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Introduction : Thymic stromal lymphopoietin (TSLP) is overexpressed in the airways of severe asthmatics and is an upstream cytokine that orchestrates inflammatory responses in asthma. TSLP exerts its effects by binding to a high affinity heteromeric receptor complex composed of TSLPR and IL-7Rα. An association of polymorphisms in TSLP with airway hyperresponsiveness, IgE, eosinophilia and asthma has been documented. TSLP has been implicated in asthma pathophysiology. Tezepelumab is a first-in-class human monoclonal antibody that binds to TSLP, thus inhibiting its interaction with TSLP receptor complex. Tezepelumab given as an add-on-therapy to patients with severe uncontrolled asthma has shown safety, tolerability and efficacy. Several trials are evaluating the long-term safety and the efficacy of tezepelumab in adults and adolescents with severe uncontrolled asthma. Areas covered : We provide an overview of the monoclonal antibody therapeutics market for severe uncontrolled asthma, examine the underlying pathophysiology that drives TSLP and discuss the use of tezepelumab for the treatment of severe uncontrolled asthma, Expert opinion : TSLP is a promising target for T2-high and perhaps some patients with T2-low asthma. The results of preliminary clinical trials are encouraging. Several unanswered questions concerning basic pathophysiological aspects of TSLP variants, the long-term safety and efficacy of tezepelumab with different phenotypes/endotypes of asthma should be addressed.

Mast cells and their mediators play a role in the control of homeostasis and in the pathogenesis of several disorders. The concept of rodent mast cell heterogeneity, initially established in the mid-1960s has been extended in humans. Human mast cells isolated and purified from different anatomic sites can be activated via aggregation of cell surface high affinity IgE receptors (FcεRI) by antigens, superantigens, anti-IgE, and anti-FcεRI. MAS-related G protein-coupled receptor-X2 (MRGPRX2) is expressed at high level in human skin mast cells (MCs) (HSMCs), synovial MCs (HSyMCs), but not in lung MCs (HLMCs). MRGPX2 can be activated by neuropeptide substance P, several opioids, cationic drugs, and 48/80. Substance P (5 × 10 -7 M - 5 × 10 -6 M) induced histamine and tryptase release from HSMCs and to a lesser extent from HSyMCs, but not from HLMCs and human cardiac MCs (HHMCs). Morphine (10 -5 M - 3 × 10 -4 M) selectively induced histamine and tryptase release from HSMCs, but not from HLMCs and HHMCs. SP and morphine were incomplete secretagogues because they did not induce the de novo synthesis of arachidonic acid metabolites from human mast cells. In the same experiments anti-IgE (3 μg/ml) induced the release of histamine and tryptase and the de novo synthesis of prostaglandin D 2 (PGD 2 ) from HLMCs, HHMCs, HSyMCs, and HSMCs. By contrast, anti-IgE induced the production of leukotriene C 4 (LTC 4 ) from HLMCs, HHMCs, HSyMCs, but not from HSMCs. These results are compatible with the heterogeneous expression and function of MRGPRX2 receptor on primary human mast cells isolated from different anatomic sites.

Background: Subcutaneous immunoglobulin G (SCIG) may be a better option than intravenous immunoglobulin G (IVIG) for patients with primary immunodeficiencies (PID) due to reduced systemic and serious adverse reactions and easier administration. The Infusione Bimensile di Immunoglobuline Sottocute (IBIS) study investigated the effects of Hizentra ® , a 20%-concentrated SCIG, administered biweekly in patients with PID. This subanalysis aimed to evaluate clinical and laboratory outcomes in the IBIS pediatric subcohort. Methods: Thirteen children with PID were observed for 12 months retrospectively (with previous IVIG/SCIG) and prospectively with biweekly Hizentra. Results: Mean ± standard deviation serum IG levels during the retrospective (833.8 ± 175.7 mg/dL) and the prospective (842.0 ± 188.0 mg/dL) phases were comparable; there were also no differences in the number of infections. Conclusions: Biweekly Hizentra is a noninferior option with respect to previous IVIG/SCIG-based treatment., Competing Interests: G.M.B. is an employee of CSL Behring. C.C., V.G., C.P., A.T., S.G., B.M., V.M., V.P., A.M., A.P., G.S., A.V., and C.A. declare no conflicts of interest.

