Observational study of sublingual specific immunotherapy in persistent and intermittent allergic rhinitis: the EFESO trial

Background: Sublingual specific immunotherapy (SLIT) is a valid treatment for allergies. However, there are few data on a large sample size regarding its clinical role in 'real life'. Study aim: We performed a multicentre, case-control study to evaluate the effectiveness of SLIT in patients with allergic rhinitis (AR). Methods: A total of 305 patients with AIR were enrolled. Cases (n=154) were defined as patients with intermittent (64%) or persistent (36%) AR who were treated daily for at least two consecutive years with specific SLIT. Controls (n=151) were defined as age-, sex- and type of allergen-matched AIR subjects who were never treated with specific immunotherapy. The main outcomes of the study were the rhinoconjunctivitis symptom score (SS) and the symptomatic medication score (MS). SS and MS were evaluated at the end of the observational period in relation to the peak of relevant pollen season or during the period of maximum allergen exposure in case of non-seasonal allergens. Results: SS mean (SD) value was 5.1 (3.0) in cases and 9.3 (3.3) in controls (-43%) (p=0.0001). MIS mean (SD) value was 2.6 (1.8) and 4.4 (2.6) in the case and control groups, respectively (-41%) (p=0.0001). At the end of the observation period, asthma-related symptoms were present in 8.5% of cases and in 20% in the control group (p=0.01). Conclusion: The EFficacia nella rinitE allergica di SlitOne (EFESO) trial shows that SLIT treatment in AIR is associated with lower SS and MS in comparison with controls. SLIT is also associated with a lower incidence of asthma and new sensitizations. As this was an observational study, our results need to be confirmed in randomized, double-blind, controlled trials.