Allergy and Atopic Diseases: An Update on Experimental Evidence

Next-generation reference interval for total IgE in the United States: A retrospective real-world analysis

OBJECTIVE

To establish a next-generation reference interval (RI) for total IgE (tIgE) and evaluate its usefulness.

METHODS

A new allergen-specific IgE (sIgE)-based tIgE RI, including a continuous RI in children, was established using the NHANES 2005-2006 project. The usefulness of the RI was evaluated by sensitivity (Sen), specificity (Spec), positive predictive value (PPV), negative predictive value (NPV), κ coefficient and consistency.

RESULTS

The new tIgE RI showed better performance in identifying allergic sensitization (Sen 0.53, Spec 0.90, PPV 0.83, NPV 0.68, κ 0.44, consistency 0.72) than allergic diseases (Sen 0.37, Spec 0.75, PPV 0.55, NPV 0.60, κ 0.13, consistency 0.59). The 2014 U.S. tIgE RI was more effective in identifying allergic diseases (consistency 0.63 vs. 0.54, P<0.001) but less accurate in identifying allergic sensitization (consistency 0.59 vs. 0.67, P<0.001) in children than in adults. The new RI improved the accuracy of identifying allergic sensitization in children to a level similar to that in adults (consistency 0.72 vs 0.73, P=0.37) and maintained its advantage in identifying allergic diseases in children (consistency 0.64 vs 0.55, P<0.001).

CONCLUSIONS

The established next-generation tIgE RI is useful for identifying allergic sensitization, especially in children.

Examining the contribution of Notch signaling to lung disease development

Notch pathway is a widely observed signaling system that holds pivotal functions in regulating various developmental cellular functions and operations. The Notch signaling mechanism is crucial for lung homeostasis, damage, and restoration. Based on increasing evidence, the Notch pathway has been identified, as critical for fibrosis and subsequently, the development of chronic fibroproliferative conditions in various organs and tissues. Recent research indicates that deregulation of Notch signaling correlates with the pathogenesis of significant pulmonary conditions, particularly chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, asthma, pulmonary arterial hypertension (PAH), lung carcinoma, and pulmonary abnormalities in some hereditary disorders. In various cellular and tissue environments, and across both physiological and pathological conditions, multiple consequences of Notch activation have been observed. Studies have ascertained that the Notch signaling cascade exhibits close associations with various other signaling systems. This study provides an updated overview of Notch signaling's role, especially its link to fibrosis and its potential therapeutic implications. This study sheds light on the latest findings regarding the mechanisms and outcomes of irregular or lacking Notch activity in the onset and development of pulmonary diseases. As our insight into this signaling mechanism suggests that modulating Notch signaling might hold potential as a valuable additional therapeutic approach in upcoming research.

de Vos W. Early-life gut microbiota associates with allergic rhinitis during 13-year follow-up in a Finnish probiotic intervention cohort

Perinatal and early-life factors reported to affect risk of allergic diseases may be mediated by changes in the gut microbiota. Here, we explored the associations between the infant gut microbiota and allergic morbidity in childhood until 13 years of age in a subgroup of the FLORA probiotic intervention cohort. A mixture of four probiotic strains with galacto-oligosaccharides was administrated to the mothers from the 36th week of the pregnancy and later to their infants until 6 months of age. The infants were monitored for the manifestations of atopic eczema, food allergy, allergic rhinitis, and asthma by a pediatrician at 2 and 5 years of age; the allergic status was subsequently verified by a questionnaire at 10 and 13 years of age. The fecal microbiota at 3 months was profiled by 16S rRNA amplicon sequencing targeting the V3-V4 region, with and without adjusting for potentially important early-life factors. Overall, the positive diagnosis for allergic rhinitis between 2 and 13 years was associated with microbiota composition both in non-adjusted and adjusted models. This association was more pronounced in children born to one parent with confirmed atopic diseases compared to those who had two atopic parents and was characterized by a lower relative abundance of Bifidobacterium and Escherichia/Shigella spp. and a higher proportion of Bacteroides. While the probiotic and galacto-oligosaccharides intervention in the entire cohort was previously shown to reduce the prevalence of eczema to a certain extent, no associations were found between the 3-month gut microbiota and childhood eczema in the studied sub-cohort.IMPORTANCEAllergic diseases have increased in prevalence during the past decades globally. Although probiotics have been considered a promising strategy for preventing certain allergy related symptoms, studies connecting the infant gut microbiota and later life allergic morbidity in various populations remain limited. The present study supports an association between the infant microbiota and allergic morbidity after first years of life, which has been rarely examined.CLINICAL TRIALSRegistered at ClinicalTrials.gov (NCT00298337).

