Allergic Rhinitis and House Dust Mite Sensitization Determine Persistence of Asthma in Children

The Impact of the Indoor Environment on Childhood Asthma

PURPOSE OF REVIEW

This manuscript reviews the impact of important indoor environmental exposures on pediatric asthma, with a focus on recent literature in the field.

RECENT FINDINGS

Studies continue to support an association between numerous indoor aeroallergens and air pollutants found in homes and schools and increased asthma morbidity overall. Several recent home and school intervention studies have shown promise, though results have been overall mixed. Indoor environmental exposures contribute to the development of asthma and impact asthma morbidity. Further research is needed to improve our understanding of how to optimize mitigation of these indoor exposures to significantly affect asthma outcomes.

Optimization of Basophil Activation Test in the Diagnosis and Qualification for Allergen-Specific Immunotherapy in Children with Respiratory Allergy to the House Dust Mite Dermatophagoides pteronyssinus

The aim of this study was to optimize a basophil activation test in the detection of allergy to the house dust mite Dermatophagoides pteronyssinus in children with allergic respiratory diseases. This study involved 32 cases, 13 girls and 19 boys aged 4-17 years, with perennial asthma or allergic rhinitis caused by D. pteronyssinus. The control group consisted of 13 girls and 19 boys aged 4-17 years with seasonal allergic asthma or rhinitis provoked by Timothy or birch pollen. House dust mite (HDM) allergy was excluded in the controls based on their medical history, skin prick test (SPT) results and sIgE determination. In all patients, a basophil activation test (BAT) was performed with five dilutions of D. pteronyssinus allergen (the dilution series ranged from 22.5 to 0.00225 ng/mL). The results were analyzed by using the receiver operating characteristics (ROC) to determine the optimal allergen concentrations, outcome measures and cut-off points that would differentiate most accurately between HDM-allergic and non-allergic patients. As a "gold standard", criteria for allergen-specific immunotherapy with D. pteronyssinus or respective pollens were applied by an experienced pediatric allergist following the guidelines of the European Academy of Allergy and Clinical Immunology. The highest diagnostic efficiency was yielded by the protocol assuming a cut-off value of 9.76% activated basophils after activation with a single allergen concentration of 2.25 ng/mL (sensitivity 90.6%, specificity 100%). This protocol yielded 3 (4.7%) misclassifications, all false negative, when compared with the "gold standard". There was a strong correlation with the BAT results at 22.5, 2.25 and 0.225 ng/mL (respectively r = 0.90 and r = 0.78, p < 0.001), as well as between the BAT at 2.25 ng/mL and SPT (r = 0.82, p < 0.001) and between the SPT and sIgE levels (r = 0.78, p < 0.001). High cross-reactivity between D. pteronyssinus and D. farinae was confirmed based on the BAT at 22.5 ng/mL (r = 0.82, p < 0.001). In conclusion, the BAT showed very good concordance with the result of a meticulous process of decision-making that combined validated allergy tests (SPT, sIgE) with expert guidelines, specialist knowledge and experience. Facing the risk of the incorrect qualification of patients for costly, long-lasting and potentially risky allergen-specific immunotherapy, the inclusion of a basophil activation test into diagnostic process seems fully justified.

A retrospective analysis of the clinical efficacy in patients treated with Alternaria alternata and Dermatophagoides farinae immunotherapy

Background

The clinical efficacy of allergen-specific immunotherapy (AIT) for Alternaria alternata (A. alt) and Dermatophagoides farinae (Der f) extracts remains largely unknown in China. We sought to retrospectively evaluate the efficacy caused by AIT agents manufactured in China of patients who are sensitized to A. alt and Der f.

Methods

Patients aged 5-27 years with asthma and perennial allergic rhinitis (AR), and AIT with A. alt and Der f were recruited, and then classified into two groups: A. alt-AIT (n = 31) and A. alt + Der f-AIT group (n = 39). All data were gathered retrospectively, including biological parameters, pulmonary function, and symptom and medication scores.

Results

70 patients who underwent A. alt and Der f AIT were enrolled. A significant improvement was observed in the values of FEV1% (P < 0.0001) and MEF 25 (P = 0.023) of lung function. Both the rhinitis symptoms and combined symptoms and medication scores for asthma decreased after AIT (by 45.3% and 80.3%, respectively, P < 0.0001 for each). Nearly 67% improvement rate (P < 0.0001) occurred in rhinoconjunctivitis quality of life, and a great increase existed in Asthma Control Test (ACT) score (P < 0.0001) after at least 1 year AIT, although there were no significant changes between these two groups. Besides, no significance was displayed in specific IgE to different allergens.

Conclusion

AIT with A. alt and Der f extracts had clinical efficacy for many patients in China, with a reduction of symptom and medication scores, and great improvement in spirometry function.

