Health-related quality of life among children with hereditary angioedema.

BACKGROUND: The clinical expressions of hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE) and its related burden may negatively affect patient quality of life. This study aimed to assess health-related quality of life (HRQoL) in children with C1-INH-HAE. METHODS: Children (N = 98: 34 C1-INH-HAE patients, 64 healthy controls) aged 3-18 years were recruited in Israel and Hungary. All individuals completed a demographic questionnaire, a disease activity and site questionnaire, and the Pediatric Quality of Life Inventory (PedsQL™) 4.0 Generic Core Scales (child self-report and maternal proxy report) to assess HRQoL. RESULTS: Among C1-INH-HAE patients, nine (26.5%) had 1-5 attacks/year, six (17.6%) had 6-18 attacks/year, eight (23.5%) had 25-60 attacks/year, and 11 (32.4%) were asymptomatic over the previous year. Children with C1-INH-HAE attacks demonstrated lower HRQoL than healthy control children across the total score, school, and psychosocial dimensions of the PedsQL™. The number of C1-INH-HAE attacks negatively correlated with the total HRQoL score (r = -0.48, p = 0.008), school-related HRQoL (r = -0.39, p = 0.02), and psychosocial HRQoL (r = -0.43, p = 0.01). Patients with multisite laryngeal, abdominal, and peripheral C1-INH-HAE attacks had a lower HRQoL compared with those who experienced solely peripheral attacks across the total score (p = 0.04), physical (p = 0.04), and school (p = 0.02) domains. There was no significant difference between asymptomatic C1-INH-HAE patients and healthy controls. CONCLUSIONS: Children with symptomatic C1-INH-HAE demonstrate impaired HRQoL compared with healthy controls. HRQoL was affected by the frequency and site of C1-INH-HAE attacks and mostly in the school and physical domains.

The relationship between anxiety and quality of life in children with hereditary angioedema.

BACKGROUND: The severe life-threatening characteristics of hereditary angioedema (HAE) with C1-inhibitor deficiency (C1-INH-HAE) can affect anxiety levels among pediatric patients. This emotional burden together with the physical restrictions of C1-INH-HAE may decrease children's health-related quality of life (HRQoL). OBJECTIVES: (i) To compare anxiety state and trait between children with C1-INH-HAE and healthy controls; (ii) to examine the relationship between the level of anxiety of children with C1-INH-HAE, their disease activity/affected sites and their HRQoL; and (iii) to predict the HRQoL of children with C1-INH-HAE based on their anxiety level and disease activity/affected sites METHODS: Thirty-three children with C1-INH-HAE (aged 5-18 years) and 52 healthy controls were recruited from Israel and Hungary. All children completed the State-Trait Anxiety Inventory for Children (STAIC), the Pediatric Quality of Life Inventory (Peds-QL) demographic questionnaire and a disease activity and site questionnaire . Disease activity was defined as the number of attacks in last year. RESULTS: Both anxiety state and trait were significantly higher among children with C1-INH-HAE as compared to the controls (44.74±10.56 vs 38.76±10.67, P<.01, 29.21±5.16 vs 25.23±4.09, P<.001 in comparison). Significant differences were found between C1-INH-HAE patients with HAE attacks, asymptomatic C1-INH-HAE patients, and healthy controls in both anxiety state (F56,2 =4.69, P=.001) and trait (F56,2 =9.06, P<.0001). A higher anxiety trait was correlated with the number of angioedema-affected sites (r=.52, P=.003). The presence of HAE attacks and higher anxiety trait predicted a lower HRQoL in children with C1-INH-HAE. CONCLUSIONS: C1-INH-HAE children have higher anxiety trait and state, which correlate with reduced HRQoL domains.

[Effect of danazol treatment on growth in pediatric patients with hereditary angioedema due to C1-inhibitor deficiency]. / A danazolkezelés hatása C1-inhibitor-hiány okozta hereditaer angiooedemás gyermekek növekedésére.