Studies of chest computed tomography (CT) in patients with primary antibody deficiency syndromes (ADS) suggest a broad range of bronchial pathology. However, there are as yet no multicentre studies to assess the variety of bronchial pathology in this patient group. One of the underlying reasons is the lack of a consensus methodology, a prerequisite to jointly document chest CT findings. We aimed to establish an international platform for the evaluation of bronchial pathology as assessed by chest CT and to describe the range of bronchial pathologies in patients with antibody deficiency. Ffteen immunodeficiency centres from 9 countries evaluated chest CT scans of patients with ADS using a predefined list of potential findings including an extent score for bronchiectasis. Data of 282 patients with ADS were collected. Patients with common variable immunodeficiency disorders (CVID) comprised the largest subgroup (232 patients, 82.3%). Eighty percent of CVID patients had radiological evidence of bronchial pathology including bronchiectasis in 61%, bronchial wall thickening in 44% and mucus plugging in 29%. Bronchiectasis was detected in 44% of CVID patients aged less than 20 years. Cough was a better predictor for bronchiectasis than spirometry values. Delay of diagnosis as well as duration of disease correlated positively with presence of bronchiectasis. The use of consensus diagnostic criteria and a pre-defined list of bronchial pathologies allows for comparison of chest CT data in multicentre studies. Our data suggest a high prevalence of bronchial pathology in CVID due to late diagnosis or duration of disease.

Asthma is a heterogeneous disease characterized by chronic airway inflammation that results in a wide spectrum of clinical manifestations. Patients with severe asthma represent a substantial share of consumption of healthcare resources and hospitalization. Moreover, these patients are at risk of increased morbidity and mortality. Recently, several phenotypes and endotypes of asthma have been identified. The identification of specific subtypes of asthma is fundamental for optimizing the clinical benefit of novel treatments. Although in most patients the disease can be controlled by some combination of pharmacologic agents, in some 5-10% of patients the disease remains uncontrolled. Several monoclonal antibodies (mAbs) targeting pathogenetic molecules (e.g., IgE, IL-5, IL- 5Rα, IL-4, IL-13, TSLP) are currently available or under development for the treatment of different forms of severe type 2 asthma. The identification of diagnostic and predictive biomarkers (e.g., IgE, blood eosinophil count, FeNO, periostin, etc.) has revolutioned the field of targeted therapy in severe asthma. Monoclonal antibodies targeting Th2-driven inflammation are generally safe in adult patients with moderate-to-severe asthma. The long-term safety of these biologics is a relevant issue that should be addressed. Unfortunately, little is known about non-type 2 asthma. Further studies are needed to identify biomarkers to guide targeted therapies of different forms of non-type 2 asthma., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Mast cells are immune cells which have a widespread distribution in nearly all tissues. These cells and their mediators are canonically viewed as primary effector cells in allergic disorders. However, in the last years, mast cells have gained recognition for their involvement in several physiological and pathological conditions. They are highly heterogeneous immune cells displaying a constellation of surface receptors and producing a wide spectrum of inflammatory and immunomodulatory mediators. These features enable the cells to act as sentinels in harmful situations as well as respond to metabolic and immune changes in their microenvironment. Moreover, they communicate with many immune and nonimmune cells implicated in several immunological responses. Although mast cells contribute to host responses in experimental infections, there is no satisfactory model to study how they contribute to infection outcome in humans. Mast cells modulate physiological and pathological angiogenesis and lymphangiogenesis, but their role in tumor initiation and development is still controversial. Cardiac mast cells store and release several mediators that can exert multiple effects in the homeostatic control of different cardiometabolic functions. Although mast cells and their mediators have been simplistically associated with detrimental roles in allergic disorders, there is increasing evidence that they can also have homeostatic or protective roles in several pathophysiological processes. These findings may reflect the functional heterogeneity of different subsets of mast cells., (© 2019 S. Karger AG, Basel.)

