Allergen immunotherapy for birch-apple syndrome: what do we know?

Immunotherapy. 2017 Nov;9(15):1271-1278. doi: 10.2217/imt-2017-0040.


Apple allergy is common in patients allergic to birch pollen, and this is defined as 'birch-apple syndrome'. Allergens responsible for cross-reactivity belong to the pathogenesis-related-10 family, and high homology in the amino acid sequences of the major allergens Bet v 1 from birch and Mal d 1 from apple has been demonstrated. Here we review the literature on the treatment of birch-apple syndrome by allergen immunotherapy. The only allergen immunotherapy method available thus far is based on the administration of birch-pollen extracts, through the subcutaneous or sublingual route, to induce tolerance to Bet v1 and to the homologous allergen Mal d 1. However, the studies performed thus far show modest efficacy, and thus other methods of immunotherapy should be investigated.

Keywords: allergen immunotherapy; apple; birch pollen; birch-apple syndrome; cross-reactivity; pathogenesis-related proteins.

Publication types

  • Review

MeSH terms

  • Antigens, Plant / immunology*
  • Antigens, Plant / therapeutic use*
  • Betula / immunology
  • Cross Reactions
  • Desensitization, Immunologic / methods*
  • Food Hypersensitivity / immunology
  • Food Hypersensitivity / therapy*
  • Humans
  • Immune Tolerance
  • Malus / immunology
  • Plant Proteins / immunology
  • Plant Proteins / therapeutic use*
  • Pollen / immunology
  • Rhinitis, Allergic, Seasonal / therapy*
  • Syndrome
  • Treatment Outcome


  • Antigens, Plant
  • MALD1 protein, Malus domestica
  • Plant Proteins
  • Bet v 1 allergen, Betula