Atopic dermatitis phenotype affects expression of atopic diseases despite similar mononuclear cell cytokine response

BACKGROUND

The atopic march refers to the coexpression and progression of atopic diseases in childhood, often beginning with atopic dermatitis (AD), although children may not progress through each atopic disease.

OBJECTIVE

We hypothesized that future atopic disease expression is modified by AD phenotype and that these differences result from underlying dysregulation of cytokine signaling.

METHODS

Children (n = 285) were enrolled into the Childhood Origins of Asthma (COAST) birth cohort and followed prospectively. Rates of AD, food allergy, allergic rhinitis, and asthma were assessed longitudinally from birth to 18 years of age. Associations between AD phenotype and food allergy, allergic rhinitis, asthma, allergic sensitization, exhaled nitric oxide, and lung function were determined. Peripheral blood mononuclear cell responses (IL-5, IL-10, IL-13, IFN-γ) to dust mite, phytohemagglutinin, Staphylococcus aureus Cowan I, and tetanus toxoid were compared among AD phenotypes.

RESULTS

AD at year 1 was associated with an increased risk of food allergy (P = .004). Both persistent and late-onset AD were associated with an increased risk of asthma (P < .001), rhinitis (P < .001), elevated total IgE (P < .001), percentage of aeroallergens with detectable IgE (P < .001), and elevated exhaled nitric oxide (P = .002). Longitudinal analyses did not reveal consistent differences in peripheral blood mononuclear cell responses among dermatitis phenotypes.

CONCLUSION

AD phenotype is associated with differential expression of other atopic diseases. Our findings suggest that peripheral blood cytokine dysregulation is not a mechanism underlying this process, and immune dysregulation may be mediated at mucosal surfaces or in secondary lymphoid organs.

Causal relationship between Butyricimonas and allergic asthma: a two-sample Mendelian randomization study

Background

Growing evidence has well documented the close association between the gut microbiome and allergic respiratory disease, which has been notably represented by allergic asthma. However, it is unclear whether this association is a causal link. Therefore, we investigated the potential causal associations between the gut microbiome and allergic asthma or other allergic diseases.

Methods

In this study, we performed two-sample Mendelian randomization (MR) analyses by using the publicly available genome-wide association study (GWAS) summary data. Single-nucleotide polymorphisms (SNPs) that significantly correlated were selected as instrumental variables. The inverse variance weighted (IVW) method was used to examine the potential causal gut microbial genera for allergic asthma and other allergic diseases. The robustness of the primary findings of the MR analyses was ensured by using different sensitivity analyses.

Results

Combining the findings from multiple analyses, the host genetic-driven increases in Butyricimonas at the genus level were positively correlated with the risk of allergic asthma. In addition, phylum Bacteroidetes and class Bacteroidia were also found to have negative associations with the risk of allergic asthma; genus Slackia was identified as having potential causal effects with allergic asthma. No clear evidence of pleiotropy and heterogeneity was observed in genus Butyricimonas. Butyricimonas was also found to have an association with allergic rhinitis, but not with other allergic diseases.

Conclusion

Our findings indicate that there are new gut microbial genera that were causally associated with the risk of allergic asthma and other allergic diseases, and offer novel insights into the pathogenesis of allergic respiratory diseases.

Prevalence, severity, and risk factors of allergic rhinitis among schoolchildren in Saudi Arabia: A national cross-sectional study, 2019

Background

Allergic rhinitis is a significant public health concern worldwide, affecting both developed and developing countries, with prevalence rates ranging between 10% and 30% in adults and over 40% in children. However, there are limited studies on allergic rhinitis prevalence in Saudi Arabia.

Objective

To explore allergic rhinitis among schoolchildren in Saudi Arabia in terms of prevalence, severity, and risk factors.

Methods

This study was conducted between March and April 2019, covering 20 regions. The study employed a multistage, stratified cluster sampling approach and selected 137 primary and 140 intermediate schools. The research utilized the methodology and questionnaires recommended by the Global Asthma Network (GAN). Data analysis was carried out using IBM SPSS Statistics (Version 23).

