Chronic urticaria: A disease at a crossroad between autoimmunity and coagulation

Comparative efficacy and safety of the treatment by Omalizumab for chronic idiopathic urticaria in the general population: A systematic review and network meta-analysis

BACKGROUND

Omalizumab is the only licensed drug that serves as a third-line treatment for chronic idiopathic urticaria (CIU). The optimum doses of omalizumab remain controversial. Therefore, this study aims to estimate the efficacy and safety of different doses of omalizumab in the treatment of CIU patients.

MATERIALS AND METHODS

Four databases were searched from the database's creation to April 8, 2023. Several keywords such as omalizumab and urticarias were used to retrieve related studies. The meta-analytical outcomes were analyzed in R 4.2.1 software and Stata 15.1 software. Cochrane risk-of-bias tool Ver. 2 was used to evaluate the risk of bias in randomized controlled trials (RCTs).

RESULTS

In total, 2331 patients were included. Five indexes were employed to assess, including weekly Itch Severity Score (ISS7), weekly Hive Severity Score (HSS7), weekly Urticaria Activity Score (UAS7), Dermatology Life Quality Index (DLQI), and adverse events (AE). A 300 mg dose of omalizumab was the optimum dose to treat CIU, followed by the 150 mg dose. Furthermore, 600 mg of omalizumab only showed a significant difference from the placebo in HSS7. No significant statistical difference was observed in AE. Meta-regression analysis revealed that time, as a covariate, was statistically significant in the comparison of omalizumab 150 mg with placebo.

CONCLUSION

300 mg of omalizumab was the optimum dosage to treat CIU patients, with a 150 mg dose also exhibiting good efficacy. Further studies are required to explore the efficacy and safety of different doses of omalizumab in the treatment of CIU patients.

Association between the severity of chronic spontaneous urticaria and sleep-disordered breathing

BACKGROUND

Chronic spontaneous urticaria (CSU) is a common mast cell-driven disease, presenting with wheals, angioedema, or both. Sleep-disordered breathing (SDB) is also a common condition and contributes to various diseases by causing chronic inflammation. Recent studies have suggested an association between CSU and SDB.

METHODS

To determine the association between the severity of SDB and that of CSU, we studied consecutive patients with CSU who visited the Sagamihara National Hospital allergy department or dermatology department between April 1 and October 31, 2018. The severity of CSU and SDB was evaluated based on the urticaria activity score 7 (UAS7) and peripheral arterial tone apnea-hypopnea index (pAHI) derived from out-of-center sleep testing (OCST) findings, respectively; their correlation was examined.

RESULTS

Of the 37 patients studied, 19 had symptom-free-to-mild CSU (UAS7 ≤15) and 18 had moderate-to-severe CSU (UAS7 ≥16). The pAHI in the latter group was significantly higher than that in the former group (18 vs. 4.2, p = 0.001). In multivariate logistic analysis, moderate-to-severe SDB (pAHI ≥15) was significantly associated with moderate-to-severe CSU even after adjusting for the BMI (adjusted odds ratio 22 [95% confidence interval, 1.7-285]).

CONCLUSIONS

The severity of SDB is correlated with that of CSU independently of the BMI. Physicians should consider comorbid SDB when treating patients with CSU.

Thrombin induces pro-inflammatory and anti-inflammatory cytokines secretion from human mast cell line (HMC-1) via protease-activated receptors

Thrombin-induced mast cell activation represents cross-talk between coagulation and inflammation. However, there is still controversy concerning the pro- or anti-inflammatory effects mast cells have in response to thrombin signaling. Human mast cell HMC-1 was incubated with 0.2 U/mL thrombin. Cells and supernatants were collected. Production of pro- and anti-inflammatory mediators was determined by quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA). Expression of proteinase-activated receptor-1 (PAR1) and -4 (PAR4) mRNA in HMC-1 cells was analyzed by qPCR. Activation of mitogen-activated protein kinases (MAPKs) was measured by immunoblotting. Furthermore, the impact of PAR1 inhibitor (SCH79797) and agonist (TFLLR-NH₂), PAR4 inhibitor (BMS986120) and agonist (AYPGKF-NH₂), and MAPK inhibitors (SB203580, PD98059, and SP600125) on the production of mediators was evaluated using qPCR and ELISA. Thrombin exposure increased pro- and anti-inflammatory mediators, expression of PAR1 and PAR4 mRNA, and phosphorylation of JNK, p38, and ERK1/2 MAPKs in HMC-1 cells. SCH79797, BMS986120, and MAPK inhibitors (SB203580, PD98059, and SP600125) were inhibited, while TFLLR-NH₂ and AYPGKF-NH₂ promoted pro- and anti-inflammatory cytokines in this process. HMC-1 produces pro- and anti-inflammatory cytokines after thrombin incubation, namely PAR1 and PAR4. Alongside HMC-1, MAPK signaling pathways are involved in the production of these mediators. The mast cells showed dual activation after thrombin stimulation.