An increased prevalence of malignant lymphoma and of gastric cancer has been observed in large cohorts of patients with common variable immunodeficiency (CVID), the most frequently symptomatic primary immunodeficiency. Surveillance strategies for cancers in CVID should be defined based on epidemiological data. Risks and mortality for cancers among 455 Italian patients with CVID were compared to cancer incidence data from the Italian Cancer Registry database. CVID patients showed an increased cancer incidence for all sites combined (Obs = 133, SIR = 2.4; 95%CI = 1.7-3.5), due to an excess of non-Hodgkin lymphoma (Obs = 33, SIR = 14.3; 95%CI = 8.4-22.6) and of gastric cancer (Obs = 25; SIR = 6.4; 95%CI = 3.2-12.5). CVID patients with gastric cancer and lymphoma had a worse survival in comparison to cancer-free CVID (HR: 4.8, 95%CI: 4.2-44.4 and HR: 4.2, 95%CI: 2.8-44.4). Similar to what observed in other series, CVID-associated lymphomas were more likely to be of B cell origin and often occurred at extra-nodal sites. We collected the largest case-series of gastric cancers in CVID subjects. In contrast to other reports, gastric cancer was the leading cause of death in CVID. Standardized mortality ratio indicated a 10.1-fold excess mortality among CVID patients with gastric cancer. CVID developed gastric cancer 15 years earlier than the normative population, but they had a similar overall survival. Only CVID diagnosed at early stage gastric cancer survived >24 months. Stomach histology from upper endoscopy performed before cancer onset showed areas of atrophic gastritis, intestinal metaplasia or dysplasia. CVID patients might progress rapidly to an advanced cancer stage as shown by patients developing a III-IV stage gastric cancer within 1 year from an endoscopy without signs of dysplasia. Based on high rate of mortality due to gastric cancer in Italian CVID patients, we hereby suggest a strategy aimed at early diagnosis, based on regular upper endoscopy and on Helicobacter pylori infection treatment, recommending an implementation of national guidelines.

Background: In Italy, there is scarce evidence on the epidemiological and economic burden induced by primary antibody deficiencies., Objective: The aim of this study was to elaborate the available epidemiological and cost data in order to estimate the annual expenditure induced by the management of patients affected by the common variable immunodeficiency (CVID) and X-linked agammaglobulinemia (XLA) requiring immunoglobulin (Ig) replacement therapy., Methods: A probabilistic cost-of-illness model was developed to estimate the number of patients with CVID and XLA, and the economic burden associated with their therapy in terms of direct or indirect costs. A systematic literature review was carried out to reveal both epidemiological and economic data. Furthermore, a probabilistic sensitivity analysis with 5000 Monte Carlo simulations was performed., Results: The epidemiological model allowed us to estimate the number of prevalent patients affected by XLA and CVID in Italy in 2017, corresponding to 1885 (95% confidence interval [CI] 944-3145) and 133 (95% CI 115-152) patients, respectively. The estimated total expenditure for the treatment and management of patients with CVID and XLA requiring Ig replacement therapy amounts to €42.68 million (95% CI €14.38-€86.1 million)., Conclusions: This information provides a comprehensive perspective of the economic issues, and facilitates better-informed public health decision making, in the management of CVID and XLA in Italy.

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine originally isolated from a murine thymic stromal cell line. TSLP exerts its biological effects by binding to a high-affinity heteromeric complex composed of thymic stromal lymphopoietin receptor chain and IL-7Rα. TSLP is primarily expressed by activated lung and intestinal epithelial cells, keratinocytes, and fibroblasts. However, dendritic cells (DCs), mast cells, and presumably other immune cells can also produce TSLP. Different groups of investigators have demonstrated the existence of two variants for TSLP in human tissues: the main isoform expressed in steady state is the short form (sf TSLP), which plays a homeostatic role, whereas the long form (lfTSLP) is upregulated in inflammatory conditions. In addition, there is evidence that in pathological conditions, TSLP can be cleaved by several endogenous proteases. Several cellular targets for TSLP have been identified, including immune (DCs, ILC2, T and B cells, NKT and Treg cells, eosinophils, neutrophils, basophils, monocytes, mast cells, and macrophages) and non-immune cells (platelets and sensory neurons). TSLP has been originally implicated in a variety of allergic diseases (e.g., atopic dermatitis, bronchial asthma, eosinophilic esophagitis). Emerging evidence indicates that TSLP is also involved in chronic inflammatory (i.e., chronic obstructive pulmonary disease and celiac disease) and autoimmune (e.g., psoriasis, rheumatoid arthritis) disorders and several cancers. These emerging observations greatly widen the role of TSLP in different human diseases. Most of these studies have not used tools to analyze the expression of the two TSLP isoforms. The broad pathophysiologic profile of TSLP has motivated therapeutic targeting of this cytokine. Tezepelumab is a first-in-class human monoclonal antibody (1) that binds to TSLP inhibiting its interaction with TSLP receptor complex. Tezepelumab given as an add-on-therapy to patients with severe uncontrolled asthma has shown safety and efficacy. Several clinical trials are evaluating the safety and the efficacy of tezepelumab in different inflammatory disorders. Monoclonal antibodies used to neutralize TSLP should not interact or hamper the homeostatic effects of sf TSLP.

