The safety profile of subcutaneous allergen immunotherapy in children with asthma in Hangzhou, East China

Efficacy and safety of subcutaneous immunotherapy in asthmatic children allergic to house dust mite: a meta-analysis and systematic review

Background

Subcutaneous immunotherapy (SCIT) has been proved to be effective and safe in adult asthma. But it is still controversial in children.

Object

To evaluate the efficacy and safety of SCIT in asthmatic children with allergy to house dust mite.

Method

We searched the databases of Cochrane Library, EMBASE and MEDLINE (from 1 January 1990 to 1 December 2022). Two reviewers independently screened studies, extracted data and critically appraised the risk of bias. We used the Revman 5 to synthesize the effect sizes.

Results

We finally selected 38 eligible studies including 21 randomized controlled trials to evaluate the efficacy and safety of SCIT and 17 observational studies to assess the safety. The results revealed that short-term asthma symptom scores were declined with a standardized mean difference (SMD) of -1.19 (95% CI: -1.87, -0.50) in 12 researches with high heterogeneity. Short-term asthma medication scores were decreased with SMD -1.04 (95% CI: -1.54, -0.54) in 12 heterogeneous researches. One study showed no significant reduction in combined symptom and medication scores without providing details. No studies we reviewed reported long-term efficacy. SCIT resulted in an obviously increased risk of adverse reactions compared with placebo. For secondary outcomes, SCIT improved life quality and reduced the numbers of annual asthma attacks and allergen-specific airway hyperreactivity, but without significant improvement in pulmonary function, asthma control or hospitalization.

Conclusions

SCIT can reduce the short-term symptom scores and medication scores regardless of different treatment duration or mono/polysensitization, but with an increased incidence of local and systemic adverse effects. Further studies on pediatric asthma are needed to evaluate the long-term efficacy, and clarify the effectiveness of SCIT in specific population using mix allergen extracts or with severe asthma. Overall, it is recommended for children with mild-moderate HDM-driven allergic asthma.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Effects of subcutaneous immunotherapy in allergic rhinitis children sensitive to dust mites

BACKGROUND

Subcutaneous immunotherapy (SCIT) is now the only treatment that can modify the natural course of allergic rhinitis (AR). However, not all children with AR benefit from SCIT.

OBJECTIVE

To evaluate the efficacy of SCIT in dust-mites-induced AR children and explore correlative factors predicting treatment response to SCIT.

METHODS

225 children aged 4-17 years old with AR were recruited from January 2016 to September 2019, and monitored at baseline, 4, 12, and 24 months after the start of SCIT treatment. The visual-analogue-score (VAS) was used to assess the clinical symptoms. Multivariate binary logistic regression analyses and receiver operating characteristic curves were used to explore correlative factors in predicting the efficacy of SCIT.

RESULTS

The significant declines in VAS started after 4 months of SCIT and continued to improve throughout the study compared with baseline. An increase in children's age (OR=0.688, 95%CI: 0.479-0.988) and those with allergic history (OR=0.097, 95%CI: 0.009-1.095) were negatively associated with the risk of poor efficacy. Polysensitized children were more likely to suffer poor efficacy (OR=15.511 95%CI: 1.319-182.355). The clinical response at month 4 (r=0.707) and month 12 (r=0.925) was related to that at month 24. The area under the curve (AUC) for improvement at month 4 and month 12 was 0.746 and 0.860, respectively.

CONCLUSION

Our study confirmed the clinical efficacy of SCIT in AR children. Children with younger age, negative allergic history, and multiple allergens may predict a worse efficacy. The onset of action and the clinical response to SCIT in the second year can be predicted as early as by month 4.

Chinese Guideline on Allergen Immunotherapy for Allergic Rhinitis: The 2022 Update