Thrombin Induces Secretion of Multiple Cytokines and Expression of Protease-Activated Receptors in Mouse Mast Cell Line

Background

Thrombin could elicit degranulation of mast cells involved in numerous physiologic and pathologic processes; however, the detailed scrutiny of this procedure and further research of possible cell signaling pathways are lacking.

Methods

P815 mouse mast cells were exposed to various concentrations of thrombin for 16 h. Expression of protease-activated receptor (PAR)1, PAR2, PAR3, and PAR4 mRNA in P815 was analyzed by quantitative real-time PCR (qRT-PCR) and the fittest concentration of thrombin was decided. Then, secretions of mediators from P815 stimulated by thrombin 0.2 U/ml were determined using enzyme-linked immunosorbent assay (ELISA) and Luminex liquichip; the possible cell signaling pathways were measured by immunoblotting. Furthermore, inhibition of thrombin inhibitor (hirudin), PAR1 inhibitor (SCH79797), and MAPK inhibitors (SB203580, PD98059, and SP600125) on the mediator section was evaluated by ELISA and Luminex liquichip.

Results

Thrombin 0.2 U/ml induced the elevated expression of PAR1, PAR2, PAR3, and PAR4, as well as the increasing level of phospho-IκBα, phospho-SAPK/JNK MAPK, phospho-P38 MAPK (Thr180/Tyr182), and phospho-ERK1/2 MAPK (p44/42) in P815. Secretion of vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α), interleukin- (IL-) 2, IL-6, chemokine ligand- (CCL-) 2, chemokine (C-X-C motif) ligand- (CXCL-) 1, and CXCL-5 from P815 increased apparently; this effect could be diminished by hirudin, whereas SCH79797 and MAPK inhibitors (SB203580, PD98059, and SP600125) diminish the secretions with weaker effect.

Conclusion

We found the expression of PAR mRNA in P815, activation of signaling pathways of nuclear factor-kappaB (NF-κB), and mitogen-activated protein kinases (MAPKs) including C-Jun NH2-terminal kinase (JNK), P38, and extracellular signal-regulated kinase 1/2 (ERK1/2), and the release of multiple inflammatory mediators stimulated by thrombin, as well as the inhibition of the inflammatory releases by hirudin, SCH79797, and MAPK inhibitors including SB203580, PD98059, and SP600125.

Coagulation and Skin Autoimmunity

Several lines of evidence indicate that the immune system, inflammation, and coagulation are simultaneously activated in autoimmune and immune-mediated skin diseases. Pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor-alpha induce the expression of the main initiator of coagulation, i.e., tissue factor. The proteases of coagulation in turn act on protease-activated receptors inducing the expression of various pro-inflammatory cytokines triggering inflammation. The cross-talk among immune system, inflammation, and coagulation amplifies and maintains the activation of all three pathways. This review focuses on three skin disorders as chronic spontaneous urticaria (CSU), angioedema, and bullous pemphigoid (BP), in which the relationships among the three systems have been investigated or their clinical consequences are relevant. Markers of thrombin generation, fibrinolysis, and inflammation have been reported to be increased in the plasma during flares of CSU and angioedema, as well as in the active phase of BP, with the marker levels reverting to normal during remission. The coagulation activation seems to be important only at local level in CSU and angioedema while both at local and systemic levels in BP which is the only condition associated with an increased thrombotic risk. The prothrombotic state in autoimmune skin diseases raises the question of the indication of anticoagulant treatment, particularly in the presence of other cardiovascular risk factors.

Chronic Spontaneous Urticaria in Patients with Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is a predominantly antibody deficiency and is one of the most common primary immunodeficiencies in adulthood. Replacement therapy with Ig has significantly reduced infectious complications; however, malignant, autoimmune, and inflammatory diseases are still current major causes of morbidity and mortality. In recent years, interest has increased regarding allergic manifestations that may be associated with primary immunodeficiencies; however, no data are currently available on chronic spontaneous urticaria (CSU). In this report, the authors describe CSU in patients with CVID attending their centre. Three CVID patients were affected by CSU and were unresponsive to antihistamines. Patients were screened for the presence of serum autoreactivity by an autologous serum skin test; only one patient was positive for serum autoreactivity. The serum of this patient was found to induce CD63 upregulation on basophils and degranulation of LAD2 mast cells. All patients were treated with omalizumab therapy at the standard dose of 300 mg every 4 weeks. The patient with autoreactive serum was the best responder to omalizumab therapy, whereas the other two patients experienced urticaria flares related to intercurrent infections. In this article, the authors describe the presence of CSU in patients with CVID for the first time. Although autoimmunity is a feature of CVID, autoreactivity was documented in one patient only, thus showing that CSU in patients with CVID reflects the heterogeneity of this immune defect.