Immunoglobulin G (IgG) replacement therapy is a standard treatment for patients with primary immunodeficiency diseases (PIDs). Hizentra®, a 20% human subcutaneous IgG (SCIG), is approved for biweekly administration for PIDs. The aim of the multicenter IBIS study was to prospectively investigate the efficacy of biweekly Hizentra® compared with previous IVIG or SCIG treatment regimens in patients with PIDs. The study consisted of a 12-month retrospective period followed by 12-month prospective observational period. The main endpoints included pre-infusion IgG concentrations, proportion of patients with serious bacterial infections (SBIs), other infections, hospitalizations due to PID-related illnesses, and days with antibiotics during the study periods. Of the 36 patients enrolled in the study, 35 patients continued the study (mean age 26.1 ± 14.4 years; 68.6% male). The mean pre-infusion IgG levels for prior immunoglobulin regimens during the retrospective period (7.84 ± 2.09 g/L) and the prospective period (8.55 ± 1.76 g/L) did not show any significant variations (p = 0.4964). The mean annual rate of SBIs/patient was 0.063 ± 0.246 for both prospective and retrospective periods. No hospitalizations related to PIDs were reported during the prospective period versus one in the retrospective period. All patients were either very (76.5%) or quite (23.5%) satisfied with biweekly Hizentra® at the end of the study. In conclusion, the IBIS study provided real-world evidence on the efficacy of biweekly Hizentra® in patients with PIDs, thus verifying the data generated by the pharmacometric modeling and simulation study in a normal clinical setting.

