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Introduction: Exposure to respiratory viruses is a significant cause of morbidity and affects virus-specific antibody levels. Little is known about determinants associated with immune response to these viruses. We aimed to investigate the determinants of respiratory syncytial virus (RSV)- and rhinovirus (RV)- specific IgG responses in both children and adults. Methods: The study is based on the EGEA cohort, composed of 530 samples of children in EGEA1 (1991-95) and 1241 samples of adults in EGEA2 (2003-07). Cumulative RV-specific IgG levels (species A, B and C) and IgG levels to RSV-G protein were measured by using micro-array technoloy. Multiple linear mixed models (random effect to account for familial dependence) were performed to assess associations between age, sex, body mass index (BMI), tobacco smoke exposure and season of blood sampling with RSV-and RV-specific IgG levels. Results: In children (11.1 ± 2.8 years old, 57% boys), higher RV-specific IgG levels were associated with older age (only for RV-B), female sex and lower BMI, while only older age was associated with higher RSV-specific IgG levels. In adults (43.5 ± 16.7 years old, 48% men), younger age, female sex, lower BMI, active smoking and all seasons except summer were associated with higher RV-specific IgG levels. Older age, active smoking and all seasons except summer were associated with higher RSV-specific IgG levels. Conclusion: Personal and seasonal determinants of RSV- and RV-specific IgG levels seem to vary according to the respiratory virus type and between children and adults, suggesting different patterns of responses along the life course. [ABSTRACT FROM AUTHOR]

Background: Immunoglobulin-E(IgE)-mediated hypersensitivity to cow's milk allergens is a frequent cause of severe and life-threatening anaphylactic reactions. Besides case histories and controlled food challenges, the detection of the IgE antibodies specific to cow's milk allergens is important for the diagnosis of cow-milk-specific IgE sensitization. Cow´s milk allergen molecules provide useful information for the refined detection of cow-milk-specific IgE sensitization. Methods: A micro-array based on ImmunoCAP ISAC technology was developed and designated milk allergen micro-array (MAMA), containing a complete panel of purified natural and recombinant cow's milk allergens (caseins, α-lactalbumin, β-lactoglobulin, bovine serum albumin-BSA and lactoferrin), recombinant BSA fragments, and α-casein-, α-lactalbumin- and β-lactoglobulin-derived synthetic peptides. Sera from 80 children with confirmed symptoms related to cow's milk intake (without anaphylaxis: n = 39; anaphylaxis with a Sampson grade of 1–3: n = 21; and anaphylaxis with a Sampson grade of 4–5: n = 20) were studied. The alterations in the specific IgE levels were analyzed in a subgroup of eleven patients, i.e., five who did not and six who did acquire natural tolerance. Results: The use of MAMA allowed a component-resolved diagnosis of IgE sensitization in each of the children suffering from cow's-milk-related anaphylaxis according to Sampson grades 1–5 requiring only 20–30 microliters of serum. IgE sensitization to caseins and casein-derived peptides was found in each of the children with Sampson grades of 4–5. Among the grade 1–3 patients, nine patients showed negative reactivity to caseins but showed IgE reactivity to alpha-lactalbumin (n = 7) or beta-lactoglobulin (n = 2). For certain children, an IgE sensitization to cryptic peptide epitopes without detectable allergen-specific IgE was found. Twenty-four children with cow-milk-specific anaphylaxis showed additional IgE sensitizations to BSA, but they were all sensitized to either caseins, alpha-lactalbumin, or beta-lactoglobulin. A total of 17 of the 39 children without anaphylaxis lacked specific IgE reactivity to any of the tested components. The children developing tolerance showed a reduction in allergen and/or peptide-specific IgE levels, whereas those remaining sensitive did not. Conclusions: The use of MAMA allows for the detection, using only a few microliters of serum, of IgE sensitization to multiple cow's milk allergens and allergen-derived peptides in cow-milk-allergic children with cow-milk-related anaphylaxis. [ABSTRACT FROM AUTHOR]