Chronic spontaneous urticaria and the extrinsic coagulation system

Chronic spontaneous urticaria (CSU) is a common skin disorder characterized by daily or almost daily recurring skin edema and flare with itch. Recently, the activation of the blood coagulation cascade has been suggested to be involved in CSU, but the trigger of the coagulation cascade remains unclear. In this article, we review recent understanding of the relationship between the pathogenesis of CSU and extrinsic coagulation reactions. In CSU, vascular endothelial cells and eosinophils may play a role as TF-expressing cells for activating the extrinsic coagulation pathway. Moreover, the expression of TF on endothelial cells is synergistically enhanced by the activation of Toll-like receptors and histamine H₁ receptors. The activated coagulation factors may induce plasma extravasation followed by degranulation of skin mast cells and edema formation recognized as wheal in CSU. Molecules involved in this cascade could be a target for new and more effective treatments of urticaria.

Clinical efficacy of omalizumab in chronic spontaneous urticaria is associated with a reduction of FcεRI-positive cells in the skin

Background. Treatment with omalizumab, a humanized recombinant monoclonal anti-IgE antibody, results in clinical efficacy in patients with Chronic Spontaneous Urticaria (CSU). The mechanism of action of omalizumab in CSU has not been elucidated in detail. Objectives. To determine the effects of omalizumab on levels of high affinity IgE receptor-positive (FcεRI⁺) and IgE-positive (IgE⁺) dermal cells and blood basophils. Treatment efficacy and safety were also assessed. Study design. In a double-blind study, CSU patients aged 18‑75 years were randomized to receive 300 mg omalizumab (n=20) or placebo (n=10) subcutaneously every 4 weeks for 12 weeks. Changes in disease activity were assessed by use of the weekly Urticaria Activity Score (UAS7). Circulating IgE levels, basophil numbers and levels of expression of FcεRI⁺ and IgE⁺ cells in the skin and in blood basophils were determined. Results. Patients receiving omalizumab showed a significantly greater decrease in UAS7 compared with patients receiving placebo. At Week 12 the mean difference in UAS7 between treatment groups was -14.82 (p=0.0027), consistent with previous studies. Total IgE levels in serum were increased after omalizumab treatment and remained elevated up to Week 12. Free IgE levels decreased after omalizumab treatment. Mean levels of FcεRI⁺ skin cells in patients treated with omalizumab 300 mg were decreased at Week 12 compared with baseline in the dermis of both non-lesional and lesional skin, reaching levels comparable with those seen in healthy volunteers (HVs). There were no statistically significant changes in mean FcɛRI⁺ cell levels in the placebo group. Similar results were seen for changes in IgE⁺ cells, although the changes were not statistically significant. The level of peripheral blood basophils increased immediately after treatment start and returned to Baseline values after the follow-up period. The levels of FcεRI and IgE expression on peripheral blood basophils were rapidly reduced by omalizumab treatment up to Week 12. Conclusions. Treatment with omalizumab resulted in rapid clinical benefits in patients with CSU. Treatment with omalizumab was associated with reduction in FcɛRI⁺ and IgE⁺ basophils and intradermal cells.

Autologous Serum and Plasma Skin Tests in Chronic Spontaneous Urticaria: A Reappraisal

AIM

The objective of this study was to assess autologous serum skin test (ASST) vs autologous plasma skin test (APST) response in chronic spontaneous urticaria (CSU) patients and study the significance of intensity of positive responses in relation to clinicoepidemiological parameters.

MATERIALS AND METHODS

One hundred CSU patients and 100 age and sex-matched controls were recruited. The demographic and clinical features were recorded in all patients and routine investigations were performed. ASST and APST tests were performed as per the standard guidelines.

RESULTS

The mean duration of illness was 4.85 ± 5.07 years, 90% patients were APST (+), 68% ASST (+), and 22 patients were only APST (+). Positive predictive value (PPV) of ASST and APST was 90.7% and 95.7%, respectively. A significant inverse association was seen between thyroid status and serum IgE levels with APST and ASST positivity.

CONCLUSION

APST appears to have better PPV and high intensity of positive response on autologous tests, and correlates with ANA positivity and angioedema.

The relation of autologous serum and plasma skin test results with urticarial activity score, sex and age in patients with chronic urticaria

Introduction

Some previous studies reported autoimmunity as an etiologic factor in chronic urticaria (CU), but the results of some autoimmunity tests in these studies are conflicting.

Aim

To concretize whether there was any relation of autologous serum skin test (ASST) and autologous plasma skin test (APST) results with sex, age and urticarial activity score (UAS) in patients with CU.

Material and methods

Fifty patients with CU and twenty healthy subjects admitted to our dermatology clinic were included in the present study. The ASST and APST were applied to all individuals.

Results

The positiveness rates of ASST and APST were significantly higher in the patient group than controls (p = 0.027, p = 0.001, respectively). Among patients, the APST positiveness rate (72%) was significantly (p < 0.05) higher than ASST (46%). It was seen that 48% of patients with negative ASST results had positive APST. However, no patient with negative APST results had positive ASST. There were significant (p < 0.05) relations of the tests’ positiveness rates with sex and old age but with UAS. The diameter of the erythematous papule was remarkably (p < 0.05) larger in APST than ASST and also significantly (p < 0.05) larger in females compared to males in both tests (p < 0.05). It was positively increased with old age (p < 0.05).

