Analysis of coagulation factors in angioedema/urticaria: increased values of D-dimer and fibrinogen in isolated angioedema.

INTRODUCTION: Recent research has shown that blood coagulation and the extrinsic coagulation cascade are involved in the pathogenesis of chronic spontaneous urticaria (CSU), but little is known about the coagulation factors in angioedema. METHODS: This study included 58 participants: 29 patients with chronic angioedema (14 with isolated angioedema and 15 with angioedema with wheals) and 29 healthy controls (HCs). We compared the values of coagulation factors in patients with isolated angioedema to those with wheals. Plasma levels of D-dimer, fibrinogen, and factor VII were measured by enzyme-linked immunosorbent assay (ELISA) for all participants. RESULTS: Significantly higher D-dimer (p = 0.016; ε² = 0.381) and fibrinogen (p = 0.044; ε² = 0.331) levels were recorded in patients with angioedema (both groups) than in the HCs, with higher levels for angioedema with wheals. Factor VII and fibrinogen levels did not differ significantly between the groups with angioedema, but coagulation factors were more often elevated in both angioedema groups than in HCs. CONCLUSIONS: One characteristic of angioedema is an elevated blood coagulation potential, which may help produce fibrin and may be important in controlling angioedema attacks.

Angioedema Without Wheals: Challenges in Laboratorial Diagnosis.

Angioedema is a prevailing symptom in different diseases, frequently occurring in the presence of urticaria. Recurrent angioedema without urticaria (AE) can be hereditary (HAE) and acquired (AAE), and several subtypes can be distinguished, although clinical presentation is quite similar in some of them. They present with subcutaneous and mucosal swellings, affecting extremities, face, genitals, bowels, and upper airways. AE is commonly misdiagnosed due to restricted access and availability of appropriate laboratorial tests. HAE with C1 inhibitor defect is associated with quantitative and/or functional deficiency. Although bradykinin-mediated disease results mainly from disturbance in the kallikrein-kinin system, traditionally complement evaluation has been used for diagnosis. Diagnosis is established by nephelometry, turbidimetry, or radial immunodiffusion for quantitative measurement of C1 inhibitor, and chromogenic assay or ELISA has been used for functional C1-INH analysis. Wrong handling of the samples can lead to misdiagnosis and, consequently, mistaken inappropriate approaches. Dried blood spot (DBS) tests have been used for decades in newborn screening for certain metabolic diseases, and there has been growing interest in their use for other congenital conditions. Recently, DBS is now proposed as an efficient tool to diagnose HAE with C1 inhibitor deficiency, and its use would improve the access to outbound areas and family members. Regarding HAE with normal C1 inhibitor, complement assays' results are normal and the genetic sequencing of target genes, such as exon 9 of F12 and PLG, is the only available method. New methods to measure cleaved high-molecular-weight kininogen and activated plasma kallikrein have emerged as potential biochemical tests to identify bradykinin-mediated angioedema. Validated biomarkers of kallikrein-kinin system activation could be helpful in differentiating mechanisms of angioedema. Our aim is to focus on the capability to differentiate histaminergic AE from bradykinin-mediated AE. In addition, we will describe the challenges developing specific tests like direct bradykinin measurements. The need for quality tests to improve the diagnosis is well represented by the variability of results in functional assays.

Serum Human ß-Defensin 2 Is Increased in Angioedema Accompanying Chronic Spontaneous Urticaria.

INTRODUCTION: Chronic spontaneous urticaria (CSU) is a common cutaneous disease caused by mast-cell degranulation. Human ß-defensin 2 (HBD2) is a well-known antimicrobial peptide that is also a pruritogen inducing vascular permeability via non-IgE-mediated mast-cell degranulation. OBJECTIVE: We investigated the associations between serum HBD2 levels and the clinical characteristics of CSU patients. METHODS: Serum samples from 124 CSU patients and 56 healthy controls were screened for the levels of HBD2 and translationally controlled tumor protein (TCTP)_ by using ELISA. The urticaria activity score over 7 days (UAS7) was used to measure disease activity in CSU patients. Accompanying angioedema was self-reported. RESULTS: Serum HBD2 levels were higher in the CSU group than in healthy subjects (median [interquartile range], 84.1 [43.5, 142.5] vs. 59.5 [26.7, 121.5], p = 0.034). In CSU patients, serum HBD2 level was negatively correlated with the peripheral basophil percentages (Spearman's rho = -0.229, p = 0.01) and vitamin D levels (-0.262, p = 0.02), but positively correlated with TCTP levels (0.252, p = 0.006). In CSU patients, HBD2 level was higher in those with than without angioedema (101.7 [50.9, 184.2] vs. 66.7 [37.9, 132.0], p = 0.019). It did not differ by aspirin hypersensitivity or atopy status, or autologous serum skin test positivity. CONCLUSION: A known mast-cell degranulator, HBD2 was elevated in the sera from CSU patients compared to healthy controls and may be involved in the pathogenesis of accompanying angioedema.

