Impaired control of the contact system in hereditary angioedema with normal C1-inhibitor.

BACKGROUND: Hereditary angioedema (HAE) comprises HAE with C1-inhibitor deficiency (C1-INH-HAE) and HAE with normal C1-INH activity (nl-C1-INH-HAE), due to mutations in factor XII (FXII-HAE), plasminogen (PLG-HAE), angiopoietin 1 (ANGPT1-HAE), kininogen 1 genes (KNG1-HAE), or angioedema of unknown origin (U-HAE). The Italian network for C1-INH-HAE (ITACA) created a registry including different forms of angioedema without wheals. OBJECTIVE: We analyzed clinical and laboratory features of a cohort of Italian subjects with nl-C1-INH-HAE followed by ITACA to identify specific biomarkers. METHODS: A total of 105 nl-C1-INH-HAE patients were studied. Plasma concentrations of cleaved high-molecular-weight kininogen (cHK), vascular endothelial growth factors (VEGFs), angiopoietins (Angs), and secreted phospholipase A2 enzymes (sPLA2 ) were evaluated. RESULTS: We identified 43 FXII-HAE patients, 58 U-HAE, and 4 ANGPT1-HAE. We assessed a prevalence of 1:1.4 × 106 for FXII-HAE and 1:1.0 × 106 for U-HAE. cHK levels in U-HAE patients were similar to controls in plasma collected using protease inhibitors cocktail (PIC), but they significantly increased in the absence of PIC. In FXII-HAE patients, cHK levels, in the absence of PIC, were significantly higher than in controls. We found a significant increase of VEGF-A, VEGF-C, and Ang1 levels in U-HAE patients compared to controls. In FXII-HAE, only VEGF-C levels were increased. Ang2 concentrations and sPLA2 activity were not modified. The levels of these mediators in ANGPT1-HAE patients were not altered. CONCLUSIONS: Our results suggest that pathogenesis of FXII-, ANGPT1-, and U-HAE moves through an unbalanced control of kallikrein activity, with bradykinin as most likely mediator. VEGFs and Ang1 participate in the pathophysiology of U-HAE increasing the basal vascular permeability.

Pediatric angioedema: Essential features and preliminary results from the Hereditary Angioedema Global Registry in Italy.

Isolated angioedema, which is a localized, non-pitting, and transient swelling of the subcutaneous or submucosal tissue not associated with pruritus, urticaria, or anaphylaxis, may be classified, based on genetic pattern and mediators, respectively, as acquired or hereditary and histamine- or non-histamine-induced. The pediatric population with C1-INH-HAE (Hereditary angioedema due to C1-inhibitor deficiency) is mostly symptomatic. The frequency of symptoms in such a population compared to adults seems to be lower, but we need more prospective data to conclude on this point. The HGR (Hereditary angioedema global registry), which collects symptoms in real time, will probably provide such information. In terms of treatments, pediatric patients are significantly disadvantaged due to the few studies aimed at registering treatment for this population.

Hereditary and Acquired Angioedema: Heterogeneity of Pathogenesis and Clinical Phenotypes.

Recurrent angioedema (AE) without wheals is increasingly recognized as a clinical entity and a frequent cause of admission to the emergency room. The Hereditary Angioedema Working Group (HAWK) classification allowed the scientific community to go beyond the semantic confusion that dominated this topic for decades. This classification distinguishes hereditary and acquired forms of AE, either related or unrelated to C1 inhibitor deficiency. Recently, additional mechanisms have been involved in the AE pathogenesis, including the uncontrolled activation of factor XII, generation of vasoactive mediators that induce dysregulation of endothelial functions, and bidirectional interactions between mast cell-derived mediators and the plasma contact system. Thus, recurrent AE can be determined by multiple and concurrent mechanisms that may generate distinct clinical phenotypes of the disease. Frequency, severity, and the location of attacks are quite different from patient to patient and, even in the same patient, they may change throughout the course of life. The severity of the clinical phenotype strongly influences the burden of the disease and patients' quality of life. Despite major advances in our understanding of recurrent AE, many unsolved questions remain, leaving several unmet needs for patients and caregivers. This review is focused on a description of different AE phenotypes and the concurrent mechanisms leading to their pathogenesis. A better definition of cellular and molecular pathways responsible for the distinct AE phenotypes may help to improve diagnosis and may lead to a personalized approach to prophylaxis and treatment of the disease.

