PURPOSE OF THE STUDY.
To compare the efficacy of 3 modalities of allergen immunotherapy (subcutaneous immunotherapy, sublingual immunotherapy tablets, and sublingual immunotherapy drops) in the management of grass pollen allergies.
There were 7759 total patients, including children and adults, from 37 randomized controlled trials were included in the meta-analysis.
A literature review identified 37 randomized controlled trials for analysis. Of these studies, 14 involved sublingual immunotherapy tablets, 14 involved sublingual immunotherapy (SLIT) drops, and 9 involved subcutaneous immunotherapy (SCIT). Data were collected on symptom and medication scores for the first pollen season after initiation of treatment and were limited to grass pollen extracts only. An indirect comparison of the different treatment modalities was performed in a Bayesian framework design.
Symptom scores were lower in all treatment modalities compared with placebo. In adults, there was no difference between the treatment modalities in terms of symptom score, but in children, sublingual immunotherapy tablets were shown to have lower symptom scores compared with sublingual immunotherapy drops. There was no significant difference seen between the treatment modalities for medication scores.
All treatment modalities have been shown to reduce symptom and medication score in grass pollen allergy when directly compared with placebo. Indirect comparisons among subcutaneous immunotherapy, sublingual immunotherapy tablets, and sublingual immunotherapy drops showed no difference in terms of symptom or medication scores.
This meta-analysis provides indirect substantiation of the comparable efficacy in adults between commercially available SCIT and SLIT options in the management of grass pollen allergy as measured by symptom and medication scores compared with placebo. Notably, in children, SLIT tablets appeared to perform better than SLIT drops compared with placebo. Unfortunately, there were no SCIT studies in children with grass pollen allergy available for review. Limitations of the study included differences in methodologies between the studies and the absence of head-to-head comparison trials between the SLIT and SCIT options. Direct comparison studies using standardized methodologies are needed to evaluate the clinical efficacy of current and future commercially available SCIT and SLIT options for grass and other pollen allergies.
- Copyright © 2015 by the American Academy of Pediatrics