Evolution of Guidelines for the Management of Hereditary Angioedema due to C1 Inhibitor Deficiency

Hereditary angioedema (HAE) is a severe and disabling condition characterized by recurrent episodes of subcutaneous or mucosal swelling in the skin and respiratory and gastrointestinal tracts. HAE due to C1-esterase inhibitor deficiency (C1-INH-HAE) is the most prevalent subtype. The present Iberian study compared C1-INH-HAE treatment guidelines published between 2010 and 2022 to identify the main differences in therapeutic approaches for on-demand treatment and short- and long-term prophylaxis (LTP). HAE guidelines evolved with the availability of new treatments and with a change in the management paradigm towards an individualized, patient-centered approach, where quality of life (QOL) is central. A parallel trend was observed towards increasingly frequent home-based treatment, which potentially facilitates timely interventions, provides greater flexibility and convenience, and is associated with increased QOL, enabling patients to lead more normal lives. Most innovations over the years were made for LTP, together with the advent of new therapies and awareness of patients' needs. Several prophylactic therapies with a high level of evidence became available, although formal head-to-head comparisons are lacking. The treatment goals became more ambitious, ranging from a reduction in the frequency, severity, and duration of attacks to achieving total disease control and normalization of patients' lives. The document also addresses relevant items such as changes in terminology (eg, the introduction of designations as "first-line") and the introduction of patient-reported outcome measures to assess patients' perceptions of their self-experienced QOL and well-being. Unmet needs in the management of C1-INH-HAE are identified.

Expert review and consensus on the t2t management of hereditary angioedema: from the scientific evidence to clinical practice

BACKGROUND

Hereditary angioedema with C1 inhibitor deficiency (HAE-C1INH) is a rare disease characterized by swelling episodes. It affects quality of life (QoL) and can be lethal, when involving upper airways. Treatment is individualized, with therapeutic options including on-demand treatment (ODT), and short- and long-term prophylaxis (STP, LTP). However, available guidelines are not always clear about treatment selection, its goals or assessment of goal achievement.

OBJECTIVE

To review the available evidence for the management of HAE-C1INH and build a Spanish expert consensus to steer HAE-C1INH management towards a treat-to-target (T2T) approach, while addressing some of the unclear aspects of the Spanish guidelines.

METHODS

We reviewed the literature on the management of HAE-C1INH with a T2T approach, focusing on: 1) treatment selection and goals; and 2) available tools to assess goal achievement. We discussed the literature based on clinical experience and drew up 45 statements on undefined management aspects. A panel of 53 HAE experts validated the statements through a two-round Delphi process.

RESULTS

The goals for ODT and STP are minimizing the morbidity and mortality of attacks, and preventing attacks caused by known triggers, respectively, while the main goal of LTP is to decrease the rate, severity and duration of attacks. Furthermore, when prescribing, clinicians should consider the reduction in adverse events, while increasing patient QoL and satisfaction. Appropriate instruments for assessing goal achievement have also been indicated.

CONCLUSIONS

We provide recommendations on previously unclear aspects of HAE-C1INH management with ODT, STP and LTP, focusing particularly on clinical and patient-oriented goals.

The Icatibant Outcome Survey: 10 years of experience with icatibant for patients with hereditary angioedema

In patients with hereditary angioedema (HAE), bradykinin causes swelling episodes by activating bradykinin B₂ receptors. Icatibant, a selective bradykinin B₂ receptor antagonist, is approved for on-demand treatment of HAE attacks. The Icatibant Outcome Survey (IOS; NCT01034969) is an ongoing observational registry initiated in 2009 to monitor effectiveness/safety of icatibant in routine clinical practice. As of March 2019, 549 patients with HAE type 1 or 2 from the IOS registry had been treated, for 5995 total attacks. This article reviews data published from IOS over time which have demonstrated that effectiveness of icatibant in a real-world setting is comparable to efficacy in clinical trials; one dose is effective for the majority of attacks; early treatment (facilitated by self-administration) leads to faster resolution and shorter attack duration; effectiveness/safety of icatibant has been shown across a broad range of patient subgroups, including children/adolescents and patients with HAE with normal C1 inhibitor levels; and tolerability has been demonstrated in patients aged ≥65 years. Additionally, this review highlights how IOS data have provided valuable insights into patients' diagnostic journeys and treatment behaviors across individual countries. Such findings have helped to inform clinical strategies and guidelines to optimize HAE management and limit disease burden. This research was sponsored by Takeda Development Center Americas, Inc. Takeda Development Center Americas, Inc., provided funding to Excel Medical Affairs for support in writing and editing this manuscript.

