Allergen Immunotherapy Adherence in the Real World: How Bad Is It and How Can It Be Improved?

Abstract

Opinion StatementAllergen immunotherapy (AIT) is the only available causal treatment for allergic respiratory diseases; however, data demonstrate a high discontinuation rate for both subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT). The complex mechanism of action of allergen immunotherapy (AIT) includes an interaction of innate and adaptive immune processes, resulting in immune tolerance, as illustrated by a decrease in specific immunoglobulin (Ig)-E, an increase in specific IgG1 and IgG4, and inhibition of inflammation involving mast cells, basophils, and eosinophils. This induction of immune tolerance leads to a significant improvement in symptoms and decreased medication scores. A 3-to 5-year course of AIT is required to obtain this disease-modifying effect, which substantially differentiates AIT frompharmacologic treatment. A carry-over effect can persist for up to 12 years. Furthermore, AIT may prevent the onset of asthma in patients with allergic rhinitis, as well as decreasing the onset of new sensitizations to inhalant allergens. Several meta-analyses and controlled studies, involving adult and pediatric subjects, have indicated that both sublingual immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) are relatively safe, effective, and well tolerated. AIT may also have a positive impact on the cost to the healthcare system, as evidence indicates the cost-benefit of such treatment. Adherence to AIT is crucial for a positive clinical outcome and non-adherence represents a major drawback for such therapy. It actually concerns not only AIT but also various pharmacologic treatments for allergic respiratory diseases, as well as for other chronic illnesses. The issue of non-adherence is an emerging and worldwide problem for chronic diseases and could be an important factor responsible for an overall decrease in treatment efficacy and increased rates of hospitalization, morbidity, and mortality. This review provides an overview of the different reasons that may account for the low adherence rate for AIT. Some of these reasons can be related to the patient's age when they begin such therapy, the allergic disease being treated, and questions about the efficacy, costs, inconvenience, and safety of AIT. Well-structured educational programs,especially by healthcare professionals, the print media, and the Internet, are needed to improve adherence to AIT.

House dust mite immunotherapy in Germany: real-world adherence to a subcutaneous allergoid and a sublingual tablet

“…Adults often prioritize other things especially when considering an allergy as a nonserious disease and neglect the treatment. In line with other studies the outcome of this study demonstrates that adherence depends on the patient's mindset and that guidance either from HCPs or parents can have significant influence on it [10,21,22].…”

“…Several factors influence medication adherence and they are weighted differently [22,31]. Patient-, physician-and therapy-related factors seem to be important, overlapping with social parameters.…”

Drop-out rate among patients treated with omalizumab for severe asthma: Literature review and real-life experience

“…One possible explanation is that compared with oral or inhaled treatments, omalizumab is regularly administered in a hospital setting under direct medical supervision thereby improving treatment adherence. Conversely, subcutaneous allergen immunotherapy, which is also regularly administered in a hospital setting to patients with respiratory allergy [ 47 ], is characterized by a lower adherence rate in comparison to omalizumab [ 6 , 48 ]. Of note, this immunotherapy is indicated in mild to moderate asthmatics with less severe symptoms [ 47 ].…”

Low adherence to inhaled corticosteroids/long-acting β2-agonists and biologic treatment in severe asthmatics

“…Our findings highlight an astonishingly low adherence to inhaled treatment in severely asthmatic patients before and during biologic therapy, regardless the type of prescribed biologic drug and the biologic treatment duration. Adherence rate assessment still represents a challenge, as currently, none of the available strategies is free from potential bias [11]. However, tracking the journey of asthma medications from the prescribers to the pharmacy where the patients buy the drug represents a quite accurate proxy of adherence rate.…”