Background: Molecular antibody reactivity profiles have not yet been studied in depth in patients treated by sublingual house dust mite (HDM) tablet immunotherapy. Humoral immune responses to a large panel of HDM mite allergens were studied using allergen microarray technology in a subset of clinically defined high and low responder patients from a double‐blind placebo‐controlled allergen‐specific immunotherapy (AIT) trial using sublingual 300 IR HDM tablets. Methods: Serum levels of IgE, IgG and IgG4 to 13 Dermatophagoides pteronyssinus molecules were measured at baseline and after 1‐year AIT, using allergen microarrays in 100 subjects exhibiting high or low clinical benefit. Results: Der p 1, Der p 2 and Der p 23 were the most frequently recognized allergens in the study population. Patients with HDM‐related asthma had significantly higher allergen‐specific IgE levels to Der p 1 and Der p 23. No significant difference in the distribution of allergen sensitization pattern was observed between high and low responders. An increase in serum allergen‐specific IgG and IgG4 occurred upon AIT, in particular to allergens Der p 1, Der p 2 and Der p 23 (p < 0.0001). Conclusions: We confirm for our study population that Der p 1‐ and Der p 23‐specific IgE levels are associated with asthma. IgE reactivity profiles were not predicitive of sublingual AIT outcomes, with 300 IR tablets as efficacious in pauci‐ and multi‐sensitized subjects. Our study is the first to demonstrate the induction of IgG and IgG4 specific for the HDM allergens Der p 1, Der p 2 and Der p 23 by sublingual AIT. [ABSTRACT FROM AUTHOR]

Rhinoviruses (RV) account for a significant number of asthma exacerbations, and RV species C may be associated with a severe course in vulnerable patient groups. Despite important evidence on the role of RV reported by clinicians and life scientists, there are still unanswered questions regarding their influence on asthma exacerbation in young patients. Thus, we measured the RVspecies-specific IgG titers in our German pediatric exacerbation cohort using a microarray-based technology. For this approach, human sera of patients with exacerbated asthma and wheeze, as well as healthy control subjects (n = 136) were included, and correlation analyses were performed. Concordantly with previously published results, we observed significantly higher cumulative levels of RV species A-specific IgG (p = 0.011) and RV-C-specific IgG (p = 0.051) in exacerbated asthma group compared to age-matched controls. Moreover, atopic wheezers had increased RV-specific IgG levels for species A (p = 0.0011) and species C (p = 0.0009) compared to non-atopic wheezers. Hypothesizing that bacterial infection positively correlates with immune memory against RV, we included nasopharyngeal swab results in our analyses and detected limited correlations. Interestingly, the eosinophil blood titer positively correlated with RV-specific IgG levels. With these observations, we add important observations to the existing data regarding exacerbation in pediatric and adolescent medicine. We propose that scientists and clinicians should pay more attention to the relevance of RV species in susceptible pediatric patients. [ABSTRACT FROM AUTHOR]

Background: While children usually experience a mild course of COVID‐19, and a severe disease is more common in adults, the features, specificities, and functionality of the SARS‐CoV‐2‐specific antibody response in the pediatric population are of interest. Methods: We performed a detailed analysis of IgG antibodies specific for SARS‐CoV‐2‐derived antigens S and RBD by ELISA in 26 SARS‐CoV‐2 seropositive schoolchildren with mild or asymptomatic disease course, and in an equally sized, age‐ and gender‐matched control group. Furthermore, a detailed mapping of IgG reactivity to a panel of microarrayed SARS‐CoV‐2 proteins and S‐derived peptides was performed by microarray technology. The capacity of the antibody response to block RBD‐ACE2 binding and virus neutralization were assessed. Results were compared with those obtained in an adult COVID‐19 convalescent population. Results: After mild COVID‐19, anti‐S and RBD‐specific IgG antibodies were developed by 100% and 84.6% of pediatric subjects, respectively. No difference was observed in regards to symptoms and gender. Mounted antibodies recognized conformational epitopes of the spike protein and were capable to neutralize the virus up to a titer of ≥80 and to inhibit the ACE2‐RBD interaction by up to 65%. SARS‐CoV‐2‐specific IgG responses in children were comparable to mildly affected adult patients. Conclusion: SARS‐CoV‐2 asymptomatic and mildly affected pediatric patients develop a SARS‐CoV‐2‐specific antibody response, which is comparable regarding antigen, epitope recognition, and the ability to inhibit the RBD‐ACE2 interaction to that observed in adult patients after mild COVID‐19. [ABSTRACT FROM AUTHOR]

