Abstract
Background: There is need for a fast, efficient, and safe way
to induce tolerance in patients with allergic rhinitis.
Methods: Patients with birch and timothy allergy were
randomized and received three doses of 0.1 ml of birch and 5-grass
allergen extracts (10,000 SQ units/ml, ALK-Abelló), or birch and placebo
or 5-grass and placebo by ultrasound-guided injections into inguinal
lymph nodes at monthly intervals. Rhinoconjunctivitis Total Symptom
Score, Medication Score and Rhinoconjunctivitis Quality of Life
Questionnaire were evaluated before treatment and after each birch and
grass pollen season during three subsequent years. Circulating
proportions of T helper subsets and allergen-induced cytokine and
chemokine production were analyzed by flow cytometry and Luminex.
Results: The three groups reported fewer symptoms, lower use of
medication and improved quality of life during the birch and grass
pollen seasons each year after treatment at an almost similar rate
independently of treatment. Nine patients had severe adverse events
which were judged to be unrelated to the therapy. Mild local pain was
the most common adverse event. IgE levels to birch decreased, whereas
birch-induced IL-10 secretion increased independently of treatment. IgG4
levels to birch and timothy and skin prick test reactivity remained
mainly unchanged. Conjunctival challenge tests with timothy extract
showed a higher threshold for allergen. In all three groups, regulatory
T cell frequencies were increased three years after treatment.
Conclusion: Intralymphatic immunotherapy against grass and
birch pollen allergy was effective, safe and associated with bystander
immune modulatory responses.
Trial registration: EudraCT (2013-004726-28).