Is faster safer? Cluster versus short conventional subcutaneous allergen immunotherapy

Comparison of adverse events between cluster and conventional immunotherapy for allergic rhinitis patients with or without asthma: A systematic review and meta-analysis

BACKGROUND

Cluster schedule of allergen-specific immunotherapy (AIT) is a cost-effective choice for allergic rhinitis (AR) patients, but its safety has been questioned due to the greater dosages required at each treatment compared with conventional immunotherapy. It remains a question that whether cluster schedule leads to a higher risk of side effects.

OBJECTIVE

This study was designed to update the evidence and investigate whether cluster schedule leads to a higher risk of local adverse reactions (LARs) and systemic adverse reactions (SARs) than cluster schedule does.

METHODS

We searched the Cochrane Central Register of Controlled Trials, EMBASE and Medline thoroughly and included studies comparing cluster and conventional schedules. A meta-analysis of 5 outcomes related to adverse events was performed after bias and heterogeneity assessments. And as a result of language limitations, we considered only articles in Chinese and English.

RESULTS

5 observational studies and 6 interventional studies were included in the meta-analysis. There were no differences between cluster and conventional schedules when analyzing SARs by the number of patients, delayed SARs, grade 2 SARs and LARs. Analyses of SARs by injection, grade 1 SARs and LARs by injection in observational studies showed that cluster schedule had a lower risk of adverse events than did conventional schedule.

CONCLUSION

Our data suggest that cluster schedule is as safe as or even safer than conventional schedule for AR patients with or without asthma (AS).

Early Efficacy Analysis of Cluster and Conventional Immunotherapy in Patients With Allergic Rhinitis

BACKGROUND

Specific immunotherapy is an important immune-modifying treatment for patients with allergic rhinitis (AR). We compared the early efficacy and safety of cluster and conventional immunotherapies for patients with AR.

METHODS

One hundred forty-nine patients with persistent AR were enrolled in a randomized and open-label trial and were divided into the following 4 groups: 60 children treated conventionally, 33 children treated using the cluster schedule, 23 adults treated conventionally, and 33 adults treated using the cluster schedule. Patients in the cluster groups reached the maintenance dose within 6 weeks, while those receiving conventional therapy reached the maintenance dose within 14 weeks. Symptom scores and skin prick test scores (SPTs) were used to evaluate clinical efficacy and adverse reactions.

RESULTS

After buildup phase of treatment, symptom scores, and SPTs were significantly lower than those prior to treatment in each group (P < .05). No significant differences were found in the efficacy of nasal symptoms scores among four groups (P > .05).However, the efficacy of SPTs using conventional schedule was higher than cluster schedule in children groups (group A and B, 57.7 vs 30.2%, P = .001). Besides, the efficacy of SPTs in adults was higher than children when using the cluster treatment (group D and B, 53.0 vs 30.2%, P = .008). No severe adverse reaction occurred.

CONCLUSIONS

Conventional and cluster immunotherapy schedules have similar efficacies, which do not vary with age; both schedules are safe and reliable. Also, SPT facilitate evaluation of clinical efficacy.

Comparison of International Systemic Adverse Reactions Due to Allergen Immunotherapy

BACKGROUND

Several classifications of systemic adverse reactions (SARs) during allergen immunotherapy have been proposed, but the comparison of their usefulness in daily clinical practice is lacking.

OBJECTIVE

The present post hoc analysis was aimed at investigating the practicality of the most relevant international classifications proposed by the European Academy of Allergology and Clinical Immunology (EAACI), the American Academy of Asthma, Allergology and Clinical Immunology/American College of Allergy, Asthma and Immunology (AAAACI/ACAAI), and the World Allergy Organization (WAO) using data provided by the longitudinal European Survey on Adverse Systemic Reactions in Allergen Immunotherapy (EASSI) based on daily clinical practice in 3 countries in Europe.

METHODS

One hundred nine SARs over 4363 allergen immunotherapy courses were classified as mild (n = 78 [71.5%]), moderate (n = 27 [24.8%]), and severe (n = 4 [3.7%]) by EASSI-doctors, which served as a criterion standard. Every SAR was further classified according to the following grading systems: EAACI 2006 Grading System (EAACI2006), WAO 2010 Grading System (WAO2010), WAO 2017 Grading System (WAO2017), and AAAAI/ACAAI Grading System. All SAR rankings were also cross-compared among each other (Kendall correlation coefficient Tau-b). In general, a low epinephrine use was identified, severe reactions occurred within 15 minutes, and milder reactions were skin only.

RESULTS

The analysis indicated disparities in mild and moderate SARs in the different grading systems. The correlation between EASSI-severity and EAACI2006, WAO2010, WAO2017, and AAAAI/ACAAI Grading System was 0.639, 0.502, 0.315, and 0.663, respectively (P < .001 in all cases). However, correlation of severe reactions was good. The best correlation with the onset of the reaction and the number of System Organ Class involved were detected in WAO grading systems.

CONCLUSIONS

Despite having a lower correlation than EAACI and AAAAI/ACAAI, the WAO grading appears to provide a moderate correlation among these classifications. The analysis might help to inform clinicians and investigators on selecting the most appropriate classification.