Sensitization trajectories to multiple allergen components in a population-based birth-cohort

Trends in Allergic Sensitization and Diseases in the Korean General Population Over a 9-Year Period

OBJECTIVES

The prevalence of allergic sensitization and diseases varies over time due to changes in climate, environment, and lifestyle. This study analyzed changes in sensitization to house dust mites (HDM) and dogs, as well as the prevalence of allergic diseases in the Korean general population over a 9-year period and identified contributing factors.

METHODS

This cross-sectional study used data from the Korea National Health and Nutrition Examination Survey conducted in 2010 and 2019. Participants were aged ≥10 years, with the analysis stratified by adolescents (10-18 years) and adults (≥19 years). We evaluated the prevalence of allergic sensitization and diseases and examined links to clinicodemographic factors across the two survey years. Multivariate logistic regression was performed to evaluate the association between sensitization and clinicopathological factors.

RESULTS

In total, 4,084 participants (2010: n=2,019, 2019: n=2,065) were enrolled. In 2010, HDM sensitization was 36.9%, declining to 36.6% in 2019. Dog sensitization decreased from 6.1% in 2010 to 5.8% in 2019. There were no significant differences between the two years among total participants; however, dog sensitization increased significantly among adolescents (2010: 8.7% vs. 2019: 15.3%; P=0.027). In 2010, HDM sensitization was negatively associated with urban residence (odds ratio [OR], 0.76; 95% CI, 0.60-0.96) and apartment dwelling (OR, 0.78; 95% CI, 0.64-0.95) but was without significance in 2019. In adolescents, dog sensitization was strongly correlated with urban residence (OR, 8.06; 95% CI, 1.53-42.49) in 2010, whereas HDM sensitization was associated with obesity (OR, 2.02; 95% CI, 1.04-3.91) in 2019. In adults, heavy drinking was linked to dog sensitization (OR, 2.35; 95% CI, 1.20-4.62) in 2010 and HDM sensitization in 2019 (OR, 1.44; 95% CI, 1.03-2.02).

CONCLUSION

The prevalence of HDM sensitization remained stable over 9 years, while dog sensitization increased in adolescents. The factors associated with sensitization differed between age groups and years. Understanding these trends and related factors in the general population can help healthcare providers develop new strategies to reduce allergic sensitization and diseases.

Machine learning-derived asthma and allergy trajectories in children: a systematic review and meta-analysis

INTRODUCTION

Numerous studies have characterised trajectories of asthma and allergy in children using machine learning, but with different techniques and mixed findings. The present work aimed to summarise the evidence and critically appraise the methodology.

METHODS

10 databases were searched. Screening, data extraction and quality assessment were performed in pairs. Trajectory characteristics were tabulated and visualised. Associated risk factor and outcome estimates were pooled using a random-effects meta-analysis.

RESULTS

89 studies were included. Early-onset (infancy) persistent, mid-onset (∼2-5 years) persistent, early-onset early-resolving (within ∼2 years) and early-onset mid-resolving (by ∼3-6 years) wheezing and eczema, respectively, were the most commonly identified disease trajectories. Intermediate/transient trajectories were rare. Male sex was associated with a higher risk of most wheezing trajectories and possibly with early-resolving eczema, while being slightly protective against mid-onset persistent eczema. Parental disease/genetic markers were associated with persistent trajectories of wheezing and eczema, respectively. Prenatal (and less so postnatal) tobacco smoke exposure was associated with most wheezing trajectories, as were lower respiratory tract infections in infancy (particularly with the early-onset resolving patterns). Most studies (69%) were of low methodological quality (particularly in modelling approaches and reporting). Few studies investigated allergic multimorbidity, allergic rhinitis and food allergy.

CONCLUSIONS

Childhood asthma/wheezing and eczema can be characterised by a few relatively consistent trajectories, with some actionable risk factors such as pre-/postnatal smoke exposure. Improved computational methodology is warranted to better assess generalisability and elucidate the validity of intermediate/transient trajectories. Likewise, allergic multimorbidity and trajectories of allergic rhinitis and food allergy need to be further elucidated.

Inverse association between the molecular spreading of IgE to grass pollen and the IgE response to Dermatophagoides pteronyssinus among children with seasonal allergic rhinitis

Background

Seasonal allergic rhinoconjunctivitis (SAR) is a worldwide health problem, especially in Westernized countries. Previous studies of the "Panallergens in Pediatrics" (PAN-PED) cohort found that molecular spreading (ie, the progressive increase in serum specific IgE antibody levels) of the IgE response to the grass pollen, Phleum pratense, molecules is directly associated with polysensitization to pollen in general.The research question is aimed at verifying whether this association can also be detected for non-pollen allergens, specifically Dermatophagoides pteronyssinnus (D.pt), to better understand the relationship between a perennial allergen (D.pt) and a seasonal allergen (Phleum pratense).To this end, our first objective was to analyze the biobank of the PAN-PED cohort serum by measuring the IgE levels to D.pt and its major recombinant molecules (Der p1, Der p2, Der p23); subsequently we investigated their correlation towards Phleum pratense IgE response, studying also the relationship between the molecular spreading of these 2 different allergens.

Methods

Among 1120 patients positive to Phleum pratense, 638 were also sensitized to D.pt. Patients underwent skin prick tests (SPT) for inhalant extracts, and their serum was tested for total IgE (tIgE), and sIgE to pollen and perennial allergens. Considering the molecular allergen detection through the component resolved diagnosis (CRD), out of 638 patients, 146 were further investigated by performing IgE tests of the 3 major D.pt. molecules: Der p1, Der p2, and Der p23.

Results

We found that a broader molecular response to Phleum pratense molecules, assessed by CRD, was associated with higher tIgE levels, polysensitization to pollens, and higher IgE levels to pollens, but also to lower IgE levels to D.pt and lower degree of sensitization to rDer p1, r Der p2, and rDer p23. In a multivariate linear model, the number of Phleum pratense molecules recognized by IgE was still inversely associated with the IgE level to D.pt extract.

Conclusions

The main finding of this study was the detection of an inverse association, never described in the literature, between the molecular spreading of the IgE response to Phleum pratense and the IgE response to D.pt. This led us to speculate on the etiopathogenetic hypothesis according to which, among the majority of pollen allergic patients, a strong and molecularly diversified IgE response may be limited to pollen allergens and may be preventing or contrasting the development of an equally strong and diversified IgE sensitization to D.pt molecules. The biological mechanisms underlying this phenomenon deserve to be investigated.

What molecular allergy teaches us about genetics and epidemiology of allergies

PURPOSE OF REVIEW

To delineate pertinent information regarding the application of molecular allergology within the realm of both genetic and epidemiological facets of allergic diseases.

RECENT FINDINGS

The emergence of molecular allergy has facilitated the comprehension of the biochemical characteristics of allergens originating from diverse sources. It has allowed for the exploration of sensitization trajectories and provided novel insights into the influence of genetics and environmental exposure on the initiation and development of allergic diseases. This review delves into the primary discoveries related to the genetics and epidemiology of allergies, facilitated by the application of molecular allergy. It also scrutinizes the impact of environmental exposure across varied geoclimatic, socioeconomic, and lifestyle contexts. Additionally, the review introduces specific models of molecular allergy within the realms of plants and animals.

SUMMARY

The utilization of molecular allergy in clinical practice holds crucially acknowledged diagnostic and therapeutic implications. From a research standpoint, there is a growing need for the widespread adoption of molecular diagnostic tools to achieve a more profound understanding of the epidemiology and natural progression of allergic diseases.