Background: Common variable immunodeficiency (CVID) encompasses a heterogeneous group of primary antibody deficiency disorders characterized by recurrent infections, autoimmunity and malignancies. Gastrointestinal manifestations are frequently associated with CVID., Objective: In this cross-sectional study, we evaluated gastric and duodenal involvement in a cohort of adult patients with CVID., Methods: Upper gastrointestinal endoscopy was performed in 58 patients (26 males, mean age 47.8±15.6 years), diagnosed with CVID according to 2014 ESID criteria. Random biopsies were collected from gastric antrum and descending duodenum for the all enrolled subjects. Intraepithelial lymphocytosis in descending duodenum was defined as the presence of 25 lymphocytes per 100 enterocytes., Results: The major histopathological findings that we found were: a) chronic active gastritis (44.8%), Helicobacter pylori-associated (8.6%), b) chronic duodenitis (39.6%) with intraepithelial lymphocytosis (31%) and absence of plasma cells (18.9%) and c) autoimmune atrophic gastritis (5.2%). Three patients (5.2%) presented Intestinal Metaplasia (IM) of the gastric antrum. This finding was associated with H. pylori infection and persisted after the eradication in one patient. IM was associated with autoimmune atrophic gastritis in two cases. Giardia lamblia infection was observed in the duodenum samples from three patients (5.2%). A diagnosis of Gastric adenocarcinoma was made in a 58-year- old woman diagnosed with gastric dysplasia one year earlier., Conclusion: In our cohort of CVID patients, gastro-duodenal histopathological findings, including malignancies, are frequent and can affect long-term prognosis. A rigorous endoscopic follow-up is needed in CVID patients irrespective of the gastrointestinal symptoms., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Background: Morbidity and mortality of primary and secondary antibody deficiencies (AD) are frequently associated with diagnostic delays. These could be avoided by a combination of factors including a widespread and effective development in screening tests., Methods: Calculated globulin (CG), derived from the difference between serum total protein and albumin levels, reflects immunoglobulin serum levels and has shown to have a predictive value in the early diagnosis of antibody deficiencies. This study investigated the possibility to use low levels of CG to detect antibody deficiency in an Italian University Hospital., Results: First, we conducted an analysis of anonymized adult samples collected at our biochemistry laboratory with a range of calculated globulin levels from 15 to 22 g/l. A CG cut-off of 19 g/l detected subjects with IgG lower than 600 mg/dl with a sensitivity of 70% and a specificity of 75%. To further verify the clinical usefulness of CG, we retrospectively evaluated the relationship between CG values and serum IgG levels in 38 patients diagnosed with CVID at our Institution. Using a CG cut-off of 19 g/l, we detected antibody deficiency in 97.3% (37/38) of the subjects present in our cohort., Conclusion: Finally, we chose a CG value of 19 g/l as the cut-off for a prospective AD screening program. The results of this study show that a screening CG test can be used as a tool to reduce diagnostic delays, improve long-term prognosis and reduce the healthcare costs of antibody deficiency., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by reduced immunoglobulin serum levels and absent or impaired antibody production. Clinical manifestations, including infections, inflammatory and autoimmune diseases, and malignancies, also involve various segments of the gastrointestinal tract. Chronic diarrhea is one of the most common gastrointestinal symptoms and may cause a wide spectrum of potentially life-threatening conditions as malabsorption and protein-energy malnutrition. We describe three female CVID adult patients presenting with chronic diarrhea, weight loss, and protein-energy malnutrition due to different underlying conditions. Our review of the literature explores the various gastrointestinal involvements in CVID and points out several histopathological findings proper of the disease, thus highlighting the relevance of the endoscopic and histological assessment in CVID patients presenting with chronic diarrhea.

Adiponectin (Acrp30) is an adipokine widely studied for its beneficial metabolic properties. It circulates as low molecular weight (LMW), medium molecular weight (MMW), and high molecular weight (HMW) oligomers. The latter exerts the most potent biological effects. Acrp30 attracted renewed interest with the finding that it was associated with the development and progression of immune disorders. The mechanisms underlying this association and the role of Acrp30 in the pathophysiology of immune-mediated conditions remain unknown. Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by chronic activation of the immune system, impaired antibody production, and imbalanced cytokine production. In the attempt to shed light on the expression of Acrp30 in CVID, we: (a) investigated total Acrp30 and its oligomerization state in CVID patients undergoing maintenance Ig replacement therapy; (b) assessed the effects of Ig replacement therapy on Acrp30 expression in treatment-naïve CVID patients, namely, patients not treated before diagnosis, before and after the first Ig administration; and (c) evaluated the correlation between Acrp30 levels and clinical phenotypes of the disease. As controls, we analyzed healthy subjects and patients affected by a non-immunodeficiency chronic inflammatory demyelinating polyneuropathy (CIDP), before and after Ig infusion. We found that total Acrp30 and HMW oligomers were decreased in CVID but not in CIDP patients versus controls. Moreover, Acrp30 levels were correlated with IgA levels and were associated with two CVID phenotypes, namely, autoimmune cytopenia and enteropathy. Receiver operating characteristic curve analysis indicated that Acrp30 modulation is specific for CVID patients. Acrp30 and HMW levels quickly and dramatically increased after Ig infusion only in eight treatment-naïve CVID patients but not in five CIDP patients. This finding indicates that Ig administration per se is not able to induce an increase of Acrp30, but the specific cellular and/or molecular background proper of CVID seems to be essential. In conclusion, our data indicate that Acrp30 is specifically related to CVID activity. Further studies are required to understand the biological role of Acrp30 and its possible use as disease biomarker in CVID.