INTRODUCTION: Attenuated androgens are used for the prevention of angioedema attacks of hereditary angioedema with C1-inhibitor deficiency. After prepuberty, their use can lead to growth retardation. AIM: We assessed the effect of danazol on the growth of pediatric patients with hereditary angioedema. METHOD: In the retrospective study on 42 patients diagnosed with hereditary angioedema, we calculated the deviation from the mid-parental target height, and analyzed it against the gender, the dose and duration of danazol treatment administered before the age of 21 years and before the age of 16 years. RESULTS: Regarding the deviation from the mid-parental target height, we did not find any significant difference between patients taking vs. not taking danazol, males vs. females taking danazol. The dose and the duration of danazol treatment did not influence that value neither before 21, nor before 16 years of age. CONCLUSIONS: Our findings suggest that treatment with the lowest effective doses of danazol does not influence growth. Orv Hetil. 2017; 158(32): 1269-1276.

Thyroid hormones and complement parameters in hereditary angioedema with C1-inhibitor deficiency.

BACKGROUND: Thyroid hormones control and up-regulate the synthesis of many plasma proteins. OBJECTIVE: To explore possible associations between thyroid hormone and complement levels in patients with hereditary angioedema resulting from the deficiency of the C1-inhibitor (C1-INH-HAE). METHODS: In this case-control study, serum thyrotropin, free triiodothyronine (FT3), and free thyroxine (FT4) levels, anti-thyroid peroxidase and antithyroglobulin antibody titers, and C1-INH concentrations were measured in 117 euthyroid patients with C1-INH-HAE and compared with their clinical properties. The control group comprised 150 healthy, age- and sex-matched, euthyroid individuals. RESULTS: The thyrotropin and antithyroglobulin levels were similar between the patients and the controls. Significantly lower FT3 (P < .001) and FT4 (P = .002) levels, as well as higher anti-thyroid peroxidase titers (P < .001), were seen in the patients with C1-INH-HAE. The proportion of patients with reduced C1-INH activity was greater among those with below-median FT4 levels than among those with above-median values (P = .02). Patients who experienced more edematous attacks per year had lower FT4 levels (within the normal range) than those afflicted by fewer episodes (P = .01). The FT3 and FT4 levels were significantly higher in patients undergoing long-term danazol therapy than in those who did not receive this drug (P = .01 and P = .02, respectively). The proportion of patients with FT4 levels in the below-median range was higher in the subset with increased d-dimer concentration (P = .009). CONCLUSION: Minor variations of the thyroid hormone levels (within the reference range) can influence the function of C1-INH in C1-INH-HAE. Our findings suggest a role for the endocrine system in the pathophysiology of C1-INH-HAE.

Risk of thromboembolism in patients with hereditary angioedema treated with plasma-derived C1-inhibitor.

BACKGROUND: Plasma-derived C1-inhibitor (C1-INH) concentrates (pdC1-INH) have been used as safe and effective treatments for hereditary angioedema with C1-INH deficiency (C1-INH-HAE) for >30 years. Notwithstanding this, sporadic reports and a study into the high-dose therapy of neonates with C1-INH concentrate administered in an off-label indication raised concerns that this drug might increase the risk of thromboembolism. OBJECTIVE: To investigate the incidence of thromboembolism and the background of the risk factors related to treatment with pdC1-INH. METHODS: Our retrospective cohort study of 144 patients with C1-INH-HAE compared the incidence of thromboembolism and its risk factors in patients who received pdC1-INH with those who did not receive pdC1-INH as well as with those treated with danazol or with tranexamic acid. RESULTS: During the observation period (29 years), 104 of the 144 subjects received pdC1-INH. The average dose per treatment was 573.59 IU. None of the patients used an indwelling central venous catheter. Multiple risk factors for thromboembolism were identified in 93 of the 104 patients treated with pdC1-INH. The incidence rate of thromboembolism was 0.0019/100 person-years in patients treated with pdC1-INH, whereas it was 0.0211/100 person-years in the not-treated group. CONCLUSION: Our cohort study did not find any evidence for an increased risk of thromboembolism during treatment with pdC1-INH, despite the presence of multiple predisposing factors.

First report of icatibant treatment in a pregnant patient with hereditary angioedema.

Hereditary angioedema resulting from C1-inhibitor deficiency (C1-INH-HAE) is a rare, autosomal dominant disorder, characterized by recurrent attacks of edema formation. The management of pregnant patients with C1-INH-HAE is often a challenge for the physician. There is limited experience with novel therapies. Plasma-derived nanofiltered C1-INH (pnfC1-INH) is the only recommended therapeutic option during pregnancy. In our 26-year-old female patient with type II C1-INH-HAE, pregnancy was confirmed in the sixth week of gestation. During this period, the patient received the bradykinin B2-receptor antagonist, icatibant, on five occasions, as acute treatment. She experienced 119 attacks, for which she received 108 vials of pnfC1-INH during her pregnancy. The patient gave birth to a healthy baby. No side effects were detected with either treatment. No reports have been published to date on multiple dosing with icatibant during the first trimester of pregnancy. This therapy proved effective and free of maternal or fetal adverse effects.