The Role of Interleukin 10 and 18 in Chronic Spontaneous Urticaria Pathogenesis in the Context of Angioedema Coexistence.

Chronic spontaneous urticaria (CSU) is defined using clinical symptoms as spontaneous occurrence of itchy wheals and/or angioedema for at least 6 weeks. Angioedema is underdiagnosed in CSU patients, and its presence has significant negative impact on health-related quality of life, daily activities, health care resource utilization, and work. Various cytokines have been found to be involved in pathogenesis of CSU. To study levels of interleukin (IL)-10 and IL-18 in CSU patients and to look for the differences in CSU subgroups divided with regard to angioedema reoccurrence, we included consecutive CSU patients into the study. To assess disease activity, urticaria activity score was used. In addition, we calculated disease duration time. In all groups, Il-10 and Il-18 serum concentrations were measured. The study involved 52 patients with CSU and 47 healthy volunteers. The IL-10 level was statistically significantly higher in patients with CSU compared to the control group. There were no significant differences in level of IL-18 between those groups. Comparison of patients with CSU and angioedema with those without angioedema showed no significant differences in level of IL-10 and IL-18. We see the need for further studies of serum levels of IL-10 and IL-18 to better understand the pathogenesis of the disease and to find markers useful in predicting the symptom type in the course of CSU.

Anti-C1-Inhibitor Autoantibody Detection by ELISA.

Enzyme-linked immunosorbent assay (ELISA) is a quantitative analytical method used to measure the concentration of molecules in biological fluids through antigen-antibody reactions. Here we describe the measurement of anti-C1-inhibitor autoantibodies by an indirect ELISA. In this method patients' sera are incubated in a microplate coated with plasma derived C1-inhibitor.

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.

Serum miR-125a-5p and CCL17 Upregulated in Chronic Spontaneous Urticaria and Correlated with Treatment Response.

Chronic spontaneous urticaria (CSU) is a common skin disorder associated with autoimmunity. MicroRNAs (miRNAs) are endogenous noncoding RNA molecules reported to be potential biomarkers for some autoimmune diseases. In this study, we investigated the association of miRNAs with CSU. A quantitative PCR (qPCR)-based array was generated from sera as obtained from 20 active CSU patients and 20 healthy controls. Upregulated or downregulated miRNAs were validated by reverse transcription qPCR in sera from 59 active CSU patients and 58 healthy controls. The expression of miR-125a-5p was significantly upregulated in CSU sera and serum levels of CCL17 were also significantly increased in CSU patients. Serum miR-125a-5p expressions were found to be further upregulated in refractory CSU cases (n = 10). In 12 CSU patients in remission, serum miR-125a-5p expression and CCL17 levels were significantly decreased as compared with that obtained in active phase patients. These results indicated that miR-125a-5p and CCL17 can serve as potential serum biomarkers for CSU.

Quantification of human C1 esterase inhibitor protein using an automated turbidimetric immunoassay.