Variability of disease activity in patients with hereditary angioedema type 1/2: longitudinal data from the Icatibant Outcome Survey

BACKGROUND

Hereditary angioedema due to C1 inhibitor deficiency (HAE-1/2) is a chronic and debilitating disease. The unpredictable clinical course represents a significant patient burden.

OBJECTIVE

To analyse longitudinal registry data from the Icatibant Outcome Survey (IOS) in order to characterize temporal changes in disease activity in patients with HAE-1/2.

METHODS

Icatibant Outcome Survey (NCT01034969) is an international observational registry monitoring the clinical outcomes of patients eligible for icatibant treatment. The current analyses are based on data collected between July 2009 and July 2019. Retrospective data for attacks recorded in the 12 months prior to IOS enrolment and for each 12-month period up to 7 years were analysed.

RESULTS

Included patients reported angioedema attacks without long-term prophylaxis (LTP; n = 315) and with LTP (n = 292) use at the time of attack onset. Androgens were the most frequently used LTP option (80.8%). At the population level, regardless of LTP use, most patients (52-80%) reporting <5 attacks in Year 1 continued experiencing this rate; similarly, many patients (25-76%) who reported high attack frequency continued reporting ≥10 attacks/year. However, year on year, 31-51% of patients experienced notable changes (increase/decrease of ≥5 attacks) in annual attack frequency. Of patients who reported an absolute change of ≥10 attacks from Year 1 to 2, 17-50% continued to experience a change of this magnitude in subsequent years.

CONCLUSION

At the population level, attack frequency was generally consistent over 7 years. At the small group level, 28.8-34.5% of patients reported a change in attack frequency of ≥5 attacks from Year 1 to Year 2; up to half of these patients continued to experience this magnitude of variation in disease activity in later years, reflecting high intra-patient variability.

HAE-AS: A Specific Disease Activity Scale for Hereditary Angioedema With C1-Inhibitor Deficiency

BACKGROUND AND OBJECTIVE

The activity of hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE) varies between patients and within individual patients. Objective: This study aims to develop a disease activity scale for C1-INH-HAE (HAE-AS) with sound measurement properties.

METHODS

Eleven countries participated in a prospective multicenter cohort study. A clinical questionnaire was self-completed by 290 adult patients with C1-INH-HAE. Patients also completed 2 quality of life scales, the SF-36v2 and the HAE-QoL. Rasch analysis and classic psychometric methods were used to preselect a series of clinical items: number of attacks by location and number of treated attacks, emergency room visits, psychological/psychiatric treatment, missed school/workdays in the previous 6 months; general health; and impairment in everyday work/activities due to pain.

RESULTS

The mean (SD) age was 41.5 (14.7; range, 18-84) years, and 69% were females. The final 12-item Rasch model showed that the HAE-AS had satisfactory reliability (person separation index, 0.748), local item independence, unidimensionality, and no item bias by age or sex. The HAE-AS provided scores in a linear measure, with a mean of 10.66 (3.92; range, 0-30). Further analysis with classic psychometric methods indicated that the HAE-AS linear measure presented moderate-to-high convergent validity with quality of life scales (SF-36v2: physical component, r=-0.33; mental component, 0.555; HAE-QoL, -0.61), and good discriminative validity by age, sex, and disease severity (P<.05).

CONCLUSIONS

The HAE-AS is a short, valid, reliable, and psychometrically sound measure of the activity of C1-INH-HAE that could prove useful for research studies.