Risk of anaphylaxis in patients with large local reactions to hymenoptera stings: a retrospective and prospective study.

BACKGROUND: In the few studies available, the risk of developing systemic reactions (SR) to hymenoptera stings in patients with previous large local reactions (LLRs) to stings ranges from 0 to 7 %. We evaluated both retrospectively and prospectively the risk of SRs in patients with LLRs to stings. METHODS: An overall number of 477 patients, 396 with an SR as the first manifestation of allergy and 81 with a history of only LLRs after hymenoptera stings, were included in the study. All patients had clinical history and allergy testing (skin tests and/or specific IgE) indicative of allergy to venom of only one kind of Hymenoptera. Of the 81 patient with LLRs, 53 were followed-up for 3 years by annual control visits, while the 396 patients with SR were evaluated retrospectively. RESULTS: Among the 396 patients with an SR, only 17 (4.2 %) had had a previous LLR as debut of allergy, after an history of normal local reactions to Hymenoptera stings. All the 81 patients with a history of only LLRs had previously had at least two LLRs, with an overall number of 238 stings and no SR. Among the 53 patients who were prospectively evaluated we found that 31 of them (58.3 %) were restung by the same type of insect, with an overall number of 59 stings, presenting only LLRs and no SR. CONCLUSIONS: Our findings confirm that patients with repeated LLRs to stings had no risk of SR, while a single LLR does not exclude such risk. This has to be considered in the management of patients with LLRs.

Multicentric Observational Study on Safety and Tolerability of COVID-19 Vaccines in Patients with Angioedema with C1 Inhibitor Deficiency: Data from Italian Network on Hereditary and Acquired Angioedema (ITACA).

Angioedema due to C1 inhibitor deficiency (AE-C1-INH) is a rare disease characterized by recurrent and unpredictable attacks of angioedema. Multiple trigger factors, including trauma, emotional stress, infectious diseases, and drugs, could elicit angioedema attacks. The aim of this study was to collect data on the safety and tolerability of COVID-19 vaccines in a population of patients affected by AE-C1-INH. Adult patients with AE-C1-INH, followed by Reference Centers belonging to the Italian Network for Hereditary and Acquired Angioedema (ITACA), were enrolled in this study. Patients received nucleoside-modified mRNA vaccines and vaccines with adenovirus vectors. Data on acute attacks developed in the 72 h following COVID-19 vaccinations were collected. The frequency of attacks in the 6 months after the COVID-19 vaccination was compared with the rate of attacks registered in the 6 months before the first vaccination. Between December 2020 and June 2022, 208 patients (118 females) with AE-C1-INH received COVID-19 vaccines. A total of 529 doses of the COVID-19 vaccine were administered, and the majority of patients received mRNA vaccines. Forty-eight attacks of angioedema (9%) occurred within 72 h following COVID-19 vaccinations. About half of the attacks were abdominal. Attacks were successfully treated with on-demand therapy. No hospitalizations were registered. There was no increase in the monthly attack rate following the vaccination. The most common adverse reactions were pain at the site of injection and fever. Our results show that adult patients with angioedema due to C1 inhibitor deficiency can be safely vaccinated against SARS-CoV-2 in a controlled medical setting and should always have available on-demand therapies.

Gadolinium-Based Contrast Agents Hypersensitivity: A Case Series.

Gadolinium-based contrast agents (GBCAs) are considered to be safe, although sometimes patients report a hypersensitivity reaction when undergoing magnetic resonance imaging (MRI). The mechanisms of these reactions and of the sensitization to GBCAs are still largely unknown. We describe four cases of patients who experienced immediate adverse reactions to GBCAs with a demonstrated cutaneous hypersensitivity suggesting an IgE-mediated mechanism.

