C1 inhibitor deficiency: 2014 United Kingdom consensus document

Prophylaxis in hereditary angioedema: a United Kingdom Delphi consensus

Hereditary angioedema (HAE) is a rare inherited disorder causing recurrent episodes of swelling that can be potentially life threatening. Treatment of HAE can be divided into on-demand treatment for swelling, and prophylaxis. The last UK consensus on HAE was in 2014 and since then, new medications for prophylaxis have been developed, with more drugs in the pipeline. International guidelines currently recommend the use of long-term prophylaxis (LTP) as the only way of achieving disease control and normalizing patient lives. Modern prophylactic medications are available in the UK, although access is restricted primarily by HAE attack frequency. To establish an updated view of UK clinicians and patients, a Delphi process was used to develop statements regarding LTP as well as other aspects of HAE management. There was consensus that UK access criteria for modern LTP agents based on numerical frequency of attacks alone are too simplistic and potentially disadvantage a cohort of patients who may benefit from LTP. Additionally, there was agreement that patients should be seen in expert centres, remote monitoring of patients is popular post-pandemic, and that the use of patient-reported outcome measures has the potential to improve patient care. Psychological health is an area in which patients may benefit, and recognition of this is important for future research and development.

A National Survey of Hereditary Angioedema and Acquired C1 Inhibitor Deficiency in the United Kingdom

BACKGROUND

Detailed demographic data on people with hereditary angioedema (HAE) and acquired C1 inhibitor deficiency in the United Kingdom are relatively limited. Better demographic data would be beneficial in planning service provision, identifying areas of improvement, and improving care.

OBJECTIVE

To obtain more accurate data on the demographics of HAE and acquired C1 inhibitor deficiency in the United Kingdom, including treatment modalities and services available to patients.

METHODS

A survey was distributed to all centers in the United Kingdom that look after patients with HAE and acquired C1 inhibitor deficiency to collect these data.

RESULTS

The survey identified 1152 patients with HAE-1/2 (58% female and 92% type 1), 22 patients with HAE with normal C1 inhibitor, and 91 patients with acquired C1 inhibitor deficiency. Data were provided by 37 centers across the United Kingdom. This gives a minimum prevalence of 1:59,000 for HAE-1/2 and 1:734,000 for acquired C1 inhibitor deficiency in the United Kingdom. A total of 45% of patients with HAE were on long-term prophylaxis (LTP) with the most used medication being danazol (55% of all patients on LTP). Eighty-two percent of patients with HAE had a home supply of acute treatment with C1 inhibitor or icatibant. A total of 45% of patients had a supply of icatibant and 56% had a supply of C1 inhibitor at home.

CONCLUSIONS

Data obtained from the survey provide useful information about the demographics and treatment modalities used in HAE and acquired C1 inhibitor deficiency in the United Kingdom. These data are useful for planning service provision and improving services for these patients.

Long-term Prophylaxis with Androgens in the management of Hereditary Angioedema (HAE) in emerging countries

Hereditary angioedema (HAE) is a rare autosomal dominant genetic disease characterized by repetitive subcutaneous or submucosal angioedema, activation of the kinin system, and increased vascular permeability. C1-inhibitor (C1-INH) deficiency, the main mechanism of HAE pathogenesis, occurs when abnormal activation of plasma kallikrein, bradykinin, and factor XII, or mutation of genes such as SERPING1 cause quantitative or functional C1-INH defects. Although androgens are not approved for HAE treatment in many countries, they are widely used in China and Brazil to reduce the frequency and severity of HAE attacks. The long-term adverse effects of androgen treatment are concerning for both physicians and patients. Virilization, weight gain, acne, hirsutism, liver damage, headache, myalgia, hematuria, menstrual disorders, diminished libido, arterial hypertension, dyslipidemia, and anxiety/depression are commonly observed during long-term treatment with androgens. These adverse effects can affect the quality of life of HAE patients and often lead to treatment interruption, especially in women and children. In-depth studies of the pathogenesis of HAE have led to the approval of alternative treatment strategies, including plasma-derived C1 inhibitor, recombinant human C1 inhibitor, plasma Kallikrein inhibitor (ecallantide; lanadelumab), and bradykinin B2 receptor antagonist (icatibant), some of which have achieved satisfactory results with mostly non-serious side effects. Therefore, a new standard of medical care may expand possibilities for the management of HAE in emerging countries.

