Sublingual Immunotherapy of Birch Pollen Associated Apple Allergy
Status:
Completed
Trial end date:
2016-12-20
Target enrollment:
Participant gender:
Summary
More than 70% of birch pollen allergic patients suffer from allergic reactions to certain
foods, e.g. stone fruits, hazelnut and some vegetables. However, specific immunotherapy (SIT)
with birch pollen extract is not effective for the treatment of associated food allergy in a
substantial number of patients. Based on our previous clinical and immunological
investigations of birch pollen related food allergy (BPRFA) the investigators hypothesize
that for effective SIT of this abundant food allergy the disease-eliciting food allergens
should be employed. To prove this concept, the investigators aim to sublingually administer
the major apple allergen, Mal d 1, to birch pollen-allergic patients with concomitant apple
allergy and evaluate clinical and immunological effects of this treatment. The investigators
choose Mal d 1 as model food allergen because (i) its cross-reactivity with Bet v 1 has been
well characterized,(ii) apple is the most frequent trigger for BPRFA and (iii)
recombinant(r)Mal d 1 was well tolerated after sublingual administration to 20 birch
pollen-allergic patients in a previous study. Sublingual administration of a defined
concentration of GMP-rMal d 1 will be compared with equal doses of GMP-rBet v 1 as a positive
control and placebo-treatment. Clinical parameters will include skin prick tests (SPT) and
objective and subjective assessment of apple and birch pollen-induced allergic symptoms.
Immunological parameters will comprise the analysis of antibody and T cell responses to Mal d
1 and Bet v 1 as well as the evaluation of basophil activation.
The proposed pilot study will be a first investigation of the concept to specifically treat
BPRFA with the involved food allergens and thus, represents an important step in the
development of an efficient and safe therapy in the future.