Home treatment of attacks with conestat alfa in hereditary angioedema due to C1-inhibitor deficiency.

Conestat alfa, a recombinant human C1 inhibitor (rhC1-INH) is a novel therapeutic option for the acute treatment of hereditary angioedema due to C1-INH (HAE-C1-INH) deficiency. Our aim was to investigate the efficacy and safety profile of conestat alfa in patients with HAE-C1-INH, under real-life conditions. We analyzed 65 edematous episodes requiring acute treatment and occurring in two female HAE-C1-INH patients. The patients were treated at home with rhC1-INH per occasion. They recorded the time of rhC1-INH administration, the time to the onset of improvement, and time to the complete resolution of symptoms, as well as the side effects. Symptom severity and patient satisfaction were measured with a visual analog scale (VAS). Thirty-three HAE attacks occurred in submucosal tissue, 17 in subcutaneous tissue, and 15 had mixed locations. After the administration of rhC1-INH, clinical symptoms improved within 0.50 (0.17-4.50 hours) hours and resolved completely within 9.00 (1.67-58.75 hours) hours. The time between the onset of the attack and the administration of rhC1-INH was correlated with the time when the symptoms stopped worsening (R = 0.3212; p = 0.0096) and the time to complete resolution of the symptoms (R = 0.4774; p < 0.0001). The time to response to the drug differed with attack location. The efficacy and safety of rhC1-INH persisted after repeated use. None of the patients experienced a recurrence of the HAE attack or drug-related systemic adverse events. The mean VAS score of patient satisfaction was 93.14. Home treatment with rhC1-INH was an effective and well-tolerated therapy for all types of HAE attacks.

Pathways of Neutrophil Granulocyte Activation in Hereditary Angioedema with C1 Inhibitor Deficiency.

Hereditary angioedema (HAE) with C1-inhibitor deficiency belongs to bradykinin-mediated angioedemas. It is characterized by recurrent subcutaneous and/or submucosal swelling episodes (HAE attacks) and erythema marginatum skin rash as a pre-attack (prodromal) phase. HAE attacks were shown to be accompanied by peripheral blood neutrophilia. We aimed to find molecular mechanisms that may explain the distinct role of neutrophil granulocytes in HAE. Plasma levels of blood cells and factors related to neutrophil activation (cytokines, chemokines, chemotactic factors, enzymes, and neutrophil extracellular trap) were measured in plasma samples obtained from patients during symptom-free periods (n = 77), during prodromal phase (n = 8) and attacks (n = 14), during a spontaneously resolved attack (n = 1), and in healthy controls (n = 79). Higher counts of white blood cells, lymphocytes, and neutrophil granulocytes were found in symptom-free patients compared with controls; these cell counts were elevated further during HAE attacks. The level of chemokine (C-C motif) ligand 5, monocyte chemoattractant protein-1, and myeloperoxidase were also higher in the symptom-free patients than in the controls. Levels of monocyte chemoattractant protein-1, leukotriene B4, neutrophil elastase, and myeloperoxidase were elevated during attacks. During erythema marginatum, white blood cells and monocyte count and levels of interleukin 8 were elevated compared with symptom-free period. Similar changes were detected during the attack follow-up. We conclude that the activation of NGs in symptom-free periods and a further increase observed during attacks suggests that NGs may be involved in the pathomechanism of HAE with C1-INH deficiency.

Complement Genetic Variants and FH Desialylation in S. pneumoniae-Haemolytic Uraemic Syndrome.

