Acquired Angioedema due to C1-Inhibitor Deficiency: A Challenging Condition.

BACKGROUND: Acquired deficiency of C1 inhibitor (AAE-C1-INH) is a very rare cause of recurrent angioedema, with few cases reported in the literature. We aimed to describe a series of patients with AAE-C1-INH who were diagnosed and received care at angioedema reference centers in Brazil, affiliated to the Brazilian Group of Studies on Hereditary Angioedema. METHODS: Fourteen patients from 8 Brazilian Angioedema Reference Centers, diagnosed with AAE-C1-INH, were included in this study. Clinical data collected included sex, date of birth, date of onset of symptoms, date of diagnosis, plasma levels of antigenic and/or functional C1-INH, levels of C4 and C1q, location and treatment of angioedema attacks, long-term prophylaxis, associated diseases, and definitive treatment. RESULTS: Fourteen patients were identified with AAE-C1-INH. Most patients (10/14; 71.4%) were female. The median age at onset of symptoms was 56.5 years (range, 14-74 years; interquartile range [IQR], 32-64 years), and median age at diagnosis was 58.0 years (range, 20-76 years; IQR, 38-65 years), with a median time until diagnosis of 2 years (range, 0-6 years; IQR, 1-3 years). The most common manifestations were cutaneous (face, eyelids, lips, trunk, hands, feet, and genitals). Most patient had low levels of C4 (13/14; 92.8%) and of antigenic C1-INH (8/14; 57.1%). Four had decreased functional activity of C1-INH (4/7; 57.1%) and C1q levels were low in 5 patients (5/12; 41.6%). Underlying diseases were identified in all 14 patients, with lymphoma of the splenic marginal zone and monoclonal gammopathy of undetermined significance being the most frequent. Nine patients (64.2%) needed long-term prophylactic treatment for recurrent angioedema and 5 patients (46.7%) required treatment for angioedema attacks. Most of them (12/14; 85.7%) had resolution of angioedema. CONCLUSION: Therapy of AAE-C1-INH aims to control symptoms; however, diagnosis and treatment of the underlying disease, when present, should be an important target and may lead to the resolution of angioedema in patients with AAE-C1-INH.

Decreasing Attacks and Improving Quality of Life through a Systematic Management Program for Patients with Hereditary Angioedema.

INTRODUCTION: Prevention of attacks is a major goal in management of patients with hereditary angioedema (HAE). We aimed to investigate the effects of a systematic intervention for HAE patients. METHODS: Thirty-three patients with HAE with C1-inhibitor deficiency, belonging to a single family, participated in a management program coordinated by an allergist/immunologist. Angioedema attacks before intervention were ascertained by interviews and emergency room charts and recorded prospectively by patients or caregivers after enrollment. Mean number of attacks/month was compared at 12 months preintervention and 8 and 14 months within intervention. Patient-reported outcome instruments were used to assess quality of life, including HAE Quality of Life (HAE-QoL) questionnaire, psychological conditions, and work impairment, at baseline and 8 and 14 months within intervention. Data were stored in REDCap platform and analyzed by adjusted Bayesian models of double Poisson regression. RESULTS: Mean number of attacks/month significantly decreased (95% credible interval [CrI] excluding 0) from 1.15 preintervention to 0.25 and 0.23, 8 and 14 months within intervention, with mean decreases of -0.89 (95% CrI: -1.21 to -0.58) and -0.92 (95% CrI: -1.22 to -0.60), respectively. HAE-QoL scores showed mean total increases of 15.2 (95% CrI: 1.23-29.77) and 26 (95% CrI: 14.56-39.02) at 8 and 14 months within the study, as compared to baseline, revealing marked improvement in quality of life. Significant increase in role-emotional and reduction of depression, stress, and anxiety were observed at 14 months. CONCLUSION: A systematic approach integrating HAE-specific care with effective handling of psychological issues decreased the number of attacks and improved quality of life, targets for best practice in HAE.

The Challenges in the Follow-Up and Treatment of Brazilian Children with Hereditary Angioedema.