Background: The determinants of successful humoral immune response to the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) are of critical importance for the design of effective vaccines and the evaluation of the degree of protective immunity conferred by exposure to the virus. As novel variants emerge, understanding their likelihood of suppression by population antibody repertoires has become increasingly important. Methods: In this study, we analyzed the SARS‐CoV‐2 polyclonal antibody response in a large population of clinically well‐characterized patients after mild and severe COVID‐19 using a panel of microarrayed structurally folded and unfolded SARS‐CoV‐2 proteins, as well as sequential peptides, spanning the surface spike protein (S) and the receptor‐binding domain (RBD) of the virus. Results: S‐ and RBD‐specific antibody responses were dominated by immunoglobulin G (IgG), mainly IgG1, and directed against structurally folded S and RBD and three distinct peptide epitopes in S2. The virus neutralization activity of patients´ sera was highly correlated with IgG antibodies specific for conformational but not sequential RBD epitopes and their ability to prevent RBD binding to its human receptor angiotensin‐converting enzyme 2 (ACE2). Twenty percent of patients selectively lacked RBD‐specific IgG. Only immunization with folded, but not with unfolded RBD, induced antibodies against conformational epitopes with high virus‐neutralizing activity. Conformational RBD epitopes required for protection do not seem to be altered in the currently emerging virus variants. Conclusion: These results are fundamental for estimating the protective activity of antibody responses after natural infection or vaccination and for the design of vaccines, which can induce high levels of SARS‐CoV‐2–neutralizing antibodies conferring sterilizing immunity. [ABSTRACT FROM AUTHOR]

Background: Sensitization to house dust mite (HDM) is a leading cause of allergic rhinitis and asthma. Despite more than 30 HDM‐derived allergens having been identified to date, specific therapeutic approaches do not yet take into account the local sensitization profiles of patients. This study aimed to identify patterns of HDM sensitization in HDM‐allergic adults living in distinct geographic areas, to inform the development of targeted diagnostic and therapeutic tools. Methods: Serum samples from 685 HDM‐allergic subjects from Canada, Europe, South Africa, and the USA were tested for levels of IgE specific for 17 micro‐arrayed HDM allergens by ImmunoCAP Immuno Solid‐phase Allergen Chip (ISAC) technology. Results: The results confirmed significant geographical variability in sensitization patterns and levels of IgE. In all areas, the major sensitizers were the group 1 and group 2 allergens and Der p 23. Der p 23 was a frequent sensitizer: 64% of the subjects had IgE specific for Der p 23, and 2.3% were monosensitized to it. In South Africa, Der p 23 was the dominant HDM allergen (86% prevalence) and Der p 7 achieved major allergen status (56%). IgE sensitization to HDM was influenced by asthmatic status, levels of allergen exposure, age, race‐ethnicity and smoking status, but not by BMI. Conclusion: Sensitization profiles to HDM allergens differ considerably among distinct geographic areas, with Der p 7 and Der p 23 being major sensitizers in South Africa. Such heterogeneity should be taken into account in the diagnosis and treatment of HDM‐allergic patients. [ABSTRACT FROM AUTHOR]