Guidelines for management of hereditary angioedema: What is new? What is missing?

Background: Hereditary angioedema is an autosomal dominant disease that presents with recurrent episodic swelling of the submucosal and/or subcutaneous tissues of the cutaneous, gastrointestinal, and respiratory systems. Evaluation and treatment guidelines have been published nationally and internationally to aid the treating provider. Methods: A review of the most cited and most recent updated guidelines was undertaken to review key points and to explore real-world feasibility of incorporating them into clinical practice. The International World Allergy Organization/European Academy of Allergy and Clinical Immunology (WAO/EAACI) Guideline for the Management of Angioedema - The 2017 Revision and Update, and the consensus reports from the Hereditary Angioedema International Working Group, the Joint Task Force on Practice Parameters focused practice parameter update, and the most recently updated US HAEA Medical Advisory Board 2020 Guidelines for the Management of Hereditary Angioedema were reviewed and summarized. Results: Key points that have been consistent throughout the guidelines include recommendations for evaluation and classification of hereditary angioedema as well as evidence-based guidelines for treatment. Further attention is required on the evaluation and continuous assessment of the burden of illness and quality of life (QoL). Conclusion: The guidelines for management of hereditary angioedema provide a framework for the clinician. However, the physician-patient dialog with regard to the patient disease experience, which includes attack frequency, severity, and Qol, must be continually assessed.

Co-occurrence between C1 esterase inhibitor deficiency and autoimmune disease: a systematic literature review

Background

Hereditary angioedema (HAE) is caused by a SERPING1 gene defect resulting in decreased (Type I) or dysfunctional (Type II) C1 esterase inhibitor (C1-INH). The prevalence of autoimmune diseases (ADs) in patients with HAE appears to be higher than the general population. A systematic literature review was conducted to examine the co-occurrence between HAE and ADs.

Methods

PubMed/EMBASE were searched for English-language reviews, case reports, observational studies, retrospective studies, and randomized controlled trials up to 04/15/2018 (04/15/2015-04/15/2018 for EMBASE) that mentioned patients with HAE Type I or II and comorbid ADs. Non-human or in vitro studies and publications of C1-INH deficiency secondary to lymphoproliferative disorders or angiotensin-converting-enzyme inhibitors were excluded.

Results

Of the 2880 records screened, 76 met the eligibility criteria and 155 individual occurrences of co-occurring HAE and AD were mentioned. The most common ADs were systemic lupus erythematosus (30 mentions), thyroid disease (21 mentions), and glomerulonephritis (16 mentions). When ADs were grouped by MedDRA v21.0 High Level Terms, the most common were: Lupus Erythematosus and Associated Conditions, n = 52; Endocrine Autoimmune Disorders, n = 21; Gastrointestinal Inflammatory Conditions, n = 16; Glomerulonephritis and Nephrotic Syndrome, n = 16; Rheumatoid Arthritis and Associated Conditions, n = 11; Eye, Salivary Gland and Connective Tissue Disorders, n = 10; and Immune and Associated Conditions Not Elsewhere Classified, n = 5.

Conclusions

Based on literature reports, systemic lupus erythematosus is the most common AD co-occurring with HAE Type I and II. Cause and effect for co-occurring HAE and AD has not been clinically established but could be related to lack of sufficient C1-INH function.

