Danazol and stanozolol in long-term prophylactic treatment of hereditary angioedema

Treatment with 17 alpha-methyltestosterone and with some synthetic androgens prevents attacks of hereditary angioedema (HAE). However, the potential hepatotoxicity of 17 alpha-alkylated androgens raises the problem of long-term prophylactic use of these agents. Therefore we compared the efficacy in preventing HAE attacks of 17 alpha-alkylated steroids (danazol and stanozolol) with non-17 alpha-alkylated derivatives (quinbolone, nandrolone decanoate and mesterolone). As the latter group proved ineffective, it seems that a drug's efficacy in preventing HAE attacks is connected to its 17 alpha-alkylation. Moreover, our long-term observations with the minimum effective dose of danazol seem to indicate the absence of important collateral effects.     

Current and future therapy for hereditary angioedema

Hereditary angioedema (HAE) is an autosomal dominant disease characterized by recurrent episodes of potentially life-threatening angioedema. Attacks of angioedema in HAE patients typically last 3 or more days, begin during childhood, and continue to occur throughout life. Tragically, patients with HAE continue to die as a direct consequence of the disease. Minimizing the morbidity and mortality associated with HAE requires both effective treatment of acute attacks as well as strategies to prevent HAE attacks. While there is currently no effective therapy available in the United States for the treatment of acute attacks of HAE, several molecules have demonstrated impressive efficacy in this setting, and it is likely that one or more of these new drugs will become available in the United States soon. This article will review both the current and the future therapeutic options for the treatment of HAE.     

Hereditary angioedema due to C1 inhibitor deficiency: patient registry and approach to the prevalence in Spain.

BACKGROUND: Hereditary angioedema (HAE) is a rare disease caused by C1 inhibitor mutations. Although more than 100 mutations have been described, epidemiologic data are lacking; therefore, we developed a Spanish HAE patient registry. OBJECTIVE: To study the prevalence of HAE and the current state of diagnosis and treatment of this disease in Spain. METHODS: Epidemiologic data were obtained by direct contact with physicians who treat patients with HAE and with patients themselves. Diagnosis was evaluated by measuring C1 inhibitor levels and function, and most families also underwent genetic studies. RESULTS: We registered 444 patients (minimal prevalence, 1.09 per 100,000 inhabitants), many of whom are asymptomatic (never having symptoms) (n = 61, 13.7%). Most symptomatic patients (62.9%) receive long-term prophylaxis with attenuated androgens (80.9%) and antifibrinolytic agents (22.8%), alone or in combination, but no patients are receiving long-term prophylaxis with C1 inhibitor. There is a long delay in diagnosis (mean, 13.1 years). Nine patients underwent a tracheotomy as a consequence of a laryngeal attack, and 30 families recalled a total of 38 relatives who died of HAE, which underlines the severity of the illness. CONCLUSIONS: The detected minimal prevalence of HAE in Spain is 1.09 per 100,000 inhabitants. Because this is a rare disease and some patients may be misdiagnosed, this prevalence could be higher.     

Fresh frozen plasma for the treatment of hereditary angioedema.

BACKGROUND: Fresh frozen plasma (FFP) has been used as a treatment option for patients with hereditary angioedema (HAE) because it contains Cl esterase inhibitor, and alternate therapies are not yet available in the United States. However, because FFP also contains other substrates, it has been hypothesized to have the potential to worsen or precipitate an acute attack of HAE. OBJECTIVE: To research patient records and the medical literature to determine whether FFP can exacerbate symptoms or precipitate an attack of HAE. METHODS: The following keywords were searched in PubMed and OVID: hereditary angioedema, angioedema and fresh frozen plasma, angioedema and FFP, and hereditary angioneurotic edema. English-language articles were searched from 1966 to the present. Also, after institutional review board approval, the medical records of patients with HAE at our institution who have received FFP since 1990 were reviewed to determine if there was evidence that FFP exacerbated the symptoms of HAE. RESULTS: The English-language literature review and our patient medical record review failed to identify instances when FFP exacerbated symptoms of HAE or precipitated an attack. Several reports and our experience suggest that FFP is an effective prophylactic agent before surgery and for treatment of acute HAE attacks without evidence of exacerbation or initiation of symptoms. CONCLUSIONS: FFP seems to be safe and effective in preventing exacerbations of HAE before surgery and for acute exacerbations of HAE without evidence of it initiating an attack or worsening a preexisting attack.     