More than 30% of the world population suffers from allergy. Allergic individuals are characterized by the production of immunoglobulin E (IgE) antibodies against innocuous environmental allergens. Upon allergen recognition IgE mediates allergen-specific immediate and late-phase allergic inflammation in different organs. The identification of the disease-causing allergens by demonstrating the presence of allergen-specific IgE is the key to precision medicine in allergy because it allows tailoring different forms of prevention and treatment according to the sensitization profiles of individual allergic patients. More than 30 years ago molecular cloning started to accelerate the identification of the disease-causing allergen molecules and enabled their production as recombinant molecules. Based on recombinant allergen molecules, molecular allergy diagnosis was introduced into clinical practice and allowed dissecting the molecular sensitization profiles of allergic patients. In 2002 it was demonstrated that microarray technology allows assembling large numbers of allergen molecules on chips for the rapid serological testing of IgE sensitizations with small volumes of serum. Since then microarrayed allergens have revolutionized research and diagnosis in allergy, but several unmet needs remain. Here we show that detection of IgE- and IgG-reactivity to a panel of respiratory allergens microarrayed onto silicon elements is more sensitive than glass-based chips. We discuss the advantages of silicon-based allergen microarrays and how this technology will allow addressing hitherto unmet needs in microarray-based allergy diagnosis. Importantly, it described how the assembly of silicon microarray elements may create different microarray formats for suiting different diagnostic applications such as quick testing of single patients, medium scale testing and fully automated large scale testing. [ABSTRACT FROM AUTHOR]

Rhinovirus (RV) infections are major triggers of acute exacerbations of severe respiratory diseases such as pre-school wheeze, asthma and chronic obstructive pulmonary disease (COPD). The occurrence of numerous RV types is a major challenge for the identification of the culprit virus types and for the improvement of virus type-specific treatment strategies. Here, we develop a chip containing 130 different micro-arrayed RV proteins and peptides and demonstrate in a cohort of 120 pre-school children, most of whom had been hospitalized due to acute wheeze, that it is possible to determine the culprit RV species with a minute blood sample by serology. Importantly, we identify RV-A and RV-C species as giving rise to most severe respiratory symptoms. Thus, we have generated a chip for the serological identification of RV-induced respiratory illness which should be useful for the rational development of preventive and therapeutic strategies targeting the most important RV types. [ABSTRACT FROM AUTHOR]

Background: Dermatophagoides pteronyssinus is one of the most important perennial allergen sources worldwide. Molecular diagnostics using the commercially available major allergens (Der p 1 and Der p 2) in combination with Der p 10 do not detect house dust mite (HDM) sensitization in a number of cases when used alone. The objective was to evaluate the IgE reactivity profiles of these patients using an experimental immunoassay biochip. Methods: Sera of HDM-allergic patients (positive skin prick test, CAP class = 1 for allergen extract, and positive intranasal provocation) were tested for IgE antibodies against Der p 1, Der p 2, and Der p 10 by ImmunoCAP fluorescence enzyme immunoassay. Negatively tested sera were examined by an experimental chip containing 13 microarrayed HDM allergens. Results: Of 97 patients tested, 16 showed negative results to Der p 1, Der p 2, and Der p 10. MeDALL chip evaluation revealed 5 patients mono-sensitized to Der p 23, and 11 patients were negative for all HDM MeDALL chip components. Seven sera were available for further testing, and 3 of them showed IgE reactivity to dot-blotted nDer p 1, and 2 reacted with high-molecular weight components (>100 kDa) in nitrocellulose-blotted HDM extract when tested with 125 I-labeled anti-IgE in a RASTbased assay. The HDM extract-specific IgE levels of the 11 patients were <3.9 kU/l. Conclusions: Recombinant allergen- based IgE serology is of great value when conventional IgE diagnostics fails. Der p 23 is an important HDM allergen, especially when major allergens are negative. Therefore, it would be desirable to have Der p 23 commercially available. Further research concerning the prevalence and clinical significance of different HDM allergens is needed. [ABSTRACT FROM AUTHOR]