Results

The completed questionnaires in the analysis comprised 3614 children aged 6-7 years old and 4068 adolescents aged 13-14 years old. The study found that 5.6% of children and 14.0% of adolescents reported current rhinoconjunctivitis, with 0.5% of children and 1.3% of adolescents experiencing severe symptoms. Several risk factors were significantly associated with rhinoconjunctivitis. In children 6-7 years old, eating cooked vegetables was inversely associated with rhinoconjunctivitis, while prematurity, wheezing in infancy, and a history of pneumonia were positively associated with the condition. In adolescents, vigorous physical activity, current exposure to cats, and frequent use of paracetamol were found to be the main risk factors associated with rhinoconjunctivitis, while high consumption of pulses and eggs was found to have a protective effect.

Conclusion

In Saudi Arabia, the prevalence of rhinoconjunctivitis in children is lower than average globally, but among adolescents, it is within the global average range. However, the prevalence of severe rhinoconjunctivitis among adolescents is twice the global average. Further research is required to examine regional differences, track trends over time, and explore risk factors that contribute to allergic rhinitis.

Allergy, asthma, and proteomics: opportunities with immediate impact

Allergy is widely discussed by researchers due to its complex mechanism that leads to disorders and injuries, but the reason behind the allergic status remains unclear. Current treatments are insufficient to improve the patient's quality of life significantly. New technologies in scientific and technological development are emerging. For instance, the union between allergy and peptidomics and bioinformatics tools may help fill the gaps in this field, diagnosis, and treatment. In this review, we look at peptidomics and address some findings, such as target proteins or biomarkers that help better understand mechanisms that lead to inflammation, organ damage, and, consequently, poor quality of life or even death.

Factors associated with allergy traits around the 2nd year of life: a brazilian cohort study

BACKGROUND

Allergic status has been strongly influenced by early exposures; however, allergic diseases are hard to measure in early life. Thus, this study proposed a latent variable allergy traits around the second year of life and analyzed pre- and perinatal factors associated with this phenomenon.

METHODS

The study used data from the BRISA birth cohort, Ribeirão Preto, Brazil (n = 3644). The theoretical model included: family allergy (history of allergic rhinitis, atopic dermatitis, and asthma); gestational period variables (socioeconomic status, mother's skin color, pregestational body mass index - BMI, smoking, gestational diabetes, and hypertension); birth variables (gestational age, 5-minute Apgar score, birth weight, type of delivery), and early life factor (exclusive breast feeding). The outcome was allergy traits around the 2nd year of life, a latent variable deduced from the shared variance among medical diagnosis of allergic rhinitis, atopic dermatitis, and food allergy. The model was analyzed by structural equation modeling.

RESULTS

Higher socioeconomic status (SC = 0.256; p < 0.001) and higher family allergy values (SC = 1.224; p < 0.001) were associated with higher allergy trait values. Hypertension during pregnancy was associated with higher values (SC = 0.170; p = 0.022) and exclusive breast feeding (SC = -0.192; p < 0.001) with low allergy trait values.

CONCLUSION

Although socioeconomic and environmental factors were associated with allergy traits around the 2nd year of life, the family component of allergy was the exposure that best explained this outcome.

Allergic rhinitis, allergic contact dermatitis and disease comorbidity belong to separate entities with distinct composition of T-cell subsets, cytokines, immunoglobulins and autoantibodies

Background

Allergic rhinitis (AR) and allergic contact dermatitis (ACD) are prevalent allergic diseases and have significant impacts on patients’ daily life. Despite many studies on AR or ACD have been conducted separately, little is known about the immune responses in patients of AR combined with ACD and the interplay between AR and ACD. Our study compared various aspects of immune elements in patients with AR or/and ACD, aiming to characterize the immune responses in AR, ACD, and AR combined with ACD.

Methods

A total of 57 patients diagnosed with AR or/and ACD and 28 healthy volunteers were included. AR patients were further divided into seasonal AR (SAR) and perennial AR (PAR). All subjects’ blood samples were taken to assess the concentration of immunoglobulins, complement C3, C4, autoantibodies and cytokines in serum by immunoturbidimetry, ELISA or Luminex200 platform. Peripheral blood mononuclear cells (PBMCs) were subjected to the analysis of lymphocyte subpopulations by flow cytometry.

Results

It indicated that AR disease caused elevated levels of IgE, IgA, IgG, IgG4, as well as IL-4, IL-15, IL-8 and IL-6 in serum. AR patients possessed a decreased CD4/CD8 ratio and an increased proportion of memory CD4 + T-cell subset, with a skewed Th2 response and an enhanced CD8 + T-cell activation. Compared with patients with sole AR or ACD condition, AR + ACD patients presented with a significantly increased proportion of memory CD8 + T-cell subset and were prone to autoimmune disorders as indicated by the increased autoantibodies. The immune elements in patients with ACD only were least affected compared with those in other conditions. Additionally, seasonal or perennial AR patients exhibited different cytokine profiles and proportions of memory T-cell subsets.

