Live, Attenuated, Tetravalent Butantan-Dengue Vaccine in Children and Adults.

BACKGROUND: Butantan-Dengue Vaccine (Butantan-DV) is an investigational, single-dose, live, attenuated, tetravalent vaccine against dengue disease, but data on its overall efficacy are needed. METHODS: In an ongoing phase 3, double-blind trial in Brazil, we randomly assigned participants to receive Butantan-DV or placebo, with stratification according to age (2 to 6 years, 7 to 17 years, and 18 to 59 years); 5 years of follow-up is planned. The objectives of the trial were to evaluate overall vaccine efficacy against symptomatic, virologically confirmed dengue of any serotype occurring more than 28 days after vaccination (the primary efficacy end point), regardless of serostatus at baseline, and to describe safety up to day 21 (the primary safety end point). Here, vaccine efficacy was assessed on the basis of 2 years of follow-up for each participant, and safety as solicited vaccine-related adverse events reported up to day 21 after injection. Key secondary objectives were to assess vaccine efficacy among participants according to dengue serostatus at baseline and according to the dengue viral serotype; efficacy according to age was also assessed. RESULTS: Over a 3-year enrollment period, 16,235 participants received either Butantan-DV (10,259 participants) or placebo (5976 participants). The overall 2-year vaccine efficacy was 79.6% (95% confidence interval [CI], 70.0 to 86.3) - 73.6% (95% CI, 57.6 to 83.7) among participants with no evidence of previous dengue exposure and 89.2% (95% CI, 77.6 to 95.6) among those with a history of exposure. Vaccine efficacy was 80.1% (95% CI, 66.0 to 88.4) among participants 2 to 6 years of age, 77.8% (95% CI, 55.6 to 89.6) among those 7 to 17 years of age, and 90.0% (95% CI, 68.2 to 97.5) among those 18 to 59 years of age. Efficacy against DENV-1 was 89.5% (95% CI, 78.7 to 95.0) and against DENV-2 was 69.6% (95% CI, 50.8 to 81.5). DENV-3 and DENV-4 were not detected during the follow-up period. Solicited systemic vaccine- or placebo-related adverse events within 21 days after injection were more common with Butantan-DV than with placebo (58.3% of participants, vs. 45.6%). CONCLUSIONS: A single dose of Butantan-DV prevented symptomatic DENV-1 and DENV-2, regardless of dengue serostatus at baseline, through 2 years of follow-up. (Funded by Instituto Butantan and others; DEN-03-IB ClinicalTrials.gov number, NCT02406729, and WHO ICTRP number, U1111-1168-8679.).

Targeted inhibition of allergen-induced histamine production by neutrophils.

Histamine is a critical inflammatory mediator in allergic diseases. We showed in a previous work that neutrophils from allergic patients produce histamine in response to allergens to which the patients were sensitized. Here, we investigate the molecular mechanisms involved in this process using peripheral blood neutrophils. We challenged these cells in vitro with allergens and analyzed histamine release in the culture supernatants. We also explored the effect of common therapeutic drugs that ameliorate allergic symptoms, as well as allergen-specific immunotherapy. Additionally, we examined the expression of histidine decarboxylase and diamine oxidase, critical enzymes in the metabolism of histamine, under allergen challenge. We show that allergen-induced histamine release is dependent on the activation of the phosphoinositide 3-kinase, mitogen-activated protein kinase p38, and extracellular signal-regulated kinase 1/2 signaling pathways. We also found a contribution of the phosphatase calcineurin to lesser extent. Anti-histamines, glucocorticoids, anti-M3-muscarinic receptor antagonists, and mainly ß2 -receptor agonists abolished the allergen-dependent histamine release. Interestingly, allergen-specific immunotherapy canceled the histamine release through the downregulation of histidine decarboxylase expression. Our observations describe novel molecular mechanisms involved in the allergen-dependent histamine release by human neutrophils and provide new targets to inhibit histamine production.

COVID-19 Pandemic in Brazil: History, Characteristics, and Evolution.

