IgE anti-respiratory syncytial virus antibodies detected in serum of pediatric patients with asthma

Association between asthma and IgG levels specific for rhinovirus and respiratory syncytial virus antigens in children and adults

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.

Surfactant Protein-A and its immunomodulatory roles in infant respiratory syncytial virus infection: a potential for therapeutic intervention?

The vast majority of early-life hospital admissions globally highlight respiratory syncytial virus (RSV), the leading cause of neonatal lower respiratory tract infections, as the major culprit behind the poor neonatal outcomes following respiratory infections. Unlike those of older children and adults, the immune system of neonates looks rather unique, therefore mostly counting on the innate immune system and antibodies of maternal origins. The collaborations between cells and immune compartments during infancy inclines bias toward a T-helper 2 (Th2) immune profile and thereby away from a T-helper 1 (Th1) immune response. What makes it more problematic is that RSV infection also tends to elicit a stronger Th2-biased immune response and drive an aberrant allergy-like inflammation. It is thus evident how RSV infections potentially pave the way for wheezing recurrences and childhood asthma later in life. Surfactant, the essential lung substance for normal breathing processes in mammals, has immunomodulatory properties including lung collectins such as Surfactant Protein-A (SP-A), which is the most abundant protein component of surfactant, and also Surfactant Protein-D (SP-D). Deficiency of SP-A and SP-D has been found to be associated with impaired pathogen clearance and exacerbated immune responses during infections. We therefore conducted a review of the literature to describe pathomechanisms of RSV infections during blunted neonatal immunity potentially facilitating allergy-like inflammatory events within the developing lungs and highlight the potential protective role of the humoral collectin SP-A to mitigate these in the "early in life" pulmonary immune system.

Antibody-mediated protection against respiratory syncytial virus in children

Respiratory syncytial virus (RSV) is a major global pathogen, causing lower respiratory tract disease in at-risk populations including young children. Antibodies form a crucial layer of protection from RSV disease, particularly in immunologically naïve infants. Such antibodies are derived from the mother via transplacental transfer and breast milk, but may be particularly low in high-risk infants such as those born preterm. Maternally derived antibodies can now be supplemented by the administration of anti-RSV monoclonal antibodies, while a rising wave of maternal and paediatric vaccine strategies are approaching. The implementation of these prophylactics may profoundly decrease the healthcare burden of RSV. In this article, we review the role of antibody-mediated immunity in protecting children from RSV. We focus on maternally derived antibodies as the main source of protection against RSV and study factors that influence the scale of this transfer. The role of passive and active prophylactic approaches in protecting infants against RSV are discussed and knowledge gaps in our understanding of antibody-mediated protection against RSV are identified.

Diagnosis of Tuberculosis in a Case of Chronic Urticaria following Omalizumab Therapy

In Italy, tuberculosis (TB) incidence in the last decade has remained constant at under 10 cases/100,000 inhabitants. In the Philippines, TB annual incidence is greater than 500 cases/100,000 inhabitants. Omalizumab is a humanized anti-IgE monoclonal antibody approved for the treatment of chronic spontaneous urticaria. We report the case of a 32-year-old Filipino woman who suffered from chronic urticaria, treated with topic steroids since June 2022 and systemic steroids for 2 weeks. In November 2022, she started omalizumab therapy at a monthly dose of 300 mg; she was not screened for TB infection. In the same month, a left laterocervical lymphadenopathy arose, which worsened in February 2023 (diameter: 3 cm). The patient recovered in April 2023 in INMI "Lazzaro Spallanzani" in Rome for suspected TB. Chest CT showed a "tree in bud" pattern at the upper-right pulmonary lobe. The patient tested positive for lymph node biopsy molecular tuberculosis. The patient started standard antituberculosis therapy. She discontinued omalizumab. To our knowledge, this is the second diagnosed TB case during omalizumab treatment, which suggests that attention should be paid to the known risk of TB during biotechnological treatments. Even if current guidelines do not recommend screening for TB before starting anti-IgE therapy, further data should be sought to assess the relationship between omalizumab treatment and active TB. Our experience suggests that screening for TB should be carried out in patients from highly tuberculosis-endemic countries before starting omalizumab therapy.