Conclusions

We can suggest that APST is more sensitive than ASST in the assessment of autoimmunity in CU. A high positiveness rate of APST results may be attributed to high numbers of autoantibodies and coagulation factors present in plasma that might probably play a role in etiopathogenesis of CU.

Platelet and other hemostatic characteristics in patients with chronic urticaria

Several publications have pointed out the importance of coagulation and fibrinolysis in the occurrence of chronic urticaria (CU), but only a few indicated the direct role of platelets. We assessed platelet aggregation and evaluated parameters of coagulation and fibrinolysis in patients with CU. Patients (n = 34) diagnosed as having CU and 36 healthy controls were enrolled. Platelet aggregation was assayed using an impedance aggregometer and adenosine diphosphate, arachidonic acid, thrombin receptor-activating peptide (TRAP), and ristocetin as agonists. In patients with CU, significantly decreased platelet aggregation to some agonists (ristocetin and TRAP) was observed. The D-dimer levels were elevated, mean platelet volume was decreased, but no alteration was observed in other coagulation assays. Elevated D-dimer levels indicated that coagulation and fibrinolysis are activated in the patients with CU. Evaluation of platelet function may contribute to identify the role of these cells in the pathogenesis of CU.

Chronic idiopathic angioedema: a single center experience

OBJECTIVE

Chronic idiopathic angioedema (CIA) is defined as three or more episodes of angioedema in a period of > 6 months without a clear etiology. In the study, we tried to explore clinical and laboratory characteristics of patients with CIA unaccompanied by urticaria.

METHODS

We retrospectively reviewed clinical and laboratory characteristics of 1238 patients with chronic urticaria and/or angioedema referred to our allergy clinic.

RESULTS

Eight hundred and forty-one (67.9%) subjects had chronic urticaria without angioedema (CU Group), 323 (26.1%) had both urticaria and angioedema (CU + CA group), and 74 (5.9%) had chronic angioedema without urticaria (CA). In 29 (39.2%) cases of CA, no etiologic factor of angioedema was discovered, thus the patients were defined as having chronic idiopathic angioedema (CIA Group). Twenty-two (75.8%) subjects had antihistamine-responsive CIA and seven (24.1%) had antihistamine-unresponsive CIA. There were no statistically significant differences in clinical (except of urticarial eruptions) and laboratory characteristics between CU, CA + CU, and CIA groups. Antihistamine responsive and antihistamine-unresponsive CIA groups had no distinguishable clinical or laboratory features.

CONCLUSIONS

We suppose that CIA, at least its antihistamine-responsive form, represents a rare form of chronic spontaneous urticaria. The reasons why in CIA there are no other clinical signs of mast cell/basophil activation, such as pruritus, urticarial, and dermatographism, are largely unknown and have to be elucidated in future studies.

Chronic urticaria and coagulation: pathophysiological and clinical aspects

Chronic urticaria (CU) is a widespread skin disease, characterized by the recurrence of transient wheals and itch for more than 6 weeks. Besides autoimmune mechanisms, coagulation factors, in particular tissue factor and thrombin, might also participate in the disease pathophysiology. Tissue factor expressed by eosinophils can induce activation of blood coagulation generating thrombin which in turn can increase vascular permeability both directly, acting on endothelial cells, and indirectly, inducing degranulation of mast cells with release of histamine, as demonstrated in experimental models. D-dimer, a fibrin degradation product, generated following activation of the coagulation cascade and fibrinolysis, has been found to be increased during urticaria exacerbations; moreover, it has been proposed as a biomarker of severity and resistance to H1-antihistamines in CU patients. The possible role of coagulation in CU is also supported by case reports, case series and a small controlled study showing the efficacy of anticoagulant therapy in this disease. The purpose of this review was to summarize the available data on the possible contribution of coagulation to the pathophysiology of CU focusing on clinical aspects and possible future therapeutic developments.

The "missing link" in autoimmunity and autism: extracellular mitochondrial components secreted from activated live mast cells

Autoimmune diseases continue to increase, but the reason(s) remain obscure and infections have not proven to be major contributors. Mast cells are tissue immune cells responsible for allergies, but have been increasingly shown to be involved in innate and acquired immunity, as well as inflammation. This involvement is possible because of their ability to release multiple mediators in response to a great variety of triggers. We recently published that activation of mast cells is accompanied by mitochondrial fission and translocation to the cell surface from where they secrete at least ATP and DNA outside the cell without cell damage. These extracellular mitochondrial components are misconstrued by the body as "innate pathogens" leading to powerful autocrine and paracrine auto-immune/auto-inflammatory responses. We also showed that mitochondrial DNA is increased in the serum of young children with autism spectrum disorders (ASD), a condition that could involve "focal brain allergy/encephalitits". Blocking the secretion of extracellular mitochondrial components could present unique possibilities for the therapy of ASD and other autoimmune diseases. Unique formulation of the flavonoid luteolin offers unique advantages.