This chapter describes the eruption and spread of the SARS-COV-2 virus throughout Brazil. We also describe the governmental measures used to combat the virus, the regional influences impacting viral spreading, and the prevalence of the disease in different Brazilian subpopulations. It is hoped that such information will contribute to the control of the virus and help to prepare the region for future pandemics.

User Experience in Social Robots.

Social robots are increasingly penetrating our daily lives. They are used in various domains, such as healthcare, education, business, industry, and culture. However, introducing this technology for use in conventional environments is not trivial. For users to accept social robots, a positive user experience is vital, and it should be considered as a critical part of the robots' development process. This may potentially lead to excessive use of social robots and strengthen their diffusion in society. The goal of this study is to summarize the extant literature that is focused on user experience in social robots, and to identify the challenges and benefits of UX evaluation in social robots. To achieve this goal, the authors carried out a systematic literature review that relies on PRISMA guidelines. Our findings revealed that the most common methods to evaluate UX in social robots are questionnaires and interviews. UX evaluations were found out to be beneficial in providing early feedback and consequently in handling errors at an early stage. However, despite the importance of UX in social robots, robot developers often neglect to set UX goals due to lack of knowledge or lack of time. This study emphasizes the need for robot developers to acquire the required theoretical and practical knowledge on how to perform a successful UX evaluation.

Informed consent for controlled human infection studies in low- and middle-income countries: Ethical challenges and proposed solutions.

In controlled human infection studies (CHIs), participants are deliberately exposed to infectious agents in order to better understand the mechanism of infection or disease and test therapies or vaccines. While most CHIs have been conducted in high-income countries, CHIs have recently been expanding into low- and middle-income countries (LMICs). One potential ethical concern about this expansion is the challenge of obtaining the voluntary informed consent of participants, especially those who may not be literate or have limited education. In some CHIs in LMICs, researchers have attempted to address this potential concern by limiting access to literate or educated populations. In this paper, we argue that this practice is unjustified, as it does not increase the chances of obtaining valid informed consent and therefore unfairly excludes illiterate populations and populations with lower education. Instead, we recommend that investigators improve the informed consent process by drawing on existing data on obtaining informed consent in these populations and interventions aimed at improving their understanding. Based on a literature review, we provide concrete suggestions for how to follow this recommendation and ensure that populations with lower literacy or education are given a fair opportunity to protect their rights and interests in the informed consent process.

Double-blind, randomized, placebo-controlled trial of allergen-specific immunotherapy with the major allergen Alt a 1.

BACKGROUND: There have been few studies conducted on the efficacy and safety of specific immunotherapy with allergen extracts of fungi compared with other allergen extracts, and there are no data on the major allergen Alt a 1 of the fungus Alternaria alternata. OBJECTIVES: We sought to evaluate the efficacy and safety of subcutaneous immunotherapy with 2 different doses of Alt a 1 in patients with rhinoconjunctivitis caused by sensitization to A alternata. METHOD: We performed a multicenter, randomized, double-blind, placebo-controlled trial with Alt a 1 administered subcutaneously in patients with allergic rhinoconjunctivitis with or without controlled asthma aged 12 to 65 years. Three groups were included: the placebo group and active groups receiving 0.2 or 0.37 µg of Alt a 1 per dose. The main end point was the combined symptom and medication score. Secondary end points were cutaneous reactivity and serum IgE and IgG4 levels to Alt a 1. Recorded adverse reactions were graded according to World Allergy Organization criteria. RESULTS: There were significant reductions in the combined symptom and medication score for the 0.37-µg dose of Alt a 1 compared with placebo at 12 months of treatment. Reduced cutaneous reactivity and IgE levels, together with increased IgG4 levels, were demonstrated for the 2 active groups versus the placebo group. A similar safety profile was found for both active groups compared with the placebo group. No serious adverse drug reactions were reported. CONCLUSION: Immunotherapy with Alt a 1 was efficacious and safe, reducing the symptoms and medication consumption associated with rhinoconjunctivitis after only 1 year of treatment. The clinical benefits were associated with reduced skin reactivity and specific IgE levels and increased IgG4 levels.