Respiratory Syncytial Virus-Specific Antibodies and Atopic Diseases in Children: A 10-Year Follow-Up

BACKGROUND

Respiratory syncytial virus (RSV) stimulates the production of specific immunoglobulin (Ig) E and IgG4 antibodies as a hallmark of the Th2 immune response. In this paper, we evaluated the occurrence of atopic diseases in 10-year-old children who were positive for RSV-specific IgG antibodies during infancy.

METHODS

The prospective follow-up of 72 children included a physical examination, an International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and the determination of RSV-specific antibodies and total and allergen-specific IgE.

RESULTS

Children with asthma had their first wheezing episode at a younger age (χ2 8.097, df = 1, p = 0.004). RSV-specific IgG4 levels at year one were positively correlated with atopic dermatitis (AD) (tau_b = 0.211, p = 0.049) and current AD (tau_b = 0.269, p = 0.012); and RSV-specific IgE levels were positively correlated with allergic rhinitis (AR) (tau_b = 0.290, p = 0.012) and current AR (tau_b = 0.260, p = 0.025). Positive RSV-specific IgE at the age of one increased the chances of asthma occurrence by 5.94 (OR = 5.94, 95% CI = 1.05-33.64; p = 0.044) and the chances of AR by more than 15 times (OR = 15.03, 95% CI = 2.08-108.72; p = 0.007). A positive family history of atopy increased the chances of asthma occurrence by 5.49 times (OR = 5.49, 95% CI = 1.01-30.07; p = 0.049), and a longer duration of exclusive breastfeeding lowered that chance (OR = 0.63, 95% CI = 0.45-0.89; p = 0.008). Prenatal smoking increased the chances of AR occurrence by 7.63 times (OR = 7.63, 95% CI = 1.59-36.53; p = 0.011).

CONCLUSION

RSV-specific IgE and RSV-specific IgG4 antibodies could be risk markers for the development of atopic diseases in children.

Gimap5 promoted RSV degradation through interaction with M6PR

Respiratory syncytial virus (RSV) is one of the main pathogens of viral pneumonia and bronchiolitis in infants and young children and life-threatening diseases among infants and young children. GTPases of the immune-associated protein family (GIMAP) are new family members of immune-associated GTPases. In recent years, much attention has been paid to the function of the GIMAP family in coping with infection and stress. Gimap5 is a member of the GIMAP family, which may be correlated with anti-infectious immunity. RT-qPCR, Western blot, and indirect immunofluorescence (IFA) were used to detect the expression of Gimap5, M6PR and IGF1R(the major RSV receptor). Transmission electron microscopy (TEM) was used to detect the degradation of RSV in Gimap5-overexpressed or -silent cell lines. Computer virtual screening was used to screen small molecule compounds targeting Gimap5 and the anti-RSV effects were explored through in vivo and in vitro experiments. GIMAP5 and M6PR were significantly downregulated after RSV infection. Gimap5 accelerated RSV degradation in lysosomes by interacting with M6PR, and further prevented RSV invasion by downregulating the expression of RSV surface receptor IGF1R. Three small molecule compounds targeting Gimap5 were confirmed to be the agonists of Gimap5. The three compounds effectively inhibited RSV infection and RSV-induced complications. Gimap5 promotes the degradation of RSV and its receptor through interacting with M6PR. Gimap5 agonists can effectively reduce RSV infection and RSV-induced complication in vivo and in vitro, which provides a new choice for the treatment of RSV.

A Pilot Study for IgE as a Prognostic Biomarker in COVID-19

Background

Laboratory biomarkers to estimate the severity of COVID‐19 are crucial during the pandemic, since resource allocation must be carefully planned.

Aim

In the present study, we aim to evaluate the effects of basal serum total immunoglobulin E (IgE) levels and changes in inflammatory parameters on the clinical progression of patients hospitalized with COVID‐19.

Methods

Patients hospitalized with confirmed COVID‐19 were included in the study. Laboratory data and total IgE levels were measured upon admission. Lymphocyte, eosinophil, ferritin, d‐dimer and CRP parameters were recorded on the baseline and on the 3^rd and 14^th days of hospitalization.