Correlation between plasma D-dimer levels and the severity of patients with chronic urticaria

Background

Beside autoimmunity, coagulation pathway is also involved in the pathogenesis of chronic urticaria (CU). Previous studies showed that plasma D-dimer levels paralleled the severity of the disease. To date, there are no data concerning D-dimer level in Thai patients with CU.

Objective

This study aimed to find the relationship between plasma D-dimer levels and the disease severity of Thai CU patients. The secondary objective is to analyze plasma D-dimer level in each group of patients who performed autologous plasma skin testing (APST) and autologous serum skin testing (ASST).

Methods

We retrospectively reviewed case record forms of chronic idiopathic urticaria (CIU) patients aged at least 18 years in Skin Allergy Clinic, Siriraj Hospital Mahidol University, Bangkok, during June 2008 to June 2011.

Results

Of 120 patients, plasma D-dimer level was abnormal in 58 patients (48.3%). The study showed statistically significant positive correlation between disease severity and plasma D-dimer level (p < 0.05, r = 0.537). There was no statistically significant difference in plasma D-dimer level between APST positive and negative groups, and also between ASST positive and negative groups. In APST negative group, plasma D-dimer level was elevated in 29 patients (47.5%) and correlated with disease severity.

Conclusion

This study showed elevated plasma D-dimer levels in nearly half of Thai patients with CIU. There was a positive correlation between plasma D-dimer levels and the severity of disease activity. Investigation for plasma D-dimer level may be an alternative way to evaluate disease severity in patients with CIU.

Role of serine proteases in inflammation: Bowman-Birk protease inhibitor (BBI) as a potential therapy for autoimmune diseases

Serine proteases, a sub-category of the protease family, participate in various physiologic and pathologic conditions. Serine proteases are involved in different arms of the immune system and play an important role in inflammation. They have been evaluated as therapeutic targets in several inflammatory diseases. The Bowman-Birk protease inhibitor (BBI), a soybean-derived serine protease inhibitor, is resistant to temperature and acidic conditions. These characteristics make it a good candidate for oral administration, with no major side effects. In addition, the therapeutic effect of BBI has been shown in inflammatory diseases and cancer. We have demonstrated the immunoregulatory and anti-inflammatory effects of BBI in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis. Here we review the role of serine proteases in inflammatory diseases, with emphasis on the potential of BBI as a novel oral therapy for multiple sclerosis.

Many faces of angioedema: focus on the diagnosis and management of abdominal manifestations of hereditary angioedema

Angioedema of the intestinal tract is an infrequent but well-described cause of abdominal pain that can occur because of inherited, acquired, allergic, or drug-induced causes. Hereditary angioedema (HAE) is a genetic disorder that causes recurrent attacks of severe edema of various body parts, including the intestinal tract. Moderate to severe abdominal pain occurs in 43-93% of such attacks due to intestinal edema. Laryngeal edema is a potentially life-threatening manifestation. Failure to recognize and diagnose HAE or other causes of intestinal angioedema can lead to years of delay in diagnosis, and in the case of HAE, often to unnecessary abdominal surgeries. Recognizing the typical history of recurrent attacks of abdominal pain, oropharyngeal/laryngeal angioedema or cutaneous angioedema, family history of similar symptoms, association of attacks with stress or menses, and exacerbation of attacks after administration of estrogens or angiotensin-converting enzyme inhibitors will increase diagnostic accuracy. Interdisciplinary treatment is often necessary after the diagnosis of HAE, first with acute management in the emergency room or the intensive care unit, followed by either drug prophylaxis against future attacks using a C1-esterase inhibitor concentrate or attenuated androgens and discontinuation of medications known to trigger attacks. Newer drugs approved for treatment of acute attacks may have future roles in the prevention of attacks if further studies support their efficacy. Gastroenterologists in particular should maintain a high index of suspicion for the possibility of HAE or other causes of intestinal angioedema in patients with a history of recurrent abdominal pain.

Evaluation of autologous plasma skin test in patients with chronic idiopathic urticaria

BACKGROUND

The pathophysiological mechanism of chronic urticaria is still poorly understood and its aetiology is considered to have an autoreactive basis. Autologous serum skin tests (ASSTs) and autologous plasma skin tests (APSTs) comprise the simplest ways for diagnosing autoreactive urticaria (with autoantibodies, histamine-releasing factor and coagulation factors, especially thrombin) in a clinical setting. However, there are still some questions about the specificity of these tests.

OBJECTIVES

To evaluate the role of autoreactivity in the pathogenesis of chronic urticaria by means of measuring plasma prothrombin fragments 1 + 2, which are used as markers of thrombin, and to compare the APST with the ASST.

METHODS

Forty-two patients (19 men and 23 women; mean age 35·7 years, range 28-76) and 35 healthy volunteers (19 men and 16 women; mean age 30·3 years, range 20-80) were included in the study. APST, negative (ASST, sodium citrate, saline) and positive (histamine) control tests were performed in the patient and control groups. The levels of plasma prothrombin fragments 1 + 2 were also assessed.

RESULTS

When the APST was evaluated without negative controls, it was positive in 67% of patients. However, the APST was positive in 0% when it was evaluated with negative controls. Levels of prothrombin fragments 1 + 2 were found to be elevated in patients with chronic idiopathic urticaria.