BACKGROUND: Impaired levels or function of C1 inhibitor (C1-INH) results in angioedema due to increased bradykinin. It is important to distinguish between angioedema related to C1-INH deficiency and that caused by other mechanisms, as treatment options are different. In hereditary (HAE) and acquired (AAE) angioedema, C1-INH concentration is measured to aid patient diagnosis. Here, we describe an automated turbidimetric assay to measure C1-INH concentration on the Optilite® analyzer. METHODS: Linearity, precision, and interference were established over a range of C1-INH concentrations. The 95th percentile reference interval was generated from 120 healthy adult donors. To compare the Optilite C1-INH assay with a predicate assay used in a clinical laboratory, samples sent for C1-INH investigation were used. The predicate results were provided to allow comparison. RESULTS: The Optilite C1-INH assay was linear across the measuring range at the standard sample dilution. Intra and interassay variability was <6%. The 95th percentile adult reference interval for the assay was 0.21-0.38 g/L. There was a strong correlation between the Optilite concentrations and those generated with the predicate assay (R2  = 0.94, P < 0.0001, slope y = 0.83x). All patients with Type I HAE (n = 24) and AAE (n = 3) tested had concentrations below the measuring range in both assays, while all patients with unspecified angioedema (UAE), not diagnosed with HAE or AAE had values within the reference range. CONCLUSION: The Optilite assay allows the automated and precise quantification of C1-INH concentrations in patient samples. It could therefore be used as a tool to aid the investigation of patients with angioedema.

Pharmacogenetics of angiotensin-converting enzyme inhibitor-induced angioedema.

Angioedema is a rare adverse effect of the commonly used angiotensin-converting enzyme inhibitors (ACEi) and is reported to occur with a prevalence of 0.1%-0.7%. Although most ACEi-induced angioedema (ACEi-A) cases are mild, severe cases requiring intensive care and even resulting in death have been reported in the literature. The mechanisms underlying ACEi-A are not yet fully understood, but bradykinin and/or substance P accumulation resulting from inhibition of ACE is believed to play a crucial role. ACEi-A occurs at variable frequencies across different racial groups, suggesting a genetic association with the development of ACEi-A. To date, one genome-wide association study and several candidate gene studies have been published on the association of genetic variation with ACEi-A. Genetic associations reported have been attributed to several distinct mechanisms: (a) genes coding for alternative enzymes responsible for the degradation of bradykinin and/or substance P in the diminution of ACE activity (b) ACE gene function, (c) bradykinin receptor genes, (d) genes implicated in immune and inflammation regulation and (e) genes in the fibrinolytic and coagulation pathway. Despite several plausible genetic associations, there are currently no genetic variants with sufficient effect to be clinically useful. The low incidence of ACEi-A suggests that a combination of genomic approaches with the capability to detect potentially important variants might be required to shed light on the mechanism of this adverse reaction. Additionally, many non-genetic risk factors associated with ACEi-A suggest the potential contribution of epigenetic dysregulation.

Diagnosing Meat Allergy After Tick Bite Without Delay.

Galactose-α-1, 3 galactose (α-gal) is a carbohydrate found in mammalian meat. In 2007, it was implicated as a cause of severe hypersensitivity reactions when a study found elevated levels of antibodies directed against this oligosaccharide among patients treated with cetuximab, a monoclonal antibody that contained an α -gal epitope. The majority of these cases were reported in the Southeast United States in a distribution similar to that of Rocky Mountain spotted fever and ehrlichiosis, and that geographic association led researchers to the conclusion that a bite from the Lone Star tick can induce this antibody. Here, we present a case of delayed urticarial angioedema due to a mammalian meat allergy caused by α-gal immunoglobulin E acquired after tick exposures, and the knowledge and patient education required to prevent recurrences. It is estimated that approximately 0.5% to 1.0% of the general population will experience an episode of angioedema in their lifetime, and this case demonstrates why clinicians in areas that are inhabited by ticks, particularly the Lone Star species, should include this cause in their differential.

Efficacy and Safety of Mepolizumab (Anti-Interleukin-5) Treatment in Gleich's Syndrome.