Detection of hepatitis C virus (HCV) core-specific antibody suggests occult HCV infection among blood donors.

BACKGROUND: Blood transfusion safety is based on reliable donor screening for transmissible infections such as the hepatitis C virus (HCV) infection. STUDY DESIGN AND METHODS: A novel HCV core-specific antibody was assayed on random single donations from 2007 first-time blood donors who tested negative for anti-HCV and HCV RNA on routine screening. Sample collection broke the code between donations and donors for ethical reasons. RESULTS: Forty-two donations (2.1%) displayed reactivity in the novel test. The specificity of the reactivity was evaluated by a peptide inhibition assay, and testing against additional nonoverlapping HCV core peptide epitopes and other HCV antigens was performed on these samples. Six donations (14.3%; 0.30% from the total) were considered to contain anti-HCV after such supplemental testing. HCV RNA detection was also performed in peripheral blood mononuclear cells (PBMNCs) and serum or plasma samples from reactive donors after virus concentration by ultracentrifugation. HCV RNA tested negative in all PBMNCs samples, and a very low amount of viral genome was detected in serum or plasma concentrates from three anti-HCV core-reactive donors (7.1%) but not among concentrates from 100 randomly selected nonreactive donors. Sequencing of these polymerase chain reaction products revealed differences between the isolates that excluded partially sample contamination from a common source. CONCLUSION: These findings argue in favor of an ongoing occult HCV infection among these blood donors and account for some rather low, but perhaps not negligible, infection risk for such donations. Future studies involving larger samples of donations from traceable donors would enlighten the significance of these findings for the viral safety of the blood supply.

Role of Histamine Release Test for the Evaluation of Patients with Immediate Hypersensitivity Reactions to Clavulanic Acid.

BACKGROUND: Immediate hypersensitivity reactions to clavulanic acid (CLV) seem to be on the increase. Diagnosis is mainly based on skin testing and the drug provocation test (DPT), procedures that are not risk free. The aim of this study was to evaluate whether the histamine release test (HRT) could help evaluate patients with selective hypersensitivity to CLV. METHODS: Eighteen patients with immediate selective hypersensitivity reactions to CLV (positive skin tests to CLV but negative to the major and minor determinants of benzylpenicillin and amoxicillin; negative DPT to benzylpenicillin and amoxicillin) and 21 controls with tolerance to CLV were included. Direct and passive HRT, using patient whole blood or 'IgE-stripped' donor blood sensitized by patient serum, respectively, were performed by stimulating the blood with CLV, and basophil histamine release was detected by fluorometric determination. RESULTS: The clinical symptoms were anaphylaxis (n = 6), urticaria (n = 9) and urticaria-angioedema (n = 3). The median time interval between the reaction and the study was 225 days (interquartile range, IQR: 120-387.5) and between drug intake and the development of symptoms 30 min (IQR: 6.25-30). We obtained similar data for both the direct and passive HRT, with a sensitivity and specificity of 55 and 85%, respectively, a positive predictive value of 76% and a negative predictive value of 69%. CONCLUSIONS: The sensitivity of both the direct and passive HRT for diagnosing patients with immediate allergy to CLV is less than 60%. However, the passive HRT has the advantage that it is based on the testing of serum samples that can be handled more easily than fresh blood samples.

Allergen immunotherapy decreases LPS-induced NF-κB activation in neutrophils from allergic patients.

BACKGROUND: Allergen-specific immunotherapy (IT) is widely used to treat allergic diseases. The molecular mechanisms have not been clarified yet completely. The present work was undertaken to analyze the effect of IT in the activation of NF-κB. METHODS: Neutrophils from 15 pollen-allergic IT-treated patients, 10 untreated pollen-allergic patients, and 10 healthy donors were in vitro stimulated with LPS. NF-κB activation (p65/p52) was measured in their nuclear extracts by enzyme-linked immunosorbent assay (ELISA). IκBα phosphorylation, NF-κB-repressing factor (NRF) activation, and thromboxane A2 (TXA2 ) and Interleukin-8 (IL-8) release were measured by ELISA. RESULTS: There was a positive correlation between the score of symptoms and NF-κB activation in human neutrophils. IT significantly decreased NF-κB activation levels in neutrophils compared with neutrophils from untreated patients. IκBα phosphorylation and NRF activation levels were, respectively, significantly lower and higher in neutrophils from IT-treated patients than from untreated patients. IL-8 and TXA2 release were significantly lower in neutrophils from IT-treated patients than from untreated patients. CONCLUSIONS: IT positive effects are at least in part mediated by the negative regulation of NF-κB activation in human neutrophils. These observations represent a novel view of neutrophils as possible cell target to treat IgE-dependent diseases through NF-κB downmodulation.