CONCLUSIONS

We suggest that as negative control tests were not performed along with the APST in previous studies, the APST showed a high rate of positivity. Thus, the use of APST for evaluating autoreactivity in clinical practice is not superior to the use of ASST and further studies should be conducted.

Pathophysiology of Hereditary Angioedema

Background

Laryngeal angioedema may be associated with significant morbidity and even mortality. Because of the potential severity of attacks, both allergists and otolaryngologists must be knowledgeable about the recognition and treatment of laryngeal angioedema. This study describes the clinical characteristics and pathophysiology of bradykinin-mediated angioedema.

Methods

A literature review was conducted concerning the clinical characteristics and pathophysiology of types I and II hereditary angioedema (HAE), type III HAE, acquired C1 inhibitor (C1INH) deficiency, and angiotensin-converting enzyme (ACE) inhibitor–associated angioedema.

Results

The diagnosis of type I/II HAE is relatively straightforward as long as the clinician maintains a high index of suspicion. Mutations in the SERPING1 gene result in decreased secretion of functional C1INH and episodic activation of plasma kallikrein and Hageman factor (FXII) of the plasma contact system with cleavage of high molecular weight kininogen and generation of bradykinin. In contrast, there are no unequivocal criteria for making a diagnosis of type III HAE, although a minority of these patients may have a mutation in the factor XII gene. Angioedema attacks and mediator of swelling in acquired C1INH deficiency are similar to those in type I or II HAE; however, it occurs on a sporadic basis because of excessive consumption of C1INH in patients who are middle aged or older. ACE inhibitor–associated angioedema should always be considered in any patient taking an ACE inhibitor who experiences angioedema. ACE is a kininase, which when inhibited is thought to result in increased bradykinin levels. Bradykinin acts on vascular endothelial cells to enhance vascular permeability.

Conclusion

Laryngeal swelling is not infrequently encountered in bradykinin-mediated angioedema. Novel therapies are becoming available that for the first time provide effective treatment for bradykinin-mediated angioedema. Because the characteristics and treatment of these angioedemas are quite distinct from each other and from histamine-mediated angioedema, it is crucial that the physician be able to recognize and distinguish these swelling disorders.

Repressor of GATA negatively regulates murine contact hypersensitivity through the inhibition of type-2 allergic responses

Repressor of GATA (ROG) inhibits Th2 cell differentiation and allergic airway inflammation in the lung. To determine the role of ROG in the pathogenesis of contact hypersensitivity (CHS), a hapten-induced mouse model of CHS using ROG Tg and ROG-deficient (ROG(-/-)) was used. ROG Tg mice showed little ear swelling, while ROG(-/-) mice showed enhanced ear swelling in comparison to wild type mice. Interstitial edema and mast cell degranulation at the local inflammation sites were mild in ROG Tg mice and exacerbated in ROG(-/-) mice. In addition, the serum total IgE and hapten-specific IgG1 levels were increased in ROG(-/-) mice. Adoptive transfer of ROG(-/-) CD4(+) T cells exacerbated CHS in wild type mice, while transfer of ROG Tg CD4(+) T cells resulted in the attenuation of CHS. These results indicate ROG negatively regulates the induction of CHS by controlling the CD4(+) T cell-mediated allergic responses, including IgE generation and mast cell degranulation.

Omalizumab therapy in three patients with chronic autoimmune urticaria

Chronic urticaria is a common skin disease. In about 45% of patients the cause is an autoantibody directed at the α-subunit of the high-affinity IgE receptor (chronic autoimmune urticaria; CAU). Omalizumab is a monoclonal anti-IgE antibody that has a proven role in the treatment of various allergic diseases. We gave omalizumab once every month for 16 weeks to three patients that were refractory to standard treatment, including high doses of antihistamines, leukotriene receptor antagonist, and corticosteroid. There was dramatic improvement in the primary efficacy variable--the change in mean urticaria activity score (UAS) from baseline (i.e., the average over the first 4-week period before omalizumab) to the final 4-week period of omalizumab treatment. There was improvement in the secondary efficacy variables, which included change from baseline in interference with sleep, interference with daily activities, daily diary record of urticaria signs and symptoms based on a scoring system, and rescue medication use. These improvements persisted for 12 weeks after discontinuation of the drug. Omalizumab may have a role in treating refractory cases of CAU.

Treatment strategies in urticaria

Urticaria is a common group of disorders encountered in dermatology and in a variety of other fields. In particular, acute urticaria and angiooedema are common medical emergencies, which are treated in the first instance in the Accident and Emergency Department, whereas chronic urticaria poses a challenge in the long-term treatment. This review presents the latest evidence about the treatment for urticaria and is based on the most recent international guidelines (GA(2)LEN, Global Allergy and Asthma Network, 2009). Patients with acute and chronic urticaria are often not treated appropriately and this review provides a guide for any clinician to treat the underlying cause as well as the symptoms of this disorder according to the latest evidence. Many new therapies are available to patients with urticaria refractory to common therapies and it is important to consider second- and third-line therapies.