Secretory proteostasis of the retinal pigmented epithelium: Impairment links to age-related macular degeneration

Secretory proteostasis integrates protein synthesis, processing, folding and trafficking pathways that are essential for efficient cellular secretion. For the retinal pigment epithelium (RPE), secretory proteostasis is of vital importance for the maintenance of the structural and functional integrity of apical (photoreceptors) and basal (Bruch's membrane/choroidal blood supply) sides of the environment it resides in. This integrity is achieved through functions governed by RPE secreted proteins, which include extracellular matrix modelling/remodelling, angiogenesis and immune response modulation. Impaired RPE secretory proteostasis affects not only the extracellular environment, but leads to intracellular protein aggregation and ER-stress with subsequent cell death. Ample recent evidence implicates dysregulated proteostasis as a key factor in the development of age-related macular degeneration (AMD), the leading cause of blindness in the developed world, and research aiming to characterise the roles of various proteins implicated in AMD-associated dysregulated proteostasis unveiled unexpected facets of the mechanisms involved in degenerative pathogenesis. This review analyses cellular processes unveiled by the study of the top 200 transcripts most abundantly expressed by the RPE/choroid in the light of the specialised secretory nature of the RPE. Functional roles of these proteins and the mechanisms of their impaired secretion, due to age and genetic-related causes, are analysed in relation to AMD development. Understanding the importance of RPE secretory proteostasis in relation to maintaining retinal health and how it becomes impaired in disease is of paramount importance for the development and assessment of future therapeutic advancements involving gene and cell therapies.

Biological therapy in hereditary angioedema: transformation of a rare disease

Introduction: Hereditary angioedema, a disabling condition, with high mortality when untreated, is caused by C1 inhibitor deficiency and other regulatory disorders of bradykinin production or metabolism. This review covers the remarkable progress made in biological therapies for this rare disorder.Areas covered: Over the past 10 years, several evidence-based parenteral treatments have been licensed, including two plasma-derived C1 inhibitor replacement therapies and one recombinant C1 inhibitor replacement for acute treatment of angioedema attacks and synthetic peptides for inhibition of kallikrein or bradykinin B2 receptors, with oral small molecule treatments currently in clinical trial. Moreover, recent advances in prophylaxis by subcutaneous C1 inhibitor to restore near-normal plasma function or by humanized antibody inhibition of kallikrein have resulted in freedom from symptoms for a high proportion of those treated.Expert opinion: This plethora of treatment possibilities has come about as a result of recent scientific advances. Collaboration between patient groups, basic and clinical scientists, physicians, nurses, and the pharmaceutical industry has underpinned this translation of basic science into treatments and protocols. These in their turn have brought huge improvements in prognosis, quality of life and economic productivity to patients, their families, and the societies in which they live.

Anaesthetic management of patients with pre-existing allergic conditions: a narrative review

This narrative review seeks to distinguish the clinical patterns of pre-existing allergic conditions from other confounding non-allergic clinical entities, and to identify the potential related risks and facilitate their perioperative management. Follow-up investigation should be performed after a perioperative immediate hypersensitivity to establish a diagnosis and provide advice for subsequent anaesthetics, the main risk factor for perioperative immunoglobulin E (IgE)-mediated anaphylaxis being a previous uninvestigated perioperative immediate hypersensitivity reaction. The concept of cross-reactivity between drugs used in the perioperative setting and food is often quoted, but usually not supported by evidence. There is no reason to avoid propofol in egg, soy, or peanut allergy. The allergenic determinants have been characterised for fish, shellfish, and povidone iodine, but remain unknown for iodinated contrast agents. Iodinated drugs may be used in seafood allergy. Evidence supporting the risk for protamine allergy in fish allergy and in neutral protamine Hagedorn insulin use is lacking. Conversely, cross-reactivity to gelatin-based colloid may occur in α-gal syndrome. Atopy and allergic asthma along with other non-allergic conditions, such as NSAID-exacerbated respiratory disease, chronic urticaria, mastocytosis, and hereditary or acquired angioedema, are not risk factors for IgE-mediated drug allergy, but there is a perioperative risk associated with the potential for exacerbation of the various conditions.