Using data crawlers and semantic Web to build financial XBRL data generators: the SONAR extension approach.

Precise, reliable and real-time financial information is critical for added-value financial services after the economic turmoil from which markets are still struggling to recover. Since the Web has become the most significant data source, intelligent crawlers based on Semantic Technologies have become trailblazers in the search of knowledge combining natural language processing and ontology engineering techniques. In this paper, we present the SONAR extension approach, which will leverage the potential of knowledge representation by extracting, managing, and turning scarce and disperse financial information into well-classified, structured, and widely used XBRL format-oriented knowledge, strongly supported by a proof-of-concept implementation and a thorough evaluation of the benefits of the approach.

Elovanoids Counteract Inflammatory Signaling, Autophagy, Endoplasmic Reticulum Stress, and Senescence Gene Programming in Human Nasal Epithelial Cells Exposed to Allergens.

To contribute to further understanding the cellular and molecular complexities of inflammatory-immune responses in allergic disorders, we have tested the pro-homeostatic elovanoids (ELV) in human nasal epithelial cells (HNEpC) in culture challenged by several allergens. ELV are novel bioactive lipid mediators synthesized from the omega-3 very-long-chain polyunsaturated fatty acids (VLC-PUFA,n-3). We ask if: (a) several critical signaling events that sustain the integrity of the human nasal epithelium and other organ barriers are perturbed by house dust mites (HDM) and other allergens, and (b) if ELV would participate in beneficially modulating these events. HDM is a prevalent indoor allergen that frequently causes allergic respiratory diseases, including allergic rhinitis and allergic asthma, in HDM-sensitized individuals. Our study used HNEpC as an in vitro model to study the effects of ELV in counteracting HDM sensitization resulting in inflammation, endoplasmic reticulum (ER) stress, autophagy, and senescence. HNEpC were challenged with the following allergy inducers: LPS, poly(I:C), or Dermatophagoides farinae plus Dermatophagoides pteronyssinus extract (HDM) (30 µg/mL), with either phosphate-buffered saline (PBS) (vehicle) or ELVN-34 (500 nM). Results show that ELVN-34 promotes cell viability and reduces cytotoxicity upon HDM sensitization of HNEpC. This lipid mediator remarkably reduces the abundance of pro-inflammatory cytokines and chemokines IL-1ß, IL-8, VEGF, IL-6, CXCL1, CCL2, and cell adhesion molecule ICAM1 and restores the levels of the pleiotropic anti-inflammatory IL-10. ELVN-34 also lessens the expression of senescence gene programming as well as of gene transcription engaged in pro-inflammatory responses. Our data also uncovered that HDM triggered the expression of key genes that drive autophagy, unfolded protein response (UPR), and matrix metalloproteinases (MMP). ELVN-34 has been shown to counteract these effects effectively. Together, our data reveal a novel, pro-homeostatic, cell-protective lipid-signaling mechanism in HNEpC as potential therapeutic targets for allergies.

Regulation and directed inhibition of ECP production by human neutrophils.