Haemolytic Uraemic Syndrome associated with Streptococcus pneumoniae infections (SP-HUS) is a clinically well-known entity that generally affects infants, and could have a worse prognosis than HUS associated to E. coli infections. It has been assumed that complement genetic variants associated with primary atypical HUS cases (aHUS) do not contribute to SP-HUS, which is solely attributed to the action of the pneumococcal neuraminidase on the host cellular surfaces. We previously identified complement pathogenic variants and risk polymorphisms in a few Hungarian SP-HUS patients, and have now extended these studies to a cohort of 13 Spanish SP-HUS patients. Five patients presented rare complement variants of unknown significance, but the frequency of the risk haplotypes in the CFH-CFHR3-CFHR1 region was similar to the observed in aHUS. Moreover, we observed desialylation of Factor H (FH) and the FH-Related proteins in plasma samples from 2 Spanish and 4 Hungarian SP-HUS patients. To analyze the functional relevance of this finding, we compared the ability of native and "in vitro" desialylated FH in: (a) binding to C3b-coated microtiter plates; (b) proteolysis of fluid-phase and surface-bound C3b by Factor I; (c) dissociation of surface bound-C3bBb convertase; (d) haemolytic assays on sheep erythrocytes. We found that desialylated FH had reduced capacity to control complement activation on sheep erythrocytes, suggesting a role for FH sialic acids on binding to cellular surfaces. We conclude that aHUS-risk variants in the CFH-CFHR3-CFHR1 region could also contribute to disease-predisposition to SP-HUS, and that transient desialylation of complement FH by the pneumococcal neuraminidase may have a role in disease pathogenesis.

A Novel Homozygous In-Frame Deletion in Complement Factor 3 Underlies Early-Onset Autosomal Recessive Atypical Hemolytic Uremic Syndrome - Case Report.

Background and Objectives: Atypical hemolytic uremic syndrome (aHUS) is mostly attributed to dysregulation of the alternative complement pathway (ACP) secondary to disease-causing variants in complement components or regulatory proteins. Hereditary aHUS due to C3 disruption is rare, usually caused by heterozygous activating mutations in the C3 gene, and transmitted as autosomal dominant traits. We studied the molecular basis of early-onset aHUS, associated with an unusual finding of a novel homozygous activating deletion in C3. Design Setting Participants & Measurements: A male neonate with eculizumab-responsive fulminant aHUS and C3 hypocomplementemia, and six of his healthy close relatives were investigated. Genetic analysis on genomic DNA was performed by exome sequencing of the patient, followed by targeted Sanger sequencing for variant detection in his close relatives. Complement components analysis using specific immunoassays was performed on frozen plasma samples from the patient and mother. Results: Exome sequencing revealed a novel homozygous variant in exon 26 of C3 (c.3322_3333del, p.Ile1108_Lys1111del), within the highly conserved thioester-containing domain (TED), fully segregating with the familial disease phenotype, as compatible with autosomal recessive inheritance. Complement profiling of the patient showed decreased C3 and FB levels, with elevated levels of the terminal membrane attack complex, while his healthy heterozygous mother showed intermediate levels of C3 consumption. Conclusions: Our findings represent the first description of aHUS secondary to a novel homozygous deletion in C3 with ensuing unbalanced C3 over-activation, highlighting a critical role for the disrupted C3-TED domain in the disease mechanism.

FHR-5 Serum Levels and CFHR5 Genetic Variations in Patients With Immune Complex-Mediated Membranoproliferative Glomerulonephritis and C3-Glomerulopathy.

Background: Factor H-related protein 5 (FHR-5) is a member of the complement Factor H protein family. Due to the homology to Factor H, the main complement regulator of the alternative pathway, it may also be implicated in the pathomechanism of kidney diseases where Factor H and alternative pathway dysregulation play a role. Here, we report the first observational study on CFHR5 variations along with serum FHR-5 levels in immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) and C3 glomerulopathy (C3G) patients together with the clinical, genetic, complement, and follow-up data. Methods: A total of 120 patients with a histologically proven diagnosis of IC-MPGN/C3G were enrolled in the study. FHR-5 serum levels were measured in ELISA, the CFHR5 gene was analyzed by Sanger sequencing, and selected variants were studied as recombinant proteins in ELISA and surface plasmon resonance (SPR). Results: Eight exonic CFHR5 variations in 14 patients (12.6%) were observed. Serum FHR-5 levels were lower in patients compared to controls. Low serum FHR-5 concentration at presentation associated with better renal survival during the follow-up period; furthermore, it showed clear association with signs of complement overactivation and clinically meaningful clusters. Conclusions: Our observations raise the possibility that the FHR-5 protein plays a fine-tuning role in the pathogenesis of IC-MPGN/C3G.

