Essentials of allergen immunotherapy: A primer for the practitioner

Studies of methylated CpG ODN from Bifidobacterium longum subsp. infantis in a murine model: Implications for treatment of human allergic disease

Background: Allergen immunotherapy (AIT) is currently the most effective immunologic form of treatment for patients with atopic allergic diseases commonly used by allergist/immunologists to reduce allergic symptoms by gradually desensitizing the immune system to specific allergens. Currently, the primary mechanism of AIT emphasizes the crucial role of immune regulation, which involves a shift from a T-helper type 2 (Th2) cell response, which promotes allergy, to a T-regulatory (Treg) cell population, which inhibits the allergic inflammatory response through the production of immunosuppressive cytokines interleukin 10 and transforming growth factor β, which play pivotal roles in suppressing the allergic reaction. In a series of previous in vitro and in vivo experiments, we have demonstrated the capacity of synthetic methylated cytosine-phosphate-guanine (CpG) oligodeoxynucleotide (ODN) moieties as well as methylated genomic DNA ODN motifs from Bifidobacterium longum subspecies infantis to activate Treg cell differentiation in contrast to the unmethylated ODN moiety, which promotes proinflammatory responses driven by Th17-mediated responses. Objective: The purpose of the present study was to continue exploring the reciprocally related effects of methylated and unmethylated forms of DNA motifs from B. longum subspecies infantis on inflammation, specifically focusing on evaluating their capacity to alleviate allergic symptoms in a murine allergic disease model. Results: We show that methylated CpG moieties (ODNA) inhibit inflammation by stimulating Treg cells whereas unmethylated CpG moieties (ODNB) promote inflammation through Th1/Th17 pathways. Conclusion: Analysis of our data confirms and extends our previous research on the mechanisms by which methylated and unmethylated forms of DNA motifs influence inflammation. Specifically, the findings demonstrate that methylated CpG moiety (OVA + ODNA) inhibits inflammation by stimulating Treg cells, whereas unmethylated CpG moiety (OVA + ODNB) promotes inflammation through Th1/Th17 pathways. Consequently, these effects were shown to alleviate or to exacerbate allergic symptoms in a murine model of allergic disease. These results set the stage for future clinical trials and studies in humans to explore the therapeutic potential of targeting CpG motifs in the treatment of allergic diseases.

Impact of COVID-19 on adverse reactions to subcutaneous specific immunotherapy in children:a retrospective cohort study

BACKGROUND

COVID-19 is a new infectious disease. To investigate whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection increases the adverse reactions of subcutaneous specific immunotherapy (SCIT) in children.

METHODS

This study was conducted by collecting relevant data from children who underwent house dust mite SCIT from April 3, 2021, to March 18, 2023, including information on the time of COVID-19 infection, symptoms, and adverse reactions after each allergen injection. A mixed effects model was used to analyze the changes in adverse reactions before and after the COVID-19 infection.

RESULTS

Among the records of adverse reactions from 2658 injections in 123 children who underwent SCIT, the overall adverse reaction rate before COVID-19 infection was 39.8% and 30.0% after COVID-19 infection. Compared with pre-infection with COVID-19, the risks of overall adverse reactions, local adverse reactions, and systemic adverse reactions of immunotherapy after COVID-19 infection were reduced (odds ratio [OR] = 0.24, 0.31, and 0.28, all P < 0.05). Among the local adverse reactions, the incidence of the unvaccinated group was the highest (15.3% vs. 7.1%). The incidence of overall and local adverse reactions to SCIT decreased in 2-vaccinated COVID-19 recipients (OR = 0.29-0.31, P < 0.05).

CONCLUSIONS

In children, SARS-CoV-2 infection does not increase the incidence of adverse reactions to SCIT. This finding can provide a basis for the implementation of allergen-specific immunotherapy (AIT) during the COVID-19 pandemic.

Allergen sensitization study in Dongying, China: An epidemiological study

BACKGROUND

To explore the relationship between specific immunoglobulin E levels in response to prevalent pollen and food allergens among patients suffering from localized allergic diseases in the Dongying area of China, and to analyze the interconnectivity among these factors.

METHODS

This research encompassed allergic patients who visited the Allergy Department of Shengli Oilfield Central Hospital from January 2022 to January 2023. We examined the specific immunoglobulin E levels in the blood of 230 patients utilizing the Fobock platform provided by Jiangsu Haoeubo Company. Statistical analysis was conducted with SPSS 25.0 statistical software. The chi-square test evaluated the relevance of differences in gender and age. A value of P < .05 was considered statistically significant.

RESULTS

In this study, eggs emerged as the allergen with the highest number of sensitized individuals, closely followed by dust mite. Conversely, the least sensitized allergen was the cypress tree, closely followed by mango. Notably, male patients exhibited higher sensitivities to cottonwood (P < .05) and egg (P < .001) compared to female patients. Children aged 0 to 10 years showed increased sensitivity to variety of allergens. A significant correlation was observed among different allergens. The top ten allergen pairs with the highest correlation included Birch Tree and Cottonwood (0.88, P < .001), Cottonwood and Pine Tree (0.86, P < .001), Birch Tree and Pine Tree (0.84, P < .001), Pine Tree and Paulownia (0.81, P < .001), Dust Mite and House Dust Mite (0.76, P < .001), Birch Tree and Paulownia (0.73, P < .001), Cashew and Pistachio (0.71, P < .001), Apple and Hazelnut (0.71, P < .001), Cottonwood and Paulownia (0.71, P < .001), and Pine Tree and Ordinary Ragweed (0.70, P < .001).

CONCLUSION

This research sheds light on the patterns of allergen sensitization in Dongying, Shandong, highlighting that egg is the most prevalent sensitizing allergen. A notably high correlation was observed between Birch Tree and Cottonwood. This study enhanced the understanding of allergic diseases, explored the causes and mechanisms of allergies, strengthened the management of allergic diseases. Furthermore, it offers valuable insights for the clinical diagnosis and prevention of allergic diseases.