Background: Neutrophils are involved in the pathophysiology of allergic asthma, where the Eosinophil Cationic Protein (ECP) is a critical inflammatory mediator. Although ECP production is attributed to eosinophils, we reported that ECP is also present in neutrophils from allergic patients where, in contrast to eosinophils, it is produced in an IgE-dependent manner. Given the key role of ECP in asthma, we investigated the molecular mechanisms involved in ECP production as well as the effects induced by agonists and widely used clinical approaches. We also analyzed the correlation between ECP production and lung function. Methods: Neutrophils from allergic asthmatic patients were challenged with allergens, alone or in combination with cytokines, in the presence of cell-signaling inhibitors and clinical drugs. We analyzed ECP levels by ELISA and confocal microscopy. Lung function was assessed by spirometry. Results: IgE-mediated ECP release is dependent on phosphoinositide 3-kinase, the extracellular signal-regulated kinase (ERK1/2) and the production of reactive oxygen species by NADPH-oxidase. Calcineurin phosphatase and the transcription factor NFAT are also involved. ECP release is enhanced by the cytokines interleukin (IL)-5 and granulocyte macrophage-colony stimulating factor, and inhibited by interferon-γ, IL-10, clinical drugs (formoterol, tiotropium and budesonide) and allergen-specific IT. We also found an inverse correlation between asthma severity and ECP levels. Conclusions: Our results suggest the molecular pathways involved in ECP production and potential therapeutic targets. We also provide a new method to evaluate disease severity in asthmatic patients based on the quantification of in vitro ECP production by peripheral neutrophils.

The impact of an enhanced health surveillance system for COVID-19 management in Serrana, Brazil.

Objective: To describe the successful implementation of an enhanced public health surveillance system based on early detection, tracing contacts, and patient follow-up and support. Study design: A prospective observational cohort study conducted in Serrana, São Paulo State, Brazil. Methods: The implementation was based on four axes: increasing the access to SARS-CoV-2 testing; correct swab collection; testing patients with mild symptoms; and patient follow-up. Positivity rate, patient demographic and clinical characteristics, dynamics of disease severity, SARS-CoV-2 genome evolution, and the impact on COVID-19 research were assessed from August 23, 2020 to February 6, 2021 (between epidemiological week 35/2020 and 5/2021, a total of 24 weeks). Results: The number of sites collecting rt-PCR for SARS-CoV-2 was increased from one to seven points and staff was trained in the correct use of personal protective equipment and in the swab collection technique. During the study period, 6728 samples were collected from 6155 participants vs. 2770 collections in a similar period before. SARS-CoV-2 RNA was detected in 1758 (26.1%) swabs vs. 1117 (36.7%) before the implementation of the surveillance system (p < 0.001). Positivity rates varied widely between epidemiological weeks 35/2020 and 5/2021 (IQR, 12.8%-31.3%). Out of COVID-19 patients, 91.1% were adults at a median age of 35 years (IQR, 25-50 years), 42.6% were men and 57.4% were women, with a SARS-CoV-2 positivity rate of 28.6% and 24.4% (p < 0.001), respectively. The most common symptoms were headache (72.6%), myalgia (65.0%), and cough (61.7%). Comorbidities were found in 20.8% of patients, the most common being hypertension and diabetes. According to the World Health Organization clinical progression scale, 93.5% of patients had mild disease, 1.6% were hospitalized with moderate disease, 3.2% were hospitalized with severe disease, and 1.4% died. The enhanced surveillance system led to the development of COVID-19 related research. Conclusions: The enhanced surveillance system in Serrana improved COVID-19 understanding and management. By integrating community and academic institutions, it was possible to monitor SARS-CoV-2 positive cases and variants, follow the epidemic trend, guide patients, and develop relevant research projects.

Plasmablast Expansion Following the Tetravalent, Live-Attenuated Dengue Vaccine Butantan-DV in DENV-Naïve and DENV-Exposed Individuals in a Brazilian Cohort.