Treatment patterns and healthcare resource utilization among patients with hereditary angioedema in the United States

BACKGROUND

Real-world data on usage and associated outcomes with hereditary angioedema (HAE)-specific medications introduced to the United States (US) market since 2009 are very limited. The purpose of this retrospective study was to evaluate real-world treatment patterns of HAE-specific medications in the US and to assess their impact on healthcare resource utilization (HCRU). This analysis used IMS PharMetrics PlusTM database records (2006-2014) of patients with HAE, ≥1 insurance claim for an HAE-specific medication, and continuous insurance enrollment for ≥3 months following the first HAE prescription claim.

RESULTS

Of 631 total patients, 434 (68.8%) reported C1-INH(IV) use; 396 (62.8%) reported using ecallantide and/or icatibant. There were 306 episodes of prophylactic use of C1-INH(IV) (defined by continuous refills averaging ≥1500 IU/week for ≥13 weeks) in 155 patients; use of ≥1 on-demand rescue medication was implicated during 53% (163/306) of those episodes. Sixty-eight (20.2%) of 336 C1-INH(IV) users eligible for the HCRU analysis were hospitalized at least once, and 191 (56.8%) visited the emergency department (ED). Eighteen patients (5.4%) had a central venous access device (CVAD); of these, 5 (27.7%) required hospitalization and 14 (77.7%) had an ED visit. The adjusted relative risk of hospitalization and/or ED visits for patients with a CVAD was 2.6 (95% CI: 0.17, 39.23) compared to C1-INH(IV) users without a CVAD.

CONCLUSIONS

Despite widespread availability of modern HAE medications in the US, we identified a subset of patients requiring long-term prophylaxis who continue to be burdened by frequent rescue medication usage and/or complications related to the use of CVADs for intravenous HAE medication.

Real-world outcomes in hereditary angioedema: first experience from the Icatibant Outcome Survey in the United Kingdom

Background

Hereditary angioedema (HAE) is a potentially life-threatening, bradykinin-mediated disease, often misdiagnosed and under-treated, with long diagnostic delays. There are limited real-world data on best-practice management of HAE in the UK.

Objectives

To characterize the clinical profile, management and outcomes of patients with HAE type I and II from three specialist centres in the UK using data from the Icatibant Outcome Survey (IOS; Shire, Zug, Switzerland), an international observational study monitoring safety and effectiveness of icatibant, a selective bradykinin B2 receptor antagonist.

Methods

We performed retrospective analyses of IOS data for patients with HAE type I and II from three centres in the UK and compared UK data with pooled IOS data from 10 countries (48 centres).

Results

Analyses included 73 UK and 579 non-UK patients with HAE type I or II. Median diagnostic delay was 6.2 and 5.9 years, respectively. Analysis of data collected from February 2008 to July 2016 included 286 icatibant-treated attacks in 58 UK patients and 2553 icatibant-treated attacks in 436 non-UK patients (median of 3.0 attacks per patient in both groups). More attacks were treated by icatibant self-administration in UK patients (95.8%) than in non-UK patients (86.8%, p < 0.001). Time to icatibant treatment, time to resolution and attack duration were not significantly different in the UK versus non-UK patients.

Conclusion

UK patients from the specialist centres studied report similar diagnostic delay and similar icatibant treatment outcomes to their non-UK counterparts. However, improvements in the timely diagnosis of HAE are still required.

Trial registration ClinicalTrials.gov NCT01034969

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?