INTRODUCTION: Hereditary angioedema (HAE) with C1 inhibitor (C1-INH) deficiency is a rare autosomal dominant disease. Although the first symptoms can appear in childhood, the diagnosis's delay has a strong impact on the patient's quality of life. We analyzed clinical and laboratory characteristics and the drug therapy of pediatric patients with HAE in Brazil. METHODS: Medical records from 18 reference centers of HAE patients under 18 years of age were evaluated after confirmed diagnosis was performed by quantitative and/or functional C1-INH. RESULTS: A total of 95 participants (51 M:44 F; mean age: 7 years old) out of 17 centers were included; 15 asymptomatic cases were identified through family history and genetic screening. Angioedema attacks affected the extremities (73.5%), gastrointestinal tract (57%), face (50%), lips (42.5%), eyelids (23.7%), genitals (23.7%), upper airways (10%), and tongue (6.3%). Family history was present in 84% of patients, and the mean delay in the diagnosis was 3.9 years. Long-term prophylaxis (51/80) was performed with tranexamic acid (39/80) and androgens (13/80); and short-term prophylaxis (9/80) was performed with tranexamic acid (6/80) and danazol (3/80). On-demand therapy (35/80) was prescribed: icatibant in 7/35, fresh frozen plasma in 16/35, C1-INH plasma-derived in 11/35, and tranexamic acid in 12/35 patients. CONCLUSIONS: This is the first study on HAE pediatric patients in Latin America. Clinical manifestations were similar to adults. Drugs such as androgens and tranexamic acid were indicated off-label, probably due to restricted access to specific drugs. Educational programs should address pediatricians to reduce late diagnosis and tailored child therapy.

Acquired Angioedema due to C1 Inhibitor Deficiency Preceding Splenic Marginal Zone Lymphoma: Further Insights from Clinical Practice.

BACKGROUND: Acquired angioedema due to C1 inhibitor deficiency (AAE-C1-INH) is a very rare disease. In clinical practice, it may be difficult to differentiate AAE-C1-INH from hereditary angioedema due to C1-INH deficiency (HAE-C1-INH). In both conditions, patients are at an increased risk of death from asphyxiation due to upper airway obstruction. The association of AAE-C1-INH with lymphoproliferative and autoimmune diseases, and with presence of anti-C1-INH antibodies has been well documented, and treatment of the underlying condition may result in complete remission of angioedema. OBJECTIVES: To discuss the clinical evaluation, diagnosis, and treatment outcomes of AAE-C1-INH in the context of the care of 2 patients with recurrent isolated angioedema. METHODS: Two patients were followed up prospectively at our clinic. Measurements of C3, C4, C1-INH, and C1q levels were carried out by nephelometry, and the functional activity of C1-INH was determined by a chromogenic assay. Hematological investigation included morphological and immunophenotyping analysis of peripheral blood, bone marrow, and spleen histopathology. Sequencing of the 8 exons and adjacent intronic regions of the SERPING1 gene was performed using the Sanger method. RESULTS: Two patients were diagnosed with AAE-C1-INH associated with splenic marginal zone lymphoma during follow-up. CONCLUSIONS: Close follow-up, including detailed clinical history, physical examination, and laboratory tests, of our patients with AAE-C1-INH was essential for the early diagnosis and successful treatment of the lymphoproliferative disease, leading to the resolution of the angioedema attacks.

Evans Syndrome at Childhood-Onset Systemic Lupus Erythematosus Diagnosis: A Large Multicenter Study.

BACKGROUND: Evans syndrome (ES) in childhood-onset systemic lupus erythematosus (cSLE) patients has been rarely reported and limited to small populations. PROCEDURES: A retrospective multicenter cohort study (Brazilian cSLE group) was performed in 10 Pediatric Rheumatology services including 850 patients with cSLE. ES was assessed at disease diagnosis and defined by the combination of immune thrombocytopenia and autoimmune hemolytic anemia. RESULTS: ES was observed in 11 of 850 (1.3%) cSLE patients. The majority of them had hemorrhagic manifestations (91%) and active disease (82%). All patients with ES were hospitalized and none died. Comparisons of cSLE patients with and without ES at diagnosis revealed similar frequencies of female gender, multiorgan involvement, autoantibodies profile, and low complement (P > 0.05). Patients with ES had a lower frequency of malar rash (9% vs. 53%, P = 0.003) and musculoskeletal involvement (18% vs. 69%, P = 0.001) than those without this complication. The frequencies of intravenous methylprednisolone (82% vs. 43%, P = 0.013) and intravenous immunoglobulin use (64% vs. 3%, P < 0.0001) were significantly higher in the ES group, with similar current prednisone dose between groups (1.1 [0.76-1.5] vs. 1.0 mg/kg/day [0-30], P = 0.195). CONCLUSIONS: Our large multicenter study identified ES as a rare and severe initial manifestation of active cSLE with good outcome. Diagnosis is challenging due to the lack of typical signs and symptoms of lupus and the requirement to exclude infection and primary immunodeficiency.