Conclusions

In this study, we illuminated the respective characteristics of immune responses in AR, ACD, and AR combined with ACD. Meanwhile, we discovered that the PAR and SAR patients possessed different cytokine profiles and T-cell compartments. It suggested that these allergic conditions belong to different disease entities. Characterizing the detailed immune changes in these allergic diseases would help to develop proper treatments targeting particular immune elements in different allergic diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00646-6.

Atopic March: Dermatologic perspectives

The progression of allergic diseases with the development of atopic dermatitis and food allergy in infancy and subsequent asthma and allergic rhinitis in the later childhood is known as 'atopic march'. There have been many arguments in favour of and against this concept. This article reviews the latest epidemiology, immunological mechanisms and translational implications in clinical practice and research, which is relevant to the dermatologists. The role of skin as a site of initiation and the potential for interventions on skin that may prevent subsequent allergic diseases is also highlighted.

[In vitro study on the individual binding ability of omalizumab with free IgE]

Objective:To investigate the individual binding ability of omalizumab to free IgE and its effect on omalizumab action. Methods:A total of 28 serum samples were collected from patients with allergic rhinitis and divided into groups with high, medium and low concentrations of free IgE. Different doses of omalizumab were administered in vitro for inhibitory binding. Enzyme linked immunosorbent assay was used to detect changes in serum free IgE after inhibition. The inhibition constant of omalizumab on serum free IgE was calculated. At the same time, the binding ability of omalizumab and individual free IgE was analyzed. Results:In general, when 100% serum free IgE was inhibited, the omalizumab required was positively correlated with the original serum free IgE concentration（9.500±7.207, 8.636±7.375, and 0.786±0.857 for the high, medium, and low IgE concentration groups, respectively）. The dose of omalizumab required for inhibition of 50% free IgE in serum was significantly lower（0.049±0.071, 0.046±0.077, 0.048±0.048 in the high, medium, and low IgE concentrations groups, respectively）. The 100% and 50% inhibition constants of serum free IgE in different individuals were different to some extent. Conclusion:Overall, the amount of omalizumab required to achieve the same inhibitory effect is proportional to the IgE concentration. In some sensitive patients, partial binding inhibition of free IgE can occur even when omalizumab is administered at less than the recommended dose. The binding ability of serum free IgE and omalizumab was different in different individuals. If this factor is used as a reference for the individual dose of omalizumab in clinical medicine, it is possible to achieve the expected efficacy more accurately.

The Association of Bullous Pemphigoid With Atopic Dermatitis and Allergic Rhinitis-A Population-Based Study

BACKGROUND

Although bullous pemphigoid (BP), atopic dermatitis (AD), and allergic rhinitis (AR) are associated with shared pathogenic mechanisms the epidemiological relationship between these conditions remains to be investigated.

OBJECTIVE

To evaluate the bidirectional association of BP with AD and AR.

METHODS

A population-based retrospective cohort study was performed comparing BP patients (n = 3924) with age-, sex-, and ethnicity-matched control subjects (n = 19,280), with respect to incident cases of AD and AR. A case-control design was additionally adopted to assess the odds of BP in individuals with a preexisting diagnosis of AD and AR.

RESULTS

The odds of BP was increased after a preexisting diagnosis of AD (fully adjusted odds ratio, 1.76; 95% confidence interval [CI], 1.44-2.15; P < 0.001) and AR (fully adjusted odds ratio, 1.13; 95% CI, 1.01-1.28; P = 0.047). Patients with BP were at an increased risk of subsequent AD (fully adjusted hazard ratio, 2.00; 95% CI, 1.60-2.51; P < 0.001) but not AR (fully adjusted hazard ratio, 1.00; 95% CI, 0.83-1.20; P = 0.997). Compared with other patients with BP, those with BP and comorbid AD and AR were more frequently managed by adjuvant drugs and long-term systemic and topical corticosteroids and had decreased all-cause mortality.

CONCLUSIONS

A history of AD and AR confers susceptibility to the development of BP. Awareness of this association may be of help for physicians managing patients with these diseases.

Is overweight/obesity a risk factor for atopic allergic disease in prepubertal children? A case-control study

OBJECTIVES

It is unclear whether body weight status (underweight/normal weight/overweight/obese) is associated with allergic disease. Our objective was to investigate the relationship between body weight status (body mass index; BMI) and atopic allergic disease in prepubertal children, and to compare children with atopic allergic diseases with non atopic healthy children.