A nationwide survey of hereditary angioedema due to C1 inhibitor deficiency in Italy.

INTRODUCTION: Hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE type I) or dysfunction (C1-INH-HAE type II) is a rare disease characterized by recurrent episodes of edema with an estimated frequency of 1:50,000 in the global population without racial or gender differences. In this study we present the results of a nationwide survey of C1-INH-HAE patients referring to 17 Italian centers, the Italian network for C1-INH-HAE, ITACA. METHODS: Italian patients diagnosed with C1-INH-HAE from 1973 to 2013 were included in the study. Diagnosis of C1-INH-HAE was based on family and/or personal history of recurrent angioedema without urticaria and on antigenic and/or functional C1-INH deficiency. RESULTS: 983 patients (53% female) from 376 unrelated families were included in this survey. Since 1973, 63 (6%) patients diagnosed with C1-INH-HAE died and data from 3 patients were missing when analysis was performed. Accordingly, the minimum prevalence of HAE in Italy in 2013 is 920:59,394,000 inhabitants, equivalent to 1:64,935. Compared to the general population, patients are less represented in the early and late decades of life: men start reducing after the 5(th) decade and women after the 6(th). Median age of patients is 45 (IQ 28-57), median age at diagnosis is 26 years (IQ 13-41). C1-INH-HAE type 1 are 87%, with median age at diagnosis of 25 (13-40); type 2 are 13% with median age at diagnosis of 31 (IQ 16-49). Functional C1INH is ≤50% in 99% of patients. Antigen C1INH is ≤50% in 99% of type 1. C4 is ≤50% in 96% of patients. The chance of having C1-INH-HAE with C4 plasma levels >50% is < 0.05. CONCLUSION: This nationwide survey of C1-INH-HAE provides for Italy a prevalence of 1:64,935. C1-INH-HAE patients listed in our database have a shorter life expectancy than the general population. An increased awareness of the disease is needed to reduce this discrepancy. Measurement of C4 antigen can exclude diagnosis of C1-INH-HAE with an accuracy > 95%. This parameter should be therefore considered for initial screening in differential diagnosis of angioedema.

New insights on latex allergy diagnosis and treatment.

Because of widespread latex manufacturing in the last decades, exposure to latex has become ever greater, as has the incidence of latex allergy among the general population as well as the high-risk groups. Clinical manifestations range from local reactions (edema, itching, erythema, and papulae), rhino-conjunctivitis, asthma, pharyngeal edema, to severe systemic reactions such as anaphylactic shock (from parenteral exposure especially during medical examinations or surgical procedures). Diagnosis is formulated on the basis of the personal history and an accurate allergological evaluation. Patients usually have a history of food intolerance or adverse reactions during medical or surgical procedures, which are believed to be the result of anesthetics or other drugs. In vivo tests are prick and patch tests and challenge tests. Challenge tests (nasal, conjunctival, bronchial, intravaginal, sublingual, oral, and cutaneous tests) are important for confirming the diagnosis, for evaluating a patient's response to the different kinds of latex exposure, and for verifying the effects of desensitizing treatments on the various organs involved in latex allergy. The most important in vitro test is the specific anti-natural rubber latex IgE assay. The only effective resolution to the latex allergy problem seems to be desensitization. The criteria of effectiveness are the capability to use latex items, to undergo medical examinations (even invasive), and to remain in an environment where latex particles can be inhaled (such as surgical departments), without symptoms. The first attempts were performed by subcutaneous administration of latex, but this protocol seems to be delicate to perform because of the side effects. Two different alternative methods (percutaneous and sublingual) were successfully performed and proved to be safer and more effective, even though further studies on a larger group of patients are needed.

Chloramine-induced anaphylaxis while showering: a case report.