Thrombin in the Activation of the Fluid Contact Phase in Patients with Hereditary Angioedema Carrying the F12 P.Thr309Lys Variant

Hereditary angioedema due to pathogenic FXII variants (HAE-FXII) is a rare dominant disease caused by increased activation of the plasma contact system. The most prevalent HAE-FXII variant, c.1032C > A p.Thr309Lys (FXII^309Lys), results in a smaller FXII protein with increased sensitivity to fluid-phase activation by poorly understood mechanisms. We aimed to investigate the functionality of the FXII^309Lys variant in 33 HAE-FXII patients, 25 healthy controls and 46 patients with congenital disorders of glycosylation (CDG). Activation of the plasma contact system was assessed by western blot and amidolytic assay in basal conditions or after treatment with either artificial or physiological activators. Recombinant wild-type and FXII^309Lys variants were expressed in S2 insect (Drosophila) cells. Amidolytic and fibrin generation assays were performed in fresh plasma samples. FXII^309Lys samples exhibited an increased electrophoretic mobility comparable with N-glycan-deficient FXII from CDG patients and asialo-FXII generated by neuraminidase treatment. They presented increased sensitivity to activation by dextran sulphate and silica which resulted in the generation of an aberrant 37-kDa heavy chain. We did not observe increased susceptibility of FXII^309Lys to proteolysis by exogenous or tPA-generated plasmin. However, both exogenous and endogenous thrombin cleaved the FXII^309Lys variant, releasing a 37-kDa fragment and resulting in enhanced proteolytic activation on the fluid phase. This model supports a sequential proteolytic activation process involving thrombin priming of FXII^309Lys, followed by kallikrein cleavage and generation of active βFXIIa. The present results and the observation that angioedema episodes in HAE-FXII patients occur predominantly during hypercoagulable situations suggest a key role for thrombin.

Treatment of Hereditary Angioedema

Hereditary angioedema due to C1-esterase inhibitor deficiency (C1-INH-HAE) is a rare autosomal dominant disease. In the last decade, new drugs and new indications for old drugs have played a role in the management of C1-INH-HAE. This review examines current therapy for C1-INH-HAE and provides a brief summary of drugs that are under development. Increased knowledge of the pathophysiology of C1-INH-HAE has been crucial for advances in the field, with inhibition of the kallikrein-kinin system (plasma kallikrein, activated factor XII) as a key area in the discovery of new drugs, some of which are already marketed for treatment of C1-INH-HAE. Pharmacological treatment is based on 3 pillars: treatment of acute angioedema attacks (on-demand treatment), short-term (preprocedure) prophylaxis, and long-term prophylaxis. The 4 drugs that are currently available for the treatment of acute angioedema attacks (purified plasma-derived human C1 esterase inhibitor concentrate, icatibant acetate, ecallantide, recombinant human C1 esterase inhibitor) are all authorized for self-administration, except ecallantide. Purified plasma-derived human C1 esterase inhibitor concentrate is the treatment of choice for short-term prophylaxis. Tranexamic acid, danazol, intravenous and subcutaneous nanofiltered purified plasma-derived human C1 esterase inhibitor concentrate, and lanadelumab can be used for long-term prophylaxis. New drugs are being investigated, mainly as long-term prophylaxis, and are aimed at blocking the kallikrein-kinin system by means of antiprekallikrein, antikallikrein, and anti-activated FXII action.

Serum complexes between C1INH and C1INH autoantibodies for the diagnosis of acquired angioedema

Acquired angioedema due to C1-inhibitor (C1INH) deficiency (AAE) is caused by secondary C1INH deficiency leading to bradykinin-mediated angioedema episodes. AAE typically presents in adulthood and is associated with B cell lymphoproliferation. Anti-C1INH autoantibodies (antiC1INHAbs) are detectable in a subset of AAE cases and considered a hallmark of the disease. When free antiC1INHAbs and malignant tumors are not detectable, diagnosis relies on the finding of low C1INH levels and/or function, lack of family history and SERPING1 mutations, age at onset and low or undetectable C1q levels, none of which is specific for AAE. We tested the diagnostic value of a novel enzyme-linked immunosorbent assay (ELISA) for the detection of circulating complexes between C1INH and antiC1INHAbs (C1INH-antiC1INHAb) in the serum of 20 European AAE patients characterized on the basis of their complement levels and function. Free antiC1INHAbs were detected in nine of 20 patients [six of immunoglobulin (Ig)G class, two of IgM class and one simultaneously presenting IgG and IgM classes], whereas C1INH-antiC1INHAb complexes were found in 18 of 20 of the AAE cases, regardless of the presence or absence of detectable free anti-C1INHAbs. Of note, nine of 20 patients showed negative free antiC1INHabs, but positive C1INH-antiC1INHAb complexes in their first measurement. In the cohort presented, IgM-class C1INH-antiC1INHAb are specifically and strongly associated with low C1q serum levels. Detection of C1INH-antiC1-INHAbs provides an added value for AAE diagnosis, especially in those cases in whom no free anti-C1INH antibodies are detected. The link between IgM-class C1INH-antiC1INHAb complexes and C1q consumption could have further implications for the development of autoimmune manifestations in AAE.