An effective vaccine against the dengue virus (DENV) should induce a balanced, long-lasting antibody (Ab) response against all four viral serotypes. The burst of plasmablasts in the peripheral blood after vaccination may reflect enriched vaccine-specific Ab secreting cells. Here we characterize the acute plasmablast responses from naïve and DENV-exposed individuals following immunization with the live attenuated tetravalent (LAT) Butantan DENV vaccine (Butantan-DV). The frequency of circulating plasmablasts was determined by flow cytometric analysis of fresh whole blood specimens collected from 40 participants enrolled in the Phase II Butantan-DV clinical trial (NCT01696422) before and after (days 6, 12, 15 and 22) vaccination. We observed a peak in the number of circulating plasmablast at day 15 after vaccination in both the DENV naïve and the DENV-exposed vaccinees. DENV-exposed vaccinees experienced a significantly higher plasmablast expansion. In the DENV-naïve vaccinees, plasmablasts persisted for approximately three weeks longer than among DENV-exposed volunteers. Our findings indicate that the Butantan-DV can induce plasmablast responses in both DENV-naïve and DENV-exposed individuals and demonstrate the influence of pre-existing DENV immunity on Butantan DV-induced B-cell responses.

An Open-label Randomized Controlled Parallel-group Pilot Study Comparing the Immunogenicity of a Standard-, Double-, and Booster-dose Regimens of the 2014 Seasonal Trivalent Inactivated Influenza Vaccine in Kidney Transplant Recipients.

BACKGROUND: Immunogenicity of influenza vaccine in transplant recipients is suboptimal and alternative vaccination regimens are necessary. METHODS: We compared the immunogenicity of a standard-dose trivalent inactivated influenza vaccination (SDTIIV), double-dose trivalent inactivated influenza vaccination (DDTIIV), and booster-dose trivalent inactivated influenza vaccination (BDTIIV) of the 2014 seasonal trivalent inactivated influenza vaccine in kidney transplant recipients. We randomized 176 participants to SDTIIV (59), DDTIIV (59), and BDTIIV regimens (58). Antibody titers were determined by hemagglutination inhibition at enrollment and 21 d postvaccination. Seroprotection rates (SPRs), seroconversion rates (SCRs), and geometric mean ratios (GMRs) were analyzed separately for participants with low (<1:40) and high (≥1:40) prevaccination antibody titers. RESULTS: Vaccination was confirmed for 172 participants. Immunogenicity analysis was done for 149 participants who provided postvaccination blood samples. In the subgroup with high prevaccination antibody titers, all vaccination regimens induced SPR > 70% to all antigens, but SCR and GMR were below the recommendations. In the subgroup with low prevaccination antibody titers, DDTIIV and BDTIIV regimens induced adequate SCR > 40% and GMR > 2.5 for all antigens, whereas SDTIIV achieved the same outcomes only for influenza B. SPRs were >70% only after DDTIIV (A/H1N1-77.8%) and BDTIIV (A/H3N2-77.8%). BDTIIV regimen independently increased seroprotection to A/H1N1 (PR = 2.58; P = 0.021) and A/H3N2 (PR = 2.21; P = 0.004), whereas DDTIIV independently increased seroprotection to A/H1N1 (PR = 2.59; P = 0.021). CONCLUSIONS: Our results suggest that DDTIIV and BDTIIV regimens are more immunogenic than SDTIIV, indicating the need for head-to-head multicenter clinical trials to further evaluate their efficacy.

Changes in the Sensitization Pattern to Alternaria alternata Allergens in Patients Treated with Alt a 1 Immunotherapy.

Alternaria alternata is the most important allergenic fungus, with up to 20% of allergic patients affected. The sensitization profile of patients sensitized to A. alternata and how it changes when treated with immunotherapy is not known. Our objective is to determine the allergen recognition pattern of allergic patients to A. alternata and to study its association to the parameters studied in a clinical trial recently published. Sera of 64 patients from the clinical trial of immunotherapy with native major allergen Alt a 1 were analyzed by immunoblotting; 98. 4% of the patients recognized Alt a 1. The percentage of recognition for Alt a 3, Alt a 4, and/or Alt a 6, Alt a 7, Alt a 8, Alt a 10 and/or Alt a 15 was 1.6%, 21.9%, 12.5%, 12.5%, and 12.5% respectively. Of the 64 patients, 45 (70.3%) only recognized Alt a 1 among the allergens present in the A. alternata extract. Immunotherapy with Alt a 1 desensitizes treated patients, reducing their symptoms and medication consumption through the elimination of Alt a 1 sensitization, which is no longer present in the immunoblotting of some patients. There may be gender differences in the pattern of sensitization to A. alternata allergens, among others.