INTRODUCTION: Sodium-N-chlorine-p-toluene sulfonamide, commonly known as chloramine-T, is a derivative of chlorine which is widely used as a disinfectant. For many years, chloramine-T has been described as a cause of immediate-type hypersensitivity, especially with regard to asthma and rhinitis, and as a cause of occupational dermatoses in cleaning personnel in hospitals, although no anaphylactic reaction has yet been reported. Hence, to the best of our knowledge we present the first case of anaphylaxis to chloramine-T with evidence of specific immunoglobulin E antibodies. CASE PRESENTATION: We describe the case of a 25-year-old Caucasian woman who was in good health and with a negative history for atopy, including no respiratory symptoms of rhinitis or asthma, and with no professional exposure to chloramine-T. She, while showering, applied a chloramine-T solution to a skin area with folliculitis on her leg, and within a few minutes developed generalized urticaria and angioedema, followed by vomiting and collapse with loss of consciousness. A skin prick test with a chloramine-T solution at 10mg/mL concentration was positive, and specific immunoglobulin E to chloramine-T was quantified at a value of 2.9 optical density as measured by the enzyme allergosorbent test technique. CONCLUSION: The strict cause-effect relationship and the results of the skin test and the in vitro test make certain the causative role of chloramine-T in this case of anaphylaxis. This suggests that chloramine-T, based on its wide use as a disinfectant, should be considered a possible cause in anaphylaxis of unknown origin.

Allergy and psychologic evaluations of patients with multiple drug intolerance syndrome.

The multiple drug intolerance syndrome is a clinical entity characterized by adverse drug reactions to at least three drugs, chemically, pharmacologically and immunogenically unrelated, manifested upon three different occasions, and with negative allergy testing. Symptoms referred by the patients are often subjective, of neurovegetative origin. The aim of the study is to characterize patients suffering from the multiple drug intolerance syndrome from a psychological point of view, and to compare them to healthy subjects. We studied 30 women suffering from the multiple drug intolerance syndrome. All subjects underwent the following psychodiagnostic tests: (1) the State Trait Anxiety Inventory-Form Y, (2) the Zung Self-rating Anxiety Scale, (3) the Zung Self-rating Depression Scale, (4) the Quality of life enjoyment and satisfaction questionnaire, (5) the Minnesota Multiphasic Inventory-2, (6) the Toronto Alexithymia Scale. The study group was compared to 30 healthy women. When compared with the control group, our patients showed: a higher anxiety, a higher grade of depression, this difference was statistically significant (p < 0.01); a high difference (p < 0.01) between the two groups as regards somatic symptoms; a higher grade of alexithymia (p < 0.01); and a worse quality of life, in all the analyzed ambits. These findings clearly demonstrate the importance of psychological symptoms in patients with the multiple drug intolerance syndrome, and show that a complex allergy and psychological work-up is mandatory in the management of these patients.

'Empty sella syndrome': a case of a patient with sodium succinate hydrocortisone allergy.

OBJECTIVE: We present the case of a woman with 'empty sella syndrome' who experienced generalized urticaria after the administration of sodium succinate hydrocortisone in two episodes. METHODS: The patient underwent an allergological evaluation (prick, intradermal, and patch tests) with hydrocortisone sodium succinate, hydrocortisone acetate, hydrocortisone, hydrocortisone sodium phosphate, methylprednisolone hemisuccinate, methylprednisolone, and preservatives held in the formulation of sodium succinate hydrocortisone (sodium phosphate and methyl-p-oxybenzoate). The basophil activation test (BAT) was also performed with hydrocortisone. The single-blind i.m. challenge test was performed with hydrocortisone sodium phosphate in 4 days. RESULTS: Skin test with hydrocortisone sodium succinate and methylprednisolone hemisuccinate was positive. On the contrary, allergological tests performed with other formulations of the same steroids and preservatives were negative. These results showed an immediate-type allergy to succinate ester. BAT was not helpful to improve our diagnostic work-up because our patient was a 'nonresponder.' Therefore, the patient underwent successfully to a challenge test with hydrocortisone sodium phosphate. CONCLUSIONS: Patients with succinate ester allergy can tolerate alternative corticosteroids without ester.