Optimum Use of Acute Treatments for Hereditary Angioedema: Evidence-Based Expert Consensus

Acute treatment of hereditary angioedema due to C1 inhibitor deficiency has become available in the last 10 years and has greatly improved patients’ quality of life. Two plasma-derived C1 inhibitors (Berinert and Cinryze), a recombinant C1 inhibitor (Ruconest/Conestat alpha), a kallikrein inhibitor (Ecallantide), and a bradykinin B2 receptor inhibitor (Icatibant) are all effective. Durably good response is maintained over repeated treatments and several years. All currently available prophylactic agents are associated with breakthrough attacks, therefore an acute treatment plan is essential for every patient. Experience has shown that higher doses of C1 inhibitor than previously recommended may be desirable, although only recombinant C1 inhibitor has been subject to full dose–response evaluation. Treatment of early symptoms of an attack, with any licensed therapy, results in milder symptoms, more rapid resolution and shorter duration of attack, compared with later treatment. All therapies have been shown to be well-tolerated, with low risk of serious adverse events. Plasma-derived C1 inhibitors have a reassuring safety record regarding lack of transmission of virus or other infection. Thrombosis has been reported in association with plasma-derived C1 inhibitor in some case series. Ruconest was associated with anaphylaxis in a single rabbit-allergic volunteer, but no further anaphylaxis has been reported in those not allergic to rabbits despite, in a few cases, prior IgE sensitization to rabbit or milk protein. Icatibant is associated with high incidence of local reactions but not with systemic effects. Ecallantide may cause anaphylactoid reactions and is given under supervision. For children and pregnant women, plasma-derived C1 inhibitor has the best evidence of safety and currently remains first-line treatment.

Use of a C1 Inhibitor Concentrate in Adults ≥65 Years of Age with Hereditary Angioedema: Findings from the International Berinert® (C1-INH) Registry

Background

Treatment of hereditary angioedema (HAE) in ‘older adults’ (those aged ≥65 years) has not been well studied. The international Berinert Patient Registry collected data on the use of intravenous plasma-derived, pasteurized, nanofiltered C1-inhibitor concentrate (pnfC1-INH; Berinert^®/CSL Behring) in patients of any age, including many older adults.

Methods

This observational registry, conducted from 2010 to 2014 at 30 US and seven European sites, gathered prospective (post-enrollment) and retrospective (pre-enrollment) usage and adverse event (AE) data on subjects treated with pnfC1-INH.

Results

The registry documented 1701 pnfC1-INH infusions in 27 older adults. A total of 1511 HAE attacks treated with pnfC1-INH administration were reported among 25 of the 27 (92.6 %) older adults. Among the older adults, mean (standard deviation [SD]) (8.8 [4.1] IU/kg) and median (6.4 IU/kg) pnfC1-INH doses were lower than those reported for 252 ‘younger adults’ (those aged <65 years: 12.9 [6.2], 12.5 IU/kg, respectively). A total of 19 AEs occurred in 8 of 23 (34.8 %) older adults with prospective data, for rates of 0.83 events per subject and 0.02 events per infusion, similar to corresponding rates in younger adults (0.91 and 0.03, respectively). None of the AEs were considered related to pnfC1-INH, and all but two events (prostatectomy, gastrointestinal bleeding) were mild or moderate in severity. Administration of pnfC1-INH outside of a healthcare setting was reported for 1609 infusions in 16 older adults, representing 94.6 % of all pnfC1-INH infusions in this age group. There were no recorded instances of difficulty with self-administration of intravenous pnfC1-INH.

Conclusions

These findings suggest a high degree of safety with intravenous pnfC1-INH use in older adults with HAE, regardless of administration setting.

Trial Registration Clinicaltrials.gov NCT01108848.

Breakthrough attacks in patients with hereditary angioedema receiving long-term prophylaxis are responsive to icatibant: findings from the Icatibant Outcome Survey

Background

Patients with hereditary angioedema (HAE) due to C1-inhibitor deficiency (C1-INH-HAE) experience recurrent attacks of cutaneous or submucosal edema that may be frequent and severe; prophylactic treatments can be prescribed to prevent attacks. However, despite the use of long-term prophylaxis (LTP), breakthrough attacks are known to occur. We used data from the Icatibant Outcome Survey (IOS) to evaluate the characteristics of breakthrough attacks and the effectiveness of icatibant as a treatment option.