The Role of Benzylpenicilloyl Epimers in Specific IgE Recognition.

The high prevalence of allergy to ß-lactam antibiotics is a worldwide issue. Accuracy of diagnostic methods is important to prove tolerance or allergy, with skin test considered the best validated in vivo method for diagnosing immediate reactions to ß-lactams. Although drug provocation test is the reference standard, it cannot be performed in highly risk reactions or in those with positive skin tests. For skin tests, the inclusion of major and minor determinants of benzylpenicillin (BP) is recommended. Commercial skin test reagents have changed along time, including as minor determinants benzylpenicillin, benzylpenicilloate (BPO), and benzylpenilloate (PO). Major determinants consists of multivalent conjugates of benzylpenicilloyl coupled through amide bond to a carrier polymer, such as penicilloyl-polylysine (PPL) or benzylpenicilloyl-octalysine (BP-OL). The chemical stability of such reagents has influenced the evolution of the composition of the commercial kits, as this requirement is necessary for improving the quality and standardization of the product. In this work, we provide a detailed study of the chemical stability of BP determinants. We observed that those structures suffer from an epimerization process in C-5 at different rates. Butylamine-Benzylpenicilloyl conjugates (5R,6R)-Bu-BPO and (5S,6R)-Bu-BPO were selected as a simple model for mayor determinant to evaluate the role of the different epimers in the immunoreactivity with sera from penicillin-allergic patients. In vitro immunoassays indicate that any change in the chemical structure of the antigenic determinant of BP significantly affects IgE recognition. The inclusion of stereochemically pure compounds or mixtures may have important implications for both the reproducibility and sensitivity of in vivo and in vitro diagnostic tests.

Effect of allergen-specific immunotherapy with purified Alt a1 on AMP responsiveness, exhaled nitric oxide and exhaled breath condensate pH: a randomized double blind study.

BACKGROUND: Little information is available on the effect of allergen-specific immunotherapy on airway responsiveness and markers in exhaled air. The aims of this study were to assess the safety of immunotherapy with purified natural Alt a1 and its effect on airway responsiveness to direct and indirect bronchoconstrictor agents and markers in exhaled air. METHODS: This was a randomized double-blind trial. Subjects with allergic rhinitis with or without mild/moderate asthma sensitized to A alternata and who also had a positive skin prick test to Alt a1 were randomized to treatment with placebo (n = 18) or purified natural Alt a1 (n = 22) subcutaneously for 12 months. Bronchial responsiveness to adenosine 5'-monophosphate (AMP) and methacholine, exhaled nitric oxide (ENO), exhaled breath condensate (EBC) pH, and serum Alt a1-specific IgG4 antibodies were measured at baseline and after 6 and 12 months of treatment. Local and systemic adverse events were also registered. RESULTS: The mean (95% CI) allergen-specific IgG4 value for the active treatment group increased from 0.07 µg/mL (0.03-0.11) at baseline to 1.21 µg/mL (0.69-1.73, P < 0.001) at 6 months and to 1.62 µg/mL (1.02-2.22, P < 0.001) at 12 months of treatment. In the placebo group, IgG4 value increased nonsignificantly from 0.09 µg/mL (0.06-0.12) at baseline to 0.13 µg/mL (0.07-0.18) at 6 months and to 0.11 µg/mL (0.07-0.15) at 12 months of treatment. Changes in the active treatment group were significantly higher than in the placebo group both at 6 months (P < 0.001) and at 12 months of treatment (P < 0.0001). However, changes in AMP and methacholine responsiveness, ENO and EBC pH levels were not significantly different between treatment groups. The overall incidence of adverse events was comparable between the treatment groups. CONCLUSION: Although allergen-specific immunotherapy with purified natural Alt a1 is well tolerated and induces an allergen-specific IgG4 response, treatment is not associated with changes in AMP or methacholine responsiveness or with significant improvements in markers of inflammation in exhaled air. These findings suggest dissociation between the immunotherapy-induced increase in IgG4 levels and its effect on airway responsiveness and inflammation.