypothesized that androgen prophylaxis could enhance plasma APP activity. METHODS: Patients with hereditary angioedema were investigated for plasma metallopeptidase activities responsible for kinin catabolism (APP, angiotensin I-converting enzyme, and carboxypeptidase N) and for CI-INH function in treated and untreated patients. RESULTS: APP activity was asymmetrically distributed in untreated patients (n = 147): the mean value was significantly lower than the value in a reference healthy and unmedicated population (n = 116; P < or = .001). Prophylaxis with androgen induced a significant increase in APP activity (P < or = .001), whereas it did not affect the other metallopeptidase activities. In both patient groups, APP activity showed a significant inverse relationship to disease severity (P < or = .001). CONCLUSION: In addition to the effect on circulating CI-INH levels, the increase in APP levels brought on by androgens could contribute to a more effective control of the kinin accumulation considered to be responsible for the symptoms of angioedema. (+info)Possible disease-modifying factors: the mannan-binding lectin pathway and infections in hereditary angioedema of children and adults. (5/40)
(+info)Acquired angioedema associated with hereditary angioedema due to C1 inhibitor deficiency. (6/40)
Angioedema caused by C1 inhibitor deficiency is a rare disorder that may be either hereditary or acquired, the latter being mainly associated with lymphoproliferative disorders. A 51-year-old woman who had suffered from episodes of acute peripheral edema since she was 12 was diagnosed with hereditary angioedema at the age of 40 and remained stable with stanozolol. Due to a worsening of her symptoms she was reassessed and low levels of C1q and an abnormal lymphocyte count were detected. Immunophenotyping of peripheral blood revealed 9% monoclonal lambda B cells with a follicular center phenotype. The histopathology was consistent with a grade II follicular lymphoma stage IV-A.With chemotherapy, the hematologic disease was controlled and C1q levels returned to normal values. This represents a rare case of a patient with hereditary angioedema who developed acquired angioedema due to a lymphoma that was associated with a reduction in the levels of C1q as her symptoms worsened. (+info)Depressed activation of the lectin pathway of complement in hereditary angioedema. (7/40)
(+info)Hereditary angioedema: new hopes for an orphan disease. (8/40)
Hereditary angioedema is a rare genetic disorder, manifested by recurrent edema leading to disfigurement, organ dysfunction and life-threatening respiratory impairment that may become fatal. The hallmark of HAE is C1 esterase inhibitor deficiency, but recent evidence points at bradykinin as the main mediator that causes hyperpermeability of small vasculature, leading to accumulation of edema fluid. Current therapeutic options for HAE are limited, and consist of drugs, replacement therapy, and supportive treatment. In view of many disadvantages of the current therapeutic modalities, new approaches to the treatment of HAE are now being offered. This review summarizes our experience with a new line of medications developed for the treatment of acute exacerbations and prophylaxis of HAE--icatibant: bradykinin receptor antagonist, ecallantide: kallikrein inhibitor, and two C1 INH preparations: Berinert-P, human plasma-derived concentrate, and Rhucin: novel recombinant C1-INH produced in transgenic rabbits. Preliminary results of these studies are encouraging and may bring new hope to the patients with this distressing condition. The exact number of HAE patients in Israel is unknown and because patients are treated individually and comprehensive laboratory assessment is partial, many cases might be missed or not treated according to accepted guidelines. We offer a new specialty center for HAE patients, addressing the medical and psychosocial needs of patients and their families. (+info)Hereditary angioedema (HAE) is a rare genetic disorder characterized by recurrent episodes of swelling in various parts of the body, including the face, lips, tongue, throat, hands, feet, and/or genitals. The swelling can also affect the gastrointestinal tract, causing abdominal pain, nausea, vomiting, and diarrhea.
HAE is caused by a deficiency or dysfunction of the C1 inhibitor protein, which is a part of the body's immune system that helps regulate inflammation and blood vessel dilation. As a result, people with HAE have uncontrolled activation of the complement system and increased levels of bradykinin, a potent vasodilator that causes the characteristic swelling.
There are three types of HAE: type I, type II, and type III. Type I and type II are caused by mutations in the gene that codes for the C1 inhibitor protein, resulting in low levels or dysfunctional C1 inhibitor protein. Type III is caused by a mutation in the coagulation factor XII gene, leading to overactivation of the contact system and increased bradykinin production.
HAE is an inherited disorder, typically passed down from parent to child in an autosomal dominant pattern. This means that a person has a 50% chance of inheriting the mutated gene from an affected parent and developing HAE. However, up to 25% of cases may occur spontaneously due to new mutations in the gene.
Treatment for HAE includes medications to prevent or reduce the severity and frequency of attacks, such as C1 inhibitor replacement therapy, attenuated androgens, and monoclonal antibodies against kallikrein. In addition, acute attacks can be treated with on-demand therapies, such as plasma-derived C1 inhibitor, icatibant, and ecallantide.
Angioedema is a medical condition characterized by rapid swelling of the skin, mucous membranes, and submucosal tissues. The swelling typically occurs in the face, lips, tongue, larynx, and extremities, and can also affect the gastrointestinal tract. Angioedema can be caused by a variety of factors, including allergic reactions, hereditary genetic mutations, and certain medications.