Benefits and risks of danazol in hereditary angioedema: a long-term survey of 118 patients.

BACKGROUND: Hereditary angioedema (HAE) due to C1 inhibitor deficiency is clinically characterized by relapsing skin swellings, abdominal pain attacks, and life-threatening upper airway obstruction. Treatment with androgens prevents attacks for those with this condition. OBJECTIVE: To examine the benefits and risks of long-term treatment with danazol. METHODS: Data were generated retrospectively from 118 German and Danish patients who had HAE due to C1 inhibitor deficiency and were treated with danazol from 2 months to 30 years. The frequency and severity of acute attacks were registered before and during danazol treatment, and adverse effects to the treatment were noted. Data were collected by using standardized questionnaires. RESULTS: In all, 111 of 118 patients responded to danazol. During treatment, 54 of the 118 patients (45.8%) became symptom free or had 1 attack or less per year. In the other patients, hereditary angioedema ran a mild course. The frequency of acute attacks during danazol treatment was reduced to 16.2%, and the attacks were considerably milder than before treatment. Laryngeal edema was reduced to 4.8%. Adverse effects (weight gain, virilization, menstrual irregularities, headache, depression, and/or liver adenomas) occurred in 93 of the 118 patients and led to discontinuation of danazol therapy in 30 patients. CONCLUSIONS: Danazol is highly beneficial in patients with frequent and severe attacks of HAE. Because the risk of adverse effects is high, close monitoring of patients is mandatory. However, many patients accept the adverse effects of prophylactic treatment to avoid the distressing and sometimes life-threatening attacks of this condition.     

Long-term prophylaxis with C1-inhibitor (C1 INH) concentrate in patients with recurrent angioedema caused by hereditary and acquired C1-inhibitor deficiency

A case of hereditary angioedema (HAE) type I (inherited C1-inhibitor [C1 INH] deficiency) and a case of late-onset acquired C1 INH with angioedema is described. In both patients, long-term prophylaxis with C1 INH had become necessary because treatment with danazol and epsilon-aminocaproic acid was not effective or not tolerated. Consequently, both patients received a pasteurized concentrate of C1 INH continuously for a period of 1 year in a dosage that kept them free of symptoms. The patient with HAE was administered 500 units of C1 INH intravenously every 4 or 5 days, whereas the patient with acquired angioedema required 1000 units of C1 INH every 5 days. As a result of this long-term prophylaxis, both patients became free or nearly free from their episodes of cutaneous and internal edema. The low plasma levels of C1 INH, C4, and C2, rose. In the patient with acquired C1 INH deficiency, the swellings increasingly reappeared after 10 months, although the patient's antibody titer did not rise during treatment. No side effects were recorded during therapy. In particular, both patients remained HIV and hepatitis B antibody negative.     

Critical role of kallikrein in hereditary angioedema pathogenesis: a clinical trial of ecallantide, a novel kallikrein inhibitor