We report a new method for detecting human IgG (hIgG) in serum on integrated-optical Mach-Zehnder interferometer biosensors realized in a high index contrast polymer material system. In the linear range of the sensor (5-200 nM) we observed excellent signal recoveries (95-110%) in buffer and serum samples, which indicate the absence of matrix effects. Signal enhancement was reached by using secondary anti-human IgG antibodies, which bind to immobilized target IgGs and allow detecting concentrations down to 100 pM. This polymer based optical sensor is fully compatible with cost-efficient mass production technologies, which makes it an attractive alternative to inorganic optical sensors. [ABSTRACT FROM AUTHOR]

Correction for ‘HIV microarray for the mapping and characterization of HIV-specific antibody responses’ by Daniela Gallerano et al., Lab Chip, 2015, 15, 1574–1589. [ABSTRACT FROM AUTHOR]

Background: Viral infections in childhood, especially to rhinovirus (RV) and respiratory syncytial virus (RSV), are associated with asthma inception and exacerbation. However, little is known about the role of RV- and RSV-specific antibodies in childhood versus adult asthma., Objective: We sought to investigate associations between RV- and RSV-specific IgG levels and asthma phenotypes in children and adults., Methods: The analysis included 1771 samples from participants of the Epidemiological Study on the Genetics and Environment of Asthma (530 children; age [mean ± SD], 11.1 ± 2.8, and 1241 adults; age [mean ± SD], 43.4 ± 16.7, among whom 274 and 498 had ever asthma, respectively). RSV- and RV-specific IgG levels were determined using microarrayed virus-derived antigens and peptides. Cross-sectional associations between standardized RSV- and RV-specific IgG levels and asthma phenotypes were estimated by multiple regression models., Results: In children, ever asthma was associated with higher IgG levels specific to RV, especially to RV-A and RV-C, and to RSV (adjusted odds ratios [95% CI] for a 1 - SD increase in IgG levels were 1.52 [1.16-1.99], 1.42 [1.10-1.83], and 1.24 [0.99-1.54], respectively). These associations were stronger for moderate to severe asthma than for mild asthma. Conversely in adults, ever asthma was associated with lower RV-A, RV-B, and RV-C IgG levels (adjusted odds ratios [95% CI] were 0.86 [0.74-0.99], 0.83 [0.73-0.95], and 0.85 [0.73-0.99], respectively)., Conclusions: Our results suggest that the association between respiratory virus-specific antibody levels and asthma varies during life, with asthma associated with higher levels of IgG to RSV, RV-A, and RV-C in children and lower levels of IgG responses to RV-A/B/C in adults., Competing Interests: This study was supported in part by NIRVANA (grant no. ANR-19-CE36-0005) and by the Danube Allergy Research Cluster Program (DARC-ARC 2.0) of the country of Lower Austria. Disclosure of potential conflict of interest: R. Valenta has received research grants from Worg Pharmaceuticals, HVD Biotech, and Viravaxx; and serves as a consultant for Viravaxx and Worg. The rest of the authors declare that they have no relevant conflicts of interest., (© 2024 The Authors.)

We used the microarray technology to develop chips containing a comprehensive set of proteins and peptides covering the proteome of HIV-1 clade C, which is the HIV-1 subtype that causes the majority of infections worldwide. We demonstrate that the HIV microarray allows simultaneous, sensitive and specific detection of antibody responses for the major immunoglobulin classes (IgG, IgA, IgM, IgE) and subclasses (IgG1-4) with minute amounts of serum samples towards a large number of HIV antigens and peptides. Furthermore, we show that the HIV chip can be used for the monitoring of antibody responses during the course of the disease and during treatment. The HIV microarray should be useful to study antibody responses to multiple HIV antigens and epitopes in HIV-infected patients to explore pathomechanisms of the disease, for diagnosis and for monitoring of treatment and of vaccine trials.