In medical terms, angioedema is defined as a self-limiting episode of localized edema in the deep dermis, subcutaneous tissue, or mucous membranes, characterized by well-circumscribed, nonpitting, nondependent swelling. The swelling can occur suddenly and may persist for up to 72 hours. In severe cases, angioedema can cause airway obstruction and be life-threatening if not treated promptly.
Angioedema can be classified into two main types: allergic or non-allergic. Allergic angioedema is caused by an immune response to an allergen, such as food, medication, or insect venom. Non-allergic angioedema can be further divided into several subtypes, including hereditary angioedema (HA), acquired angioedema (AAE), and drug-induced angioedema.
Hereditary angioedema is a rare genetic disorder caused by mutations in the C1 inhibitor gene, leading to uncontrolled activation of the complement system and increased production of bradykinin, a potent vasodilator. Acquired angioedema is similar to hereditary angioedema but occurs later in life and is associated with underlying medical conditions such as lymphoproliferative disorders or autoimmune diseases. Drug-induced angioedema can be caused by a variety of medications, including ACE inhibitors, angiotensin receptor blockers (ARBs), and nonsteroidal anti-inflammatory drugs (NSAIDs).
The diagnosis of angioedema is typically based on clinical presentation, medical history, and laboratory tests. Treatment depends on the underlying cause of the condition but may include antihistamines, corticosteroids, epinephrine, and medications that target the complement system or bradykinin pathway. In severe cases, hospitalization and intensive care may be necessary to manage airway obstruction and other complications.
The Complement C1 Inhibitor protein, also known as C1-INH, is a protein involved in the regulation of the complement system and the contact system, which are parts of the immune system. The complement system helps to eliminate pathogens (e.g., bacteria, viruses) from the body, while the contact system helps to regulate blood coagulation and inflammation.
C1-INH works by inhibiting the activation of C1, an enzyme complex that is the first component of the classical complement pathway. By inhibiting C1, C1-INH prevents the activation of downstream components of the complement system, thereby helping to regulate the immune response and prevent excessive inflammation.
Deficiencies or dysfunction in the C1-INH protein can lead to a group of genetic disorders known as C1 inhibitor deficiency disorders, which include hereditary angioedema (HAE) and acquired angioedema (AAE). These conditions are characterized by recurrent episodes of swelling in various parts of the body, such as the face, hands, feet, and airway, which can be painful and potentially life-threatening if they affect the airway.
Hereditary angioedema (HAE) is a rare genetic disorder that affects the body's immune system and causes recurring episodes of swelling (angioedema). The two most common types of HAE are Type I and Type II, which are caused by mutations in the SERPING1 gene.
Type I HAE: This is the most common form of HAE, accounting for about 85% of cases. In Type I HAE, there is a deficiency of C1 inhibitor (C1-INH), a protein that helps regulate the immune system and prevent inflammation. As a result, levels of bradykinin, a peptide that causes blood vessels to dilate and leads to swelling, are increased. This can cause episodes of swelling in various parts of the body, including the face, hands, feet, and airways.
Type II HAE: This form of HAE is less common than Type I, accounting for about 15% of cases. In Type II HAE, there are normal or even elevated levels of C1-INH in the blood, but the protein is dysfunctional and cannot properly regulate the immune system. This also leads to increased levels of bradykinin and episodes of angioedema.
Both types of HAE can be serious and potentially life-threatening if swelling occurs in the airways and obstructs breathing. Treatment typically involves medications that help control the production of bradykinin or block its effects, as well as measures to prevent and manage symptoms during an acute attack.
Complement C1 Inactivator proteins are a part of the complement system, which is a group of proteins in the blood that play a crucial role in the body's immune defense system. Specifically, Complement C1 Inactivator proteins are responsible for regulating the activation of the first component of the complement system, C1.
The complement system is activated in response to the presence of foreign substances such as bacteria or viruses in the body. The activation of C1 leads to a cascade of reactions that result in the destruction of the foreign substance. However, if this process is not properly regulated, it can lead to damage to the body's own cells and tissues.
Complement C1 Inactivator proteins help to prevent this by regulating the activation of C1. They do this by binding to and inhibiting the activity of C1, preventing it from initiating the complement cascade. A deficiency in Complement C1 Inactivator proteins can lead to a condition called hereditary angioedema, which is characterized by recurrent episodes of swelling in various parts of the body.
Factor XII, also known as Hageman factor, is a protein that plays a role in the coagulation cascade, which is the series of events that leads to the formation of a blood clot. It is one of the zymogens, or inactive precursor proteins, that becomes activated and helps to trigger the coagulation process.
When Factor XII comes into contact with negatively charged surfaces, such as damaged endothelial cells or artificial surfaces like those found on medical devices, it undergoes a conformational change and becomes activated. Activated Factor XII then activates other proteins in the coagulation cascade, including Factor XI, which ultimately leads to the formation of a fibrin clot.
Deficiencies in Factor XII are generally not associated with bleeding disorders, as the coagulation cascade can still proceed through other pathways. However, excessive activation of Factor XII has been implicated in certain thrombotic disorders, such as deep vein thrombosis and disseminated intravascular coagulation (DIC).
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