Successful sublingual immunotherapy with birch pollen has limited effects on concomitant food allergy to apple and the immune response to the Bet v 1 homolog Mal d 1.
BACKGROUND
Cross-reactivity between the major birch pollen allergen, Bet v 1, and the apple protein, Mal d 1, frequently causes food allergy.


OBJECTIVE
To investigate the effects of successful sublingual immunotherapy (SLIT) with birch pollen extract on apple allergy and the immune response to Bet v 1 and Mal d 1.


METHODS
Before and after 1 year of SLIT, Bet v 1-sensitized patients with oral allergy syndrome to apple underwent nasal challenges with birch pollen and double-blind placebo-controlled food challenges with apple. Bet v 1-specific and Mal d 1-specific serum antibody levels and proliferation in PBMCs and allergen-specific T-cell lines (TCLs) were determined. Bet v 1-specific TCLs were mapped for T-cell epitopes.


RESULTS
In 9 patients with improved nasal provocation scores to birch pollen, apple-induced oral allergy syndrome was not significantly reduced. Bet v 1-specific IgE and IgG(4) levels significantly increased. Bet v 1-specific T-cell responses to all epitopes and those cross-reactive with Mal d 1 significantly decreased. However, neither Mal d 1-specific IgE and IgG(4) levels nor Mal d 1-induced T-cell proliferation changed significantly. In contrast, Mal d 1-specific TCLs showed increased responses to Mal d 1 after 1 year of SLIT.


CONCLUSIONS
This longitudinal study indicates that pollen SLIT does not efficiently alter the immune response to pollen-related food allergens, which may explain why pollen-associated food allergy is frequently not ameliorated by pollen immunotherapy even if respiratory symptoms significantly improve.


CONCLUSIONS
SLIT with birch pollen may have no clinical effect on associated apple allergy.
Kinaciyan
Tamar
T
Department of Dermatology, Division of Immunology, Allergy and Infectious Diseases, Center for Physiology and Pathophysiology, Medical University of Vienna, Austria. barbara.bohle@meduniwien.ac.at
Jahn-Schmid
Beatrice
B
Radakovics
Astrid
A
Zwölfer
Bettina
B
Schreiber
Claudia
C
Francis
James N
JN
Ebner
Christof
C
Bohle
Barbara
B
D000286:Administration, Sublingual; D000328:Adult; D000485:Allergens / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology*; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D029662:Betula / Q000276:immunology; D002460:Cell Line; D003888:Desensitization, Immunologic; D004311:Double-Blind Method; D005260:Female; D005512:Food Hypersensitivity / Q000453:epidemiology / Q000276:immunology* / Q000628:therapy*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D027845:Malus / Q000276:immunology; D008875:Middle Aged; D008969:Molecular Sequence Data; D009061:Mouth Mucosa / Q000276:immunology; D010940:Plant Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology*; D011058:Pollen / Q000737:chemistry / Q000276:immunology*; D040681:Structural Homology, Protein
D000485:Allergens; D052179:Antigens, Plant; C095551:MALD1 protein, Malus domestica; D010940:Plant Proteins; C061312:Bet v 1 allergen, Betula