Duration of Allergen Immunotherapy for Long-Term Efficacy in Allergic Rhinoconjunctivitis

Abstract

RationaleSubcutaneous and sublingual immunotherapy are effective for allergic rhinitis. An important question is whether allergen immunotherapy provides a sustained clinical effect after treatment cessation. In view of potential side effects, cost and the necessary patient commitment, long-term benefit is an important consideration for the recommendation of immunotherapy over standard pharmacotherapy.Purpose of reviewIn this review, we analyse the existing evidence for long-term effects of both routes of administration in the context of double-blind, placebo-controlled, randomised clinical trials that included a follow-up phase of at least 1 year after treatment cessation.Recent findingsOverall, evidence suggests that 3 years of either subcutaneous or sublingual immunotherapy result in clinical benefit and immunological changes consistent with allergen-specific tolerance sustained for at least 2–3 years after treatment cessation.SummaryThe data presented here support recommendations in international guidelines that both routes of administration should be continued for a minimum of 3 years. Gaps in the evidence remain regarding the long-term efficacy of immunotherapy for perennial rhinitis and studies performed in children.

30 years of sublingual immunotherapy

“…In this long‐term trial, it was seen that, dependently on the duration of SLIT, there was a 3‐5 years lasting effect followed by a worsening that could be rapidly controlled again with a new course of SLIT. The long‐term effect was subsequently confirmed in the follow‐up observations of RDBPC big trials . Of note, a recent trial with the nasal provocation challenge, showed 2 years of treatment were not sufficient to achieve a long‐standing effect …”

Rewiring of gene networks underlying mite allergen‐induced CD4 + Th‐cell responses during immunotherapy

“…Successful SCIT is typically a biphasic process, in which symptom improvement commences in responsive subjects within a few months and peaks within the first treatment year; however, “consolidation” of the clinical effects of SCIT requires a 2nd (sometimes 3rd) year of maintenance treatment to prevent slow reversion to pretreatment allergen‐responder status 22,23 . Current understanding of the mechanism(s) underlying desensitization derive principally from studies on the early phase of SCIT, which suggest important roles for T‐regulatory cells, allergen‐specific IgG4 and a broad range of other negative control mechanisms 1‐2,4 .…”

Allergen-Specific Immunotherapy With Liposome Containing CpG-ODN in Murine Model of Asthma Relies on MyD88 Signaling in Dendritic Cells

“…Usually, successful treatment is long lasting (38), but there are some conflicting reports as to whether the protective effect of immunotherapy persist after discontinuation (74,75). It appears that the optimum duration for long-term modulation of allergic symptoms in humans by allergen-specific immunotherapy is approximately three years (76), while in mice allergen-specific immunotherapy appears to require at least 8weeks (77). Here we showed that short-term treatment with low dose of allergens and CpG efficiently reduced key features of allergic asthma.…”