Intralymphatic immunotherapy improves grass pollen allergic rhinoconjunctivitis: A 3-year randomized...

Area of Science:

• Immunology
• Allergy Research
• Clinical Trials

Background:

• Allergic rhinoconjunctivitis is a widespread health issue.
• Current allergen immunotherapy options suffer from poor patient adherence due to cost, complexity, and time commitment.
• Novel approaches to allergen immunotherapy are necessary.

Purpose of the Study:

• To evaluate the long-term efficacy of intralymphatic allergen immunotherapy (ILIT) for grass pollen rhinoconjunctivitis.
• To assess the impact of a booster ILIT injection on treatment outcomes.
• To develop and utilize a novel evaluation tool incorporating symptom scores and environmental allergen levels.

Main Methods:

• A 3-year, double-blind, randomized, placebo-controlled trial involving 36 patients with grass pollen rhinoconjunctivitis.
• Treatment groups received either 3 ILIT injections with an ILIT booster, 3 ILIT injections with a placebo booster, or 3 placebo injections with a placebo booster.
• Primary outcome measured by a combined symptom and medication score (cSMS), analyzed with a linear regression model. Secondary outcomes included changes in specific IgE and IgG4 levels and skin/nasal provocation tests.

Main Results:

• A significant reduction in cSMS was observed in the ILIT group during the first follow-up season (48.5% decrease), but not in subsequent seasons.
• A novel regression model indicated a 37% reduction in cSMS, independent of pollen counts.
• Booster injections showed no significant additional benefit. Significant changes in grass-specific IgE and IgG4 were noted in ILIT groups, but provocation tests remained unchanged.

Conclusions:

• Intralymphatic allergen immunotherapy (ILIT) offers a significant short-term benefit for grass pollen allergy symptoms and reduces the need for rescue medication.
• The effectiveness of ILIT appears concentrated in the initial season post-treatment.
• Booster injections do not enhance the therapeutic effect of ILIT in this study.