Association between environmental mercury exposure and allergic disorders in Korean children: Korean National Environmental Health Survey (KoNEHS) cycles 3-4 (2015-2020)

Although previous studies have suggested potential adverse effects of mercury on a child's immune system, the associations have been inconsistent. We aimed to determine the association between urinary mercury levels and allergic diseases in Korean children with high mercury exposure. Data from 853 and 710 children aged 6-11 years in the Korean National Environmental Health Survey (KoNEHS) cycle 3 (2015-2017) and cycle 4 (2018-2020) were analyzed. We examined the association between mercury exposure and the prevalence of atopic dermatitis (AD), asthma, allergic rhinitis (AR), and allergic multimorbidity. After adjusting for all covariates, the urinary mercury level was positively associated with AD in the 2015-2017 study (OR = 1.34, 95% CI = 1.01, 1.79) and AR in 2018-2020 study (OR = 1.46, 95% CI = 1.01, 2.10). Pooled effects showed OR of 1.34 (95% CI = 1.01, 1.79) for AD and 1.47 (95% CI = 1.01, 2.12) for allergic multimorbidity. The association with allergic multimorbidity was greater in boys (OR = 1.88, 95% CI = 1.01, 3.49) than in girls (OR = 1.25, 95% CI = 0.73, 2.14). These results suggest that environmental mercury exposure may exacerbate symptoms of atopic dermatitis and allergic multimorbidity in children.

[Characteristics of allergen component in dust mite-induced allergic rhinitis patients]

Objective:To investigate the characteristics of allergen component in dust mite（DM） -induced allergic rhinitis（AR） patients, and provide reference for the diagnosis and treatment of AR. Methods:DM-induced AR patients with or without allergic asthma（AA） who visited the Allergy Department of Tongji Hospital, Huazhong University of Science and Technology between 2021 and 2022 were enrolled. Patients'age, gender, and visual analog scale（VAS） for symptoms were recorded. sIgE and sIgG4 levels of allergen components such as Der f1, Der f2, Der p1, Der p2, Der p7, Der p10, Der p21, and Der p23 were detected using a protein chip method. The sensitization characteristics of the allergen components in the patients were observed, and the correlation between sIgE, sIgG of each component and VAS as well as the component differences between AR and AR with AA（AR&AA） were evaluated. Results:A total of 87 DM-induced AR patients were enrolled, with 42.5% of them were AR&AA, their VAS scores were significantly higher than those of AR patients（6.38±1.95 vs 5.25±1.85, P=0.009 8）. The order of sensitization rates for DM components was as follows: Der p2（82.8%）, Der f2（81.6%）, Der p1（74.7%）, Der f1（70.1%）, and Der p23（35.6%）. The order of positive rates for sIgG4 was: Der p2（21.8%）, Der f2（13.8%）, Der p21（8.0%）, and Der p7（6.9%）. There were no correlation between the sIgE, sIgG4 levels or positive numbers of components and VAS scores, but there were positive correlations between sIgE, sIgG4 concentrations of components. Compared with AR patients, AR&AA patients had higher levels of sIgE for Der p（60.5[7.2-91.1]vs 14.0[4.8-45.1], P=0.02）, Der f（49.8[15.7-81.6]vs 21.3[7.0-50.2], P=0.04）, Der p1（27.2[0.7-51.5]vs 2.6[0.2-24.9], P=0.02）, Der p2（20.0[1.4-60.6]vs 5.5[0.6-19.1], P=0.004）, and Der f2（58.9[16.0-89.2]vs 23.4[0.9-56.8], P=0.009）, and a higher proportion of AR with AA patients had sIgE levels of Der p1（70.3% vs 48.0%, P=0.038） and Der p23（27.0% vs 14.0%, P=0.039） that were ≥3 grades. Conclusion:Der p1/f1, Der p2/f3, and Der p23 are the major components of DM sensitized AR patients. Multiple component sensitization and sIgE, sIgG4 levels of each component are not correlated with the severity of AR. The sIgE levels of the Der p1/f1, Der p2/f3, and Der p23 components in AR&AA patients are higher than AR.

The Effect of Environmental Factors on Immunological Pathways of Asthma in Children of the Polish Mother and Child Cohort Study

The FOXP3 transcription factor is a marker of regulatory T cells (Tregs), and is essential in the process of their activation and proper expression by promoting immune homeostasis. To assess the influence of the environment on the development of asthma, we hypothesized that in our cohort, exposure to environmental factors is associated with asthma risk in children, and that FOXP3 levels vary with their incidence and are negatively correlated with developing asthma. This prospective study conducted in Poland uses a cohort of 85 children (42 with and 43 without asthma diagnosis) aged 9 to 12 years recruited for the Polish Mother and Child Cohort Study. We collected questionnaires and organized visits to assess patients' clinical condition (skin prick tests, lung function assessments). Blood samples were taken to determine immune parameters. Breastfed children had lower risk of asthma. Asthma risk was higher in children who live in the city, with antibiotic course before the age of 2 and antibiotic therapy more than twice a year. Environmental factors were associated with childhood asthma. Breastfeeding, the coexistence of other allergic diseases, and the frequency of housekeeping affect FOXP3 levels, which are negatively correlated with the risk of asthma.