Validation of Early Increase in Complement Activation Marker sC5b-9 as a Predictive Biomarker for the Development of Thrombotic Microangiopathy After Stem Cell Transplantation.

Hematopoietic stem cell transplantation (HSCT)-associated thrombotic microangiopathy (TA-TMA) is a multifactorial complication. Complement dysregulation may play an important role in the pathogenesis of TA-TMA. Our previous observations suggested that early increase of soluble C5b-9 (sC5b-9), before the development of other complications, can predict the development of later TA-TMA. The present study aims to validate our earlier findings in an independent cohort enrolling 67 pediatric patients who underwent allogeneic HSCT during the study period (October 2015-January 2019). Five different TA-TMA diagnostic criteria were applied, and all important clinical and laboratory parameters of TA-TMA activity were registered. Complement pathway activities, components and sC5b-9 levels were systematically measured before transplantation and on days 28, 56, and 100 after HSCT. A strong and remarkable association still have been found between early increase of sC5b-9 (10 of 10 patients with TA-TMA vs. 27 of 57 without TA-TMA; P = 0.002) and the development of TA-TMA during 100 days post-transplantation. An increase in sC5b-9 concentration had 100% sensitivity and 53% specificity for TA-TMA in the cohort. All TA-TMA cases have been observed during cyclosporine immunosuppression, no TA-TMA was diagnosed during tacrolimus or mycophenolat mofetil therapy. In the majority of patients TA-TMA was mild and self-limiting, without any signs of organ damage. No additional complement parameters were closely associated with the development of TA-TMA. Early raise of the sC5b-9 activation marker was predictive for later development of TA-TMA throughout the whole study period. In patients with a marked increase, early and frequent monitoring of TA-TMA activity markers should be attempted, to facilitate subsequent therapy decisions in time. However, patients with TA-TMA were only identified during or after cyclosporine immunosuppression. Further studies enrolling higher number of patients are necessary to determine the role of immunosuppression in the pathogenesis of TA-TMA.

Clinical Characteristics and Safety of Plasma-Derived C1-Inhibitor Therapy in Children and Adolescents with Hereditary Angioedema-A Long-Term Survey.

BACKGROUND: Plasma-derived C1-inhibitor (pdC1-INH) is a first-line therapy for hereditary angioedema (HAE) with C1-inhibitor deficiency (C1-INH-HAE) in pediatric patients. OBJECTIVE: We intended to study the clinical characteristics and safety of treatment with pdC1-INH in this population. METHODS: In the prospective, long-term survey, real-world data on pdC1-INH (Berinert, CSL Behring) use in pediatric patients, diagnosed and followed up at our Angioedema Reference Center, were analyzed for the period from 1986 to 2018. RESULTS: A total of 70 pediatric patients (31 boys and 39 girls) experienced a total of 3009 HAE attacks. The most common location of HAE attacks was subcutaneous. HAE attacks of any location were more frequent in girls versus boys, except for genital edema. Among the 70 patients, 37 received pdC1-INH for 456 HAE attacks, or as prophylaxis (69 vials). On average, 14.2 vials were administered per patient. The distribution of pdC1-INH use in the different age groups was as follows: no use (0-1 years), 0.11 vials/year (1-3 years), 0.7 vials/year (3-6 years), 1.26 vials/year (6-12 years), and 1.28 vials/year (12-18 years). No systemic allergic reactions, viral transmission, development of anti-C1-INH antibodies, or thromboembolic events occurred in relation to treatment with this drug. CONCLUSION: We confirmed that the clinical manifestations and the use of pdC1-INH are different in the various age groups of pediatric patients with C1-INH-HAE. Our long-term survey shows that the use of pdC1-INH is safe in this patient population.

Changes of coagulation parameters during erythema marginatum in patients with hereditary angioedema.