Characterization of chronic arthritis in a multicenter study of 852 childhood-onset systemic lupus erythematosus patients.

Chronic arthritis (CA) is an unusual condition in childhood-onset systemic lupus erythematosus (cSLE) and data in children is very limited. The aim of the study is to assess CA in a large population of cSLE patients, in a multicenter cross-sectional study including 852 cSLE patients followed in ten Pediatric Rheumatology referral services in state of São Paulo, Brazil. CA was observed in 32/852 (3.7 %) cSLE patients mostly in hands and ankles. Chronic monoarthritis was diagnosed in four cSLE patients, oligoarthritis in nine and polyarthritis in 19. In the latter group, six had rhupus syndrome. Two oligoarticular patients had Jaccoud's arthropathy. CA was an isolated manifestation observed at disease onset in 13/32 (41 %) cSLE patients, and juvenile idiopathic arthritis (JIA) was the first diagnosis in 18/32 (56 %). The comparison of last visit of patients with CA and without this manifestation revealed higher frequency of splenomegaly (28 vs. 11 %, p = 0.002). The median of SLICC/ACR-DI score [1(0-9) vs. 0(0-7), p = 0.003] was significantly higher in CA patients compared to patients without this manifestation, likewise the frequency of musculoskeletal damage (31 vs. 9 % p = 0.001). Frequencies of treatment with nonsteroidal anti-inflammatory drugs (75 vs. 26 %, p < 0.0001), hydroxychloroquine sulfate (87 vs. 59 %, p = 0.001) and methotrexate (47 vs. 22 %, p = 0.001) were significantly higher in CA patients. This large multicenter study allowed us to characterize CA as a rare and early manifestation of cSLE, frequently mimicking JIA at disease onset. It is predominantly polyarticular, involving more often hands and ankles and it is associated with significant musculoskeletal accrual damage.

Chronic Spontaneous Urticaria: A Survey of 852 Cases of Childhood-Onset Systemic Lupus Erythematosus.

BACKGROUND: Data regarding the prevalence of chronic spontaneous urticaria (CSU) in childhood-onset systemic lupus erythematosus (cSLE) patients and possible associated factors are limited to a few case reports. The objectives of this study were to assess CSU in a large cSLE population, in order to evaluate the demographic data, clinical manifestations, disease activity/damage, laboratory abnormalities and treatment. METHODS: A retrospective multicenter cohort study (Brazilian cSLE group) was performed in 10 Pediatric Rheumatology services and included 852 cSLE patients. CSU was diagnosed according to the guidelines of the European Academy of Allergy and Clinical Immunology, the Global Allergy and Asthma European Network, the European Dermatology Forum and the World Allergy Organization. Patients with CSU (evaluated at urticaria diagnosis) and patients without CSU (evaluated at the last visit) were assessed for lupus clinical/laboratory features and treatment. RESULTS: CSU was observed in 10/852 cSLE patients (1.17%). The median of cSLE duration at urticaria diagnosis was 0 (-3 to 5) years. Comparison of cSLE patients with and without CSU revealed a greater frequency of constitutional symptoms (40 vs. 8%, p = 0.006), reticuloendothelial system involvement (30 vs. 3%, p = 0.003), mucocutaneous (90 vs. 28%, p < 0.0001) and musculoskeletal manifestations (50 vs. 6%, p < 0.0001) and methylprednisolone pulse therapy use (60 vs. 9%, p < 0.0001) in the former group. The frequency of immunosuppressive treatment was lower in patients with CSU (p = 0.018). The median SLE Disease Activity Index 2000 (12 vs. 2, p < 0.0001) and erythrocyte sedimentation rate (40 vs. 19 mm/1st hour, p = 0.024), was higher in patients with CSU. CONCLUSIONS: To our knowledge, this is the first study with evidence that CSU may be linked to cSLE. We also demonstrated that this particular skin manifestation occurs predominantly at disease onset and is associated with lupus moderate/high disease activity without major organ involvement.

Efficacy of dupilumab for the treatment of severe skin disease in cytotoxic T lymphocyte antigen-4 insufficiency: A role of type 2 inflammation?

We report on the successful treatment of a severe, recalcitrant dermatitis caused by CTLA-4 insufficiency with dupilumab, raising the possibility of a role of type 2 immunity in clinical conditions associated with CTLA-4 insufficiency.

Type I and type IIb autoimmune chronic spontaneous urticaria: Using common clinical tools for endotyping patients with CSU.