In the last few decades, there has been a progressive increase in the prevalence of allergic rhinitis (AR) in China, where it now affects approximately 250 million people. AR prevention and treatment include allergen avoidance, pharmacotherapy, allergen immunotherapy (AIT), and patient education, among which AIT is the only curative intervention. AIT targets the disease etiology and may potentially modify the immune system as well as induce allergen-specific immune tolerance in patients with AR. In 2017, a team of experts from the Chinese Society of Allergy (CSA) and the Chinese Allergic Rhinitis Collaborative Research Group (C2AR2G) produced the first English version of Chinese AIT guidelines for AR. Since then, there has been considerable progress in basic research of and clinical practice for AIT, especially regarding the role of follicular regulatory T (TFR) cells in the pathogenesis of AR and the use of allergen-specific immunoglobulin E (sIgE) in nasal secretions for the diagnosis of AR. Additionally, potential biomarkers, including TFR cells, sIgG4, and sIgE, have been used to monitor the incidence and progression of AR. Moreover, there has been a novel understanding of AIT during the coronavirus disease 2019 pandemic. Hence, there was an urgent need to update the AIT guideline for AR by a team of experts from CSA and C2AR2G. This document aims to serve as professional reference material on AIT for AR treatment in China, thus improving the development of AIT across the world.

Safety Profile and Issues of Subcutaneous Immunotherapy in the Treatment of Children with Allergic Rhinitis

This study aims to evaluate safety issues of house dust mite subcutaneous immunotherapy (SCIT) among allergic rhinitis (AR) children. A retrospective cohort study was done between 2015 and 2020 to investigate the side effects of SCIT among AR children caused by a house dust mite allergy. Among 1098 patients who received house dust mite subcutaneous immunotherapy injections, 284 patients (25.87%) had side effects (SE). SE were found to be 699 times higher or in 2.27% of the 30,744 subcutaneous immunotherapy injections. A total of 17.9% of the patients had local SE during SCIT administration. Systemic side effects occurred in 8.38% of children receiving SCIT and in 0.53% of the total population who received SCIT injections. Only 2/92 (2.18%) of patients suffered an allergic reaction within 30 minutes of injection and these patients responded well to antiallergic medication. Severe anaphylaxis occurred in 0.091% of the 1098 patients in the SCIT group and in 0.0033% of the 30,774 SCIT injections. Systemic SE after SCIT occurred in 8.38% of patients receiving SCIT or 0.53% of the total number of SCIT injections. Anaphylactic episodes occurred in 16 patients (1.46%) and 15 patients (1.37%) who had first and second episodes. One severe attack was found and it was resolved with adrenaline. This study demonstrates that in pediatric patients with AR who received HDM SCIT for 18 months with high adherence, some experienced significant local SE and systemic SE caused by SCIT, but this did not interfere with the course of AR treatment or the effectiveness of SCIT.

Systemic Allergic Reactions and Anaphylaxis Associated with Allergen Immunotherapy

Subcutaneous allergen immunotherapy (SCIT) is a proven treatment of allergic rhinitis, asthma, atopic dermatitis, and prevention of Hymenoptera venom anaphylaxis. The known benefit of SCIT, however, must be considered in each patient relative to the potential risks of systemic allergic reactions (SRs). A mean of 1 SR per 1000 injection visits (0.1%) was estimated to occur between 2008 and 2018. Life-threatening anaphylactic events are estimated to occur in 1/160,000 injection visits. The factors that contribute to SRs and fatal reactions (FRs) are reviewed. Risk management strategies are proposed to prevent and decrease future SCIT associated with SRs, anaphylaxis, and FR.

Safety of house dust mite subcutaneous immunotherapy in preschool children with respiratory allergic diseases

Background

Allergen immunotherapy (AIT) is the only causal therapy for IgE-mediated allergy. There is less evidence about the safety and efficacy of AIT especially subcutaneous immunotherapy (SCIT) in children under 5 years old. We aimed to investigate the side effects and associated risk factors of house dust mite (HDM) SCIT in preschool children with respiratory allergic diseases.

Methods

The preschool children who had HDM-related allergic rhinitis with/without asthma were enrolled and undergone standardized HDM SCIT in our department from June 2013 to December 2019. Local reactions (LRs) and systemic reactions (SRs) were recorded and categorized according to World Allergy Organization recommendations. Demographic data and other therapeutic-related parameters were also recorded to investigate potential risk factors for these side effects.