Methods

Data on LTP use, attacks, and treatments were recorded. Attack characteristics, treatment characteristics, and outcomes (time to treatment, time to resolution, and duration of attack) were compared for attacks that occurred with versus without LTP.

Results

Data on 3228 icatibant-treated attacks from 448 patients with C1-INH-HAE were analyzed; 30.1% of attacks occurred while patients were using LTP. Attack rate, attack severity, and the distribution of attack sites were similar across all types of LTP used, and were comparable to the results found in patients who did not receive LTP. Attacks were successfully treated with icatibant; 82.5% of all breakthrough attacks were treated with a single icatibant injection without C1-INH rescue medication. Treatment outcomes were comparable for breakthrough attacks across all LTP types, and for attacks without LTP.

Conclusions

Patients who use LTP should be aware that breakthrough attacks can occur, and such attacks can be severe. Thus, patients with C1-INH-HAE using LTP should have emergency treatment readily available. Data from IOS show that icatibant is effective for the treatment of breakthrough attacks.

Trial Registration NCT01034969

Efficacy and safety of an intravenous C1-inhibitor concentrate for long-term prophylaxis in hereditary angioedema

BACKGROUND

The plasma-derived, pasteurized, nanofiltered C1-inhibitor concentrate (pnfC1-INH) is approved in the United States as an intravenous (IV) on-demand treatment for hereditary angioedema (HAE) attacks, and, in Europe, as on demand and short-term prophylaxis.

OBJECTIVE

This analysis evaluated Berinert Patient Registry data regarding IV pnfC1-INH used as long-term prophylaxis (LTP).

METHODS

The international registry (2010-2014) collected prospective and retrospective usage, dosing, and safety data on individuals who used pnfC1-INH for any reason.

RESULTS

The registry included data on 47 subjects (80.9% female subjects; mean age, 44.8 years), which reflected 4082 infusions categorized as LTP and a total of 430.2 months of LTP administration. The median absolute dose of pnfC1-INH given for LTP was 1000 IU (range, 500-3000 IU), with a median time interval between infusion and a subsequent pnfC1-INH-treated attack of 72.0 hours (range, 0.0-166.4 hours). Fifteen subjects (31.9%) had no pnfC1-INH-treated HAE attacks within 7 days after pnfC1-INH infusion for LTP; 32 subjects (68.1%) experienced 246 attacks, with rates of 0.06 attacks per infusion and 0.57 attacks per month. A total of 81 adverse events were reported in 16 subjects (34.0%) (0.02 events per infusion; 0.19 events per month); only 3 adverse events were considered related to pnfC1-INH (noncardiac chest pain, postinfusion headache, deep vein thrombosis in a subject with an IV port).

CONCLUSION

In this international registry, IV pnf-C1-INH given as LTP for HAE was safe and efficacious, with a low rate of attacks that required pnfC1-INH treatment, particularly within the first several days after LTP administration.

The Humanistic, Societal, and Pharmaco-economic Burden of Angioedema

Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a rare disorder characterized by intermittent and unpredictable episodes of swelling which cause disfigurement, disability, pain, or, in case of laryngeal swelling, risk of death. Historical factors, including the intermittent nature of the disorder, the lack of awareness of this ultra-rare condition amongst medical personnel, lack of specialist centers, and limited treatment options have contributed to under-diagnosis and under-treatment of the condition. Incorrect treatment of attacks has been common, even when medical help is sought. This has lead to reduced health-seeking behavior and alternative coping strategies, sometimes even denial, in many families, while a minority of HAE-affected patients have become serial emergency room attenders with chronic pain and ongoing requirement for opiate-based painkillers. Both strategies have incurred not only physical but also psychological and economic consequences.In the last 10 years, new and effective acute therapies have been made available, some of which have also provided short-term and long-term prophylaxis options, together with a better understanding of older prophylactic drugs. Improved awareness of HAE amongst the general public, family members, and physicians has reduced the long delay in diagnosis and increased the number of patients receiving effective and up-to-date therapies to improve the physical impact of the disorder.Data on the impact of treatment on the psychological outcomes is scarce, but the limited information available suggests that access to specialist advice and treatment leads to psychological as well as physical improvement.HAE also has profound effects on individual and family economic output, directly via absenteeism from school or work and indirectly via lost opportunities. Economic improvements associated with better treatments are offset by the high cost of new acute treatments, resulting in difficult pharmaco-economic calculations. Worldwide, cost considerations present potentially insurmountable barriers to treatment for many patients, depending on the healthcare system in the individual country.