Misdiagnosis trends in patients with hereditary angioedema from the real-world clinical setting

BACKGROUND

Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) causes swelling in the skin and upper airways and pain in the abdomen because of mucosal swelling. C1-INH-HAE is frequently misdiagnosed, leading to delays in diagnosis, inadequate treatment, and unnecessary procedures.

OBJECTIVE

To evaluate the history of misdiagnosis in patients participating in the Icatibant Outcome Survey (IOS).

METHODS

The IOS is an observational study in which safety and effectiveness of icatibant have been evaluated since 2009. As part of the IOS, patients record any misdiagnoses received before being diagnosed as having C1-INH-HAE.

RESULTS

In January 2016, a total of 418 of 633 IOS patients with C1-INH-HAE type I or II had provided misdiagnosis data. Of these, 185 of 418 (44.3%) received 1 or more prior misdiagnoses. The most common misdiagnoses were allergic angioedema (103 of 185) and appendicitis (50 of 185). A variety of other misdiagnoses were reported, including a substantial number of gastrointestinal disorders (excluding appendicitis). Misdiagnosis rates were similar between males (41.1%) and females (46.5%) and between C1-INH-HAE type I (43.7%) and type II (51.6%). Patients with family members diagnosed as having C1-INH-HAE were significantly less likely to be misdiagnosed than patients without a family history (140 of 366 [41.7%] vs 38 of 58 [65.5%], respectively; P = .001). Patients with a prior misdiagnosis had longer median delay to C1-INH-HAE diagnosis (13.3 years) than patients without (1.7 years; P < .001).

CONCLUSION

From this large database, approximately 50% of patients with C1-INH-HAE type I or II have previously had their conditions misdiagnosed, most commonly as allergic angioedema or appendicitis. Misdiagnosis results in marked delays in receiving the correct diagnosis, during which time patients cannot access effective, lifesaving treatment.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01034969.

Long-term safety of icatibant treatment of patients with angioedema in real-world clinical practice

The Icatibant Outcome Survey (IOS) is an observational study monitoring safety and effectiveness of icatibant in the real‐world setting. We analyzed safety data from 3025 icatibant‐treated attacks in 557 patients (enrolled between July 2009 and February 2015). Icatibant was generally well tolerated. Excluding off‐label use and pregnancy, 438 patients (78.6%) did not report adverse events (AEs). The remaining 119 (21.4%) patients reported 341 AEs, primarily gastrointestinal disorders (19.6%). Of these, 43 AEs in 17 patients (3.1%) were related to icatibant. Serious AEs (SAEs) occurred infrequently. A total of 143 SAEs occurred in 59 (10.6%) patients; only three events (drug inefficacy, gastritis, and reflux esophagitis) in two patients were considered related to icatibant. Notably, no SAEs related to icatibant occurred in patients with cardiovascular disease, nor in those using icatibant at a frequency above label guidelines. Additionally, no major differences were noted in AEs occurring in on‐label vs off‐label icatibant users.

The Icatibant Outcome Survey: experience of hereditary angioedema management from six European countries

BACKGROUND

Hereditary angioedema (HAE) due to C1-inhibitor deficiency (C1-INH-HAE) is a rare, potentially fatal, bradykinin-mediated disease. Icatibant is a bradykinin B2 receptor antagonist originally approved in 2008 in the European Union and 2011 in the United States as an acute therapy option for HAE attacks in adults.