BACKGROUND: Hereditary angioedema (HAE) is a rare, autosomal-dominant disorder caused by C1 inhibitor gene mutation. Patients with HAE experience intermittent attacks of edema affecting the oropharynx, abdomen, gastrointestinal tract, and limbs. C1 inhibitor is the primary endogenous inhibitor of the kallikrein-kinin (contact) cascade. Unregulated kallikrein activation generates bradykinin, the likely mediator of the swelling and pain characterizing HAE attacks. Ecallantide, a novel, recombinant protein, potently inhibits kallikrein. This is the first placebo-controlled assessment in human beings of a therapeutic intervention to improve symptoms of HAE attacks under the hypothesis that the contact cascade is the putative pathway responsible for HAE pathology. OBJECTIVE: To determine the safety and efficacy of ecallantide in patients with HAE. METHODS: This double-blind, placebo-controlled, ascending-dose study assessed efficacy and tolerability of ecallantide (5, 10, 20, or 40 mg/m(2) intravenously) in individuals experiencing acute HAE attacks (N = 49). Twelve patients were assigned to each dose level: 10 to ecallantide and 2 to placebo, per cohort. RESULTS: Ecallantide treatment ameliorated the symptoms of HAE attacks: 72.5% (29/40) of patients treated with ecallantide versus 25.0% (2/8) of placebo patients reported significant improvement in symptoms within 4 hours (P = .0169). Ecallantide was well tolerated at all doses. CONCLUSION: Ecallantide, a potent, specific inhibitor of plasma kallikrein, significantly improved HAE symptoms over placebo. The trial provides strong support for the role of the kallikrein-kinin cascade and its end product, bradykinin, in the pathophysiology of HAE. Further clinical trials are underway. CLINICAL IMPLICATIONS: Ecallantide is a promising new therapy for HAE attacks.     

Acute pancreatitis due to hereditary angioedema.

BACKGROUND: Hereditary angioedema (HAE) is an infrequent disorder characterized by abnormalities in the levels and/or function of complement C1 esterase inhibitor. Clinical manifestations of HAE are due to recurrent episodic swelling of the subcutaneous or submucosal tissue. When swelling involves the gastrointestinal mucosa, patients may present with nausea, vomiting, diarrhea, and severe abdominal pain. However, HAE is almost never suspected as a potential cause of acute pancreatitis. OBJECTIVE: To describe a patient with HAE-associated pancreatitis requiring intensive medical care that responded favorably to conservative and supportive measures. METHODS: Various tests were performed, including abdominal imaging, measurement of pancreatic enzymes levels, liver function tests, measurement of complement levels, and endoscopic retrograde cholangiopancreatography. RESULTS: The results of these tests confirmed the diagnosis of HAE-associated acute pancreatitis. No other obvious origin, such as gallstones or alcohol use, was identified. CONCLUSION: This case illustrates the need for a high clinical suspicion of acute pancreatitis when caring for patients with HAE who present with abdominal symptoms. There continues to be an urgent need for better and additional therapeutic options for HAE patients, including those to prevent and abort ongoing attacks.     

Hereditary angioedema: a decade of human C1-inhibitor concentrate therapy

BACKGROUND: C1-inhibitor (C1-INH) is a serine protease inhibitor regulating the complement, kinin-kallikrein, coagulation, and fibrinolytic systems. Hereditary angioedema (HAE) is caused by an inherited deficiency of C1-INH characterized by sudden, recurrent edematous swellings of the subcutaneous or submucosal tissues. The optional therapy for the acute management of HAE is administration of human C1-INH (hC1-INH) concentrate. However, hC1-INH is not available in many countries, in which case fresh frozen plasma is an alternative. OBJECTIVE: To summarize our experience with hC1-INH concentrate in patients with HAE. METHODS: Clinical and laboratory information on the effectiveness and safety of hC1-INH administered to relieve 468 acute edematous attacks in 61 patients with HAE was analyzed. RESULTS: Severe abdominal or subcutaneous attacks and laryngeal edema were consistently relieved by the administration of 500 U hC1-INH concentrate. Symptoms improved within 15 to 60 minutes of administration. Progression of the attacks was never observed, and there were no recurrent attacks within 72 hours. hC1-INH concentrate requirements did not change after repeated use. hC1-INH concentrate proved effective in the management of 94 attacks in 22 children and 6 attacks in 4 pregnant women. Adverse reactions, viral infections, and antibody formation against the purified protein did not occur. CONCLUSION: The administration of hC1-INH concentrate in HAE is highly effective and safe for the treatment of acute attacks and short-term prophylaxis and in pediatric patients and pregnant women. CLINICAL IMPLICATIONS: Human C1-INH concentrate is effective and safe for the treatment of acute HAE attacks as well as for short-term prophylaxis.     

