Research Shows Long-Term Clinical Results of Allergen-Specific Immunotherapy

By Jeff Craven, /alert Contributor
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Patients who underwent allergen-specific immunotherapy (allergen-SIT) saw symptomatic improvement after 1 year, and these results persisted to 3 years and 5 years of therapy, according to a recent letter to the editor published in Pulmonology.

“Currently, allergen-specific immunotherapy remains the single curative approach to allergic diseases with the potential to modify its course,” J. Coutinho Costa, MD, from the University Hospital Centre of Coimbra – Hospital Geral in Coimbra, Portugal, and colleagues wrote in their study. “It is proven to be the only therapy that alters the natural history of allergic disease, prevents progression, prevents the development of new sensitizations and may even prevent the development of asthma in patients with allergic rhinitis.

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The researchers performed a prospective analysis of 35 patients (mean age, 28.1 years) with mainly allergic rhinitis with an average of 3.9 exacerbations per year and a mean Control of Allergic Rhinitis and Asthma Test (CARAT) score of 18 points prior to therapy. Patients received allergen-SIT and were monitored in allergology appointments for 5 years between 2013 and 2017. Of the patients who underwent allegen-SIT, 29% of patients received therapy for dermatophagoides pteronyssinus (Dpt), 23% received therapy for Dpt/dermatophagoides farina, 14% for Dpt/Lepidoglyphus destructor and 31% for Gramineae mixture.

After 1 year of therapy, patients reported mean 0.14 exacerbations per year and a mean CARAT score of 22.8; these results were statistically significant and also extended out to 3 years of therapy (0.05 exacerbations per year; mean CARAT score = 24.2) and at 5 years of therapy (0.19 exacerbations per year; mean CARAT score = 23.8). The researchers found no statistically significant differences regarding bronchodilator and anti-inflammatory therapy at 1 year, 3 years and 5 years of therapy and they noted the safety profile of allergen-SIT was mild.

The Global Initiative for Asthma (GINA) 2017 report currently states patients with allergic rhinitis and house dust mite sensitization with exacerbations after treatment with a low-high dose therapy of corticosteroids can be considered for sublingual allergen immunotherapy (SLIT) if forced expiratory volume in 1 second (FEV1) is predicted at greater than 70%, the researchers said, and allergen-SIT has been added as a new add-on therapy recommendation for patients with exacerbation who have undergone step 3 or step 4 therapy, the researchers said.

“[T]he current evidence provides support for the efficacy and safety of allergen-SIT in the treatment of respiratory allergy, namely in clinical control of allergic asthma and rhinitis, representing a safe alternative or an add-on therapy to conventional inhaler therapy,” the researchers wrote in their study. “However, it is essential to select patients to undergo this treatment and which extracts to be used to optimize the cost/benefit.”