Gleich's syndrome (GS) is characterized by recurrent episodes of angioedema, increase in body weight, fever, hypereosinophilia, and elevated serum IgM. The exact etiology remains unclear. Currently, the only treatment strategy is the administration of high dose of steroids during the acute phases. We report the case of a 37-year-old man suffering from GS with recurrent episodes of angioedema, fever, hypereosinophilia [6,000/mm3 (45%)], and high eosinophil cationic protein (ECP) (>200 µg/l), treated with oral steroids during the acute phase (prednisone 50-75 mg/day), the dose of maintenance being 25 mg/day. No monoclonal components were identified, and genetic tests exclude mutations including Bcr/Abl, JAK2 V617F, c-KIT D816V, and FIP1L1-PDGFRA. Using Luminex technology, we observed higher serum levels of interleukin (IL)-5, CCL2, and CCL11 during the acute exacerbations in comparison with the clinical remission phases though CCL11 did not achieve statistical significance. The flow-cytometric analysis identified a CD3+ CD8- lymphocyte population with high frequency of IL-4-, IL-5-, and IL-13-producing cells. No clinical benefit was observed after therapeutic strategies with imatinib, interferon-α, cyclosporine-A, and azathioprine. Due to high IL-5 serum levels, an intravenous treatment with anti-IL-5 monoclonal antibody mepolizumab (750 mg every 4 weeks) was started. A reduction in the rate of exacerbation phases/year (10 ± 3 vs 2 ± 1; p < 0.005), in the eosinophils count both in percentage (28.8 ± 12.8 vs 9.8 ± 3.9; p < 0.001) and absolute value (2,737 ± 1,946 vs 782 ± 333; p < 0.001) were observed as well as the ECP serum levels (132.7 ± 62.7 vs 21 ± 14.2 µg/l; p < 0.05). The daily dose of prednisone was significantly reduced (25 vs 7.5 mg). Any adverse effects were recorded. To the best of our knowledge, this case is the first report of the disease successfully treated with mepolizumab, and it could represent a novel therapeutic strategy in GS.

NSAIDs hypersensitivity: questions not resolved.

PURPOSE OF REVIEW: NSAIDs are the drugs most frequently involved in hypersensitivity reactions (HSR). These are frequently prescribed at all ages. HSR are of great concern and can affect people at any age. These drugs can induce reactions by stimulating the adaptive immune system (IgE or T cell), known as selective responders or more frequently by abnormalities in biochemical pathways related with prostaglandin metabolism. These are known as cross-intolerant. With some exceptions, skin testing and in-vitro studies are of little value in selective responders. RECENT FINDINGS: In the last years, several classifications have been provided based on clinical symptoms, time interval between drug intake and appearance of symptoms, response to other nonchemically related NSAIDs and the underlying disease. Based on this classification, several well differentiated categories within each group of entities cross-intolerant and selective responders are now recognized. The most complex groups for evaluation are cross-intolerant in which three major groups exist: NSAIDs exacerbated respiratory disease, NSAIDs exacerbated cutaneous disease and NSAIDs-induced urticaria/angioedema in the absence of chronic spontaneous urticaria. Within the selective responders, there are two mechanisms involved: drug-specific IgE or T-cell effector responses. New entities have been added to this classification like mixed reactions within the cross-intolerant category, that must manifest as anaphylaxis and multiple immediate selective reactions. SUMMARY: The precise evaluation of patients with NSAIDs hypersensitivity following established guidelines will improve not only our understanding but also the management of these entities. As the number of patients affected with NSAIDs is important, further studies are warranted.

Clinical Features of Hereditary and Mast Cell-mediated Angioedema Focusing on the Differential Diagnosis in Japanese Patients.

Objective The present study was designed to identify the clinical characteristics that permit the differential diagnosis of hereditary angioedema (HAE) and mast cell-mediated angioedema (Mast-AE) during the first consultation. Methods The medical histories and laboratory data of 46 patients with HAE and 41 patients with Mast-AE were compared. Results The average age of onset in the HAE group (19.8±9.0 years) was significantly lower than that in the Mast-AE group (35.2±12.0 years). The incidence of familial angioedema (AE) in the HAE group (73.9%) was significantly higher than that in the Mast-AE group (9.7%). The frequency of history of AE in the extremities, larynx, or gastrointestinal tract was significantly higher in the HAE group. The frequency of AE episodes of the lips and eyelids was significantly lower in the HAE group. The serum C4 concentration and CH50 titer were lower than the normal limit in 91.3% and 45.6% of the patients in the HAE group, respectively; in Mast-AE group the serum C4 concentration and CH50 titer were significantly lower than the normal limit in 4.8% and 0% of the patients, the difference between the two groups was statistically significant. A C1-inhibitor (C1-INH) activity level of <50% was observed in all of the HAE patients, but none of the Mast-AE patients. The mean serum IgE titer in the HAE group (120.8±130.5 IU/mL) was significantly lower than that in the Mast-AE group (262.2±314.9 IU/mL). Conclusion The parameters within the patients' medical histories, such as the age at the onset of AE, a family history of AE, and the locations of past AE episodes are critical for the successful diagnosis of the disease. Measurements of the C4 and C1-INH activity are very useful for differential diagnosis of HAE from Mast-AE.