Intravenous immunoglobulin (IVIg) is accepted as an effective and well-tolerated treatment for primary and secondary immunodeficiencies (ID) and immune thrombocytopenia (ITP). Adverse reactions of IVIg are usually mild, comprising transient flu-like symptoms, change in blood pressure and tachycardia. However IVIg therapy can be burdensome for both patients and healthcare facilities, since the infusion may take up to 4h to administer. The objective of our multicentre, prospective, open-label phase III trial was to evaluate the tolerability and safety of human normal immunoglobulin 50g/l (Ig VENA) at high intravenous infusion rates in adult patients with ID and ITP who had previously tolerated IVIg treatment, by progressively increasing infusion rate up to 8ml/kg/hr. 39 ID patients received three infusions, 5 ITP patients received up to a maximum of 5 infusions for a maximum of 5days. Overall 55 adverse events were reported in 18 patients, and all were mild and self-limiting. Two serious adverse events occurred in ID patients and 1 in an ITP patient; none was fatal or treatment-related. No clinically significant changes or abnormalities were observed in vital signs, laboratory results and HRQoL. In summary, in this study, more rapid IVIg infusions were well tolerated by ID and ITP patients, while maintaining their quality of life, helping to minimise the time spent in outpatient hospital visiting to potentially optimise adherence to treatment., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In patients with primary antibody deficiencies, subcutaneous administration of IgG (SCIG) replacement is effective, safe, well-tolerated, and can be self-administered at home. A new SCIG replacement at 20% concentration (Hizentra ® ) has been developed and has replaced Vivaglobin ® (SCIG 16%). An observational prospective multi-centric open-label study, with retrospective comparison was conducted in 15 Italian centers, in order to investigate whether and to what extent switching to Hizentra ® would affect frequency of infusions, number of infusion sites, patients' satisfaction, and tolerability in patients previously treated with Vivaglobin ® or intravenous immunoglobulins (IVIG). Any variations of dosage, frequency and duration of the infusions, and of number of infusion sites induced by Hizentra ® with respect to the former treatment were recorded. Practical advantages and disadvantages of Hizentra ® , with respect to the medicinal product formerly used, and the variations in patients' therapy-related satisfaction were monitored by means of the TSQM (Treatment Satisfaction Questionnaire for Medication); number, frequency, and duration of infectious events and adverse effects were recorded. Eighty-two patients switched to Hizentra ® : 19 (23.2%) from IVIG and 63 (76.8%) from Vivaglobin ® . The mean interval between infusions was not affected by the shift (7.0 ± 2.0 days with previous treatment versus 7.1 ± 1.2 during Hizentra ® ). A decrease in the number of infusion sites with Hizentra ® was recorded in 12 out of 56 patients for whom these data were available. At 6 months, 89.7% of patients were satisfied with Hizentra ® ; no difference in terms of effectiveness, side effects, convenience, and global satisfaction was observed. No difference in the incidence of adverse events was reported.

Background: Hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE) is characterized by recurrent attacks of swelling that affect various body sites. Such attacks are a frequent cause of visits to the emergency department and are often treated in the hospital. In recent years, self-administration of C1-inhibitor (C1-INH) concentrates at home has become an increasingly used option, with a positive impact on patient outcomes and quality of life., Methods: This was an observational study of 6 months' duration in 56 patients with C1-INH-HAE referred to a HAE center in southern Italy. The patients received three types of treatment for their swelling attacks: C1-INH concentrates administered at home (n = 25); icatibant administered at home (n = 12); and C1-INH concentrates administered in the hospital (n = 19). The objectives of this observational study were to compare therapy compliance (defined as the proportion of treated attacks) and quality of life in home- and hospital-treated patients, and to identify factors associated with the decision to use home therapy., Results: Overall, 918 attacks were reported over 6 months, of which 544 (59.2 %) were treated. Total number of reported attacks and the mean (±SD) number of attacks per patient, respectively, in the three groups were: 611 and 24.4 (±26.1) for home-based C1-INH; 191 and 15.9 (±12.0) for home-based icatibant; 166 and 6.1 (±6.5) for hospital-based C1-INH. Differences in attack frequency between home- and hospital-based treatments were statistically significant (p = 0.002), while patient demographic characteristics and the disease severity score did not correlate with the use of home therapy. Compliance with therapy was significantly better with home-based therapy (71.2 % of treated attacks with C1-INH and 44.0 % with icatibant) than with hospital-based therapy (21.6 %, p = 0.003). Quality of life showed an opposite trend, with patients on hospital-based treatment reporting the highest quality of life., Conclusions: Home-based therapy was associated with better compliance compared with hospital-based therapy. The choice to adopt home-based therapy appeared to correlate with a high attack frequency. Home-based therapy is a valid treatment option for patients with C1-INH-HAE and should be offered to all such patients, and especially to those with high attack frequency.