Adrenalin treatment for hereditary angioneurotic edema.

In two patients studied with HAE the repeated use of 1.0 cc of 1:1000 epinephrine every hour for episodes threatening the upper airway resulted in both subjective and objective improvement of signs and symptoms in a manner we interpret as helpful. No harmful side effects have been encountered in these two young, otherwise healthy, people. Until a more definite therapy is found, we believe repeated high doses of adrenalin should be considered in young patients with HAE presenting with symptoms and signs of airway involvement.     

Recombinant human C1 esterase inhibitor for the treatment of hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE)

The lack of C1 inhibitor function that results in excessive production of bradykinin causing the angioedema seen in hereditary angioedema (HAE) is well established. Several drugs have been developed to treat and prevent attacks in patients suffering from HAE due to C1 inhibitor deficiency (C1-INH-HAE). Plasma-derived C1INH has been used to replace the deficiency of C1 inhibitor (C1INH) and has been approved for both treatment of attacks and for prophylactic therapy to prevent attacks. Plasma kallikrein inhibitor (ecallantide) and bradykinin receptor antagonist (icatibant) are both effective for treatment of acute attacks, but their short half-life limits the use for prophylaxis. Androgens, in particular danazol, are effective for long-term prophylaxis, but adverse event profile can limit its use. Recombinant C1 inhibitor derived from transgenic rabbits has recently been approved for use in treatment of C1-INH-HAE attacks and is effective and appears safe with minimal adverse event profile.     

Detection of C1 inhibitor mutations in patients with hereditary angioedema

BACKGROUND: Hereditary angioedema (HAE) results from a deficiency in the functional level of C1 inhibitor caused by mutations in the C1 inhibitor gene. The mutations responsible for HAE have been shown to be heterogeneous. OBJECTIVE: Because the identification of C1 inhibitor mutations may depend, in part, on the technique used to screen for mutations, we screened the entire C1 inhibitor coding region to identify mutations in a cohort of patients with HAE. METHODS: By using single-stranded conformational polymorphism analysis, 24 subjects with HAE from 16 different kindreds were screened for C1 inhibitor polymorphisms. C1 inhibitor mutations were identified by sequencing the exons containing identified polymorphisms. RESULTS: All 24 subjects with HAE had identifiable polymorphisms, involving exons 2, 3, 4, 5, or 8. Fourteen different C1 inhibitor mutations were identified: 8 missense, 1 nonsense, 4 frameshift, and 1 small deletion mutations. No large deletions or duplications were found. Nine of the 14 mutations represent newly recognized C1 inhibitor mutations, 6 of which involve exon 4. CONCLUSIONS: Single-stranded conformational polymorphism is an effective approach for identifying new mutations in HAE. Elucidation of the range of C1 inhibitor mutations causing HAE is important for both defining which residues are required for C1 inhibitor secretion or function and providing the basis for future studies to define the relationship between the C1 inhibitor genotype and disease severity.     

Hereditary angioedema: The use of fresh frozen plasma for prophylaxis in patients undergoing oral surgery

Six patients with hereditary anagioedema (HAE) undergoing 7 episodes of dental surgery received transfusions with fresh frozen plasma one day before surgery. Although the morbidity observed in these patients following similar procedures had been high, no significant complications of surgery were noted with this therapy. Thus, fresh frozen plasma infusion appears to provide a safe and effective method of prophylaxis in patients with HAE. Following infusion of fresh frozen plasma, serum levels of C4 esterase inhibitor (C1EI) rose transiently, and then fell to preinfusion levels within 1 to 12 days. In all but one patient the rise in C4 was greater than could be accounted for by the amount of C4 infused. In no patient did the level of C1EI or C4 rise to within the normal range. The data raise the question of the role of C1EI in the pathogenesis of angioedema in these patients.     