Results

The study enrolled 202 patients, of which 102(50.5%) were males. The average age was 50.17 ± 19.68. Of the COVID‐19 patients, 41 (20.3%) showed clinical progression. Serum total IgE concentrations were markedly higher (172.90 [0‐2124] vs 38.70 [0‐912], p<0.001) and serum eosinophil levels were significantly lower (0.015 [0‐1.200] vs 0.040 [0‐1.360], p=0.002) in clinically worsened COVID‐19 patients when compared to stable patients. The optimal cut‐off for predicting clinical worsening was 105.2 ng/L; with 61% sensitivity, 82% specificity, 46.3% positive predictive value and 89.2% negative predictive value (area under the curve=0.729). Multivariable analysis to define risk factors for disease progression identified higher total IgE and CRP levels as independent predictors.

Conclusions

Our single‐center pilot study determined that total IgE levels may be a negative prognostic factor for clinical progression in patients hospitalized due to COVID‐19 infection. Future studies are required to determine the impact of individuals' underlying immune predispositions on outcomes of COVID‐19 infections.

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Spectrum of Disease Manifestations in Patients with Selective Immunoglobulin E Deficiency

BACKGROUND

Selective IgE deficiency (SIgED) has been previously evaluated in selected patients from allergy units. This study investigates the effects of SIgED on the entire population in a hospital setting and sought to delineate in detail the clinical aspects of SIgED.

METHODS

A retrospective study of the data obtained from electronic medical records of 52 adult patients (56% female) with a mean age of 43 years and IgE levels of <2.0 kU/L with normal immunoglobulin (Ig) IgG, IgA, and IgM levels, seen at our hospital, without selection bias, from 2010 to 2019.

RESULTS

Recurrent upper respiratory infections were recorded in 18 (34.6%) patients, pneumonia was recorded in 16 (30.7%) patients, bronchiectasis was recorded in 16 (30.7%) patients, and asthma was recorded in 10 (19.2%) patients. Eighteen patients (34.6%) suffered autoimmune clinical manifestations either isolated (19%) or combining two or more diseases (15%), Hashimoto's thyroiditis being the most frequent (19%), which was followed by arthritis (10%) and thrombocytopenia and/or neutropenia (5.7%). Other less frequent associations were Graves' disease, primary sclerosing cholangitis, Sjögren's syndrome, and autoimmune hepatitis. Eczematous dermatitis (15.3%), chronic spontaneous urticaria (17.3%), and symptoms of enteropathy (21%) were also highly prevalent. Thirty percent of patients developed malignancies, with non-Hodgkin lymphomas (13.4%) being the most prevalent.

CONCLUSIONS

The clinical manifestations of SIgED encompass a variety of infectious, non-infectious complications, and malignancy. Since it cannot be ruled out that some type of selection bias occurred in the routine assessment of IgE serum Ievels, prospective studies are required to better characterize SIgED and to determine whether it should be added to the list of antibody deficiencies.

The Role of Atopy in COPD and Asthma

Common to several allergic diseases is the generation of immunoglobulin E (IgE) by plasma cells, when exposed to an innocuous antigen. Asthma and chronic obstructive pulmonary disease (COPD) are two prevalent chronic airway inflammatory diseases. Asthma is mediated in some patients through eosinophilic inflammatory mechanisms that include allergic sensitization and Th2-mediated immune airway response. COPD, on the other hand is mainly considered a Th1-mediated inflammatory process with neutrophilic predominance or a non-Th2 inflammation, occasionally associated with the presence of airway bacteria or viruses. IgE production appears to play an important role in the development of both COPD and asthma, as it has been associated to respiratory symptoms, lung function, bacterial and viral infections, airway remodeling and bronchial hyperreactivity in both diseases. The aim of this review is to summarize all current data concerning the role of specific and total IgE in COPD and asthma and to highlight similarities and differences in view of possible therapeutic interventions.

Viruses and asthma: the role of common respiratory viruses in asthma and its potential meaning for SARS-CoV-2

Viral infections and atopic diseases are closely related and contribute to each other. The physiological deficiencies and immune mechanisms that underlie atopic diseases can result in a suboptimal defense against multiple viruses, and promote a suitable environment for their proliferation and dissemination. Viral infections, on the other hand, can induce per se several immunological mechanisms involved in allergic inflammation capable to promote the initiation or exacerbation of atopic diseases such as atopic asthma. In a world that is affected more and more by factors that significantly impact the prevalence of atopic diseases, coronavirus disease 2019 (COVID-19) induced by the novel coronavirus severe acute respiratory syndrome (SARS-CoV-2) is having an unprecedented impact with still unpredictable consequences. Therefore, it is of crucial importance to revise the available scientific literature regarding the association between common respiratory viruses and asthma, as well as the newly emerging data about the molecular mechanisms of SARS-CoV-2 infection and its possible relation with asthma, to better understand the interrelation between common viruses and asthma and its potential meaning on the current global pandemic of COVID-19.