Skin autoimmunity and blood coagulation

Evidence exists that the immune and coagulation systems are simultaneously activated in some systemic autoimmune disorders. Although proinflammatory mediators induce tissue factor (TF) expression, the main initiator of blood coagulation, activated proteases of coagulation may act on protease-activated receptors (PAR) triggering inflammation. Such a cross-talk amplifies and maintains the activation of both systems. This review focuses on the involvement of immune and coagulation system in two skin disorders as chronic urticaria (CU), autoimmune in about 45% of cases, and bullous pemphigoid (BP), the prototype of autoimmune blistering diseases. Several investigators demonstrated the activation of coagulation in CU through the involvement of eosinophils, of TF pathway with thrombin generation and increased vascular permeability. Preliminary data indicate that anticoagulant treatment with heparin and warfarin may be effective in reducing the symptoms of this disorder. The activation of coagulation seems to display local and systemic implications in BP. Eosinophils' recruitment and thrombin generation locally contribute to the bulla formation and tissue damage. The systemic activation of coagulation may explain the increased thrombotic risk observed in these patients. Taken together, these data provide the rationale for proposing clinical trials on the anticoagulant treatment in both CU and BP patients.

Coagulation/fibrinolysis and inflammation markers are associated with disease activity in patients with chronic urticaria

BACKGROUND

The evaluation of disease severity and activity of chronic urticaria (CU) is essential for the adequate treatment of patients. However, there is no reliable biomarker for such evaluations. Recently, markers of blood coagulation and fibrinolysis have been revealed to be elevated in severe cases of CU. In this article, we studied the coagulation/fibrinolysis and inflammation markers and their relationship to disease activity in patients with CU.

METHODS

Plasma fibrin degradation products (FDP), d-dimer and serum C-reactive protein (CRP) were measured with the assessment of disease severity and skin reaction to autologous serum in 82 patients with CU and 37 patients with acute urticaria, idiopathic angioedema (AE) or inducible types of urticaria (IU).

RESULTS

The levels of FDP in patients with CU were significantly higher than those in patients with IU, but no other differences in FDP, d-dimer and CRP were observed among patients with different types of urticaria. These markers of patients with CU were well correlated with each other and significantly associated with disease severity of CU, but not with skin reactions to autologous serum. In 37 patients with CU, levels of all these parameters reduced as their disease condition improved, while they increased when the disease became aggravated. Regarding FDP, this relationship was observed even if FDP concentrations were within normal range throughout the study.

CONCLUSIONS

The measurement of plasma FDP, d-dimer and serum CRP may be useful for the assessment of disease activity of CU.

Urticarial lesions: if not urticaria, what else? The differential diagnosis of urticaria: part I. Cutaneous diseases

Acute urticaria is self-limiting, and a cause can be identified in many patients. Chronic urticaria is a long lasting disease, and patients are commonly examined for an autoimmune origin and for associated diseases. Although the diagnosis of urticaria is straightforward in most patients, it may pose some difficulties at times and it may require a careful differential diagnosis with a number of conditions. Urticarial syndromes comprise both cutaneous and systemic disorders. Part I of this two-part series focuses on the clinical and histologic features that characterize common urticaria and on the cutaneous diseases that may manifest with urticarial lesions and must be considered in the differential diagnosis.

LEARNING OBJECTIVES

After completing the learning activity, participants should be able to distinguish between the typical wheals of urticaria and urticarial lesions suggesting other diagnoses and to assess patients with urticarial lesions in order to exclude or confirm other cutaneous diseases.

Clinical evaluation and treatment of chronic urticaria

Chronic urticaria is a common disease characterized by recurrent pruritic wheals with surrounding erythema for >6 weeks. It is associated with a significant health care burden and affects patient quality of life. The etiology of chronic urticaria is often difficult to elucidate; however, known etiologies include autoimmune urticaria, physical urticarias (eg, cold, cholinergic, and delayed pressure urticaria), and idiopathic urticaria. The etiology is unknown in many patients, leading to a diagnosis of chronic idiopathic urticaria. The diagnosis of chronic idiopathic urticaria can be challenging for the primary care physician because of the disease's chronic symptoms. Diagnosis requires a detailed patient history and comprehensive physical examination, with additional testing tailored to the patient's history. Effective treatments include antihistamines, leukotriene receptor antagonists in combination with antihistamines, and oral immunomodulatory drugs, including corticosteroids, cyclosporine, dapsone, hydroxychloroquine, and sulfasalazine. Newer experimental therapies include intravenous immunoglobulin and omalizumab. This article reviews the pathophysiology, diagnosis, and treatment of chronic urticaria.

What'S new in urticaria?