OBJECTIVE

To compare demographics, disease characteristics and treatment outcomes of icatibant-treated HAE attacks in patients with C1-INH-HAE enrolled in the Icatibant Outcome Survey across six European countries: Austria, France, Germany, Italy, Spain and the UK.

METHODS

The Icatibant Outcome Survey [IOS; Shire, Zug, Switzerland (NCT01034969)] is an international observational study monitoring the safety and effectiveness of icatibant. Descriptive, retrospective analyses compared IOS country data derived during July 2009-April 2015.

RESULTS

Overall, 481 patients with C1-INH-HAE provided demographic data. A significant difference across countries in age at onset (P = 0.003) and baseline attack frequency (P < 0.001) was found although no significant differences were found with respect to gender (majority female; P = 0.109), age at diagnosis (P = 0.182) or delay in diagnosis (P = 0.059). Icatibant was used to treat 1893 attacks in 325 patients with majority self-administration in all countries. Overall, significant differences (all P < 0.001) were found across countries in time to treatment [median 1.8 h; median range: 0.0 (Germany-Austria) to 4.4 (France) h], time to resolution [median 6.5 h; median range: 3 (Germany-Austria) to 12 (France) h] and attack duration [median 10.5 h; median range: 3.1 (Germany-Austria) to 18.5 (France) h].

CONCLUSION

These data form the first European cross-country comparison of disease characteristics and icatibant use in patients with C1-INH-HAE who are enrolled in IOS. International variation in icatibant practice and treatment outcomes across the six European countries assessed highlight the need to further investigate the range of country-specific parameters driving regional variations in icatibant use.

Comparing acquired angioedema with hereditary angioedema (types I/II): findings from the Icatibant Outcome Survey

Icatibant is used to treat acute hereditary angioedema with C1 inhibitor deficiency types I/II (C1-INH-HAE types I/II) and has shown promise in angioedema due to acquired C1 inhibitor deficiency (C1-INH-AAE). Data from the Icatibant Outcome Survey (IOS) were analysed to evaluate the effectiveness of icatibant in the treatment of patients with C1-INH-AAE and compare disease characteristics with those with C1-INH-HAE types I/II. Key medical history (including prior occurrence of attacks) was recorded upon IOS enrolment. Thereafter, data were recorded retrospectively at approximately 6-month intervals during patient follow-up visits. In the icatibant-treated population, 16 patients with C1-INH-AAE had 287 attacks and 415 patients with C1-INH-HAE types I/II had 2245 attacks. Patients with C1-INH-AAE versus C1-INH-HAE types I/II were more often male (69 versus 42%; P = 0·035) and had a significantly later mean (95% confidence interval) age of symptom onset [57·9 (51·33-64·53) versus 14·0 (12·70-15·26) years]. Time from symptom onset to diagnosis was significantly shorter in patients with C1-INH-AAE versus C1-INH-HAE types I/II (mean 12·3 months versus 118·1 months; P = 0·006). Patients with C1-INH-AAE showed a trend for higher occurrence of attacks involving the face (35 versus 21% of attacks; P = 0·064). Overall, angioedema attacks were more severe in patients with C1-INH-HAE types I/II versus C1-INH-AAE (61 versus 40% of attacks were classified as severe to very severe; P < 0·001). Median total attack duration was 5·0 h and 9·0 h for patients with C1-INH-AAE versus C1-INH-HAE types I/II, respectively.

Clinical Pattern and Acute and Long-term Management of Hereditary Angioedema Due to C1-Esterase Inhibitor Deficiency

BACKGROUND

Hereditary angioedema due to C1-esterase inhibitor deficiency (HAE-C1-INH) is a life-threatening disease.

OBJECTIVES

To describe the clinical characteristics and management of patients with HAE-C1-INH during routine clinical practice.

METHODS

An observational, retrospective study was performed in patients with HAE-C1-INH. Demographic, clinical, and analytical data were collected from 2 periods: period A (October 2009-September 2010) and period B (October 2007-September 2009).