Features of the Human Antibody Response against the Respiratory Syncytial Virus Surface Glycoprotein G

Respiratory syncytial virus (RSV) infections are a major cause of serious respiratory disease in infants. RSV occurs as two major subgroups A and B, which mainly differ regarding the surface glycoprotein G. The G protein is important for virus attachment and G-specific antibodies can protect against infection. We expressed the surface-exposed part of A2 strain-derived G (A2-G) in baculovirus-infected insect cells and synthesized overlapping peptides spanning complete A2-G. The investigation of the natural IgG response of adult subjects during a period of one year showed that IgG antibodies (i) recognize G significantly stronger than the fusion protein F0, (ii) target mainly non-conformational, sequential peptide epitopes from the exposed conserved region but also buried peptides, and (iii) exhibit a scattered but constant recognition profile during the observation period. The IgG subclass reactivity profile (IgG₁ > IgG₂ > IgG₄ = IgG₃) was indicative of a mixed Th1/Th2 response. Two strongly RSV-neutralizing sera including the 1st WHO standard contained high IgG anti-G levels. G-specific IgG increased strongly in children after wheezing attacks suggesting RSV as trigger factor. Our study shows that RSV G and G-derived peptides are useful for serological diagnosis of RSV-triggered exacerbations of respiratory diseases and underlines the importance of G for development of RSV-neutralizing vaccines.

Effects of cinnamaldehyde on anti-respiratory syncytial virus: A protocol of systematic review and meta-analysis

BACKGROUND

Previous reports found that cinnamaldehyde has effects on anti-respiratory syncytial virus (ARSV). However, their results are still contradictory. Therefore, this study will systematically address the effects of cinnamaldehyde on ARSV.

METHODS

The following electronic bibliographic databases will be retrieved from their outset to the March 31, 2020: MEDLINE, EMBASE, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Technology Periodical Database, China Biology Medicine, and China National Knowledge Infrastructure. No language and publication time limitations will be exerted in this study. All relevant case-controlled studies or randomized controlled studies exploring the effects of cinnamaldehyde on ARSV will be included. Study quality of case-controlled studies will be assessed by Newcastle-Ottawa scale, and that of randomized controlled studies will be identified by Cochrane risk of bias tool. All data pooling and analysis will be performed using RevMan 5.3 software.

RESULTS

This study will summarize the up-to-date high-quality evidence to synthesize outcome data on the effects of cinnamaldehyde on ARSV.

CONCLUSION

Findings of this study may provide beneficial evidence for both clinicians and future studies regarding the effects of cinnamaldehyde on ARSV.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202040074.

Host Components Contributing to Respiratory Syncytial Virus Pathogenesis

Respiratory syncytial virus (RSV) is the most prevalent viral etiological agent of acute respiratory tract infection. Although RSV affects people of all ages, the disease is more severe in infants and causes significant morbidity and hospitalization in young children and in the elderly. Host factors, including an immature immune system in infants, low lymphocyte levels in patients under 5 years old, and low levels of RSV-specific neutralizing antibodies in the blood of adults over 65 years of age, can explain the high susceptibility to RSV infection in these populations. Other host factors that correlate with severe RSV disease include high concentrations of proinflammatory cytokines such as interleukins (IL)-6, IL-8, tumor necrosis factor (TNF)-α, and thymic stromal lymphopoitein (TSLP), which are produced in the respiratory tract of RSV-infected individuals, accompanied by a strong neutrophil response. In addition, data from studies of RSV infections in humans and in animal models revealed that this virus suppresses adaptive immune responses that could eliminate it from the respiratory tract. Here, we examine host factors that contribute to RSV pathogenesis based on an exhaustive review of in vitro infection in humans and in animal models to provide insights into the design of vaccines and therapeutic tools that could prevent diseases caused by RSV.