Urticaria, a perplexing disease of ever-changing explanations, is being renovated almost everyday by newer facts and findings accumulated from different parts of the globe. Cost of the urticaria treatment gradually grows higher and higher whereas the ailment disturbs the quality of life very adversely. Disorder of coagulation cascade has recently thrown some new light into its mechanism. Non-allergic angioedema induced by bradykinin caused by genetic defects and ACE-inhibitors has also been noted. Role of H. pylori in the pathogenesis of urticaria has also been re-reviewed. Urticaria could sometimes mimic erythema multiforme and is termed urticaria multiforme. Skin biopsy showed features of vasculitis in good number of urticaria irrespective of clinical features. Contact sensitization showed positive results in certain cases thus proving contact urticaria. Topical clobetasol, systemic omalizumab and NB UVB have shown promising results in certain forms of urticaria.

Allergic skin diseases

The skin is one of the largest immunologic organs and is affected by both external and internal factors, as well as innate and adaptive immune responses. Many skin disorders, such as atopic dermatitis, contact dermatitis, urticaria, angioedema, psoriasis, and autoimmune blistering disorders, are immune mediated. Most of these diseases are chronic, inflammatory, and proliferative, in which both genetic and environmental factors play important roles. These immunologic mechanisms might have implications for potential targets of future therapeutic interventions.

C5a-induced in vitro basophil activation in patients with chronic urticaria: a pilot study

BACKGROUND

Complement component 5a (C5a) might be involved in the formation of wheals in patients with chronic urticaria (CU). We sought to compare the in vitro responsiveness of basophils to C5a in patients with CU and in a control group.

METHODS

Basophil surface expression of activation marker CD63 induced by C5a, anti-FcepsilonRI mAb or anti-IgE pAb was measured using flow cytometry in 17 patients with CU and in 10 healthy controls.

RESULTS

Patients with CU showed significantly greater basophil CD63 surface expression induced by C5a (median [interquartile range]; 16.4% [13-25.1]; P = 0.011) than the group of healthy controls (10.7% [7.2-16.8]). In contrast, basophil CD63 response to anti-IgE and anti-FcepsilonRI was lower in the CU group (12.3% [6-36.3]; 25.9% [12.5-60.5]) than in the control group (51.7% [6.7-84.3]; 62.1% [9.7-89.2]), although not statistically significant.

CONCLUSION

Results of this pilot study suggest that patients with CU might have an enhanced basophil response to stimulation with C5a, indicating that further studies in CU basophil responsiveness are needed.

Clinical Immunology Review Series: An approach to the patient with angio-oedema

Angio-oedema is a common reason for attendance at the accident and emergency department and for referral to immunology/allergy clinics. Causative factors should always be sought, but a large proportion of patients have the idiopathic form of the disease. A minority of patients represent a diagnostic and treatment challenge. Failure to identify the more unusual causes of angio-oedema may result in life-threatening situations. Common and rare causes of angio-oedema will be discussed in this article, as well as the diagnostic and treatment pathways for the management of these patients. A comprehensive history and close monitoring of response to treatment are the most cost-effective diagnostic and treatment tools.

Update on chronic urticaria: focusing on mechanisms

PURPOSE OF REVIEW

This review discusses some of the recent advances in basic and clinical research focused on chronic urticaria. It is a concise summary of issues that occupied researchers' attention in the previous year, and it discusses a selection of novel findings that further our understanding of the pathomechanism of this disease.

RECENT FINDINGS

Particular consideration is given to the role of basophils, the coagulation cascade, fibrinolysis, and hormonal pathways in chronic urticaria pathogenesis. The description of clinical data is focused on prognostic issues, disease severity, and the effects of the disease on patients' quality of life.

SUMMARY

Mast cells are the key elements in chronic urticaria pathogenesis, whereas basophils should be regarded as bystanders and serve as biomarkers in some chronic urticaria subsets. The coagulation cascade, hormonal factors, and the psychological status of the patients seem to contribute substantially to the course and activity of the disease. Nonsedating second-generation antihistamines should be considered as first-line symptomatic treatment for chronic urticaria. Of note, the dosage should be increased up to four-fold if required before switching to second-line therapies.

An update on childhood urticaria and angioedema

PURPOSE OF REVIEW

The present review serves to address urticaria - both acute and chronic - as well as the differential diagnosis of urticarial syndromes in the pediatric population. We also wish to update the reader on progress in the pathophysiology, diagnosis and treatment of urticaria.

RECENT FINDINGS

Acute and chronic urticaria represent syndromes caused by a variety of triggers. Recent literature continues to describe subtypes of urticaria that may be differentially responsive to particular therapies. Recent associations highlight the need to fully evaluate patients for allergic and infectious triggers of urticaria. It is important to distinguish idiopathic urticaria from related conditions such as anaphylaxis, systemic conditions and autoimmune urticaria. Although antihistamines remain a cornerstone of therapy, particular urticaria subtypes may also respond to novel therapies such as omalizumab. Chronic urticaria has a significant impact on a patient's quality of life.

SUMMARY

Urticaria is a common condition. Our understanding of distinct urticaria subtypes differentially responsive to targeted therapies continues to increase. Due to the myriad of triggers that may cause urticaria, careful individualized patient assessment is necessary to exclude potential etiologies prior to a diagnosis of idiopathic urticaria.