RESULTS

We studied 112 patients with HAE-C1-INH (57.1% females). Age at onset of symptoms was 14.4 years (lower in patients who had experienced attacks in the previous year). In period B (n=87), 62.1% of patients presented at least 1 edema attack (median, 3.5 attacks/patient/2 years), and 19.1% of attacks were treated. In period A (n=77), 58.4% of patients were on maintenance therapy. Stanozolol was the most widely used drug (48.9%), with a mean weekly dose of 6.7 mg. At least 1 attack was recorded in 72.7% of patients (median, 3.0 attacks/patient/year), and 31.5% of the attacks were treated. Treatment of acute attacks increased by 12.4%.

CONCLUSION

Age at onset of symptoms is associated with clinical expression of disease. The higher age at onset of symptoms, the fewer number of attacks per patient and year, and the lower dose of attenuated androgens necessary to control the disease than in other series lead us to hypothesize that HAE-C1-INH could have a less severe expression in Spain. Acute attacks seem to be treated increasingly often.

Hereditary angioedema with F12 mutation: factors modifying the clinical phenotype

BACKGROUND

Hereditary angioedema (HAE) with normal C1 inhibitor (C1Inh) associated with the c.983C>A and c.983C>G mutations of the F12 gene (FXII-HAE) is a rare condition, and presents with highly variable clinical expression. On the basis of data gathered from a large carrier cohort, we assessed the modifiers affecting the clinical phenotype.

METHODS

We analyzed clinical and biological data recorded from 118 mutation carriers (80 symptomatic and 38 asymptomatic), 58 noncarrier relatives from 40 families, and 200 healthy donors. Disease severity was scored in relation to frequency and location of edema, as well as age at disease onset. To predict FXII-HAE disease severity, we analyzed the biological phenotype [C1Inh, C4, spontaneous amidase, angiotensin-I-converting enzyme (ACE), aminopeptidase P (APP), and carboxypeptidase N/M (CPN)] by means of logistic regression (Akaike information criterion) and odds ratio (OR).

RESULTS

Meaningful variables contributed to FXII-HAE, with the kinin catabolism enzymes ACE and CPN exhibiting a significant inverse relationship with disease severity (OR = 0.36, 95% CI 0.23-0.59, P < 0.001; OR = 0.58, 95% CI 0.36-0.91, P < 0.05, respectively). CPN activities were 37.5 (28.5-41.3) nmol/ml/min and 38.5 (32.8-45.6) for FXII-HAE asymptomatic and symptomatic carriers, respectively, and 37.9 (30.5-43.7) nmol/ml/min for noncarriers. Angiotensin-I-converting enzyme activities were 58 (44-76) and 49 (35-59) nmol/ml/min for FXII-HAE asymptomatic and symptomatic carriers, respectively, and 56 (49-66) nmol/ml/min for noncarriers.

CONCLUSIONS

The FXII-HAE is associated with modifiers, for example kinin catabolism enzymes, ACE and CPN, different from those recognized in HAE with C1Inh deficiency.

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.

Open-label, multicenter study of self-administered icatibant for attacks of hereditary angioedema

BACKGROUND

Historically, treatment for hereditary angioedema (HAE) attacks has been administered by healthcare professionals (HCPs). Patient self-administration could reduce delays between symptom onset and treatment, and attack burden. The primary objective was to assess the safety of self-administered icatibant in patients with HAE type I or II. Secondary objectives included patient convenience and clinical efficacy of self-administration.

METHODS

In this phase IIIb, open-label, multicenter study, adult patients were trained to self-administer a single 30-mg icatibant subcutaneous injection to treat their next attack. Icatibant-naïve patients were treated by an HCP prior to self-administration. Evaluations included adverse event (AE) reporting, a validated questionnaire for convenience, and visual analog scale for efficacy.

RESULTS

A total of 151 patients were enrolled; 104 had an attack requiring treatment during the study, and 97 patients (19 naïve) were included in the self-administration cohort. Recurrence or worsening of HAE symptoms (22 of 97) was the most commonly reported AE; rescue medications including icatibant (N = 3) and C1-inhibitor concentrate (N = 6) were used in 13 cases. Overall, 89 of 97 patients used a single injection of icatibant. No serious AEs or hospitalizations were reported. Most patients (91.7%) found self-administration preferable to administration in the clinic. The median time to symptom relief (3.8 h) was comparable with results from controlled trials of icatibant.