BACKGROUND: Hereditary angioedema (HAE) with C1-inhibitor deficiency (C1-INH-HAE) is characterized by recurrent episodes of subcutaneous/submucosal edema, which may be preceded by erythema marginatum (EM) as a prodromal symptom. Our aim was to analyze the changes occurring in the parameters of the coagulation system during the development of EM and HAE attacks. MATERIALS AND METHODS: Eight C1-INH-HAE patients (1 male, 7 females, median age: 41.7 years) were studied. Blood samples were obtained from all patients (during symptom-free periods, EM, and HAE attacks), as well as from 20 sex- and age-matched healthy controls. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, D-dimer, Factor V, Factor VII, Factor X, Factor XI, and Factor XII levels were measured. RESULTS: D-dimer levels were significantly lower, whereas aPTT was significantly prolonged in healthy controls vs. the values measured during the symptom-free period (p = 0.0497; p = 0.0043), in the presence of EM (p = 0.002; p = 0.0002), or during HAE attacks (p < 0.0001; p = 0.0002). We observed the following differences between samples taken during HAE attacks vs. in symptom-free periods: D-dimer levels were significantly elevated (p = 0.0391), while aPTT was significantly shorter during HAE attacks (p = 0.0159). D-dimer levels were significantly higher during EM than in symptom-free periods (p = 0.0078). Comparing the samples drawn during EM or during HAE attacks, there were no significant differences in the study parameters. CONCLUSIONS: D-dimer levels were elevated during EM and this suggests that EM may be part of the HAE attack. Nevertheless, further research into the complement and kinin-kallikrein systems is needed in more patients for a better understanding of the pathomechanism of EM.

Evaluation of the efficacy and safety of home treatment with the recombinant human C1-inhibitor in hereditary angioedema resulting from C1-inhibitor deficiency.

OBJECTIVE: Conestat alpha, a C1-inhibitor produced by recombinant technology (rhC1-INH) is an acute treatment for edematous attacks occurring in hereditary angioedema (HAE) with C1-inhibitor deficiency (C1-INH-HAE). Our study evaluated the efficacy and safety of rhC1-INH administered during HAE attacks, and for short-term prophylaxis (STP). MATERIALS & METHOD: Our prospective study analyzed the course of 544 HAE attacks experienced by the 21 C1-INH-HAE patients treated, as well as the outcome of 97 instances of STP implemented with rhC1-INH. Using a purpose-designed questionnaire, the patients recorded relevant, treatment-related information. RESULTS: Time to the administration of rhC1-INH was 90.0 min (median) after the onset of HAE attacks. The symptoms started to improve as early as 60 min after the injection of rhC1-INH, and the attack resolved 730.0 min after treatment. The interval between the onset of the HAE attack and the administration of rhC1-INH correlated with time until the onset of improvement (R = 0.2053 p < 0.0001), and with time to the complete resolution of symptoms (R = 0.2805, p < 0.0001). Nine patients received STP with rhC1-INH in 97 instances. STP successfully prevented the HAE attack within 72 h of the event on 93/97 occasions. No local and serious systemic adverse events/effects were observed. CONCLUSIONS: Treatment with rhC1-INH is effective and safe both for acute management, and for STP. Following the onset of an HAE attack, early administration of rhC1-INH may reduce time to the improvement and to the complete resolution of symptoms. Repeated administration of rhC1-INH does not impair its efficacy.

Patterns of C1-Inhibitor/Plasma Serine Protease Complexes in Healthy Humans and in Hereditary Angioedema Patients.

C1-inhibitor (C1-INH) is an important regulator of the complement, coagulation, fibrinolytic and contact systems. The quantity of protease/C1-INH complexes in the blood is proportional to the level of the in vivo activation of these four cascade-like plasma enzyme systems. Parallel determination of C1-INH-containing activation complexes could be important to understand the regulatory role of C1-INH in diseases such as hereditary angioedema (HAE) due to C1-INH deficiency (C1-INH-HAE). We developed in-house ELISAs to measure the concentration of complexes of C1-INH formed with active proteases: C1r, C1s, MASP-1, MASP-2, plasma kallikrein, factor XIIa, factor XIa, and thrombin, as well as to determine total and functionally active C1-INH. We measured the concentration of the complexes in EDTA plasma from 6 healthy controls, from 5 with type I and 5 with type II C1-INH-HAE patients during symptom-free periods and from five patients during HAE attacks. We also assessed the concentration of these complexes in blood samples taken from one C1-INH-HAE patient during the kinetic follow-up of a HAE attack. The overall pattern of complexed C1-INH was similar in controls and C1-INH-HAE patients. C1-INH formed the highest concentration complexes with C1r and C1s. We observed higher plasma kallikrein/C1-INH complex concentration in both type I and type II C1-INH-HAE, and higher concentration of MASP-1/C1-INH, and MASP-2/C1-INH complexes in type II C1-INH-HAE patients compared to healthy controls and type I patients. Interestingly, none of the C1-INH complex concentrations changed significantly during HAE attacks. During the kinetic follow-up of an HAE attack, the concentration of plasma kallikrein/C1-INH complex was elevated at the onset of the attack. In parallel, C1r, FXIIa and FXIa complexes of C1-INH also tended to be elevated, and the changes in the concentrations of the complexes followed rather rapid kinetics. Our results suggest that the complement classical pathway plays a critical role in the metabolism of C1-INH, however, in C1-INH-HAE, contact system activation is the most significant in this respect. Due to the fast changes in the concentration of complexes, high resolution kinetic follow-up studies are needed to clarify the precise molecular background of C1-INH-HAE pathogenesis.