Recombinant C1-Inhibitor

Background

Recombinant human C1-inhibitor (rhC1INH; Ruconest?) has been developed for treatment of acute angioedema attacks in patients with hereditary angioedema (HAE) due to heterozygous deficiency of C1INH. Previous reports suggest that administration of plasma-derived C1INH products may be associated with an increased risk for thromboembolic complications.

Objectives

Our aim is to evaluate the effects of rhC1INH on coagulation and fibrinolysis in symptomatic HAE patients.

Methods

Levels of various coagulation and fibrinolytic parameters were determined in pre- and postexposure plasma samples from HAE patients included in a randomized clinical trial. Patients were treated with either saline, or 50 or 100 U/kg rhC1INH for an acute angioedema attack.

Results

Prior to rhC1INH treatment, the majority of patients had low to normal activated partial thromboplastin times (aPTT) and increased levels of prothrombin fragment 1+2, thrombin-antithrombin complexes, D-dimers and plasmin-antiplasmin complexes, all of which indicate activation of both coagulation and fibrinolysis. Infusion of rhC1INH at doses up to 100 U/kg did not affect these parameters except for a dose-dependent prolongation of aPTT, confirming that rhC1INH is an inhibitor of the contact system, and that F1+2 levels decreased.

Conclusion

Coagulation and fibrinolytic systems are activated in HAE patients suffering from an acute angioedema attack. Treatment with rhC1INH at 50 or 100 U/kg had no effect on parameters reflecting activation of these systems except for a significant effect on aPTT, which likely reflects a pharmacodynamic effect of rhC1INH, and a reduction on plasma levels of the prothrombin activation fragment F1+2. We conclude that these results argue against a prothrombotic effect of treatment with this rhC1INH product in HAE patients.     

Quality of life in patients with hereditary angioedema in Canada

BackgroundHereditary angioedema (HAE) is associated with decreased quality of life (QoL), which has typically been measured using a generic non–disease-specific questionnaire.ObjectiveWe aimed to assess the QoL in patients with HAE type I and II in Canada using a previously validated HAE-specific questionnaire.MethodsAn online questionnaire was sent to the members of two Canadian HAE patient groups to collect data on demographics, HAE clinical course, and QoL scores. All patients 18 years of age or older with HAE type I or II were eligible. The impact of the available clinical factors on the QoL scores was evaluated. Multiple linear regression was performed using clinically relevant factors to predict HAE QoL outcome.ResultsAmong the 72 patients in the study, the mean total HAE QoL score was 102 (±23) (SD) on a scale of 25 to 135, with higher scores indicating better QoL. Although the total QoL scores correlated positively with patients’ level of satisfaction and perceived control (P < .001 for both), it correlated negatively with the number of acute attacks (P = .03). Yet, the types of treatment did not have an impact on the QoL. Predictors, including sex, comorbidities, and the number of attacks, only explained 12% of the variance in the total QoL scores.ConclusionHAE continues to impair QoL in Canadian patients despite receiving recommended treatment. Although the frequency of attacks affects QoL, patients’ experience with their HAE care also affects QoL substantially. The study highlights the importance of considering patients’ experience with their HAE care as physicians develop an appropriate management plan.     

Hepatitis B surface antigen-1018 ISS adjuvant-containing vaccine: a review of HEPLISAV™ safety and efficacy

Immunization represents the most effective approach to the prevention of hepatitis B virus infection and the long-term complications of chronic disease, including liver cancer and liver failure. Current vaccines require three doses to achieve maximal immunogenicity and fail to produce long-lasting protection in 5-10% of immune-competent individuals and in a much larger proportion of immune-compromised patients. Immunostimulatory DNA sequence (ISS) vaccine adjuvants, when combined with vaccine antigens, may increase immunogenicity and reduce the number of required doses to achieve this goal. 1018 ISS plus recombinant hepatitis B surface antigen has been demonstrated to achieve these goals in immune competent and vaccine-hyporesponsive populations without compromising recipient safety.