CONCLUSIONS

With appropriate training, patients were successfully able to recognize HAE attacks and decide when to self-administer icatibant. This, coupled with the patient-reported high degree of satisfaction, convenience and ease of use supports the adoption of icatibant self-administration in clinical practice.

Piperacillin-induced DRESS: distinguishing features observed in a clinical and allergy study of 8 patients

BACKGROUND

DRESS (drug reaction with eosinophilia and systemic symptoms) syndrome is characterized by fever, rash, eosinophilia, and multiorgan failure. Previous reports have described differences in clinical and laboratory findings of DRESS syndrome depending on the inducing drug. Piperacillin has been reported as the drug responsible for this syndrome in 3 patients.

OBJECTIVE

To analyze and describe the clinical, laboratory, and allergy study findings of piperacillin-induced DRESS.

PATIENTS AND METHODS

Retrospective case series of patients diagnosed with DRESS associated with piperacillin-tazobactam (Pip/Taz) according to the Kardaun diagnostic score criteria. Assessment of causality was established using the Spanish Pharmacovigilance System and the lymphocyte transformation test (LTT). The allergy study included skin and epicutaneous tests.

RESULTS

Eight patients were diagnosed with DRESS due to Pip/Taz (3 probable and 5 definite cases). Skin rash was observed in all cases and facial edema in 50%; the mean latency period was 18 days. Fever was present in 7 patients. Liver and kidney injuries were detected in 6 and 3 patients, respectively. All patients had eosinophilia and a full recovery. The LTT to Pip/Taz was strongly positive in all patients, with a stimulation index of over 6. Three of 3 patients had a positive intradermal test to Pip/Taz, and 1 of 4 had a positive patch test. All patients had a negative LTT to carbapenems.

CONCLUSIONS

We have reported on the first case series of piperacillin-induced DRESS. A latency period of 18 days, skin rash, eosinophilia, fever, liver injury, and good prognosis were the most common features. The allergy study, and the LTT in particular, was highly useful for identifying Pip/Taz as the culprit drug and piperacillin as the responsible active ingredient.

Current status of implementation of self-administration training in various regions of Europe, Canada and the USA in the management of hereditary angioedema

Results from a 16-question survey about self-administration of hereditary angioedema (HAE) therapy, administered in Europe, Canada and the USA, were used to guide discussion at an international HAE expert meeting. The aim was to capture information about current practice in self-administered HAE therapy in these countries, including self-administration training, the key benefits of switching to self-administration, the barriers to self-administration and trends in self-administration. Overall, switching to self-administration therapy is looked upon favourably from both patient and clinician perspectives by virtue of the potential improvement in quality of life arising from optimisation of therapy and early intervention. The recent changes to product licences allowing self-administration provide additional options for the management of HAE.

Management of dental-oral procedures in patients with hereditary angioedema due to C1 inhibitor deficiency

BACKGROUND

Hereditary angioedema due to C1 inhibitor deficiency (HAE-C1-INH) has considerable implications for dental health care providers, since dental procedures may trigger severe and even life-threatening episodes. The aim of the present study was to analyze the efficacy and safety of premedication with attenuated androgens (AAs), plasma-derived human C1 esterase inhibitor concentrate (pdhC1INH), or both to prevent the development of upper airway angioedema after dental-oral procedures in patients with HAE-C1-INH.

MATERIAL AND METHODS

All dental-oral procedures performed on patients with HAE-C1-INH who were followed up at La Paz University Hospital, Madrid, Spain were reviewed. Demographic data, maintenance treatment, preprocedure prophylaxis, disease severity, and occurrence of upper airway angioedema were recorded.

RESULTS

Twenty-four patients (14 male/10 female; mean age, 42.6 years) underwent 66 procedures. Most procedures were performed on patients with severe HAE-C1-INH (20 procedures) or moderate HAE-C1-INH (26 procedures). Only 9 procedures were performed without short-term prophylaxis. Mild upper airway angioedema developed after 3 procedures performed without short-term prophylaxis in patients with minimal or asymptomatic HAE-C1-INH. A statistically significant association was found between development of mild postprocedure upper airway angioedema and lack of maintenance treatment with AA, lack of increased dose of preprocedure AA, and failure to administer preprocedure pdhC1INH (P = .002, Fisher exact test).