Hereditary angioedema attack: what happens to vasoactive mediators?

Hereditary angioedema is a disabling, life-threatening condition caused by deficiency (type I) or dysfunction (type II) of the C1 inhibitor protein (C1-INH-HAE) leading to bradykinin accumulation and recurrent episodes of edema attack. Vascular leakage is a complex process sustained by the coordinated production of several permeabilizing factors including vascular endothelial growth factors (VEGFs), angiopoietins (ANGPTs) and phospholipase A2 enzymes (PLA2). We previously reported that patients with C1-INH-HAE in remission have increased plasma levels of VEGFs, ANGPTs and secreted PLA2. In this study, we sought to analyze plasma levels of these mediators in 15 patients with C1-INH-HAE during the acute attack compared to remission. Plasma concentrations of VEGF-A, VEGF-C and VEGF-D were not altered during attack compared to remission. Moreover, VEGF-D concentrations were not altered also in remission phase compared to controls. Concentrations of ANGPT1, a vascular stabilizer, were increased during attacks compared to symptoms-free periods, whereas ANGPT2 levels were not altered. The ANGPT2/ANGPT1 ratio was decreased during angioedema attacks. Platelet activating factor acetylhydrolase activity was increased in patients with C1-INH-HAE in remission compared to controls and was decreased during angioedema attacks. Our results emphasize the complexity by which several vasoactive mediators are involved not only in the pathophysiology of C1-INH-HAE, but also during angioedema attacks and its resolution.

Serum fetuin-A, tumor necrosis factor alpha and C-reactive protein concentrations in patients with hereditary angioedema with C1-inhibitor deficiency.

BACKGROUND AND AIMS: Hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE) is characterized by localized, non-pitting, and transient swelling of submucosal or subcutaneous region. Human fetuin-A is a multifunctional glycoprotein that belongs to the proteinase inhibitor cystatin superfamily and has structural similarities to the high molecular weight kininogen. Fetuin-A is also known a negative acute phase reactant with anti-inflammatory characteristics. In this study we aimed to determine serum fetuin-A, C-reactive protein (CRP) and tumor necrosis factor alpha (TNFα) concentrations in patients with C1-INH-HAE during symptom-free period and during attacks and compare them to those of healthy controls. Further we analyzed possible relationship among these parameters as well as D-dimer levels which was known as marker of HAE attacks. PATIENTS AND METHODS: Serum samples of 25 C1-INH-HAE patients (8 men, 17 women, age: 33.1 ± 6.9 years, mean ± SD) were compared to 25 healthy controls (15 men, 10 women, age: 32.5 ± 7.8 years). Serum fetuin-A and TNFα concentrations were determined by ELISA, CRP and D-dimer by turbidimetry. RESULTS: Compared to healthy controls patients with C1-INH-HAE in the symptom-free period had significantly decreased serum fetuin-A 258 µg/ml (224-285) vs. 293 µg/ml (263-329), (median (25-75% percentiles, p = 0.035) and TNFα 2.53 ng/ml (1.70-2.83) vs. 3.47 ng/ml (2.92-4.18, p = 0.0008) concentrations. During HAE attacks fetuin-A levels increased from 258 (224-285) µg/ml to 287 (261-317) µg/ml (p = 0.021). TNFα and CRP levels did not change significantly. We found no significant correlation among fetuin-A CRP, TNFα and D-dimer levels in any of these three groups. CONCLUSIONS: Patients with C1-INH-HAE have decreased serum fetuin-A concentrations during the symptom-free period. Given the anti-inflammatory properties of fetuin-A, the increase of its levels may contribute to the counter-regulation of edema formation during C1-INH-HAE attacks.