Background: Mechanisms triggering the pathogenesis of chronic spontaneous urticaria (CSU) have been identified as type I autoallergic (which is associated with IgE antibodies against autoantigens) and type IIb autoimmune (which is driven by autoantibodies to FceR1 and/or IgE). Objective: Our aim was to define presumptive endotypes in patients with CSU by using tests amenable to use in routine clinical practice. Methods: A retrospective analysis of the medical records of 394 patients with CSU with or without chronic inducible urticaria or angioedema was performed. Patients were assigned to 1 of 4 groups as follows: (1) type I endotype of CSU, if they presented at least 1 of the following: allergic disease, total IgE level of at least 40UI/mL, and positive result of skin tests to inhalant allergen(s), (2) type IIb endotype of CSU, if they presented at least 1 of following: autoimmune disease, low total IgE level less than 40 IU/mL, positive autologous serum skin test result, positive for antinuclear antibodies in a titer of at least 1:160, and elevated level of anti-thyroid peroxidase, (3) overlap of type I/type IIb endotypes of CSU, if they presented with at least 1 marker of both type I and type IIb, and (4) non-type I/type IIb endotype of CSU, if they presented with none of the markers of type I or type IIb. Results: The mean age at onset of symptoms was 34 years; 82.2% of those with CSU were female, and angioedema and chronic inducible urticaria were found in 74.8% and 31.9% of patients, respectively. Of the patients with CSU, 38% presented with the type I endotype and 51% presented with type I/type IIb overlap, whereas 9% presented with the type IIb endotype and 2% presented with the non-type I/type IIb endotype. Eosinopenia was associated with type IIb and type I/type IIb overlap as opposed to the type I and non-type I/type IIb endotypes (P = .02). Conclusions: Most patients with CSU presented with features of the type 1 (autoallergic) endotype, whether associated with type IIb (autoimmune) endotype or not.

Recessive SERPING1 Variant Leads to Kinin-Kallikrein System Control Failure in a Consanguineous Brazilian Family with Hereditary Angioedema.

Background: Hereditary angioedema (HAE) is a severe and potentially life-threatening disease. The most common forms are caused by variants in SERPING1, resulting in C1-inhibitor (C1-INH) deficiency (HAE-C1-INH). C1-INH is a serine protease inhibitor (SERPIN) that regulates multiple proteases pathways, including the kallikrein-kinin system (KKS) and its complement. In HAE-C1-INH patients, C1-INH deficiencies affect KKS control, resulting in the development of kallikrein activity in plasma and the subsequent release of bradykinin (BK). While the overwhelming majority of disease-causing SERPING1 variants are dominant, very few recessive variants have been described. We present a large Brazilian HAE-C1-INH family with a recessive form of HAE-C1-INH. Methods: Blood samples of family members were investigated for protein levels of C1-INH, C4, C1q, and C1-INH function. The SERPING1 gene was sequenced. Results: In two severely affected sisters, we identified a homozygous missense variant in SERPING1 (NM_000062.3:c.964G>A;p.Val322Met). Fourteen family members were asymptomatic heterozygous carriers of the variant. Data regarding C1-INH function in the plasma showed that homozygous p.Val322Met strongly impacts C1-INH function to inhibit C1s and kallikrein (PKa). When heterozygously expressed, it affects the C1-INH control of C1s more than that of PKa. Conclusions: These studies of the variant's effects on the structure-function relationship reinforce prior observations suggesting that C1-INH deficiency is a conformational disease.

Pregnancy in Patients With Hereditary Angioedema and Normal C1 Inhibitor.

Background: HAE with normal C1 inhibitor (HAE-nC1-INH) has been identified as a bradykinin mediated angioedema. Estrogens are one of the main trigger factors. Pregnancy in HAE with C1 inhibitor deficiency showed variable course, however, few reports are available for HAE-nC1-INH. We evaluated the course of pregnancies in women diagnosed with HAE-nC1-INH. Methods: Women with diagnosis of HAE-nC1-INH according to the following criteria: clinical manifestations similar to HAE-C1-INH, normal biochemical evaluation and family history were included. A questionnaire about pregnancies was applied after consent. Genetic evaluation for known mutations was performed in all patients. Results: A total of 45 pregnancies occurring in 26 HAE-nC1-INH patients were evaluated (7/26 patients with F12 variant). Spontaneous abortion was reported in 8/45 (17.8%) pregnancies. Onset of attacks started before the pregnancy in 18/26 patients; during the pregnancy in 2/26; and after the pregnancy in 6/26. HAE attacks occurred in 24/37 pregnancies (64,7%): during the 1st trimester in 41.7%; 2nd trimester in 12.5%; 3rd trimester in 20.8%; 1st and 3rd trimesters in 4.2% and during the whole pregnancy in 20.8%. Among 15/18 patients who had attacks before pregnancy, symptoms persisted with worsening in 9/15; improvement in 4/15; no change in 1/15, and no response in 1/15. Conclusions: The occurrence of abortion in HAE-nC1-INH was similar to the expected for not affected women. The 1st trimester of the pregnancy was more symptomatic for HAE-nC1-INH women. Considering the strong relevance of estrogens in HAE-nC1-INH, pregnancy could worsen the course of disease.

