1These authors contributed equally to this study.
Efficacy of birch-pollen immunotherapy on cross-reactive food allergy confirmed by skin tests and double-blind food challenges
Article first published online: 12 MAY 2004
Clinical & Experimental Allergy
Volume 34, Issue 5, pages 761–769, May 2004
How to Cite
Bolhaar, S. T. H. P., Tiemessen, M. M., Zuidmeer, L., Van Leeuwen, A., Hoffmann-Sommergruber, K., Bruijnzeel-Koomen, C. A. F. M., Taams, L. S., Knol, E. F., Van Hoffen, E., Van Ree, R. and Knulst, A. C. (2004), Efficacy of birch-pollen immunotherapy on cross-reactive food allergy confirmed by skin tests and double-blind food challenges. Clinical & Experimental Allergy, 34: 761–769. doi: 10.1111/j.1365-2222.2004.1939.x
- Issue published online: 12 MAY 2004
- Article first published online: 12 MAY 2004
- Submitted 16 September 2003; revised 17 September 2003; accepted 14 January 2004
- Bet v 1;
- human regulatory T cells;
- Mal d 1;
- recombinant allergens
Background The effect of birch-pollen immunotherapy (IT) on cross-reactive food allergies is controversial.
Objective The aim of this study was to investigate the effect of birch-pollen IT on apple allergy and to evaluate recombinant allergens and double-blind placebo-controlled food challenges (DBPCFCs) as monitoring tools.
Methods Twenty-five adult birch-pollen- and apple-allergic patients were randomly divided into two groups, either receiving birch-pollen IT or symptomatic drugs only. IgE and IgG4 antibodies against birch pollen, apple, natural Bet v 1 and Mal d 1 were measured. In addition, skin prick tests (SPT) were performed using recombinant Bet v 1 (rBet v 1) and Mal d 1 (rMal d 1). Clinical outcome was evaluated by DBPCFC. CD4+CD25+ regulatory T cells (Tregs) were isolated from peripheral blood and tested in functional assays.
Results Birch-pollen IT resulted in a significant decrease of SPT reactivity for rBet v 1 (30-fold) and rMal d 1 (10-fold) already after 3 months. IgG4 antibodies were potently induced against Bet v 1, displaying cross-reactivity to Mal d 1. Visual analogue scale scores decreased >10-fold in 9/13 patients of the IT group, with three patients converting to negative. In the control group, no decrease was observed. Birch-pollen IT did not lead to detectable changes in the number or function of the CD4+CD25+ Tregs.
Conclusions This trial supports the claims that birch-pollen IT also decreases allergy to foods containing Bet v 1-homologous allergens. Recombinant allergens and DBPCFCs have proven to be useful tools for monitoring the effect of birch-pollen IT on linked food allergies.