CONCLUSIONS

Increased doses of prophylactic AA, administration of pdhC1INH, or both were good options for ambulatory management of dental-oral procedures in patients with HAE-C1-INH. Prophylaxis with pdC1INH or increased doses of AA is advisable before dental-oral procedures, even in patients with low disease severity.

Angio-oedema due to hereditary C1 inhibitor deficiency in children

Hereditary angio-oedema due to C1 inhibitor deficiency (HAE-C1-INH) is a rare inherited disorder characterised by recurring and debilitating episodes of cutaneous swelling and abdominal pain and less frequent episodes of laryngeal oedema. Symptom onset is usually in childhood and early adolescence, with earlier disease onset associated with greater disease severity. Although HAE-C1-INH attacks are generally less frequent and less severe in children than in adults, they can cause significant physical and psychological impairment and affect advancement in school. There are often significant delays in the diagnosis of HAE-C1-INH due to its variable clinical presentation and because abdominal symptoms can often mimic other common paediatric gastrointestinal disorders. In recent years, several disease-specific agents have become available for the acute and prophylactic treatment of HAE-C1-INH. Although these treatments have not been evaluated rigorously in controlled clinical trials in children with HAE-C1-INH, paediatric data on efficacy and safety are available for some agents. Early diagnosis and initiation of appropriate therapy in children with HAE-C1-INH can help reduce the burden of this illness in the paediatric population.

Histological and immunohistochemical assessment of liver biopsies in morbidly obese patients

AIMS

To study liver lesions in morbidly obese patients who underwent liver biopsy at the time of bariatric surgery to define histological lesions, especially inflammatory infiltrate, diagnostic categories and the possible influence of gender in this respect.

METHODS AND RESULTS

110 biopsies (36 males-M- and 76 females -F-) were evaluated and categorised, according to the NAS (NAFLD -non alcoholic fatty liver disease- Activity Score) system and other criteria, as non-NAFLD (15.5%, F predominance), non-alcoholic steatohepatitis (NASH) (16.5%, M predominance), non-alcoholic hepatosteatosis (NAHS) (21%, F predominance) and, the most numerous group, NASH-borderline (NASH-BORD) (47%), with three subgroups, characterised by centrozonal lesions, portal area preferential involvement or affecting both areas. The predominant form of hepatocytesteatosis was mixed with a multivesicular component that was present in most cases with fibroinflammatory portal involvement. Nuclear glycogenosomes were found in greater number of biopsies in patients in the third and sixth decades. Portal inflammation was present in a large number of cases (M predominance); the application of immunohistochemical techniques (myeloperoxidase and CD68 antibodies) to evaluate lobular inflammation revealed "surgical hepatitis" in one third of the cases, and the presence of microgranulomas (CD68+) (M predominance), which were more abundant with increasing lesion severity.

CONCLUSIONS

Portal inflammation and multivesicular hepatocytesteatosis are highly prevalent in morbidly obese patients. This study identifies a new subtype of NASH-BORD characterized by centrizonal and porto-periportal area involvement and the existence of liver biopsies without steatosis. CD68+ microgranulomas constitute an unequivocal marker of lobular inflammation in surgical biopsies and of lesion severity, which is gender-related.

Evidence-based recommendations for the therapeutic management of angioedema owing to hereditary C1 inhibitor deficiency: consensus report of an International Working Group

Angioedema owing to hereditary deficiency of C1 inhibitor (HAE) is a rare, life-threatening, disabling disease. In the last 2 years, the results of well-designed and controlled trials with existing and new therapies for this condition have been published, and new treatments reached the market. Current guidelines for the treatment for HAE were released before the new trials and before the new treatments became available and were essentially based on observational studies and expert opinion. To provide evidence-based HAE treatment guidelines supported by the new studies, a conference was held in Gargnano del Garda, Italy, from September 26 to 29, 2010. The meeting hosted 58 experienced HAE expert physicians, representatives of pharmaceutical companies and representatives of HAE patients' associations. Here, we report the topics discussed during the meeting and evidence-based consensus about management approaches for HAE in adult/adolescent patients.