Efficacy of House Dust Mite Sublingual Immunotherapy in Patients with Atopic Dermatitis: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Sensitization to house dust mites (HDMs) is frequent in patients with atopic dermatitis. OBJECTIVE: To investigate the efficacy of sublingual immunotherapy (SLIT) with Dermatophagoides pteronyssinus extract in patients with atopic dermatitis sensitized to HDM. METHODS: In this randomized, double-blind, placebo-controlled trial, we enrolled 91 patients 3 years or older, with SCORing Atopic Dermatitis (SCORAD) score greater than or equal to 15 and positive skin test result and/or IgE to D pteronyssinus. Patients were stratified according to age (<12 and ≥12 years) to receive HDM SLIT or placebo for 18 months. Primary outcome was a greater than or equal to 15-point decrease in SCORAD score. Secondary outcomes were decreases in SCORAD and objective SCORAD, Eczema Area and Severity Index, visual analog scale for symptoms, and pruritus scale scores; Investigator's Global Assessment 0/1; and decrease greater than or equal to 4 points in Dermatology Life Quality Index. Background therapy was maintained. RESULTS: A total of 66 patients completed the study (35 HDM SLIT, 31 placebo). After 18 months, 74.2% and 58% of patients in the HDM SLIT group and the placebo group, respectively, showed greater than or equal to 15-point decrease in SCORAD score (relative risk, 1.28; 95% CI, 0.89-1.83). Significant SCORAD score decreases from baseline of 55.6% and 34.5% in HDM SLIT and placebo groups (mean difference, 20.4; 95% CI, 3.89-37.3), significant objective SCORAD score decreases of 56.8% and 34.9% in HDM SLIT and placebo groups (mean difference, 21.3; 95% CI, 0.66-41.81), and more patients with Investigator's Global Assessment 0/1 in the HDM SLIT group as compared with the placebo group (14 of 35 vs 5 of 31; relative risk, 2.63; 95% CI, 1.09-6.39) were observed at 18 months. CONCLUSIONS: Our results suggest that HDM SLIT may be effective in HDM-sensitized patients as an add-on treatment for atopic dermatitis.

Unnecessary Abdominal Surgeries in Attacks of Hereditary Angioedema with Normal C1 Inhibitor.

Hereditary angioedema (HAE) is an autosomal dominant disease mostly due to the deficiency of C1 inhibitor (C1-INH). HAE with normal C1-INH was first described in 2000 and associated with mutations in the coagulation factor XII in 2006. Both diseases are associated with high bradykinin production, resulting in increased vascular permeability. Gastrointestinal edema due to HAE can be misdiagnosed as acute abdomen and unnecessary surgical procedures may be performed. The present study evaluates the prevalence of surgical procedures and/or acute abdomen in HAE patients with the coagulation factor XII mutation. It is a retrospective study where patients were diagnosed with recurrent angioedema without urticaria, normal C1-INH levels, and positive family history of angioedema. All patients were evaluated for the known mutations located at exon 9 of the F12 gene. Medical records were evaluated and questionnaires were applied to 52 patients with normal C1-INH levels (age range 13-76 years; 47/52, 90.38% women; 5/52, 9.61% men). F12 mutation was present in 32/52 patients (61.5%). Acute abdominal pain was diagnosed in 16/52 (30.76%) patients, appendicitis in 9/16 (56.2%), and undetermined diagnosis in 7/16 (43.7%). Among patients diagnosed with acute abdominal pain, 13/16 (81.2%) underwent surgery and 3/16 (18.7%) improved without surgical intervention. We conclude that many HAE patients with coagulation factor XII mutation were misdiagnosed with acute abdomen and subjected to unnecessary invasive procedures. It is critical to disseminate information about this rare mutation in patients with otherwise normal C1-INH activity, in order to speed up diagnosis and avoid misconduct.