Results

A total of 91 children (60 boys, 65.93%; 31 girls, 34.07%; mean age 4.13 years old) were included in the study. Among the 91 patients, 3109 SCIT injections were recorded, 62/91 (68.13%) experienced 186 immediate LRs, 4 /91(4.40%) experienced 6 delayed LRs, 11/91 (12.09%) children experienced 44 immediate SRs, 21/44 (47.73%) were grade 1 SRs, 21/44 (47.73%) were grade 2, 2/44 (4.55%) were grade 3, no grade 4 or 5 SRs occurred. Furthermore, 1/91 (1.10%) experienced 1 delayed SRs, manifested by urticaria 2 days later after allergen injection. 9/91 (9.89%) experienced 2 or more times SRs. Multivariable logistic regression analysis showed BMI (OR 1.506; 95%CI 1.091 to 2.079; p < 0.05) and sIgE against HDM (OR 1.497; 95%CI 1.082 to 2.071; p < 0.05) were risk factors for LRs. No variable was found to correlate with SRs (all p > 0.05).

Conclusions

HDM subcutaneous immunotherapy is considered to be safe in preschool children with respiratory allergic diseases. Higher BMI and HDM sIgE level in children are risk factors for developing LRs. The incidence of SRs and the rate of severe SRs are low in preschool children.

[Systemic reactions to subcutaneous immunotherapy for bronchial asthma and/or allergic rhinitis in children and their risk factors]

OBJECTIVE

To investigate the incidence of systemic reactions (SR) to subcutaneous immunotherapy (SCIT) for bronchial asthma and/or allergic rhinitis in children and their risk factors.

METHODS

A retrospective analysis was performed on 198 children with bronchial and/or allergic rhinitis. According to the presence or absence of SR and local reactions (LR) during SCIT, the patients were divided into two groups: SR (with SR and LR, n=31) and control (without SR or LR, n=142). A multivariate logistic regression analysis was used to determine the risk factors associated with SR.

RESULTS

Among the 198 patients who received 8 157 injections of SCIT, 25 (12.6%) experienced SR (31 times, 0.38%), including grade I SR (18 times, 58%), grade II SR (10 times, 32%), grade III SR (3 times, 10%), and no grade IV SR. The multivariate logistic regression analysis showed that multiple sensitization with both food and inhaled allergens, specific IgE to dust mites (grade 6), total IgE (grade 6), and a history of LR were independent risk factors for SR (P<0.05).

CONCLUSIONS

SCIT is a safe treatment for bronchial asthma and/or allergic rhinitis in children, with a low incidence of SR. Children with multiple sensitization with both food and inhaled allergens, a hypersensitive state (specific IgE to dust mites, grade 6; total IgE, grade 6), and a history of LR have an increased risk of SR to SCIT.

Allergen immunotherapy for respiratory allergy: to what extent can the risk of systemic reactions be reduced?

INTRODUCTION

Allergen immunotherapy is an effective treatment for respiratory allergy, but the administration to patients of extracts of the causative allergen may elicit systemic reactions, which include, particularly with subcutaneous immunotherapy (SCIT), anaphylaxis. In the past, the occurrence (tough rare) of fatal reactions has represented a serious problem that has limited the prescription of SCIT.

AREAS COVERED

The authors analyzed in this review the safety data of SCIT, especially concerning the years following the identification of uncontrolled asthma at the moment of allergen injection as the major risk of life-threatening reactions and fatalities. The safety of SLIT, which is far better than SCIT, was analyzed and its specific risk factors for systemic reactions were highlighted.

EXPERT OPINION

Presently, the safety profile of SCIT and SLIT is satisfactory, provided the treatment is administered by physicians experienced in this treatment, who are aware of the known risk factors for severe reactions and who implement all measures to avoid them. For SLIT, which is self-administered by the patient, receiving the first dose under medical control is recommended.

House dust mite subcutaneous immunotherapy in Chinese patients with allergic asthma and rhinitis

The efficacy of allergen immunotherapy (AIT) has been reported with different allergens including house dust mites (HDM). HDM are the most prevalent allergens in patients with asthma and/or rhinitis in China. In addition to improving symptoms, reducing medication need, and improving quality of life, AIT can change the course of allergic disease and induce allergen-specific immune tolerance. To date, the use of AIT is becoming more acceptable in China, and there are many studies about the current clinical practice immunotherapy. In this paper we discuss the main aspects of AIT undertaken in China; including symptom and medication scores, pulmonary function and airway hyperresponsiveness, specific allergen sensitivity, safety evaluation, and mechanisms underlying AIT. This review will provide some important information on AIT treatment strategies to doctors, healthcare professionals and organizations involved in the AIT in China. According to the studies in China, successful AIT may induce antibody responses and cellular reactions in relation to the significant improvement in clinical symptoms, reducing the need for medications and maintenance of stable pulmonary functions.