Basophil-derived IL-4 is involved in the alternative activation of mouse monocytes, as recently shown in vivo. Whether this applies to human basophils and monocytes has not been established yet. Here, we sought to characterise the interaction between basophils and monocytes and identify the molecular determinants. A basophil-monocyte co-culture model revealed that IL-3 and basophil-derived IL-4 and IL-13 induced monocyte production of CCL17, a marker of alternative activation. Critically, IL-3 and IL-4 acted directly on monocytes to induce CCL17 production through histone H3 acetylation, but did not increase the recruitment of STAT5 or STAT6. Although freshly isolated monocytes did not express the IL-3 receptor α chain (CD123), and did not respond to IL-3 (as assessed by STAT5 phosphorylation), the overnight incubation with IL-4 (especially if associated with IL-3) upregulated CD123 expression. IL-3-activated JAK2-STAT5 pathway inhibitors reduced the CCL17 production in response to IL-3 and IL-4, but not to IL-4 alone. Interestingly, monocytes isolated from allergen-sensitised asthmatic patients exhibited a higher expression of CD123. Taken together, our data show that the JAK2-STAT5 pathway modulates both basophil and monocyte effector responses. The coordinated activation of STAT5 and STAT6 may have a major impact on monocyte alternative activation in vitro and in vivo., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Human heart mast cells (HHMC), by elaborating vasoactive mediators, cytokines and chemokines, are the main primary effector cells of anaphylaxis. Mast cells have been identified perivascularly, close to myocytes and in the arterial intima in human heart tissue. Mast cells isolated from human heart tissue (HHMC) of patients undergoing cardiac transplantation express high-affinity receptors for IgE (FcepsilonRI) and C5a receptors. Activation of HHMC in vitro with anti-IgE or anti-FcepsilonRI induced the release of preformed mediators (histamine, tryptase, chymase, and renin) and the de novo synthesis of LTC(4) (approximately =18 ng/l0(6) cells) and PGD(2) (approximately =18 ng/l0(6) cells). Complement is activated and anaphylatoxin forms during anaphylaxis. C5a causes rapid release of histamine and tryptase from HHMC. These cells are activated in vitro by therapeutic (general anesthetics, protamine, etc.) and diagnostic agents (radiocontrast media, etc.) which can cause anaphylactoid reactions. Low concentrations of histamine and cysteinyl leukotrienes given to subjects undergoing diagnostic catheterization caused significant systemic and coronary hemodynamic effects. These results indicate that HHMC probably have a role in anaphylactic reactions., (Copyright 2010 S. Karger AG, Basel.)

Introduction: The multicenter prospective study provides information on adverse reactions to intravenous and subcutaneous immunoglobulin treatment in a cohort of 262 patients with common variable immunodeficiency. Severe adverse reactions are a rare but unpredictable event that might occur also in patients who tolerate substitutive intravenous or subcutaneous immunoglobulin therapy for months or years., Results: Subcutaneous therapy has been proved to be a safe option in the 13 patients who had to stop intravenous treatment and who remained out of immunoglobulin replacement for long periods of time. However, severe reactions to subcutaneous therapy occurred at the first or after several subcutaneous immunoglobulin administrations in 2 out of 13 patients., Conclusion: Therefore, patients with previous severe reactions to intravenous immunoglobulin should be considered at particularly high risk for reaction to subcutaneous administration. In these cases, switching from in-hospital administration to home self-administration should be done with extreme care.