Hereditary Angioedema: a Challenging Diagnosis for the Gastroenterologist

Hereditary angioedema (HAE) caused by a deficiency of C1 esterase inhibitor enzyme (C1-INH) is a very rare, autosomal dominantly inherited genetic disorder, characterized by recurrent peripheral angioedema, painful abdominal attacks and episodes of laryngeal edema. Abdominal attacks are frequent symptoms in adult HAE patients, occurring in more than 90% of the cases. Angioedema in the bowel or abdomen can occur in the absence of cutaneous manifestations and may be easily misdiagnosed unless the clinician has a high degree of awareness to include HAE in the differential diagnosis. Misdiagnosis is associated with inadequate treatments, including unnecessary surgical procedures. Any patient who presents recurrent episodes of swelling should be evaluated for HAE caused by C1-INH deficiency. New therapies could save lives and dramatically improve their quality of life.

Managing the female patient with hereditary angioedema

Hereditary angioedema (HAE) is a rare disorder resulting from decreased functional levels of C1-inhibitor (C1-INH), which manifests as periodic episodes of localized edema which can be extremely painful, debilitating and even fatal if the swelling affects the larynx. HAE can complicate many aspects of obstetric/gynecologic care, and an awareness of the disease is critical for clinicians involved in the care of women because of potential HAE-related complications pertaining to pregnancy, labor and delivery, and other women's health issues. This article provides a review of published literature specific to HAE and its management in female patients, including important concerns regarding obstetric/gynecologic care. A growing body of relevant experience is presented to help guide the care of women with HAE.

Overview of Laboratory Testing and Clinical Presentations of Complement Deficiencies and Dysregulation

Historically, complement disorders have been attributed to immunodeficiency associated with severe or frequent infection. More recently, however, complement has been recognized for its role in inflammation, autoimmune disorders, and vision loss. This paradigm shift requires a fundamental change in how complement testing is performed and interpreted. Here, we provide an overview of the complement pathways and summarize recent literature related to hereditary and acquired angioedema, infectious diseases, autoimmunity, and age-related macular degeneration. The impact of complement dysregulation in atypical hemolytic uremic syndrome, paroxysmal nocturnal hemoglobinuria, and C3 glomerulopathies is also described. The advent of therapeutics such as eculizumab and other complement inhibitors has driven the need to more fully understand complement to facilitate diagnosis and monitoring. In this report, we review analytical methods and discuss challenges for the clinical laboratory in measuring this complex biochemical system.

Optimizing hereditary angioedema management through tailored treatment approaches

Hereditary angioedema (HAE) is a rare but serious and potentially life threatening autosomal dominant condition caused by low or dysfunctional C1 esterase inhibitor (C1-INH) or uncontrolled contact pathway activation. Symptoms are characterized by spontaneous, recurrent attacks of subcutaneous or submucosal swellings typically involving the face, tongue, larynx, extremities, genitalia or bowel. The prevalence of HAE is estimated to be 1:50,000 without known racial differences. It causes psychological stress as well as significant socioeconomic burden. Early treatment and prevention of attacks are associated with better patient outcome and lower socioeconomic burden. New treatments and a better evidence base for management are emerging which, together with a move from hospital-centered to patient-centered care, will enable individualized, tailored treatment approaches.