C1-inhibitor deficiencies (hereditary angioedema): where are we with therapies?

Anesthetic Management of the Hypertensive Patient: Part I

Hypertension is an important health challenge that affects millions of people across the world and is a major risk factor for cardiovascular disease. It is critical that anesthesia providers have a working knowledge of the systemic implications of hypertension. This review article will discuss the medical definitions of hypertension, the physiology of maintaining blood pressure, outpatient treatment of hypertension, anesthetic implications, and the common medications used by anesthesia providers in the treatment of hypertension. Part I will provide an overview of hypertension and blood pressure regulation. In addition, drugs affecting predominantly renal control of hypertension, such as diuretics, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and renin-inhibiting agents, will be discussed. In part II, the remaining major antihypertensive medications will be reviewed as well as anesthetic implications of managing patients with hypertension.

Mucosal-dominant pemphigus vulgaris in a captopril-taking woman with angioedema

We describe a 39-year-old woman with an apparent captopril-induced, contact mucosal-dominant pemphigus vulgaris and angioedema, who took captopril during a bout of arterial hypertension. This exposure suggests that captopril and pathophysiology of angioedema stimulated the development of pemphigus vulgaris, which was diagnosed using the novel, indirect immunofluorescence BIOCHIP mosaic, with the modification to detect serum IgG4 autoantibodies. We discuss the patient, who experienced a chain of events leading to the active stage of pemphigus vulgaris, and review concepts of pemphigus vulgaris inducible by drugs and pathological immunity.

Brazilian guidelines for the diagnosis and treatment of hereditary angioedema

Hereditary angioedema is an autosomal dominant disease characterized by edema attacks with multiple organ involvement. It is caused by a quantitative or functional deficiency of the C1 inhibitor, which is a member of the serine protease inhibitor family. Hereditary angioedema is unknown to many health professionals and is therefore an underdiagnosed disease. The causes of death from hereditary angioedema include laryngeal edema with asphyxia. The estimated mortality rate in patients in whom the disease goes undetected and who are therefore incorrectly treated is 25-40%. In addition to edema of the glottis, hereditary angioedema often results in edema of the gastrointestinal tract, which can be incapacitating. Patients with hereditary angioedema may undergo unnecessary surgical interventions because the digestive tract can be the primary or only organ system involved, thus mimicking acute surgical abdomen. It is estimated that patients with hereditary angioedema experience some degree of disability 20-100 days per year. The Experts in Clinical Immunology and Allergy of the "Associação Brasileira de Alergia e Imunopatologia -ASBAI" developed these guidelines for the diagnosis, therapy, and management of hereditary angioedema.

Acute urticaria and angioedema: diagnostic and treatment considerations

Urticaria is defined as wheals consisting of three features: (i) central swelling of various sizes, with or without surrounding erythema; (ii) pruritus or occasional burning sensations; and (iii) the skin returning to normal appearance, usually within 1-24 hours. Angioedema is defined as: (i) abrupt swelling of the lower dermis and subcutis; (ii) occasional pain instead of pruritus; (iii) commonly involving the mucous membranes; and (iv) skin returning to normal appearance, usually within 72 hours. Acute urticaria and angioedema is defined by its duration (<6 weeks) compared with chronic urticaria and angioedema. The most common causes are infections, medications, and foods. The best tools in the evaluation of these patients are a comprehensive history and physical examination. There are a variety of skin conditions that may mimic acute urticaria and angioedema and the various reaction patterns associated with different drugs. Oral antihistamines are first-line treatment. In the event of a life-threatening reaction involving urticaria with angioedema, epinephrine may be needed to stabilize the patient. This review focuses on the value of a comprehensive clinical evaluation at the onset of symptoms. It underscores the importance of coordination of care among physicians, and the development of an action plan for evidence-based investigations, diagnosis, and therapy.

Clinical Immunology Review Series: An approach to the patient with angio-oedema

Angio-oedema is a common reason for attendance at the accident and emergency department and for referral to immunology/allergy clinics. Causative factors should always be sought, but a large proportion of patients have the idiopathic form of the disease. A minority of patients represent a diagnostic and treatment challenge. Failure to identify the more unusual causes of angio-oedema may result in life-threatening situations. Common and rare causes of angio-oedema will be discussed in this article, as well as the diagnostic and treatment pathways for the management of these patients. A comprehensive history and close monitoring of response to treatment are the most cost-effective diagnostic and treatment tools.

New treatments addressing the pathophysiology of hereditary angioedema

Hereditary angioedema is a serious medical condition caused by a deficiency of C1-inhibitor. The condition is the result of a defect in the gene controlling the synthesis of C1-inhibitor, which regulates the activity of a number of plasma cascade systems. Although the prevalence of hereditary angioedema is low – between 1:10,000 to 1:50,000 – the condition can result in considerable pain, debilitation, reduced quality of life, and even death in those afflicted. Hereditary angioedema presents clinically as cutaneous swelling of the extremities, face, genitals, and trunk, or painful swelling of the gastrointestinal mucosa. Angioedema of the upper airways is extremely serious and has resulted in death by asphyxiation.

Subnormal levels of C1-inhibitor are associated with the inappropriate activation of a number of pathways – including, in particular, the complement and contact systems, and to some extent, the fibrinolysis and coagulation systems.

Current findings indicate bradykinin, a product of contact system activation, as the primary mediator of angioedema in patients with C1-inhibitor deficiency. However, other systems may play a role in bradykinin's rapid and excessive generation by depleting available levels of C1-inhibitor.

There are currently no effective therapies in the United States to treat acute attacks of hereditary angioedema, and currently available agents used to treat hereditary angioedema prophylactically are suboptimal. Five new agents are, however, in Phase III development. Three of these agents replace C1-inhibitor, directly addressing the underlying cause of hereditary angioedema and re-establishing regulatory control of all pathways and proteases involved in its pathogenesis. These agents include a nano-filtered C1-inhibitor replacement therapy, a pasteurized C1-inhibitor, and a recombinant C1-inhibitor isolated from the milk of transgenic rabbits. All C1-inhibitors are being investigated for acute angioedema attacks; the nano-filtered C1-inhibitor is also being investigated for prophylaxis of attacks. The other two agents, a kallikrein inhibitor and a bradykinin receptor-2 antagonist, target contact system components that are mediators of vascular permeability. These mediators are formed by contact system activation as a result of C1-inhibitor consumption.