Common Variable Immunodeficiency belongs to the group of rare diseases encompassing antibody deficiency syndromes of highly variable clinical presentation and outcome. The multicenter prospective study on a cohort of 224 patients with Common Variable Immunodeficiency provides an updated view of the spectrum of illnesses which occurred at the clinical onset and over a long period of follow-up (mean time: 11 years) and information on the effects of long-term immunoglobulin treatment. The mean age at the time of diagnosis was 26.6 years. Seventy-five patients were younger than 14 years of age. The mean age at the onset of symptoms was 16.9 years. This implicates with a mean diagnostic delay of 8.9 years. Respiratory tract infections were the most prominent clinical problem observed at diagnosis and during the follow-up. Intravenous immunoglobulin administration induced a significant reduction in the incidence of acute infections, mainly acute pneumonia and acute otitis. However, a progressive increase in the prevalence of patients with chronic diseases, mainly sinusitis and lung disease, was observed in all age groups, including the pediatric population. The morbidity of Common Variable Immunodeficiency due to all associated clinical conditions increased over time despite an adequate replacement with intravenous immunoglobulins. Our data stressed the need to develop international guidelines for the prevention and therapy of chronic lung disease, chronic sinusitis, chronic diarrhoea, and chronic granulomatosis in patients with humoral immunodeficiencies.

A significant percentage of allergic diseases (e.g. certain cases of intrinsic asthma, chronic idiopathic urticaria, and atopic dermatitis) cannot be explained by the classical mechanisms of IgE/allergen-mediated activation of basophils and mast cells. We found that protein Fv, an endogenous protein synthesized in the human liver and increased during viral hepatitis, act as a superallergen by binding to IgE of the VH3 family and activating human basophils and mast cells. Similarly, envelope gp120 of HIV-1 and protein A of Staphylococcus aureus are viral and bacterial superallergens, respectively, because they interact with IgE VH3+. Protein L binds to the V domain of he kappa light chains of IgE. Our results demonstrate that endogenous, viral and bacterial products activate primary effector cells of allergic disorders to release proinflammatory mediators and cytokines thereby acting as immunoglobulin superantigens (superallergens).

Human mast cells, by elaborating vasoactive mediators and cytokines, are the primary effector cells of anaphylaxis. A body of evidence implicates human heart mast cells (HHMCs) in anaphylaxis. These cells have been identified perivascularly, in dose proximity to myocytes and in the arterial intima in human heart tissue. The membrane surface of mast cells from human heart tissue of patients undergoing cardiac transplantation expresses the high affinity receptors for IgE (FcepsilonRI) and C5a receptors. Activation of HHMCs in vitro with anti-IgE or anti-FcepsilonRI induced the release of preformed mediators (histamine, tryptase and chymase) and the de novo synthesis of LTC4 (approximately equal to 18 ng/10(6) cells) and PGD2 (approximately equal to 18 ng/10(6) cells). Complement activation and anaphylatoxin formation occur during anaphylaxis in human. C5a caused rapid release of histamine and tryptase from HHMCs. These cells are activated in vitro by therapeutic (general anaesthetics, protamine, etc.) and diagnostic agents (radio contrast media, etc.) that may cause non-IgE-mediated anaphylactic reactions. Administration of low concentrations of histamine and cysteinyl leukotrienes in subjects undergoing diagnostic catheterization caused significant systemic and coronary haemodynamic effects. Taken together, these results indicate that the human heart can be both the site and the target of anaphylactic reactions.

Histamine is synthesized and released by human basophils, mast cells, and neurons. Its pleiotropic effects are mediated by the activation of 4 receptors: H(1), H(2), H(3), and H(4). With the advent of selective antagonists (the antihistamines widely used to treat allergic disorders), the H(1)-receptor was the first member of the receptor family to be pharmacologically defined. Increasing evidence indicates that, in addition to exerting immediate vascular and bronchial responses, histamine might modulate the immune reaction by interacting with T cells, macrophages, basophils, eosinophils, and monocytes. We have shown that, in vitro, histamine induces a concentration-dependent release of IL-6 and beta-glucuronidase from macrophages isolated from the human lung parenchyma. These effects are inhibited by fexofenadine, an H(1)-receptor antagonist, but not by ranitidine, an H(2)-receptor antagonist. This observation raises the possibility that long-term treatment with fexofenadine might have beneficial effects on immune dysregulation and tissue damage/remodeling associated with histamine-mediated macrophage activation.