Panniculitis in childhood-onset systemic lupus erythematosus: a multicentric cohort study.

OBJECTIVE: To evaluate prevalence, clinical manifestations, laboratory abnormalities, treatment and outcome in a multicenter cohort of childhood-onset systemic lupus erythematosus (cSLE) patients with and without panniculitis. METHODS: Panniculitis was diagnosed due to painful subcutaneous nodules and/or plaques in deep dermis/subcutaneous tissues and lobular/mixed panniculitis with lymphocytic lobular inflammatory infiltrate in skin biopsy. Statistical analysis was performed using Bonferroni correction(p < 0.004). RESULTS: Panniculitis was observed in 6/847(0.7%) cSLE. Painful subcutaneous erythematosus and indurated nodules were observed in 6/6 panniculitis patients and painful subcutaneous plaques in 4/6. Generalized distribution was evidenced in 3/6 and localized in upper limbs in 2/6 and face in 1/6. Cutaneous hyperpigmentation and/or cutaneous atrophy occurred in 5/6. Histopathology features showed lobular panniculitis without vasculitis in 5/6(one of them had concomitant obliterative vasculopathy due to antiphospholipid syndrome) and panniculitis with vasculitis in 1/6. Comparison between cSLE with panniculitis and 60 cSLE without panniculitis with same disease duration [2.75(0-11.4) vs. 2.83(0-11.8) years,p = 0.297], showed higher frequencies of constitutional involvement (67% vs. 10%,p = 0.003) and leukopenia (67% vs. 7%,p = 0.002). Cutaneous atrophy and hyperpigmentation occurred in 83% of patients. CONCLUSIONS: Panniculitis is a rare skin manifestation of cSLE occurring in the first three years of disease with considerable sequelae. The majority of patients have concomitant mild lupus manifestations.

Hereditary Angioedema with Normal C1 Inhibitor and F12 Mutations in 42 Brazilian Families.

BACKGROUND: Hereditary angioedema (HAE) with normal C1 inhibitor (C1-INH) is a rare condition with clinical features similar to those of HAE with C1-INH deficiency. Mutations in the F12 gene have been identified in subsets of patients with HAE with normal C1-INH, mostly within families of European descent. OBJECTIVES: Our aim was to describe clinical characteristics observed in Brazilians from 42 families with HAE and F12 gene mutations (FXII-HAE), and to compare these findings with those from other populations. METHODS: We evaluated a group of 195 individuals, which included 102 patients clinically diagnosed with FXII-HAE and their 93 asymptomatic relatives. RESULTS: Genetic analysis revealed that of the 195 subjects, 134 individuals (77.6% females) carried a pathogenic mutation in F12. The T328K substitution was found in 132 individuals, and the c.971_1018+24del72 deletion was found in 2 patients. The mean age at onset of symptoms in patients with FXII-HAE was 21.1 years. The most common symptoms were subcutaneous edema (85.8% of patients), abdominal pain attacks (69.7%), and upper airway edema (32.3%). Of male individuals carrying F12 mutations, 53.3% (16 of 30) were symptomatic. Compared with reports from Europe, fewer female patients (68.6%) reported an influence of estrogen on symptoms. CONCLUSIONS: Our study included a large number of patients with FXII-HAE, and, as the first such study conducted in a South American population, it highlighted significant differences between this and other study populations. The high number of symptomatic males and patients with estrogen-independent FXII-HAE found here suggests that male sex and the absence of a hormonal influence should not discourage clinicians from searching for F12 mutations in cases of HAE with normal C1-INH.

Brazilian Guidelines for Hereditary Angioedema Management - 2017 Update Part 1: Definition, Classification and Diagnosis.

Hereditary angioedema is an autosomal dominant disease characterized by recurrent angioedema attacks with the involvement of multiple organs. The disease is unknown to many health professionals and is therefore underdiagnosed. Patients who are not adequately diagnosed and treated have an estimated mortality rate ranging from 25% to 40% due to asphyxiation by laryngeal angioedema. Intestinal angioedema is another important and incapacitating presentation that may be the main or only manifestation during an attack. In this article, a group of experts from the "Associação Brasileira de Alergia e Imunologia (ASBAI)" and the "Grupo de Estudos Brasileiro em Angioedema Hereditário (GEBRAEH)" has updated the Brazilian guidelines for the diagnosis and treatment of hereditary angioedema.