Fc-Mediated Antibody Effector Functions During Respiratory Syncytial Virus Infection and Disease

Respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infections and hospitalization in infants under 1 year of age and there is currently no market-approved vaccine available. For protection against infection, young children mainly depend on their innate immune system and maternal antibodies. Traditionally, antibody-mediated protection against viral infections is thought to be mediated by direct binding of antibodies to viral particles, resulting in virus neutralization. However, in the case of RSV, virus neutralization titers do not provide an adequate correlate of protection. The current lack of understanding of the mechanisms by which antibodies can protect against RSV infection and disease or, alternatively, contribute to disease severity, hampers the design of safe and effective vaccines against this virus. Importantly, neutralization is only one of many mechanisms by which antibodies can interfere with viral infection. Antibodies consist of two structural regions: a variable fragment (Fab) that mediates antigen binding and a constant fragment (Fc) that mediates downstream effector functions via its interaction with Fc-receptors on (innate) immune cells or with C1q, the recognition molecule of the complement system. The interaction with Fc-receptors can lead to killing of virus-infected cells through a variety of immune effector mechanisms, including antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). Antibody-mediated complement activation may lead to complement-dependent cytotoxicity (CDC). In addition, both Fc-receptor interactions and complement activation can exert a broad range of immunomodulatory functions. Recent studies have emphasized the importance of Fc-mediated antibody effector functions in both protection and pathogenesis for various infectious agents. In this review article, we aim to provide a comprehensive overview of the current knowledge on Fc-mediated antibody effector functions in the context of RSV infection, discuss their potential role in establishing the balance between protection and pathogenesis, and point out important gaps in our understanding of these processes. Furthermore, we elaborate on the regulation of these effector functions on both the cellular and humoral side. Finally, we discuss the implications of Fc-mediated antibody effector functions for the rational design of safe and effective vaccines and monoclonal antibody therapies against RSV.

Respiratory viral infections and atopic development: From possible mechanisms to advances in treatment

Atopic sensitization and allergic diseases are increasing in modernized countries. These diseases affect millions of individuals, but the mechanisms behind their development are not fully understood. One hypothesis relates to early life respiratory viral infections driving the development of atopic disease including asthma. This review presents the current state of the field, focusing on epidemiologic data supporting a role for early life respiratory viruses in the development of specific IgE, both against aeroallergens and the respiratory virus. Our own work using the Sendai mouse model is then summarized to provide a potential mechanistic explanation for how a respiratory viral infection could drive development of atopic sensitization and disease. We then discuss the components of this mechanistic pathway that have and have not been validated in humans. Finally, we discuss areas ripe for research, as well as potential and current therapeutics that might disrupt the link between respiratory viral infections in early life and atopic sensitization/disease.

Therapeutic Effect of Omalizumab in Severe Asthma: A Real-World Study in Korea

Purpose

Omalizumab, an anti-immunoglobulin E (IgE) monoclonal antibody, has proved to be effective for the treatment of severe asthma. However, there is no direct evidence of effectiveness of omalizumab in Korean patients with severe asthma. We sought to evaluate the real-world effectiveness of omalizumab in Korean adult patients suffering from severe asthma and to identify predictors of favorable response.

Methods

A retrospective analysis of electrical medical records was performed on severe allergic asthmatic patients with omalizumab treatment group (OT group) for more than 6 months between March 2008 and February 2016. Propensity score matching was applied to define the standardized treatment control group (STC group) treated without omalizumab. Asthma-related outcomes were compared between the 2 groups, and analyzed before and after omalizumab use in the OT group. Responders to treatment were defined as patients showing >50% reduction in asthma exacerbations and/or systemic steroid requirement during the outcome period.

Results

One hundred twenty-four patients with severe asthma (62 in the OT group; 62 in the STC group) were enrolled in the study. Proportion of patients having the reduction of asthma exacerbation (53.2% vs 35.5%, P=0.015) and the rate of responders (67.7% vs 41.9%, P=0.007) were significantly higher in the OT group than in the STC group. Significant reductions were noted in asthma exacerbation (P=0.006), hospitalization (P=0.009), hospitalization days (P=0.006), systemic corticosteroid requirements (P=0.027), and sputum eosinophil count (P=0.031) in OT group compared with STC group. There were no significant differences in changes of forced expiratory volume in the 1 second (FEV1) levels between the 2 groups. No predictors of responders were found for omalizumab treatment.

Conclusions

Omalizumab can reduce exacerbations/hospitalization/systemic steroid burst in Korean adult patients with severe asthma.