METHODS

A prospective cross sectional study of 707 prepubertal children aged 3-10 years was performed; the participants were 278 atopic children with physician-diagnosed allergic disease (allergic rhinitis and asthma) (serum total IgE level >100 kU/l and eosinophilia >4%, or positivity to at least one allergen in skin test) and 429 non atopic healthy age- and sex-matched controls. Data were collected between December 2019 and November 2020 at the Pediatric General and Pediatric Allergy Outpatient Clinics of Bezmialem Vakıf University Hospital.

RESULTS

Underweight was observed in 11.6% of all participants (10.8% of atopic children, 12.2% of healthy controls), and obesity in 14.9% of all participants (18.0% of atopic children, 12.8% of controls). Obese (OR 1.71; 95% CI: 1.08-2.71, p=0.021), and overweight status (OR 1.62; 95% CI: 1.06-2.50, p=0.026) were associated with an increased risk of atopic allergic disease compared to normal weight in pre-pubertal children. This association did not differ by gender. There was no relationship between underweight status and atopic allergic disease (OR 1.03; 95% CI: 0.63-1.68, p=0.894).

CONCLUSIONS

Overweight and obesity were associated with an increased risk of atopic allergic disease compared to normal weight among middle-income and high-income pre pubertal children living in Istanbul.

Influences of CD8+ Tregs on Peripheral Blood Mononuclear Cells from Allergic Rhinitis Patients

OBJECTIVES

CD8+ (or CD4+ ) CD25+ fork-head box transcription factor (Foxp3)+ regulatory T cells (CD8+ or CD4+ Tregs) all play a significant role in immune homeostasis and tolerance. However, the role of CD8+ Tregs in allergic rhinitis (AR) have not been clearly elucidated. The present study was aimed to assess the influence of CD8+ Tregs on peripheral blood mononuclear cells (PBMCs) from AR patients.

STUDY DESIGN

Prospective cross-sectional study.

METHODS

Patients with AR were enrolled. PBMCs were obtained, and CD4+ and CD8+ Tregs were separated from PBMCs and cultured in vitro. We examined percentages of these Tregs in total CD4+ or CD8+ T cells, respectively. After that, we evaluated levels of interleukin (IL)-10 and transforming growth factor (TGF)-β in Tregs cultures. Finally, we administered CD4+ and CD8+ Tregs from AR patients into PBMCs cultures and examined contents of IL-4 and IL-5.

RESULTS

The percentages of CD4+ or CD8+ Tregs in the total CD4+ or CD8+ T cells from PBMCs in AR patients were reduced compared to normal subjects. However, IL-10 and TGF-β and their mRNAs were increased in CD4+ and CD8+ Tregs cultures from AR patients, and there were no significant differences in their levels between these two Tregs cultures. IL-4 and IL-5 were increased in AR subjects' PBMCs compared to normal ones and decreased after the AR CD4+ or CD8+ Tregs administration. However, there were no statistical differences in IL-4 and IL-5 concentrations between these two Tregs treatments.

CONCLUSIONS

The findings demonstrate that CD8+ Tregs may alleviate inflammatory responses in AR condition.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:E316-E323, 2021.

Allergic diseases do not impair the cognitive development of children but do damage the mental health of their caregivers

This study aimed to investigate whether children with atopic diseases exhibited different neurodevelopment function from healthy controls and whether their caregivers had differential parental stress. In total, we recruited 109 patients with atopic diseases (mean age 6.8 years, 54.1% male) and 82 healthy children (mean age 6.3 years, 54.9% male). Based on the children’s age, they underwent developmental, cognitive evaluations and attention deficit/hyperactivity disorder (ADHD) symptoms. The parenting stress of children’s caregivers was evaluated using the Chinese Health Questionnaire (CHQ-12) and Family APGAR. Of the children with atopic diseases, 87.2%, 74.3%, 29.4%, and 8.3% of them had allergic rhinitis, asthma, atopic dermatitis, and urticaria, respectively. None of these conditions were associated with children’s cognitive profiles or ADHD symptoms. However, the caregivers of patients who had asthma suffered from higher CHQ-12 scores than those of patients without asthma. Furthermore, the number of atopic diseases had a dose–response effect on caregivers’ CHQ-12 scores. In conclusion, allergic diseases did not impair the cognitive development of children. However, caregivers of patients with asthma or multiple atopic diseases may suffer a greater mental health burden with regard to caring for their children. Such caregivers may require support to effectively fulfill their parenting roles.