Specific immunotherapy: beyond the clinical scores

Abstract

Objective: The efficacy of specific immunotherapy always has been evaluated by clinical scores (symptoms or medication intake). Nonetheless, specific immunotherapy possesses some special or "additional" effects, including the carryover effect and the preventive actions, which are unique. Those effects are the consequence of the complex mechanism of action, which induces profound and persistent modifications in the immune response to allergens. The literature is reviewed to evaluate the available experimental data on this.

Data sources: The main databases (EmBase, Medline, Scopus) were searched.

Study selection: Clinical trials of immunotherapy, either randomized or not, including placebo-controlled trials, were selected.

Results: Currently, the carryover effect (persistence of the benefit after stopping the treatment) is well ascertained for injection immunotherapy, whereas fewer data are available for the sublingual route. On the contrary, the demonstration of the prevention of asthma onset relies on 2 randomized studies for sublingual immunotherapy, and 1 single study for subcutaneous immunotherapy.

Conclusion: Although additional confirmatory data are needed, possibly obtained with a rigorous methodology, the long-lasting and preventive effects of specific immunotherapy always should be taken into account when the efficacy is evaluated. The additional effects also may have relevant socioeconomic implications.